AU2020104180A4 - An Electric Disc Brake Caliper - Google Patents

Abstract

The present invention is a brake caliper for a disc rotor on a trailer. The caliper comprises a body, a mounting bracket to enable the body of the caliper to sit over the disc rotor, brake pads for the caliper a piston for the caliper and gearing to increase the torque exerted by the piston on the disc rotor. The brake caliper is characterized in that it has an electric servo motor directly in line with the piston to apply the brake pads. 3/4 6 121 1 23 25 24 3 20 2 Figure 3

Description

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I AN ELECTRIC DISC BRAKE CALIPER TECHNICAL FIELD

[0001] The present invention relates to vehicle braking systems and, more particularly, to an electric disc brake caliper for trailers.

BACKGROUND

[0002] Vehicles use brakes to stop. On a motor vehicle the brakes are usually hydraulically powered disc brakes. On a trailer, the brakes are usually electrically powered drum brakes. However, disc brakes are a lot more efficient than drum brakes.

[0003] Drum brakes are cumbersome, inefficient and more difficult to repair than disc brakes. Drum brakes have to be consistently adjusted as the brake shoes wear. If the brake shoes on a drum brake get too hot, then it results in brake fade. Disc brakes do not get brake fade. Drum brakes are less efficient than disc brakes. With a drum brake, you are pulling the shoes against the drum. With a disc brake, you are pushing the brake pads against the disc rotor. As a result, disc brakes can stop a vehicle in a much shorter distance than a drum brake. Therefore, there is a need in the market for an efficient electric disc brake for trailers.

[0004] One common problem with trailers is that they can sway. The swaying action is often caused by wind or imbalances in the position of weight within the trailer. Swaying can cause the trailer to veer off course and result in a car accident. However, conventional hydraulically powered braking systems for trailers are not adaptable for anti-sway technology. The anti-sway technology comprises a control unit, which can apply brakes to wheels or sets of wheels. Hydraulically powered braking systems for trailers comprise an actuator. The actuator applies brakes to all wheels of the trailer simultaneously. However, efficient anti-sway systems require independent controlling of the braking on each wheel. Therefore, there is a need in the market for an efficient electric disc brake that can be used in conjunction with anti-sway systems for trailers.

[0005] The object of the present invention is to overcome or at least substantially ameliorate the aforementioned problems.

SUMMARY OF THE INVENTION

[0006] According to the present invention, there is provided a brake caliper for a disc rotor on a trailer, the caliper comprising:

(a) a body;

(b) a mounting bracket to enable the body of the caliper to sit over the disc rotor;

(c) brake pads for the caliper;

(d) a piston for the caliper;

(e) gearing to increase the torque exerted by the piston on the disc rotor; and

the brake caliper is characterized in that it has an electric servo motor directly in line with the piston to apply the brake pads.

[0007] The advantage of having the electric servo motor directly in line with the piston is that it makes the brake caliper more compact than prior art brake calipers. There is a lack of room underneath most trailer chassis because of various components, such as suspensions and axles. More brake torque can be generated with the caliper of the present invention than prior art brake calipers.

[0008] In order to have an anti-sway system, the vehicle should have electric brakes. An anti-sway system cannot be used efficiently with hydraulic brakes. Therefore, the caliper of the present invention may comprise a control unit to automatically brake any one or more of the rotors to stop the vehicle from swaying.

[0009] It is preferred that the servo and the gearing are contained within the body of the caliper, as opposed to outside the body of the caliper. This also makes the brake caliper more compact.

[0010] Preferably, the caliper uses slide pins to keep the caliper centred over the disc rotor. This prevents uneven brake pad wear. This also ensures that both brake pads are apply pressure to the disc rotor evenly.

[0011] More preferably, the caliper has grease nipples for the ball valve so that the piston does not seize up. This prevents the caliper from seizing due to a lack of lubricant.

[0012] The caliper is preferably zinc coated to inhibit rust. The piston is preferably made of stainless steel to reduce the chance of the piston seizing.

[0013] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention.

-Y BRIEF DESCRIPTION OF DRAWINGS

[0014] An embodiment of the invention will be described with reference to the following drawing, in which:

[0015] Figure 1 is a perspective view of an electric brake caliper attached to a disc brake.

[0016] Figure 2 is a perspective view of an electric brake caliper according an embodiment of the present invention.

[0017] Figure 3 is an exploded view of the electric brake caliper of figure 2.

[0018] Figure 4 is a side section view of the electric brake caliper of figure 2.

DETAILED DESCRIPTION

[0019] Figure 1 shows a perspective view of a disc rotor 10 for a wheel of a trailer (not shown). The disc rotor 10 has a brake caliper 12. The caliper 12 comprises a body 14, a mounting bracket 16 to enable the body 14 to sit over the disc rotor 10 and brake pads (which are hidden underneath the body 14).

[0020] The caliper 12 also comprises a piston 20 (see figure 3) with an O-ring 22 and a seal 24, an electric servo motor 26 to control the piston 20, gearing 28 to increase the torque exerted by the piston 20 on the disc rotor 10.

[0021] The electric servo motor 26 and the gearing 28 attaches to a flange 16 using screws 18. The flange then mounts the caliper 12 using screws 19.

[0022] A thrust bearing washer 21 is used to allow a shaft 23 to rotate forwards and backwards. The shaft 23 is held by a grub screw 25 (compare figures 3 and 4) which screws into the shaft 23.

[0023] Unlike in prior art brake calipers, in the present invention the servo motor 26 is directly in line with the piston 20 to push on the back of the brake pads. The advantage of having the electric servo motor 26 directly in line with the piston 20 is that it makes the brake caliper 12 more compact than prior art brake calipers. As shown in figure 1, there is a lack of room underneath most trailer chassis because of various components, such as the suspensions system 30 and axle (which is not shown in figure 1). More brake torque can be generated with the caliper of the present invention than prior art brake calipers. This is because there is direct linear force on the piston 20. In the prior art patents for brake calipers such as

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US20190120311A1, US20180045258A1, US20170045105A1, US20070209888A1 and US7950503, offset gearing is used to apply the torque indirectly using a rubber belt. The rubber belt will expand as it gets hot, which causes a loss of friction and thereby a loss in torque. The present invention does not suffer from this problem.

[0024] The brake caliper 12 uses slide pins 32 and 34 (see figure 1) to keep the brake caliper 12 centred over the disc rotor 10.

[0025] The brake caliper 12 has grease nipples so that the piston 20 does not seize up. The holes 36 in which the grease is injected by the nipples is shown in figures 2 and 4.

[0026] The electric servo motor 26 and the gearing 24 are contained within the body 14 of the caliper 12, as opposed to outside the caliper 12. If the caliper 12 of the present invention is used on a trailer and debris hits the outside of the caliper 12 on the electric servo motor 26 and gearing 24, then they could fall off the caliper 12 if they were not contained within the caliper 12. Therefore, the present invention has an advantage over prior art calipers which have the motor and gearing outside the body of the caliper.

[0027] In use, an electrical signal from the brake pedal in the vehicle towing the trailer is electrically transmitted to the electric servo motor 26 which pushes on the brake pads 16 and 18 and applies friction on the disc rotor 10 to stop the trailer.

[0028] The caliper 12 is connected to a control unit (not shown) to automatically brake any one or more of the rotors to stop the trailer from swaying. The control unit applies brakes to an appropriate wheel(s) on the trailer to compensate for a sway in the motion of the trailer in a particular direction. The application of the brake on the relevant wheel(s) stops the trailer from swaying. Trailers tend to sway when the trailer is overloaded on one side or the other, or when wind force is applied on one side of the trailer, or when road conditions and speed contribute to the sway. The control unit can apply the brake to one wheel or more wheels depending on the different situations. Currently available sway control systems apply the brakes to all of the wheels simultaneously when using disc brakes. This is a less controlled and efficient way of preventing sway.

Concluding Remarks

[0029] In the present specification and claims (if any), the word 'comprising' and its derivatives including 'comprises' and 'comprise' include each of the stated integers but does not exclude the inclusion of one or more further integers.

[0030] Reference throughout this specification to 'one embodiment' or 'an embodiment' means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases 'in one embodiment' or 'in an embodiment' in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[0031] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

Claims (5)

1. A brake caliper for a disc rotor on a trailer, the caliper comprising:

(a) a body;

(b) a mounting bracket to enable the body of the caliper to sit over the disc rotor;

(c) brake pads for the caliper;

(d) a piston for the caliper;

(e) gearing to increase the torque exerted by the piston on the disc rotor; and

the brake caliper is characterized in that it has an electric servo motor directly in line with the piston to apply the brake pads.

2. The caliper of claim 1, wherein the caliper further comprises a control unit to automatically brake any one or more of the rotors to stop the vehicle from swaying.

3. The caliper of claim 1, wherein the electric servo motor and the gearing are contained within the body of the caliper.

4. The caliper of claim 1, wherein caliper has grease nipples for the ball valve so that the piston does not seize up.

5. The caliper of claim 1, wherein the caliper uses slide pins to keep the caliper centered over the disc rotor.