Description:TECHNICAL FIELD
001 The present disclosure generally relates to locking mechanisms and assemblies, and more particularly, the present disclosure relates to a locking assembly with a lock cylinder operated with a key on one side and a knob on another side.

BACKGROUND
002 Typically, a lock assembly is provided for doors that allow the door to be secured and prevent unauthorized opening of the door. Such lock assembly may include a cylinder lock activated by a key or a knob. The key or the knob is rotated to actuate a bolt which extends and retracts in a horizontal direction to engage or disengage with a corresponding slot in the door frame to lock or unlock the door.
003 Some of the lock assemblies include a lock cylinder which can be operated by key from one side and by a knob on other side. Such type of lock cylinder is also commonly called as 1CK cylinder. The conventional 1 CK lock cylinder includes a buffer on the plug side (key side) called as the plug buffer, a buffer on the knob side called as the knob spindle buffer, a cam, and pin tumblers. The buffers have male female profiles which get engaged with each other when the key is inserted. The knob side buffer rotates the cam when the key is inserted. Further, the knob is always in contact with the cam through a rotatable spindle also called as knob spindle. The cam when rotated in an installed condition with suitable lock, operates the lock from unlocked to locked condition and vice-versa. And hence, every time the knob is rotated, the lock is operated. The knob spindle buffer has protruding lugs outside its periphery which are engaged with the slot provided on the knob spindle. Hence every time knob spindle rotates, the knob spindle buffer also rotates along with the cam. Similarly, the plug buffer also has protruding lugs outside its periphery which are engaged with the slot provided on the plug. Hence every time the plug rotates, the plug buffer also rotates along with it. To operate the lock from the cylinder side a key with correct combinations matching with the assembled pin tumblers inside the lock cylinder is required. The key length is designed such that once the key is completely inserted in the key slot and the plug, it pushes the plug buffer by a specific distance such that the lugs provided on the plug buffer gets engaged with the female profile on the knob spindle buffer. When the correct key is rotated, it rotates the plug which further rotates the plug buffer. The plug buffer through the lugs which are in engagement with the female profile on the knob spindle buffer rotates the knob spindle buffer. Once the knob spindle buffer gets rotated, it rotates the cam through the knob spindle and thus operates the lock.
004 The problem with this type of mechanism is that the male female profiles on the buffers are very small and flimsy. The complete lock mechanism operates on the successful engagement of the plug buffer and knob spindle buffer. Further, if any of the male part or female part gets damaged due to the lug breakage of male part or profile damage of the female part, the complete mechanism stops functioning and the key or knob will stop operating the lock mechanism.
005 Therefore, there is a need for a lock assembly with a locking mechanism which eliminates the aforementioned drawbacks of the conventional locking mechanism in 1CK lock assemblies.

OBJECTS
006 The principal object of an embodiment of this invention is to provide a lock assembly with a lock cylinder which is operated by a key on one side and operated by a knob on another side.
007 Another object of an embodiment of this invention is to provide the lock assembly with a coupling mechanism at the knob side which engages with a key inserted through a plug at the key side, wherein the coupling mechanism eliminates the requirement of a buffer at the knob side.
008 Yet another object of an embodiment of this invention is to provide the lock assembly with a plug buffer comprising two protruding members extending radially outwards from a periphery of a body of the plug buffer, wherein a profile of first member is wider than a profile of other member.
009 Still another object of an embodiment of this invention is to provide the lock assembly with a cam comprising a slot with a profile which matches with the profile of the protruding members on the plug buffer, which ensures that the plug buffer enters the cam only from one direction, therefore ensuring that the protruding members get engaged with the cam in the correct orientation.
010 Yet another object of an embodiment of this invention is to provide the lock assembly which eliminates the need for a female buffer at the knob side and eliminates the dependency of engagement of male lug/ member of the plug buffer with a female profile in the knob buffer, therefore providing increased durability, reliability and improved locking mechanism.
011 These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS
012 The embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
013 Fig. 1 depicts a sectional view of a lock assembly, according to an embodiment of the invention as disclosed herein;
014 Fig. 2 is an exploded view of the lock assembly, according to an embodiment of the invention as disclosed herein; and
015 Fig. 3 is a schematic view of a cam and a plug buffer of the lock assembly, according to an embodiment of the invention as disclosed herein.

DETAILED DESCRIPTION
016 The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
017 The embodiments herein achieve a lock assembly with a lock cylinder operated by a key on one side and by a knob on another side, having a coupling mechanism at the knob side which engages with a key inserted through a plug at the key side, wherein the coupling mechanism eliminates the requirement of a buffer at the knob side. The embodiments herein achieve the lock assembly with a plug buffer comprising two protruding members extending radially from a periphery of a body of the plug buffer, wherein a profile of one member is wider than a profile of the other member. Further, the embodiments herein achieve the lock assembly with a cam comprising a slot which matches with the profile of the plug buffer with the two protruding members, which ensures that the plug buffer and the protruding member enters the cam only from one direction, therefore ensuring that the plug buffer gets engaged with the cam in the correct orientation always. Furthermore, the embodiments herein achieve the lock assembly which eliminates the need for a female buffer at the knob side and eliminates the dependency of engagement of male member of the plug buffer with a female profile in the knob buffer, therefore providing increased durability, reliability and improved locking mechanism. Referring now to the drawings, and more particularly to FIGS. 1 through 3, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
018 Fig. 1 is a sectional view of the lock assembly (100), according to an embodiment of the invention as disclosed herein. The lock assembly (100) includes a lock cylinder which is operable with a key (100A) on one side and a knob (109) on another side. The lock assembly (100) includes a tubular plug (101) for receiving a key, a plug buffer (102), a coupling mechanism comprising a pin (103) and a first spring (104), a cam (105), a second spring (106), a rotatable cylindrical body (108), and a knob (109). The plug buffer (102) is connected to the plug (101) and comprises a body with at least two protruding members (102a, 102b) of predetermined profile and predetermined dimensions, extending radially outwards from a periphery of the body of the plug buffer (102). In an embodiment, the plug buffer (102) comprises two protruding members (102a, 102b) positioned diametrically opposite on the periphery of the body of the plug buffer (102), wherein width of a first protruding member (102a) is greater than a width of a second protruding member (102b). Further, the plug buffer (102) is designed to receive the pin (103) through a hole (102c) defined into the body of the plug buffer (102) and to house the first spring (104), as shown in Fig.2.
019 The pin (103) comprises a first end (103a) and a second end (103b). The first spring (104) is placed on the pin (103) towards the first end (103a) at a predetermined position. The first spring (104) is housed within the plug buffer (102) and is positioned towards the first end (103a) of the pin (103) such that the first spring (104) compresses when the pin (103) is pushed towards the cylindrical body (108) on insertion of the correct key and provides a friction between the pin (103) and the plug buffer (102) when the pin (103) is rotated due to rotation of the key (100A). The second spring (106) is provided towards the second end (103b) of the pin (103) at a predetermined position. The pin (103) passes through the hole (102c) defined in the plug buffer (102) such that the first end (103a) of the pin (103) is positioned towards the plug (101) and is operatively coupled with the key (100A), such that when the correct key is inserted, the pin (103) is pushed towards the cylindrical body (108) and allowing engagement of the plug buffer (102) with the cam (105). The second end (103b) of the pin (103) extends outside the hole (102c) of the plug buffer (102) and is positioned such that it is received by an opening defined in the cylindrical body (108). The second spring (106) is placed inside the opening defined in the cylindrical body (108) towards the second end (103b) of the pin (103). The second spring (106) compresses when the pin (103) is pushed towards the cylindrical body (108) after the insertion of the key (100A). In an embodiment of the invention, the pin (103) is held firmly with the plug buffer (102) by a circlip (107).
020 Further, the cam (105) is operatively connected with the plug buffer (102) and the cylindrical body (108). The cam (105) comprises a slot defined in a body of the cam (105) such that slot matches with a profile of the plug buffer (102). The slot comprises a wider first part (105a) corresponding to the first protruding member (102a) of the at least two protruding members of the plug buffer (102) and a second narrow part (105b) corresponding to the second protruding member (102b) of the plug buffer (102). The slot has a predetermined profile and predetermined dimension such that when the at least two protruding members (102a, 102b) of the plug buffer (102) are aligned with the slot defined in the cam (105), the plug buffer (102) enters into the slot partially. In an embodiment (as shown in Fig. 3), the plug buffer (102) comprises of two protruding members (102a, 102b) wherein width of the first protruding member (102a) is greater than the width of the second protruding member (102b), and the slot in the cam (105) is designed such that the profile of the slot matches with the profile of the plug buffer (102) with the two protruding members (102a, 102b). The cam (105) partially receives the plug buffer (102) when the two protruding members (102a, 102b) are correctly aligned with the profile of the slot i.e. the first protruding member (102a) is aligned with a wider first part of the slot (105a) and the second protruding member (102b) is aligned with a narrow second part of the slot (105b). This arrangement ensures that the protruding members (102a, 102b) and the plug buffer (102) enter the cam (105) only from one side in the correct orientation.
021 When a correct key is inserted, the key (100A) first pushes the pin (103) which compresses the first spring (104). Further, when the key (100A) is rotated in a predetermined direction such that the orientation of the at least two protruding members (102a, 102b) of the plug buffer (102) matches with the slot in the cam (105), the plug buffer (102) gets pushed towards the cam (105) thus entering partially inside the slot in the cam (105). The length of the protruding members (102a, 102b) is designed such that the plug buffer (102), at this position is in contact with the plug (101) as well as the cam (105). When the correct key is inserted inside the plug (101) and rotated, it rotates the plug (101) which further rotates the plug buffer (102). The plug buffer (102) through the at least two protruding members (102a, 102b) of the plug buffer (102) which are in engagement with the cam (105) through the slot provided on the cam (105), rotates the cam (105). The rotation of the cam (105) results in the rotation of the cylindrical body (108) and the knob (109), thus operating the lock.
022 The technical advantages achieved by the embodiments disclosed herein include elimination of female buffer at the knob side of the lock assembly, elimination of dependency on the engagement of male protruding members of the plug buffer with the female profile of the knob spindle buffer, increased durability and ease of operation and maintenance of the lock assembly compared to the conventional existing mechanisms.
023 The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

, Claims:CLAIMS
We claim,
1. A lock assembly (100) operated by a key (100A) on one side and a knob (109) on another side, having a plug (101) at the key side for receiving the key (100A), a rotatable cylindrical body (108) operationally connected with the knob (109), and a cam (105) operationally connected between the plug (101) and the cylindrical body (108) such that the cam (105) rotates when the key (100A) is rotated or the knob (109) is operated, the lock assembly (100) comprising:
a plug buffer (102) disposed inside the plug (101), said plug buffer (102) operatively coupled with said cam (105), wherein said plug buffer (102) includes:
at least two protruding members (102a, 102b) of predetermined profile and predetermined dimensions, extending radially outwards from a periphery of a body of said plug buffer (102), and
a hole (102c) defined in said body of said plug buffer (102) at a predetermined position;
a coupling mechanism having:
a pin (103) received through said hole (102c) of said plug buffer (102) and extending towards and into an opening defined in said cylindrical body (108);
wherein said pin (103) is operationally coupled with said key (100A) such that said pin (103) is displaced towards said cylindrical body (108) when the key (100A) is inserted through said plug (101) and pushed to operate said lock assembly (100); and
a first spring (104) disposed around said pin (102) towards a first end (103a) of said pin (103); and
a second spring (106) disposed towards a second end (103b) of said pin (103) and inside an opening of said cylindrical body (108), wherein said second spring (106) is compressed when said pin (103) is displaced towards said cylindrical body (108).

2. The lock assembly (100), as claimed in claim 1, wherein said cam (105) comprises a slot with a predetermined profile and predetermined dimensions defined in a body of the cam (105), such that when a profile of said plug buffer (102) with said at least two protruding members (102a, 102b) is aligned with said profile of said slot of the cam (105) when said key (100A) is inserted through said plug (101) and rotated in a predetermined direction.

3. The lock assembly (100) as claimed in claim 3, wherein said plug buffer (102) comprises said first protruding member (102a) and said second protruding member (102b), wherein a width of said fist protruding member (102a) is greater than a width of said second protruding member (102b).

4. The lock assembly (100) as claimed in claim 4, wherein said slot of the cam (105) comprises a wider first part (105a) and a narrow second part (105b) such that said plug buffer (102) is inserted in said slot when said first protruding member (102a) is engaged/passed inside said wider first part (105a) and said second protruding member (102b) is engaged/passed inside said narrow second part (105b) of the slot of said cam (105).
5. The lock assembly (100) as claimed in claim 3, wherein a length of said at least two protruding members (102a, 102b) is such that said plug buffer (102) is in contact with said plug (101) and said cam (105), when said plug buffer (102) is inserted in said cam (105).

6. The lock assembly (100) as claimed in claim 1, wherein said pin (103) is secured within said plug buffer (102) through a circlip (107) at a predetermined position.

7. The lock assembly (100) as claimed in claim 1, wherein said second spring (106) provides friction between said pin (103) and said plug buffer (102) when said pin (103) and said plug buffer (102) is rotated.