Claims:
WE CLAIM:
1. An abuse prevention control circuit (200) for lift-axles of a multi-axle truck (50), said control circuit (200) configured to prevent simultaneous retraction of a pusher lift-axle (110a) and a tag lift-axle (110b) even after a pusher axle override switch (70a) of said pusher lift-axle (110a) and a tag axle override switch (70b) of said tag lift-axle (110b) are pressed simultaneously, said control circuit (200) comprising:
• a normally closed pusher relay switch (210a) connected between a pusher-lift axle control valve (140a) and said pusher axle override switch (70a); and
• a normally closed tag relay switch (210b) connected between a tag-lift axle control valve (140b) and said tag axle override switch (70b).
2. The control circuit (200) as claimed in claim 1, includes a first signal delay device (220a) connected between said pusher axle override switch (70a) and said pusher-lift axle control valve (140a), said first signal delay device (220a) configured to ensure a delayed actuation of said pusher-relay switch (210a) when all the override switches are simultaneously operated and in a condition when both override switches are already pressed followed by the turning ON of the ignition which results in the flow of electric current to both the normally closed switches at the same instance.
3. The control circuit (200) as claimed in claim 1, includes a second signal delay device (220b) connected between said tag axle override switch (70b) and said tag-lift axle control valve (140b), said second signal delay device (220b) configured to ensure a delayed actuation of said tag-relay switch (210b) when all the override switches are simultaneously operated and in a condition when both override switches are already pressed followed by the turning ON of the ignition which results in the flow of electric current to both the normally closed switches at the same instance.
4. The control circuit (200) as claimed in claim 1, wherein said lift-axle control valves (140a, 140b) are pressure actuated valves having spools configured to move in response to the signals received from said override switches (70a, 70b).
5. The control circuit (200) as claimed in claim 1, includes an indication means to alert and inform the driver regarding the lifting of a lift-axle.
6. The control circuit (200) as claimed in claim 1, wherein said indication means is selected from the group consisting of LED lights, display, voice information, and beep alarm.
7. The control circuit (200) as claimed in claim 1, control circuit (200) includes a reverse gear switch (70c), said reverse gear switch (70c) configured to facilitate lifting of both the lift axles when the truck is to be driven in a reverse direction.
8. The control circuit (200) as claimed in claim 1, said control circuit (200) includes a PCB-controller (230) configured to permit the actuation of only one LACV at a time.
Dated this 18th day of October, 2019

MOHAN RAJKUMAR DEWAN
of R.K. DEWAN & COMPANY
IN/PA-25
APPLICANT’S PATENT ATTORNEY

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT CHENNAI
, Description:

FIELD
The present disclosure relates to the field of multi-axle vehicles having at least two lift-axles.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicate otherwise.
Lift-axle - The term “lift-axle” hereinafter refers to a multi-axle truck, wherein the “lift-axle” is capable of deployment and retraction as and when needed.
Load-bellow - The term “load-bellow” hereinafter refers to an air spring that is simply a flexible but sufficiently strong rubber and/or plastic bag inflated to a certain pressure and height to mimic a coil/leaf spring. The “load-bellow” is configured to support the load on the lift-axle when the lift-axle is in a deployed state.
Lift-bellow - The term “lift-bellow” hereinafter refers to an air spring that is simply a flexible but sufficiently strong rubber and/or plastic bag inflated to a certain pressure and height to mimic the coil springs. The “lift-bellow” is configured to raise/retract the lift-axle when the lift-axle is not needed.
Pusher lift-axle - The term “pusher lift-axle” hereinafter refers to a lift-axle that is positioned in the central region of the chassis of the truck.
Tag lift-axle - The term “tag lift-axle” hereinafter refers to a lift-axle that is positioned near the rear end of the chassis of the truck.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Multi-axle trucks or vehicles are widely used in the transportation industry. Further, the multi-axle trucks are provided with at least one lift axle feature to facilitate varied load carrying capacity as and when needed.
Each of the lift-axles is provided with a separate control mechanism for retracting the lift-axle. There is a general practice of untrained drivers to drive laden trucks with lift axle up condition by pressing lift-axle override switches. This is generally followed by all drivers to increase life of tires of the lift axle and to get more fuel efficiency. But such abuse utilization of the override switch has adverse effect on vehicle reliability and safety. With the introduction of vehicle having multiple lift axles, this becomes even more critical and abuse prone as far as laden lift operation of the lift axles is considered. For example – In a 6 axle (49 tons) rigid truck, the driver can drive vehicle with 49 tons load with both the lift axles in lifted condition, thereby overloading the remaining 4 axles and thereby posing a serious safety and reliability issue.
Electrical override switches are provided inside the driver cabin to control the retraction of the axles. When the override switches for both the pusher and tag lift-axle are pressed at the same time, both the pusher and tag lift-axle are simultaneously retracted. This results in a sudden increase in the load on the main axles, suspension, tyres of the main axles, and chassis of the truck. Therefore, the life and reliability of the main axles, suspension, tyres, and chassis are reduced. Though the truck drivers are instructed to not to retract both lift-axles simultaneously, they usually neglect the instruction.
There is, therefore, felt a need of an abuse prevention control circuit for a multi-axle truck that alleviates the above mentioned drawbacks.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide an abuse prevention control circuit for lift-axles of a multi-axle truck.
Another object of the present disclosure is to provide an abuse prevention control circuit that prevents simultaneous lifting of two or more lift-axles.
Yet another object of the present disclosure is to provide an abuse prevention control circuit that automatically sequences the lifting/retraction of lift-axles.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure is about an abuse prevention control circuit for controlling the operation of a lift-axle of a multi-axle truck. The abuse prevention control circuit is configured to prevent simultaneous retraction of a Pusher lift-axle and a Tag lift-axle even after a pusher axle override switch and a tag axle override switch are pressed simultaneously.
In an embodiment, the control circuit includes a normally closed pusher-relay switch connected between a pusher-lift axle control valve and the pusher axle override switch, and a normally closed tag-relay switch connected between a tag lift-axle control valve and the tag axle override switch.
In another embodiment, the control circuit includes a first signal delay device connected between the pusher axle override switch and the pusher-lift axle control valve. The first signal delay device is configured to ensure a delayed actuation of the pusher-relay switch when all the override switches are simultaneously operated and/or in a condition wherein both switches are already pressed and then ignition is turned-on which results in the flow of electric current to both the normally closed switches at the same instance.
In yet another embodiment, the control circuit includes a second signal delay device connected between the tag axle override switch and the tag-lift axle control valve. The second signal delay device is configured to ensure a delayed actuation of the tag-relay switch when all the override switches are simultaneously operated and/or in a condition wherein both switches are already pressed and then ignition is turned-on which results in the flow of electric current to both the normally closed switches at the same instance.
In another embodiment, each of the lift-axle control valves is a pressure actuated valve having a spool configured to move in response to the signal received from the override switches.
In yet another embodiment, the truck includes an indication means to alert and inform the driver regarding the lifting of a lift-axle.
In an embodiment, the indication means is selected from the group consisting of LED lights, display, voice information, and beep alarm.
The control circuit includes a reverse gear switch which is configured to facilitate lifting of both the lift axles when the truck is to be driven in a reverse direction.
In another embodiment, the control circuit includes a PCB-controller that permits the actuation of only one LACV at a time.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWING
An abuse prevention control circuit for controlling the operation of lift axles of a multi-axle truck of the present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a multi-axle truck provided with two lift-axles in various configurations of the operative state of lift-axles;
Figure 2 illustrates an abuse prevention system for a multi-axle truck, in accordance with an embodiment of the present disclosure;
Figure 3 shows a conventional electric control circuit for the lift-axles;
Figures 4a and 4b show an abuse prevention electric/electronic control circuit for the lift-axles; and
Figure 5 shows an abuse prevention electric/electronic circuit for the lift-axles in accordance with another embodiment.
LIST OF REFERENCE NUMERALS USED IN DETAILED DESCRIPTION AND DRAWING
AT-1, AT-2, AT-3, AT-4 – Air tanks
50 – Multi-axle truck
70a – Pusher axle override switch
70b – Tag axle override switch
70c – Reverse gear switch
100 – Conventional control system for lift-axles
110a – Pusher lift-axle
110b – Tag lift-axle
115a – First electrical signal
115b – Second electrical signal
125a – First relay valve (for pusher lift bellows)
125b – Second relay valve (for tag lift bellows)
135a – First quick release valve
135b – Second quick release valve
140a – Pusher lift-axle control valve
140b – Tag lift-axle control valve
145a – First pressure limiting valve
145b – Second pressure limiting valve
150a – Load bellows of pusher lift-axle
150b – Load bellows of tag lift-axle
155 – Load sensing valve
160a – Lift bellows of pusher lift-axle
160b – Lift bellows of tag lift-axle
200 – Abuse prevention electrical/electronic control circuit
210a – Pusher relay switch
210b – Tag relay switch
220a – First signal delay device
220b – Second signal delay device
230 – Smart controller
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not forbid the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
When an element is referred to as being "mounted on," “engaged to,” "connected to," or "coupled to" another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Terms such as “inner,” “outer,” "beneath," "below," "lower," "above," "upper," and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
A multi-axle truck of the present disclosure has several main axles and at least two lift-axles. It is observed that the main axles are subjected to a severe overload condition, when both the two lift-axles are simultaneously retracted/lifted. There are a plurality of load-bellows and lift-bellows associated with each lift-axle of the truck. The trucks (which may also include other multi-axle land vehicles) currently available in the market are not provided with a fool-proof arrangement that will prevent simultaneous retraction of both the lift-axles when the truck is being driven in forward direction.
There is no system currently available in the market which can automatically prevent the abuse of lift-axle and main axles of the truck.
The present disclosure will address the above issue and will avoid the simultaneous retraction of both the lift-axles when the truck is being driven in forward direction.
Figures 1a shows a multi-axle truck 50 with various operating configurations of a pusher lift-axle 110a and a tag lift-axle 110b. The load carrying capacity of the multi-axle truck 50 depends on the number and the type of lift-axle that is/are deployed.
Figure 2 shows a pneumatic circuit for the operation of the pusher lift-axle 110a and the tag lift-axle 110b of the multi-axle truck 50. The pneumatic circuit includes two sets of load-bellows (150a, 150b), two sets of lift-bellows (160a, 160b), a plurality of pressurized air-tanks (AT-1, AT-2, AT-3, AT-4), a first relay valve 125a, a second relay valve 125b, a first quick release valve 135a, a second quick release valve 135b, a first quick release valve 135a, a second quick release valve 135b, a first pressure limiting valve 145a, a second pressure limiting valve 145b, a load sensing valve 155, a pusher lift-axle control valve (LACV-p) (140a), a tag lift-axle control valve (LACV-t) (140b), a plurality of fluid lines fluidly connecting different components of the pneumatic circuit, a plurality of T-joints. Each of the LACV(s) is controlled by electric signals received from a push axle override switch 70a, a tag axle override switch 70b, a reverse gear switch 70c, and/or the load sensing valve 155. The electrical power required for the operation of the system is derived from a battery through a supply line and the circuit is grounded to chassis with ground line as shown in Figure 2.
The air tanks (AT-1, AT-2, AT-3, and AT-4) supply pressurized air to the pneumatic circuit. The first relay valve 125a regulates and direct pressurized air from the control valve 140a to the lift bellows 160a of the pusher lift-axle 110a and the first quick release valve 135a directs and regulates air from LACV 140a to load bellows 150a of the pusher lift axles 110a. Similarly, the second quick release valve 135b regulates and direct pressurized air from the control valve 140b to the load bellows 150b of the tag lift-axle 110b and the second relay valve 125b directs and regulates pressurized air from LACV 140b to the lift bellows 160b of the tag lift-axle 110b.
Each of the load-bellows (150a, 150b) is configured to support the load in the vehicle and each of the lift-bellows (160a, 160b) is configured for raising/retracting the corresponding lift-axle.
In an embodiment, the control valve (140a, 140b) can be selected from the group of valves consisting of an electrical valve, electronic valve, pneumatic valve, and electro-pneumatic valve.
For the purpose of explanation, let us consider that the control valves (140a and 140b) are electrical valves. These valves are operated based on the signals received from a plurality of lift-axle override switches (70a, 70b), and a reverse gear switch 70c provided in the driver cabin.
Each of the control valves (140a and 140b) is provided with a solenoid actuator (not specifically shown in figures). The solenoid actuator controls the opening and closing of ports of the respective control valve (140a and 140b) in accordance with the signals received from override switches (70a, 70b), and the reverse gear switch 70c or load sensing valve 155 that are in fluid communication with the load-bellows (150a or 150b).
Separate override switches are provided in the driver cabin for enabling the lifting of any/both the lift-axle(s). A pusher axle override switch 70a controls the retraction of the pusher lift-axle 110a, while the tag axle override switch 70b controls the retraction of the tag lift-axle 110b. The reverse gear switch 70c controls the retraction of the pusher lift-axle 110a and tag lift-axle 110b while the truck is to be driven in the reverse direction.
In an embodiment the override switches (70a, 70b) and the reverse gear switch 70c may be located on the outside of the cabin, on the chassis, or where space is available. An override switch sends an electrical signal to the solenoid coil of a corresponding LACV (140a or 140b), wherein the solenoid coil operates the corresponding LACV, and lifts the corresponding lift-axle (110a or 110b) by directing the flow of pressurized air towards the lift-bellow (160a or 160b) to inflate the lift-bellows (160a or 160b) of the corresponding lift-axle, and by exhausting the load-bellow (150a or 150b).
A conventional control circuit 100 for the lift-axles is shown in Figure 3. When the pusher axle override switch 70a is pressed a first electrical signal 115a is sent to the pusher-LACV 140a. When the tag axle override switch 70b is pressed a second electric signal 115b is sent to the tag-LACV 140b. In the conventional control circuit 100 when both the switches (70a and 70b) are pressed, both the lift axle gets lifted/retracted. The simultaneous retraction of the lift-axles is not desirable as it increases the load on the main axles.
Figures 4a and 4b show an abuse prevention electric/electronic control circuit 200 in accordance with the present disclosure. By using the control circuit 200, the above mentioned issue will be addressed by only allowing one lift axle to be lifted in a rated laden condition, even if both the lift axle override switches (70a and 70b) are simultaneously pressed by the truck driver.
The control circuit 200 uses two normally closed electric relay switches, viz. a pusher relay switch 210a and a tag relay switch 210b, as shown in Figures 4a and 4b. If the pusher axle override switch 70a is pressed, a tag relay switch 210b of the tag lift-axle circuit will get actuated and the electric circuit of the tag lift-axle circuit will get open, such that, even after pressing the tag axle override switch 70b the electric signal will not reach the tag-LACV 140b. This will allow the retraction of only the pusher lift-axle 110a and automatic prevention of retraction of the tag lift-axle 110b.
In another case, if the tag axle override switch 70b is pressed, the pusher relay switch 210a of the pusher lift-axle 110a will get actuated and the electric circuit of the pusher axle override switch gets open, such that even after pressing pusher axle override switch 70a the electric signals will not reach the pusher-LACV 140a. This will allow the retraction of only the tag lift-axle 110b and automatic prevention of the retraction of pusher lift-axle 110a.
If both the switches 70a and 70b are pressed at the same time there is a first signal delay device 220a connected between the pusher axle override switch 70a and the pusher relay switch 210a, which will ensure a delayed actuation of the tag-relay switch 210b. In another embodiment, a second signal delay device 220b connected between the tag axle override switch 70b and the tag-relay switch 210b, which will ensure a delayed actuation of the tag-relay switch 210b. This prevents the simultaneous lifting of both the lift axles.
Figure 5 shows an abuse prevention electric/electronic control circuit 200, in accordance with another embodiment of the present disclosure. In an embodiment, the two normally closed relay switches as shown in Figure 4 are replaced with a PCB-controller 230 which will allow the actuation of only one LACV (140a or 140b) i.e. only one lift-axle at a time. The PCB-controller 230 is programmable and can be re-programmed as per requirement.
The first signal delay device 220a is configured to ensure a delayed actuation of the pusher-relay switch 210a when all the override switches are simultaneously operated and in a condition when both override switches are already pressed followed by the turning ON of the ignition which results in the flow electric current to both the normally closed switches at the same instance.
The second signal delay device 220b configured to ensure a delayed actuation of the tag-relay switch 210b when all the override switches are simultaneously operated and in a condition when both override switches are already pressed followed by the turning ON of the ignition which results in the flow electric current to both the normally closed switches at the same instance.
The reverse gear switch 70c is pressed when the truck is to be driven in reverse gear. When the reverse gear switch 70c is pressed both the lift axles are retracted or lifted. The truck can be properly steered in the reverse direction when both the lift axles are in their lifted position.
In another embodiment, an intelligent device/system is introduced which will prevent manual lifting of both the lift axles simultaneously, by pressing override switch in the rated laden condition. This system will allow only one lift axle to be lifted at a time whose override switch is activated first.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of an abuse prevention control circuit for lift-axles of a multi-axle truck that:
• prevent simultaneous retraction of two or more lift-axles;
• prevent a sudden increase in the loading of main axles, suspension, chassis and tyres of the truck; and
• will automatically sequence the operation of lift-axles.
The foregoing description of the specific embodiments so fully reveals 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.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, or step, or group of elements, or steps, but not the exclusion of any other element, or step, or group of elements, or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.