Claims:1. A helical drive-based auto adjuster for air disc brakes, comprising:
a piston (1) that is coupled with an at least a tappet (2);
the at least one tappet (2) that is coupled with a helical drive (4) by a one-way clutch, through an accordion spring and roller mechanism, with the rotation of the at least one tappet (2) being controlled by the helical drive (4) and a drive ring (5);
a plurality of clutch plates (6 and 7), with the disposition of the plurality of clutch plates (6 and 7) against a drive ring flange being configured to keep the alternate clutch plates in stationary condition; and
an at least an overload spring (3) that is disposed concentrically to provide slipping torque to the plurality of clutch plates (6 and 7) and the drive ring (5), with: said helical drive (4), said drive ring (5), and said plurality of clutch plates (6 and 7) being co-axially disposed with said at least one tappet (2) and said piston (1),
with said auto adjuster being configured to monitor and automatically maintain the required clearance between the rotor of the air disc brake and friction, during every braking.
2. The helical drive-based auto adjuster for air disc brakes as claimed in claim 1, wherein the drive transfer between the helical drive (4), the drive ring (5), the clutch plates (6 and 7), and the at least one tappet (2) takes place in all the braking conditions of forward and reverse. , Description:TITLE OF THE INVENTION: HELICAL DRIVE-BASED AUTO ADJUSTER FOR AIR DISC BRAKES
FIELD OF THE INVENTION
The present disclosure is related to air disc brakes. Particularly, the present disclosure is related to a helical drive-based auto adjuster for air disc brakes.
BACKGROUND OF THE INVENTION
Air disc brakes used in commercial buses and trucks are internally actuated either by twin piston or single piston, depending on the vehicle application requirement. Considering the cost and requirement of optimized specific usage, it becomes essential to develop an air disc brake with fewer internal adjusting components.
Indian Patent Application Number 201617026001 discloses a disc brake including a pivoting lever having eccentric journals, which act on a pair of tappets. The tappets are adjusted in length by rotation, and each tappet has a tappet gear. A centrally located intermediate gear is provided between the tappet gears to form a gear train synchronizing the rotation of the two tappets and, therefore, ensuring that they remain of the same length. The centrally located intermediate gear includes a socket for receiving a centrally located adjuster. The adjuster may be installed and removed from the disc brake through an aperture at the rear of the brake caliper, without any substantial disassembly of the brake and without de-synchronizing the tappets, or even interrupting the gear train between the tappets.
However, the gear trains of the tappets, the intermediate components and the adjuster parts have more losses owing to more number of components used in Adjusting and transmission. Thereby reduces the mechanical efficiency and shall have wider variation in the adjustment clearance on wear and tear.
There is, therefore, a need in the art for a helical drive-based auto adjuster for air disc brakes, which overcomes the aforementioned drawbacks and shortcomings.
SUMMARY OF THE INVENTION
A helical drive-based auto adjuster for air disc brakes is disclosed. The auto adjuster, during every braking, is configured to monitor and automatically maintain the required clearance between a rotor of the air disc brake and friction. Said auto adjuster comprises a piston that is coupled with an at least a tappet.
The at least one tappet is coupled with a helical drive by a one-way clutch, through an accordion spring and roller mechanism.
The rotation of the at least one tappet is controlled by the helical drive and a drive ring.
Said auto adjuster also comprises a plurality of clutch plates, with the disposition of the plurality of clutch plates against a drive ring flange being configured to keep the alternate clutch plates in stationary condition.
An at least an overload spring is disposed concentrically to provide slipping torque to the plurality of clutch plates and the drive ring.
Said helical drive, said drive ring, and said plurality of clutch plates are co-axially disposed with said at least one tappet and said piston.
The drive transfer between the helical drive, the drive ring, the clutch plates, and the at least one tappet takes place in all the braking conditions of forward and reverse.
The method of working of the auto adjuster is also disclosed. The disclosed auto adjuster is: simple; cost-effective; manufacturing-friendly; and comprises fewer internal adjusting components. Further, the disclosed auto adjusted does not required any maintenance throughout the lifetime of the brake, hence no removal is required.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 illustrates the cross-sectional view of an embodiment of a helical drive-based auto adjuster for air disc brakes, in accordance with the present disclosure; and
Figure 2 illustrates an embodiment of a helical drive-based auto adjuster for air disc brakes, in accordance with the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
Throughout this specification, the use of the words "comprise", “have”, “contain”, and “include”, and variations such as "comprises", "comprising", “having”, “contains”, “containing”, “includes”, and “including” may imply the inclusion of an element or elements not specifically recited. The disclosed embodiments may be embodied in various other forms as well.
Throughout this specification, the phrases “at least a”, “at least an”, and “at least one” are used interchangeably.
Throughout this specification, the use of the word “plurality” is to be construed as being inclusive of at least one.
Throughout this specification, the use of the phrase “auto adjuster” is to be construed as a set of technical components that are communicatively or operably associated with each other, and function together as part of a mechanism to achieve a desired technical result.
A helical drive-based auto adjuster for air disc brakes is disclosed (hereinafter ‘auto adjuster’). As illustrated in Figure 1 and Figure 2, an embodiment of said auto adjuster comprises: a piston (1); an at least a tappet (2); an at least an overload spring (3); a helical drive (4); a drive ring (5); and a plurality of clutch plates (6 and 7). Said helical drive (4), said drive ring (5), and said plurality of clutch plates (6 and 7) are co-axially disposed with said at least one tappet (2) and said piston (1).
In an embodiment of the present disclosure, the piston (1) is coupled with the at least one tappet (2), and the rotation of the at least one tappet (2) is controlled by the helical drive (4) and the drive ring (5). The at least one tappet (2) is coupled with the helical drive (4) by means of a one-way clutch, through an accordion spring and roller mechanism. This configuration allows the auto adjuster to adjust only in a forward direction. Alternatively, any other one-way clutches known in the art can also be used. Further, any other alternative configurations known in the art can be used and said alternative configuration may allow the auto adjuster to adjust in reverse direction as well.
In another embodiment of the present disclosure, the disposition of the plurality of clutch plates (6 and 7) against a drive ring flange is configured to keep the alternate clutch plates in stationary condition. The at least one overload spring (3) is disposed concentrically to provide slipping torque to the plurality of clutch plates (6 and 7) and the drive ring (5).
In yet another embodiment of the present disclosure, the helical drive (4) with the at least one overload spring (3), and the plurality of clutch plates (6 and 7) facilitate the maintaining of the required wear clearance between a rotor of the air disc brake and friction, by automatically adjusting in the forward direction and slipping during an overload condition.
In yet another embodiment of the present disclosure, the auto adjuster, during every braking, is configured to monitor and automatically maintain the required clearance between the rotor of the air disc brake and the friction. If excess clearance is observed between the rotor of the air disc brake and the friction, outer splines of the helical drive (4) move axially forward and touch inner splines of the drive ring (5). The helical drive (4) rotates, since the drive ring (5) is held by the at least one overload spring (3).
Since the at least one tappet (2) is coupled with the helical drive (4) through the accordion spring and roller mechanism, said at least one tappet (2) also rotates. As the at least one tappet (2) has only the rotational degree of freedom, said at least one tappet (2) linearly moves the piston (1) forward. Said forward movement of the piston (1) continues until the friction touches the rotor of the air disc brake. At the same time, the drive ring (5) slips against the plurality of clutch plates (6 and 7).
During the return stroke, the helical drive (4) slips because it is coupled with the at least one tappet (2) through the accordion spring and roller mechanism; hence, the at least one tappet (2) does not rotate.
In yet another embodiment of the present disclosure, the axial clearance between the outer splines of the helical drive (4) and the inner splines of the drive ring (5) maintains the backslash.
During excess clearance between the friction and the rotor of the air disc brake, the helical drive (4) moves axially crossing the backlash distance, and contacts the inner splines of the drive ring (5); hence, the helical drive (4) rotates, and, thereby rotates the at least one tappet (2) in the forward direction. Correspondingly, the piston (1) advances linearly.
In yet another embodiment of the present disclosure, the helical drive (4) moves forward and rotates until the drive ring (5) slips beyond the overload torque due to the at least one overload spring (3). During the return stroke, the helical drive (4) rotates in opposite direction and slips against the at least one tappet (2). Thereby, it does not rotate the at least one tappet (2).
In yet another embodiment of the present disclosure, the drive transfer between the helical drive (4), the drive ring (5), the clutch plates (6 and 7), and the at least one tappet (2) takes place in all the braking conditions of forward and reverse.
The disclosed helical drive-based auto adjuster for air disc brakes is: simple; cost-effective; manufacturing-friendly; and comprises fewer internal adjusting components. Further, the disclosed auto adjusted does not required any maintenance throughout the lifetime of the brake, hence no removal is required.
It will be apparent to a person skilled in the art that the above description is for illustrative purposes only and should not be considered as limiting. Various modifications, additions, alterations and improvements without deviating from the spirit and the scope of the disclosure may be made by a person skilled in the art. Such modifications, additions, alterations and improvements should be construed as being within the scope of this disclosure.

LIST OF REFERENCE NUMERALS
1 – Piston
2 – At Least One Tappet
3 – At Least One Overload Spring
4 – Helical Drive
5 – Drive Ring
6 and 7 – Plurality of Clutch Plates