DESC:TECHNICAL FIELD
[0001] The present subject matter generally relates to trolleys for lifting load, and more particularly, relates to caster wheel assemblies for trolleys and a method for operating such trolleys.

BACKGROUND
[0002] Typically, trolley is the device used for carrying load or to transport the material from one point to another. In industries, trolleys are widely used for carrying various equipments ranging from heavy load equipments such as huge parts of machinery to small load equipments such as nuts and bolts. In these trolleys, caster wheels are used. By virtue of their swivelling action, they allow trolleys to be easily manoeuvred in confined spaces. Generally, the trolleys are allowed to be pushed and pulled by virtue of these caster wheels for easy manoeuvring in and around industrial factories to transport loads.

BRIEF DESCRIPTION OF DRAWINGS
[0003] The detailed description is described with reference to the accompanying figures, which is related to a movable load-carrying device which is a trolley being one embodiment of the present subject matter. However, the present subject matter is not limited to the depicted embodiment(s). In the figures, the same or similar numbers are used throughout to reference features and components.
[0004] Fig. 1 depicts an exploded view of a wheel assembly of an exemplary movable load-carrying device in accordance with an existing prior art.
[0005] Fig. 2 illustrates an exploded view of a wheel assembly in accordance with an embodiment of the present subject matter.
[0006] Fig. 3 illustrates a left-side view of wheel assembly in accordance with an embodiment of the present subject matter.
[0007] Fig. 3(a) illustrates a side-view of wheel assembly with a plunger assembly being engaged in one or more grooves with wheel assembly having a cross-sectional axis X-X’ in accordance with an embodiment of the present subject matter.
[0008] Fig. 3(b) illustrates a side-view of wheel assembly with a plunger assembly being disengaged from one or more grooves with wheel assembly having a cross-sectional axis X-X’ in accordance with an embodiment of the present subject matter.
[0009] Fig. 4 shows a cross sectional view (X-X’) of the wheel assembly defining plunger assembly being engaged in one or more grooves in accordance with an embodiment of the present subject matter.
[00010] Fig. 5 shows a cross sectional view (X-X’) of the wheel assembly defining plunger assembly being disengaged from one or more grooves in accordance with an embodiment of the present subject matter.
[00011] Fig. 6(a) illustrates a top view of a wheel mounting bracket with the plunger assembly in accordance with an embodiment of the present subject matter.
[00012] Fig. 6(b) depicts a front view of the wheel mounting bracket along with the wheel and the plunger assembly in accordance with an embodiment of the present subject matter.
[00013] Fig. 7 depicts a movable load-carrying device in accordance with an embodiment of the present subject matter.
[00014] Fig. 7(a) depicts a brake release mechanism in accordance with an embodiment of the present subject matter.
[00015] Fig. 7(b) depicts a side view of the movable-load carrying device coupled with brake release mechanism in accordance with an embodiment of the present subject matter.
[00016] Fig. 7(c) depicts a side view of the brake release mechanism in accordance with an embodiment of the present subject matter.
[00017] Fig. 8 depicts a flowchart depicting the steps of operating movable-load carrying device in accordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION
[00018] Various features and embodiments of the present subject matter here will be discernible from the following further description thereof, set out hereunder. It is contemplated that the concepts of the present subject matter may be applied to any kind of vehicle within the spirit and scope of this subject matter. The detailed explanation of the constitution of parts other than the present subject matter which constitutes an essential part has been omitted at suitable places.
[00019] Typically, trolleys are mounted on wheel which enables clockwise and counter clockwise rotation for movement from one place to other place for carrying designated loads and parts. Trolleys can be taken from one place to another place by pushing it and by pulling it as wheel bearing can rotate in clockwise or counter clockwise direction.
[00020] Conventionally, it is advisable for safety reasons that trolleys must be pushed and not pulled for safety of the operators. However, for any person, pulling a trolley is easier than pushing. This is because when we push an object on the horizontal plane, then the vertical component of the force will act vertically downward and will increase the weight of the object leading to an increase in friction. If the friction will be more then it will be difficult to move the object as friction acts in the opposite direction of force. On the other hand, if we pull the trolley, then the vertical component acts in the upward direction, reducing the force of friction. So, when there will be less force of friction, it is easier in that case to move the trolley. Hence, it is easier to pull than to push the trolley.
[00021] However, if the trolleys are capable of moving through both pull and push operation, it tends to lead to the operator pulling the trolley most of the times due to easiness in pulling as explained above. This may lead to physical injuries in case of slopes additional force and sudden stoppages of the trolley at dead ends by which the wheels and trolley might hit the feet and legs of the operator, leading to accidents. Further, since there are no strong measures to stop pulling of wheel or moving of trolley in clockwise direction, operator might be tempted to pull the trolley as less energy is required in pulling and ignore the safety concerns.
[00022] Moreover, the operator due to heavy weight of the trolley might topple due to pulling, which will result in falling of the trolley as well of the heavy parts kept on the trolley falling onto the operator, thereby severely giving him physical injuries. The parts kept on the trolley might be damaged and subsequently, the trolley itself might have to be replaced due to falling of trolley. Thus, pulling of trolleys is not desirable.
[00023] A known solution to solve the afore-mentioned problem and make the trolley to move only through pushing in a forward direction is through is to replace the existing wheels with unidirectional wheels. In such cases, the trolley can be moved in only one direction through pushing, however it may not be used for both push pull activities during sudden blockages or dead-end situations wherein the trolley needs to be pulled back and rotated to make clear way. Thus, new trolleys will have to bought for such situations.
[00024] Thus, there arises a need for a wheel assembly and a trolley capable of moving in single direction through pushing only during clear way provided for movement of the trolley and also being capable of being pulled for a certain amount of time for pulling it back in a backward direction when the trolley comes to a dead-end with making minimal constructional changes in the existing trolley and wheel assembly and without affecting mechanical strength of the wheel assembly, and to solve further mentioned shortcomings of the prior art.
[00025] Thus, it is an objective of the present subject matter to provide a cost-effective wheel assembly for a trolley, a trolley and a method of operating such trolley wherein such trolley is capable of moving in a single forward direction through pushing only.
[00026] It is yet another objective of the present subject matter to provide a wheel assembly which prevents pulling of the trolley and enables pulling of the trolley only when the trolley comes to a dead-end.
[00027] It is another objective of the present subject matter to provide a wheel assembly requiring minimal constructional changes to achieve the above objective without affecting the mechanical strength of the existing wheel.
[00028] The present subject matter along with all the accompanying embodiments and their other advantages would be described in greater detail in conjunction with the figures in the following paragraphs.
[00029] The present subject matter discloses a wheel assembly for a movable load-carrying device comprising a wheel, a wheel mounting bracket being capable of mounting said wheel, a wheel stopper being disposed on an outer portion of the wheel and a plunger assembly being abutted to the wheel mounting bracket wherein the wheel stopper having one or more grooves on an outer portion of the wheel stopper. The plunger assembly is engaged in said one or more grooves in response to an operator pulling said movable load-carrying device in a backward direction to prevent pulling of said load-carrying device, thereby said plunger assembly acting as a restraining member for arresting movement of said wheel.
[00030] In another embodiment, the plunger assembly comprises a hollow plunger, wherein a first portion of said hollow plunger being abutted to an outer portion of said wheel stopper and a locking pin being disposed within said hollow plunger.
[00031] In yet another embodiment, a first end of said one or more grooves is equal to the surface level of said wheel stopper and a second end of said one or more grooves gradually forming a depression within said wheel stopper.
[00032] In another embodiment, the locking pin is engaged in said depression within said wheel stopper in response to said operator pulling said movable load-carrying device in said backward direction to prevent said movable load-carrying device from moving in said backward direction.
[00033] In another embodiment, the depression is equal to a depth of 5 millimeters from said surface level of said wheel stopper.
[00034] In yet another embodiment, a spring is fixed between said hollow plunger and said locking pin to provide a load to said locking pin.
[00035] In another embodiment, the wheel mounting bracket is having a provision for mounting said plunger assembly on a same side as that of wheel stopper being disposed on said outer portion of said wheel.
[00036] In yet another embodiment, the hollow plunger being welded to a wheel mounting bracket.
[00037] In another embodiment, the wheel assembly includes a mounting assembly to mount said wheel to said wheel mounting bracket.
[00038] In yet another embodiment, the mounting assembly includes a washer, a spacer, and a bearing for securely mounting said wheel assembly to said wheel mounting bracket.
[00039] The present subject matter further discloses a movable load-carrying device comprising a wheel assembly having one or more wheels, one or more wheel mounting brackets for mounting said one or more wheels, one or more wheel stoppers being disposed on an outer portion of said one or more wheels, and said one or more wheel stoppers having one or more grooves being disposed within an outer portion of said one or more wheel stoppers, and one or more plunger assembly being abutted to said one or more wheel mounting bracket. The movable load-carrying device further includes a brake mechanism comprising an actuator for applying pressure by an operator of said movable load-carrying device. The actuator is disposed on a side of said movable load-carrying device being same as that of a side wherein said operator holds said movable load-carrying device by a handle. The brake release mechanism further has a wire mechanism being operatively coupled to said actuator at one end and being coupled to said one or more wheels of said movable load-carrying device at the other end. The movable load-carrying device is capable of moving in a forward direction by pushing said movable load-carrying device and said movable load-carrying device being prevented from moving in a backward direction through said one or more plunger assembly of said wheel assembly is engaged in said one or more grooves in response to said operator pulling said movable load-carrying device in said backward direction during a clear way being provided for movement of said movable load-carrying device. During a dead end situation for movement of said movable load-carrying device, the movable load-carrying device is capable of moving in said backward direction by applying said brake release mechanism to enable pulling of said movable load-carrying device for rotating said one or more wheels in response to said operator applying continuous pressure to said actuator, said wire mechanism operatively transferring said pressure to said wheel assembly to disengage said one or more plunger assembly from said one or more grooves. Once the movable-load carrying device is switched from dead end to clear way for movement of the movable load-carrying device, the movable load-carrying device is again prevented from pulling in said backward direction by said wheel assembly being engaged in said one or more grooves of said one or more wheel stopper in response to said operator removing continuous pressure from said actuator, subsequent to said movable load-carrying device being rotated to achieve a clear way from said dead end situation for movement of said movable load-carrying device.
[00040] In another embodiment, the one or more wheels includes two fixed wheels being disposed on a side of said movable load-carrying device wherein said operator holds said movable-load carrying device through said handle.
[00041] In yet another embodiment, the one or more wheels includes two swiveling wheels being disposed on an opposite side of said operator holding said movable load-carrying device.
[00042] In another embodiment, the rotation of said movable load-carrying device being up to 180 degrees.
[00043] In yet another embodiment, the engaging and disengaging of said one or more plunger assembly in said one or more grooves of said one or more wheel stopper occurs in one or more swiveling wheels.
[00044] In another embodiment, the one or more plunger assembly comprises one or more hollow plunger, wherein a first portion of said one or more hollow plunger being abutted to an outer portion of said one or more wheel stopper and one or more locking pin, said one or more locking pin being disposed within said one or more hollow plunger.
[00045] In another embodiment, a first end of said one or more grooves is equal to the surface level of said one or more wheel stopper and a second end of said one or more grooves gradually forming a depression within said one or more wheel stopper.
[00046] In yet another embodiment, one or more locking pin is engaged in said depression within said one or more wheel stopper in response to said operator pulling said movable load-carrying device in a backward direction to prevent said movable load-carrying device from moving in said backward direction.
[00047] In another embodiment, the depression being of a depth of 5 millimeters from said surface level of said one or more wheel stopper.
[00048] In another embodiment, one or more spring is fixed between said one or more hollow plunger and said one or more locking pin to provide a load to said one or more locking pin.
[00049] In another embodiment, the one or more wheel mounting bracket includes a provision for mounting said one or more plunger assembly on a same side as that of said one or more wheel stoppers being disposed on said outer portion of said one or more wheels.
[00050] In another embodiment, the one or more hollow plungers being welded to one or more wheel mounting brackets.
[00051] In another embodiment, the wheel assembly includes a mounting assembly to mount said wheel to said wheel mounting bracket.
[00052] In one more embodiment, the mounting assembly includes a washer, a spacer and a bearing for securely mounting said wheel assembly to said wheel mounting bracket.
[00053] In another embodiment, the brake release mechanism includes a connecting member wherein a first end of said connecting member being connected to said actuator and a second end of said connecting member being connected to said wire mechanism.
[00054] The present subject matter further discloses a method for operating a movable load-carrying device with selective rotation of one or more wheels. The method comprising the steps of loading of said movable load-carrying device, pushing said movable load-carrying device in a forward direction by an operator through one or more wheel assembly, wherein said one or more wheel assembly having one or more plunger assembly during a clear way being provided for movement of said movable load-carrying device, engaging said one or more plunger assembly in one or more wheel stoppers to prevent pulling of said movable load-carrying device in a backward direction during said clear way for movement of said movable load-carrying device, wherein said plunger assembly acts a restraining member to stop movement of movable load-carrying device in said backward direction and enable movement of said movable load-carrying device in said forward direction only through pushing of said movable load-carrying device, disengaging said one or more plunger assembly from one or more wheel stoppers to enable pulling of said movable load-carrying device in a backward direction for rotating said one or more wheel assembly during a dead end situation for movement of said movable load-carrying device by said operator applying continuous pressure to a brake release mechanism; and engaging said one or more plunger assembly in said one or more wheel stoppers to prevent pulling of said movable load-carrying device in a backward direction in response to said operator removing continuous pressure from said brake release mechanism, subsequent to said movable load-carrying device being rotated to achieve a clear way from said dead end situation for movement of said movable load-carrying device.
[00055] In another embodiment, the engaging said one or more plunger assembly in said one or more wheel stoppers includes engaging said one or more plunger assembly in one or more grooves being formed on an outer portion of said one or more wheel stoppers.
[00056] In yet another embodiment, the one or more plunger assembly from said one or more wheel stoppers includes disengaging said one or more plunger assembly from one or more grooves being formed on an outer portion of said one or more wheel stoppers.
[00057] In another embodiment, disengaging of said one or more plunger assembly from one or more wheel assembly being enabled by applying continuous pressure by an operator of said movable load-carrying device to said brake release mechanism, wherein said brake release mechanism includes an actuator for applying pressure by said operator and a wire mechanism, said wire mechanism being operatively coupled to said actuator at one end and being coupled to said one or more wheels of said movable load-carrying device at the other end.
[00058] In yet another embodiment, engaging said one or more plunger assembly in said one or more wheel stoppers to prevent pulling of said movable load-carrying device in a backward direction being enabled in response to said operator removing continuous pressure from said brake release mechanism, subsequent to said movable load-carrying device being rotated to achieve a clear way from said dead end situation for movement of said movable load-carrying device.
[00059] The present subject matter is further described with reference to accompanying figures. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.
[00060] The present subject matter may be implemented in any two-wheeled vehicle. However, for the purpose of explanation and by no limitation, the present invention, and corresponding additional advantages and features are described through the following embodiments depicting a trolley.
[00061] Fig. 1 illustrates an exploded view of existing wheel assembly in accordance with a prior art. Existing movable load-carrying device (700) has a wheel assembly (100) comprising one or more wheels (102) which are caster wheels wherein polyurethane wheels are injection-molded, mechanically, and chemically bonded to polyolefin center. Such caster wheels are non-marking, non-conductive and superior to rubber in withstanding grease, oil, cutting, chunking and abrasive wear. Such wheel assembly (100) has a bearing (133) that constraints the relative motion to only desired motion and reduces frictions between moving parts. A cylindrical wheel spacer (132) is fitted inside the bearing (133). The purpose of the spacer (132) is to hold the stationary ring of the bearing (133) and to provide rigidity. It also consists of a flange washer (131) designed to maintain sufficient load to tighten bolts and gasket of a flange. A dust cover (134) is placed on both sides of the wheel to prevent entry of dust inside the wheels (102). Several hex bolts and nuts are used for holding wheel (102) and a wheel mounting bracket (110). Such wheel mounting bracket (110) has two horizontal holes to fix the wheel and four vertical positioned holes to mount to the movable load-carrying device or trolley (700). However, such existing wheel assemblies can move in single direction only. It cannot move in counter-clockwise direction, thereby when the trolley meets a dead end, one must either lift the entire trolley to move it to clear way or the contents of the trolley have to be transferred to a separate trolley. Thus, the existing wheel assemblies poses several problems and challenges.
[00062] For clarity purposes, existing components of wheel assembly in prior art and the present subject matter have been marked with same reference numerals to avoid ambiguity.
[00063] Fig. 2 and Fig. 3 illustrates an exploded view of a wheel assembly and a side-view of the wheel assembly in accordance with an embodiment of present subject matter. The present subject matter discloses a wheel assembly (100) for a movable load-carrying device (not shown) comprising a wheel (102), a wheel mounting bracket (110) being capable of mounting said wheel (102), a wheel stopper (105) being disposed on an outer portion (107) of the wheel (102) and a plunger assembly (120) being abutted to the wheel mounting bracket (110) wherein the wheel stopper (105) having one or more grooves (105a) on an outer portion of the wheel stopper (105). The plunger assembly (120) is engaged in said one or more grooves (105a) in response to an operator pulling said movable load-carrying device in a backward direction to prevent pulling of said load-carrying device, thereby said plunger assembly (120) acting as a restraining member for arresting movement of said wheel (102).
[00064] The plunger assembly (120) comprises a hollow plunger (122), wherein a first portion of said hollow plunger (122) is abutted to an outer portion of said wheel stopper (105) and a locking pin (125) being disposed within said hollow plunger (122). A spring (127) is fixed between said hollow plunger and said locking pin to provide a load to said locking pin. The wheel assembly (100) further comprises a mounting assembly includes a washer (131), a spacer (132), and a bearing (133) for securely mounting said wheel (102) to said wheel mounting bracket (110). Referring to Fig. 6 (a) and Fig. 6(b) which shows a top view and a front view of wheel mounting bracket (110) along with the hollow plunger (122) and locking pin (125) and the mounting assembly (130). Here, the wheel mounting bracket (110) is having a provision (not shown) for mounting said plunger assembly (120) on a same side as that of wheel stopper (105) being disposed on said outer portion of said wheel (102). Further, the hollow plunger (122) is welded to the wheel mounting bracket (110).
[00065] Herein, a first end of said one or more grooves (105a) is equal to the surface level of said wheel stopper (105) and a second end of said one or more grooves (105a) gradually forming a depression (not shown) within said wheel stopper (105). The depression is equal to a depth of 5 millimeters from said surface level of said wheel stopper (105).
[00066] For brevity purposes, referring to Fig. 3(a), Fig 3(b) Fig.4 and Fig. 5 together, which illustrates a side-view of wheel assembly with a plunger assembly being engaged in one or more grooves with wheel assembly having a cross-sectional axis X-X’ and the plunger assembly being disengaged from one or more grooves with wheel assembly having a cross-sectional axis X-X’, a cross sectional view (X-X’) of the wheel assembly defining plunger assembly being engaged in one or more grooves and a cross sectional view (X-X’) of the wheel assembly defining plunger assembly being disengaged from one or more grooves respectively in accordance with an embodiment of the present subject matter. Referring to Fig. 3(a) and Fig.4, the plunger assembly (120) comprising the locking pin (125) is engaged with the wheel assembly (100) when the movable load-carrying device (not shown) is moving in a forward direction by pushing. Here pulling of the movable load-carrying device is prevented due to plunger assembly (120) being engaged with the wheel assembly (100). Herein, the plunger assembly (120) gets engaged (402) with one or more grooves (105a) in the wheel stopper (105). In Fig. 3(b) and Fig. 5, when the movable load-carrying device meets a dead end, and the operator must pull it back, the plunger assembly (120) disengages (502) from the wheel (102) and the wheel mounting bracket (110). Herein, the plunger assembly (120) gets disengaged from one or more grooves (105a) in the wheel stopper (105).
[00067] Referring to Fig. 7, Fig. 7 (a), Fig. 7 (b) and Fig. 7 (c) which discloses a side view of movable load-carrying device in accordance with an embodiment of the present subject matter. The movable load-carrying device (700) comprises a wheel assembly (100) having one or more wheels (102), one or more wheel mounting brackets (110) for mounting said one or more wheels (102), one or more wheel stoppers (105) being disposed on an outer portion (107) of said one or more wheels (102), and said one or more wheel stoppers (105) having one or more grooves (105a) being disposed within an outer portion of said one or more wheel stoppers (105), and one or more plunger assembly (120) being abutted to said one or more wheel mounting bracket (110). The movable load-carrying device (700) further includes a brake release mechanism (710) comprising an actuator (705) for applying pressure by an operator of said movable load-carrying device (700). The actuator (705) is disposed on a side of said movable load-carrying device (700) being same as that of a side wherein said operator holds said movable load-carrying device (700) by a handle (701).
[00068] The brake release mechanism (710) further has a wire mechanism (707) being operatively coupled to said actuator (705) at one end and being coupled to said one or more wheels (102) of said movable load-carrying device (700) at the other end. The movable load-carrying device (700) is capable of moving in a forward direction by pushing said movable load-carrying device (700) and said movable load-carrying device (700) being prevented from moving in a backward direction through said one or more plunger assembly (120) of said wheel assembly (100) is engaged in said one or more grooves (105a) in response to said operator pulling said movable load-carrying device (700) in said backward direction during a clear way being provided for movement of said movable load-carrying device (700).
[00069] During a dead end situation for movement of said movable load-carrying device (700), the movable load-carrying device (700) is capable of moving in said backward direction by applying said brake release mechanism (710) to enable pulling of said movable load-carrying device (700) for rotating said one or more wheels (102) in response to said operator applying continuous pressure to said actuator (105), said wire mechanism (707) operatively transfers said pressure to said wheel assembly (100) to disengage said one or more plunger assembly (120) from said one or more grooves (105a).
[00070] Once the movable-load carrying device (700) is switched from dead end to clear way for movement of the movable load-carrying device (700), the movable load-carrying device (700) is again prevented from pulling in said backward direction by said plunger assembly (120) being engaged in said one or more grooves (105a) of said one or more wheel stopper (105) in response to said operator removing continuous pressure from said actuator (705), subsequent to said movable load-carrying device (700) being rotated to achieve a clear way from said dead end situation for movement of said movable load-carrying device (700).
[00071] Herein, the one or more wheels (102) includes two fixed wheels being disposed on a side of said movable load-carrying device (700) wherein said operator holds said movable-load carrying device (700) through said handle (701). Further, the moveable load-carrying device (700) includes two swiveling wheels being disposed on an opposite side of said operator holding said movable load-carrying device (700). The rotation of said movable load-carrying device (700) is up to 180 degrees. Moreover, the engaging (402) and disengaging (502) of said one or more plunger assembly (120) in said one or more grooves (105a) of said one or more wheel stopper (105) occurs in one or more swiveling wheels (102).
[00072] Further, the one or more plunger assembly (120) comprises one or more hollow plunger (122), wherein a first portion of said one or more hollow plunger (122) being abutted to an outer portion of said one or more wheel stopper (105) and one or more locking pin (125), said one or more locking pin (125) being disposed within said one or more hollow plunger (122). Further, a first end of said one or more grooves (105a) is equal to the surface level of said one or more wheel stopper (105) and a second end of said one or more grooves (105a) gradually forming a depression (not shown) within said one or more wheel stopper (105). Herein, one or more locking pin (125) is engaged in said depression (not shown) within said one or more wheel stopper (105) in response to said operator pulling said movable load-carrying device (700) in a backward direction to prevent said movable load-carrying device (700) from moving in said backward direction. Further, the depression being of a depth of 5 millimeters from said surface level of said one or more wheel stopper (105). Also, one or more spring (127) is fixed between said one or more hollow plunger (122) and said one or more locking pin (125) to provide a load to said one or more locking pin (125). The one or more wheel mounting bracket (110) includes a provision (not shown) for mounting said one or more plunger assembly (120) on a same side as that of said one or more wheel stoppers (105) being disposed on said outer portion of said one or more wheels (102).
[00073] Referring to Fig. 7 (c), the brake release mechanism (710) includes a connecting member (706) wherein a first end of said connecting member (706) being connected to said actuator (705) and a second end of said connecting member (706) being connected to said wire mechanism (707).
[00074] Referring to Fig. 8, the present subject matter further discloses a method for operating a movable load-carrying device with selective rotation of one or more wheels. The method comprising the steps of loading (801) of said movable load-carrying device (700), pushing said movable load-carrying device (700) in a forward direction (802) by an operator through one or more wheel assembly (100), wherein said one or more wheel assembly (100) having one or more plunger assembly (120) during a clear way being provided for movement of said movable load-carrying device (700), engaging (803) said one or more plunger assembly (120) in one or more wheel stoppers (105) to prevent pulling of said movable load-carrying device (700) in a backward direction during said clear way for movement of said movable load-carrying device (700), wherein said plunger assembly (120) acts a restraining member to stop movement of movable load-carrying device (700) in said backward direction and enable movement of said movable load-carrying device (700) in said forward direction only through pushing of said movable load-carrying device (700), disengaging (806) said one or more plunger assembly (120) from one or more wheel stoppers (105) to enable pulling of said movable load-carrying device (700) in a backward direction for rotating (807) said one or more wheel assembly (100) during a dead end situation (804) for movement of said movable load-carrying device (700) by said operator applying continuous pressure (805) to a brake release mechanism (710); and engaging (803) said one or more plunger assembly (120) in said one or more wheel stoppers (105) to prevent pulling of said movable load-carrying device (700) in a backward direction in response to said operator removing continuous pressure (807) from said brake release mechanism (710), subsequent to said movable load-carrying device (700) being rotated to achieve a clear way from said dead end situation for movement of said movable load-carrying device (700).
[00075] Herein, the engaging (803) of said one or more plunger assembly (120) in said one or more wheel stoppers (105) includes engaging said one or more plunger assembly (120) in one or more grooves (105a) being formed on an outer portion of said one or more wheel stoppers (105). Further, disengaging (806) said one or more plunger assembly (120) from said one or more wheel stoppers (105) includes disengaging (806) said one or more plunger assembly (120) from one or more grooves (105a) being formed on an outer portion of said one or more wheel stoppers (105). Moreover, disengaging (806) of said one or more plunger assembly (120) from one or more grooves (105a) being enabled by applying continuous pressure (806) by an operator of said movable load-carrying device to said brake release mechanism (710) , wherein said brake release mechanism (710) includes an actuator (705) for applying pressure by said operator and a wire mechanism (707), said wire mechanism (707) being operatively coupled to said actuator (705) at one end and being coupled to said one or more wheels (102) of said movable load-carrying device (700) at the other end.
[00076] Further, engaging (803) said one or more plunger assembly (120) in said one or more wheel stoppers (105) to prevent pulling of said movable load-carrying device (700) in a backward direction being enabled in response to said operator removing continuous pressure from said brake release mechanism (710), subsequent to said movable load-carrying device being rotated to achieve a clear way from said dead end situation (804) for movement of said movable load-carrying device (700).
[00077] Thus, the present subject matter provides a cost-effective wheel assembly for achieving push and pull mechanism of the trolley without affecting the mechanical strength of the existing wheel. The existing construction of the wheel is being retained with minimal changes performed to the wheel mounting bracket and the wheel. The wheel mounting bracket also has a provision for mounting the plunger assembly, thus it does not require separate mounting provision for mounting said plunger assembly to it. The operator with the help of the present subject matter is capable of driving the trolley in a single direction by pushing it during clear way. He is unable to pull the trolley in a backward direction, thus there arises no situation wherein his legs might get hurt due to trolley being pulled backwards. Thus, the movement of trolley is restricted in a backward direction by pulling of the trolley by the plunger assembly being engaged with the wheel. When a dead end arrives, the operator can disengage the plunger assembly and pull it back to rotate the trolley sufficiently. Once the trolley is pulled back and rotated to get the adequate space for clear way, the plunger assembly again engages with the wheel stopper to prevent pulling of the trolley, thereby eliminating chances of any accidents.
[00078] While certain features of the claimed subject matter have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes that fall within the true spirit of the claimed subject matter.

List of reference signs:
100 wheel assembly
102 wheel
105 wheel stopper
105a one or more grooves
107 outer portion of wheel
110 wheel mounting bracket
120 plunger assembly
122 hollow plunger
125 locking pin
127 loaded spring
130 mounting assembly
131 flange washer
132 spacer
133 bearing
134 wheel dust cover
X-X’ cross sectional axis
402 plunger assembly engaged in grooves
502 plunger assembly disengaged from grooves
700 movable load-carrying device
701 handle
705 actuator
706 connecting member
707 wire
710 brake release mechanism
,CLAIMS:We claim:
1. A wheel assembly (100) for a movable load-carrying device (700), said wheel assembly (100) comprising:
a wheel (102);
a wheel mounting bracket (110), said wheel mounting bracket (110) being capable of mounting said wheel (102);
a wheel stopper (105), said wheel stopper (105) being disposed on an outer portion (107) of said wheel (102); and
a plunger assembly (120), said plunger assembly (120) being abutted to said wheel mounting bracket (110);
wherein said wheel stopper (105) having one or more grooves (105a) on an outer portion of said wheel stopper (105); and
wherein said plunger assembly (120) being engaged in said one or more grooves (105a) in response to an operator pulling said movable load-carrying device (700) in a backward direction to prevent pulling of said load-carrying device (700), thereby said plunger assembly (120) acting as a restraining member for arresting movement of said wheel (102).

2. The wheel assembly (100) as claimed in Claim 1, wherein said plunger assembly (120) comprises a hollow plunger (122), wherein a first portion of said hollow plunger (122) being abutted to an outer portion of said wheel stopper (105) and a locking pin (125), said locking pin (125) being disposed within said hollow plunger (122).
3. The wheel assembly (100) as claimed in Claim 1, wherein a first end of said one or more grooves (105a) being equal to the surface level of said wheel stopper (105) and a second end of said one or more grooves (105a) gradually forming a depression within said wheel stopper (105).
4. The wheel assembly (110) as claimed in Claim 3, wherein said locking pin (125) being engaged in said depression within said wheel stopper (105) in response to said operator pulling said movable load-carrying device (700) in said backward direction to prevent said movable load-carrying device (700) from moving in said backward direction.
5. The wheel assembly (110) as claimed in Claim 3, wherein said depression being of a depth of 5 millimeters from said surface level of said wheel stopper (105).
6. The wheel assembly (110) as claimed in Claim 2, wherein a spring (127) being fixed between said hollow plunger (122) and said locking pin (125) to provide a load to said locking pin (125).
7. The wheel assembly (110) as claimed in Claim 1, wherein said wheel mounting bracket (110) having a provision for mounting said plunger assembly (120) on a same side as that of wheel stopper (105) being disposed on said outer portion (107) of said wheel (102).
8. The wheel assembly (110) as claimed in Claim 2, wherein said hollow plunger (122) being welded to a wheel mounting bracket (110).
9. The wheel assembly (110) as claimed in Claim 1, wherein said wheel assembly (110) includes a mounting assembly (130) to mount said wheel (102) to said wheel mounting bracket (110).
10. The wheel assembly (110) as claimed in Claim 9, wherein said mounting assembly (130) includes a washer (131), a spacer (132) and a bearing (133) for securely mounting said wheel assembly (110) to said wheel mounting bracket (110).
11. A movable load-carrying device (700) comprising:
a wheel assembly (100), said wheel assembly (100) comprising:
one or more wheels (102);
one or more wheel mounting brackets (110), said one or more wheel mounting brackets (110) for mounting said one or more wheels (102);
one or more wheel stoppers (105), said one or more wheel stoppers (105) being disposed on an outer portion (107) of said one or more wheels (102), and said one or more wheel stoppers (105) having one or more grooves (105a) being disposed within an outer portion of said one or more wheel stoppers (105); and
one or more plunger assembly (120), said one or more plunger assembly (120) being abutted to said one or more wheel mounting bracket (110); and
a brake release mechanism (710), said brake release mechanism (710) comprising:
an actuator (705) for applying pressure by an operator of said movable load-carrying device (700), said actuator (705) being disposed on a side of said movable load-carrying device (705) being same as that of a side wherein said operator holds said movable load-carrying device (700) by a handle (701); and
a wire mechanism (707), said wire mechanism (707) being operatively coupled to said actuator (705) at one end and being coupled to said one or more wheels (102) of said movable load-carrying device (700) at the other end;
wherein said movable load-carrying device (700) being capable of moving in a forward direction by pushing said movable load-carrying device (700) and said movable load-carrying device (700) being prevented from moving in a backward direction through said one or more plunger assembly (120) of said wheel assembly (100) being engaged (402) in said one or more grooves (105a) in response to said operator pulling said movable load-carrying device (700) in said backward direction during a clear way being provided for movement of said movable load-carrying device (700);
wherein said movable load-carrying device (700) being capable of moving in said backward direction by applying said brake release mechanism (710) to enable pulling of said movable load-carrying device (700) for rotating said one or more wheels (102) in response to said operator applying continuous pressure to said actuator (705), said wire mechanism (707) operatively transferring said pressure to said wheel assembly (110) to disengage (502) said one or more plunger assembly (120) from said one or more grooves (105a) during a dead end situation for movement of said movable load-carrying device (700); and
wherein said movable load-carrying device (700) being prevented from pulling in said backward direction by said wheel assembly (100) being engaged (402) in said one or more grooves (105a) of said one or more wheel stopper (105) in response to said operator removing continuous pressure from said actuator (705), subsequent to said movable load-carrying device (700) being rotated to achieve a clear way from said dead end situation for movement of said movable load-carrying device (700).

12. The movable load-carrying (700) device as claimed in Claim 11, wherein said one or more wheels (102) includes two fixed wheels being disposed on a side of said movable load-carrying device (700) wherein said operator holds said movable-load carrying device (700) though said handle (701).
13. The movable load-carrying device (700) as claimed in Claim 11, wherein said one or more wheels (102) includes two swiveling wheels being disposed on an opposite side of said operator holding said movable load-carrying device (700).
14. The movable-load carrying device (700) as claimed in Claim 11, wherein said rotation of said movable load-carrying device (700) being up to 180 degrees.
15. The movable load-carrying device (700) as claimed in Claim 11, wherein said engaging (402) and disengaging (502) of said one or more plunger assembly (120) in said one or more grooves (105a) of said one or more wheel stopper (105) occurs in one or more swiveling wheels (102).
16. The movable load-carrying device (700) as claimed in Claim 11, wherein said one or more plunger assembly (120) comprises one or more hollow plunger (122), wherein a first portion of said one or more hollow plunger (122) being abutted to an outer portion of said one or more wheel stopper (105) and one or more locking pin (125), said one or more locking pin (125) being disposed within said one or more hollow plunger (122).
17. The movable load-carrying device (700) as claimed in Claim 11, wherein a first end of said one or more grooves (105a) being equal to the surface level of said one or more wheel stopper (105) and a second end of said one or more grooves (105a) gradually forming a depression within said one or more wheel stopper (105).
18. The movable load-carrying device (700) as claimed in Claim 15, wherein said one or more locking pin (125) being engaged (402) in said depression within said one or more wheel stopper (105) in response to said operator pulling said movable load-carrying device (700) in a backward direction to prevent said movable load-carrying device (700) from moving in said backward direction.
19. The movable load-carrying device (700) as claimed in Claim 17, wherein said depression being of a depth of 5 millimeters from said surface level of said one or more wheel stopper (105).
20. The movable load-carrying device (700) as claimed in Claim 16, wherein one or more spring (127) being fixed between said one or more hollow plunger (122) and said one or more locking pin (125) to provide a load to said one or more locking pin (125).
21. The movable load-carrying device (700) as claimed in Claim 11, wherein said one or more wheel mounting bracket (110) having a provision for mounting said one or more plunger assembly (120) on a same side as that of said one or more wheel stoppers (105) being disposed on said outer portion (107) of said one or more wheels (102).
22. The movable load-carrying device (700) as claimed in Claim 16, wherein said one or more hollow plungers (122) being welded to one or more wheel mounting brackets (110).
23. The movable load-carrying device (700) as claimed in Claim 11, wherein said wheel assembly (110) includes a mounting assembly (130) to mount said wheel (102) to said wheel mounting bracket (110).
24. The movable load-carrying device (700) as claimed in Claim 23, wherein said mounting assembly (130) includes a washer (131), a spacer (132) and a bearing (133) for securely mounting said wheel assembly (110) to said wheel mounting bracket (110).
25. The movable load-carrying device (700) as claimed in Claim 11, wherein said brake release mechanism (710) includes a connecting member (706) wherein a first end of said connecting member (706) being connected to said actuator (705) and a second end of said connecting member (706) being connected to said wire mechanism (707).
26. A method for operating a movable load-carrying device (700) with selective rotation of one or more wheels (102), said method comprising the steps of:
loading (801) of said movable load-carrying device (700);
pushing said movable load-carrying device in a forward direction (802) by an operator through one or more wheel assembly (100), wherein said one or more wheel assembly (100) having one or more plunger assembly (120) during a clear way being provided for movement of said movable load-carrying device (700);
engaging said one or more plunger assembly (120) in one or more wheel stoppers (105) to prevent pulling of said movable load-carrying device (700) in a backward direction (803) during said clear way for movement of said movable load-carrying device (700), wherein said plunger assembly (120) acts a restraining member to stop movement of movable load-carrying device (700) in said backward direction and enable movement of said movable load-carrying device (700) in said forward direction only through pushing of said movable load-carrying device (700),
disengaging (806) said one or more plunger assembly (120) from one or more wheel stoppers (105) to enable pulling of said movable load-carrying device (700) in a backward direction for rotating (807) said one or more wheel assembly (100) during a dead end situation (804) for movement of said movable load-carrying device (700) by said operator applying continuous pressure (806) to a brake release mechanism (710); and
engaging (803) said one or more plunger assembly (120) in said one or more wheel stoppers (105) to prevent pulling of said movable load-carrying device (700) in a backward direction in response to said operator removing continuous pressure from said brake release mechanism (710), subsequent to said movable load-carrying device (700) being rotated to achieve a clear way from said dead end situation for movement of said movable load-carrying device (700).
27. The method for operating a movable load-carrying device with selective rotation of one or more wheels as claimed in Claim 26, wherein engaging (803) said one or more plunger assembly (120) in said one or more wheel stoppers (105) includes engaging said one or more plunger assembly (120) in one or more grooves (105a) being formed on an outer portion of said one or more wheel stoppers (105).
28. The method for operating a movable load-carrying device with selective rotation of one or more wheels as claimed in Claim 26, wherein disengaging (806) said one or more plunger assembly (120) from said one or more wheel stoppers (105) includes disengaging (806) said one or more plunger assembly (120) from one or more grooves (105a) being formed on an outer portion of said one or more wheel stoppers (105).
29. The method for operating a movable load-carrying device with selective rotation of one or more wheels as claimed in Claim 28, wherein disengaging (806) of said one or more plunger assembly (120) from one or more wheel assembly (110) being enabled by applying continuous pressure by an operator (805) of said movable load-carrying device (700) to said brake release mechanism (710), wherein said brake release mechanism (710) includes an actuator (705) for applying pressure by said operator and a wire mechanism (707), said wire mechanism (707) being operatively coupled to said actuator (705) at one end and being coupled to said one or more wheels (102) of said movable load-carrying device (700) at the other end.
30. The method for operating a movable load-carrying device with selective rotation of one or more wheels as claimed in Claim 21, wherein engaging (803) said one or more plunger assembly (120) in said one or more wheel stoppers (105a) to prevent pulling of said movable load-carrying device (700) in a backward direction being enabled in response to said operator removing continuous pressure from said brake release mechanism (710), subsequent to said movable load-carrying device (700) being rotated to achieve a clear way from said dead end situation for movement of said movable load-carrying device (700).