Disk brake caliper having cage bridge
A brake apparatus includes a caliper with two housing members secured together by an E-section cage. The housing members straddle a rotor, so as to be able to urge one or more pistons disposed therein to apply brake pads against the rotor, thereby effectuating a braking force on the rotor. The E-section cage provides support for the housing members and reduces the clam shell effect generated by application of the breaking force.
This application is a Continuation in Part of application Ser. No. 11/108,425, filed Apr. 18, 2005.
BACKGROUND OF THE INVENTIONThis invention relates generally to a vehicular disk brake apparatus and more particularly to the brake caliper thereof, having a reinforced cage for reducing load.
In general, a vehicular or automotive brake operates on a hydraulic system, in which the depression of a brake pedal causes a plunger in the master cylinder to push hydraulic fluid to a braking unit at the wheels. A disk brake is one kind of braking unit. In a conventional opposed caliper disk brake, a fixed caliper straddles a rotor, which is attached to the wheel. In a floating caliper disk brake, the caliper urges piston or pistons on one side of the rotor to apply a pad, while at the same time pushing the caliper housing away from the rotor, drawing the outboard pad up to the rotor. In either case, when fluid from the master cylinder is introduced into the caliper, it urges one or more pistons in the caliper to apply brake pad(s) against the rotor, thereby effectuating a braking force on the rotor and causing the wheel to slow down or stop.
A typical caliper is formed in the shape of a clam for straddling the rotor. Current designs either utilize a one member housing, or two member housing, straddling over the top of the rotor and held together by bolts. In straddling the rotor, one member is disposed on the inboard side of the rotor and the other member is disposed on the outboard side of the rotor. The members have piston(s) disposed therein.
A basic problem in calipers of this type is that they are subject to high shearing and bending forces, with the load bearing on the bridge section. When such forces are transmitted through the caliper, they act to spread the caliper apart like a clam, a phenomenon often referred to as the “clam shell” effect. The result is decreased braking efficiency, as some of the force generated by the master cylinder is lost in the spreading of the caliper, and there is also the consequent effect of increasing pedal travel, tapered pad wear, spongy pedal and loss of modulation.
To minimize this deflection, caliper designs have typically utilized either a monoblock or a bolting design. For example, in a monoblock caliper, the caliper is formed from a solid body with a bridge section integrally joining the inboard and outboard members of the caliper housing. This type of caliper requires a rather massive bridge section to effectively reduce the clam shell effect that causes the caliper to open at the bottom. A massive bridge is undesirable, however, as it gets in the way of maximizing the rotor diameter.
In a caliper where the members are connected by bolts, as shown in
For the foregoing reasons, there is a need for a disk brake assembly having a brake caliper that is sufficiently stiff to reduce the clam shell effect.
SUMMARY OF THE INVENTIONThe present invention is directed to an improved brake caliper that satisfies the need for reducing the clam shell effect. A disk brake apparatus having the features of the present invention comprises a rotor and a brake caliper for applying braking force to the rotor. The brake caliper is basically comprised of a first housing member and second housing member straddling the rotor, with the first and second housing members connected by a bridge. The caliper housing members have actuating pistons disposed therein, with brake pads associated therewith for engaging the rotor.
The bridge is generally comprised of a cross member and associated anchors. For example, in an embodiment as shown in
Further, the bridge can take a variety of form and shape that incorporates the basic combination of cross member and associated anchors. As an example, the bridge can be comprised of a cross member and anchor plates. As another example, the bridge can take the shape of the letter “Y” with two anchor arms spread at an angle and joined by a vertical member. Moreover, the cross member can take various shape, such as tubular or, as shown in figure
The bridge, as such, provides structural support for the caliper housing members. The caliper housing is commonly made of low tensile strength materials in order to reduce weight, as the weight of the caliper, which tends to be relatively heavy, can affect the operation and suspension of the chassis. However, a low strength caliper will have low load capacity and low structural stiffness. The C-bridge provides structural rigidity by using high tensile strength materials, creating a “bending moment” situation, which improves support to the low strength caliper housing members. By using high strength materials only where needed, the strength of the caliper can be maximized while still minimizing weight.
One key advantage of the present invention to be noted is the use of high tensile strength anchors (i.e. the downward turning arms) in between the pistons of the caliper, especially as assembled to the center portion of the caliper. The use of high strength downward turning arms allows for a stronger bridge design to reduce deflection.
Structurally, the first and second members each have at least one channel provided therein respectively for receiving the anchor members of the bridge, and at least one hole formed therein respectively in substantial alignment with the channels. The bridge has at least two holes formed in the anchor members. The bridge anchor members are capable of fitting flush in the channels of the first and second members, such that the holes in the bridge anchor members coaxially align with the holes in the first and second members. A securing means, such as a bolt, capable of passing through the holes in the first and second caliper housing members and engaging the holes in the bridge, acts to secure the first member and second member to the bridge.
In another embodiment of the brake caliper, the first and second members are secured by a plurality of bridges. Accordingly, the first and second members include a plurality of channels therein for receiving the anchor members of the bridges and a plurality of holes and securing means for connected the bridges to the first and second members.
In yet another embodiment of the invention, first and second members of the brake caliper do not have channels formed therein. Instead, the outside face of the bridge abuts the inside face of the first and second members, such that the holes in the bridge coaxially align with the holes the in first and second members. In this embodiment, the bridge extends into the pad area between the housing members. As such, the bridge could provide additional pad support and retention. This would increase the center rigidity by increasing the cross-section thickness.
An advantage of using a bridge such as the C-section is that it provides superior rigidity, which correspondingly would require less master cylinder volume to fill the pistons since deflection in the caliper is reduced.
In a preferred embodiment of the invention as shown in
In the preferred embodiment shown in
In other contemplated embodiments of the invention, the rectangular frame may include more than two side members or multiple cross members. For example, the rectangular frame may include two side members joined by two cross members with or without endplates. In yet another alternative embodiment, the rectangular frame may include two side members connected by endplates but without a cross member. However, the preferred embodiment is as shown in
An advantage of the E-section cage is that it provides even greater structural rigidity than the C-section bridge because of the rectangular frame. The shoulder blocks on the rectangular frame allow the first and second housing members to be connected at the shoulders in addition to being connected at the anchors at the midpoint of the rectangular frame, resulting in greater overall rigidity. Hence, the E-section cage allows the mechanical stress to be spread over the body of the cage, with much of the load taken by the shoulder blocks on the rectangular frame, thereby further reducing deflection in the caliper. The greater rigidity of the cage is achieved without sacrificing efficient heat ventilation because of the frame structure and the cut-out in the endplates.
DRAWINGS
An embodiment of a brake caliper is shown in
Referring to
First and second members 12, 14 can also be secured by a plurality of C-section bridges 16. Accordingly, first and second members 12, 14 would include a plurality of channels 18, 22 therein for receiving anchor arms 16b, 16c, and a plurality of holes 20, 24 for securing means 26 to connect C-section bridges 16 to first and second members 12, 14.
In another embodiment of the invention, first and second members 12, 14 of brake caliper 10 do not have channels 18, 22 formed therein. Instead, the outside face of C-section bridge 16 abuts the inside face of first and second members 12, 14, such that holes 16d, 16e in C-section bridge 16 coaxially align with holes 20, 24 in first and second members 12, 14.
The preferred embodiment of the invention is shown in
In the preferred embodiment as shown in
The embodiments described herein demonstrate an improved brake caliper having a reinforced cage. This brake caliper design will reduce the clam shell effect. Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.
Claims
1. A disk brake assembly including a rotor, a brake caliper for applying braking force to said rotor, said brake caliper having first and second housing members straddling said rotor, said first and second housing members connected by a cage, said cage comprising:
- a rectangular frame including at least two side members joined by at least one cross member;
- each said side member integrally connected to at least one anchor;
- said side members connected by at least one endplate; and
- each said endplate having a shoulder block integral to the outside face of said endplate.
2. The brake caliper as recited in claim 1, wherein each said first and second housing member has a recessed inboard surface.
3. The brake caliper as recited in claim 1, wherein said anchor has at least one hole formed therein to be in substantial alignment with corresponding holes on said first and second housing members.
4. The brake caliper as recited in claim 1, wherein said shoulder block integral to said endplate has at least one hole formed therein to be in substantial alignment with corresponding holes on said first and second housing members.
5. The brake caliper as recited in claims 3 and 4, wherein securing means capable of engaging said holes in said anchors and said shoulder blocks via said corresponding holes in said first and second housing members function to secure said first housing member and said second housing member to said cage.
6. A disk brake assembly including a rotor, a brake caliper for applying braking force to said rotor, said brake caliper having first and second housing members straddling said rotor, said first and second housing members each having a recessed inboard surface and each having holes therein, said first and second housing members connected by a cage, said cage comprising:
- a rectangular frame including at least two side members joined by at least one cross member;
- each said side member integrally connected to at least one anchor;
- each said anchor having at least one hole formed therein to be in substantial alignment with corresponding holes on said first and second housing member;
- said side members connected by at least one endplate;
- each said endplate having a shoulder block integral to the outside face of said endplate; and
- each said shoulder block having at least one hole formed therein to be in substantial alignment with corresponding holes on said first and second housing members;
- wherein said cage fits between said recessed inboard surfaces of said first and second housing members such that said holes on said anchors and said shoulder blocks are in substantial alignment with corresponding holes on said first and second housing members so as to permit securing means capable of engaging said holes in said anchors and said shoulder blocks via said corresponding holes in said first and second housing members to secure said first housing member and said second housing member to said cage.
Type: Application
Filed: Apr 6, 2006
Publication Date: Oct 19, 2006
Inventor: Warren Gilliland (Camarillo, CA)
Application Number: 11/399,573
International Classification: F16D 55/228 (20060101);