Spot-type disc brake

Abstract

There is disclosed a spot-type disc brake having a non-rotating brake carrier to receive the brake torque with brake shoes disposed on both sides of the brake disc. A yoke or frame embraces the disc and is movably guided in the brake carrier and held without clearance by resilient means. The frame transmits the operating force of an actuating device to the brake shoe disposed on the side of the disc remote from the actuating device. The frame is rigidly supported at and movable with respect to three guide points on the brake carrier. A biased spring is disposed between the brake carrier and frame. The spring .[.tensions.]. .Iadd.forces .Iaddend.the frame .[.at.]. .Iadd.against .Iaddend.its guide points and .Iadd.the spring force .Iaddend.acts on the frame at a point distant from the three guide points.

We claim: 
     
       1. A spot-type disc brake comprising: a brake disc;   a brake actuating means;   a pair of brake shoes each having a backing plate and a brake pad, one of said brake shoes being disposed on one side of said disc actuated by said actuating means and the other of said brake shoes being disposed on the other side of said disc;   a non-rotating brake carrier carrying said brake shoes and receiving braking torque, said carrier being immovable relative to said disc;   a frame embracing said disc and movably guided with respect to said carrier in a direction toward and away from said disc, said frame transmitting the actuating force of said actuating means to said other of said brake shoes;   said brake actuating means including a housing rigidly connected to said frame and having a force receiving contact surface below said frame which is inclined upward toward said frame in a direction away from said disc;   at least three guide points to rigidly support and movably guide said frame, at least two of said guide points being rigidly connected to said carrier; and   a biased spring having two arms each engaging a different one of two circular holes formed in and extending through said carrier parallel to, spaced from and below said frame and a loop interconnecting said two arms under tension resting against said contact surface to apply a horizontal and vertical component of force to a point on said contact surface to hold said frame without clearance against said guide points, said point on said contact surface being spaced from said guide points;   each of said arms including deflection on the ends thereof fastened in an associated one of said holes of said carrier and fastened in said backing plate of said one of said brake shoes.   
     
     
       2. A brake according to claim 1, wherein said point on said contact surface is disposed outside an imaginary triangle formed by imaginary lines interconnecting said guide points.   
     
     
       3. A brake according to claim 1, wherein said two of said guide points include two bolts immovably secured to said carrier.   
     
     
       4. A brake according to claim 3, wherein said two bolts are disposed on an axis parallel to said disc.   
     
     
       5. A brake according to claim 4, wherein the third of said guide points includes a recess in a backing plate of said other of said brake shoes, and     a pin formed in said frame engaging said recess. .Iadd.   
     
     
       6.  In a spot-type disc brake having a brake disc;   a brake actuating means;   a pair of brake shoes, one of said brake shoes being disposed on one side of said disc and actuated by said actuating means, and the other of said brake shoes being disposed on the other side of said disc;   a non-rotating brake carrier receiving braking torque, said carrier being immovable relative to said disc;   a frame or yoke element embracing said disc and movably guided with respect to said carrier in a direction toward and away from said disc, said element transmitting the actuating force of said actuating means to said other of said brake shoes; and   said brake actuating means including a housing and being in force transmitting contact with said element;   the improvement comprising only three guide points to rigidly support and movably guide said element, two of said guide points being rigidly connected to said carrier and disposed above said element to rigidly support and movably guide said element, said two of said three guide points exerting a downward force on said element and a third of said three guide points being disposed in one of said actuating means and a backing plate of said other of said brake shoes, said third of said three guide points exerting an upward force on said element; and   a single biasing spring having at least one end connected to said carrier at a point radially spaced from said two of said three guide points and said element and another portion thereof acting on one of said actuating means and said element to apply an upward component of force to hold said element without clearance against all of said three guide points;   said spring acting on said one of said actuating means and said element at a point spaced axially from all of said three guide points, said point being outside an imaginary triangle formed by imaginary lines interconnecting all of said three guide points;   said actuating means being secured to said element;   said third of said three guide points including a recess in a backing plate of said other of said brake shoes, and   a pin formed in said element engaging said recess; and     said spring is fastened to said carrier and acts on said actuating means, said spring projecting away from said carrier and disposed under said element and said actuating means;   said spring being a wire spring having two arms fastened in holes of said carrier and a loop acting upwardly on said actuating means;   said actuating means including a contact surface for said loop of said spring which is inclined upward toward said element in a direction away from said disc. .Iaddend. .Iadd.     
     
     
       7.  A brake according to claim 6, wherein said two of said guide points include two bolts immovably secured to said carrier. .Iaddend. .Iadd.8. A brake according to claim 7, wherein     said two bolts are disposed on an axis parallel to said disc. .Iaddend.   
     
     
        .Iadd.9.  A brake according to claim 1, wherein each of said arms includes deflections on the end thereof fastened in an associated one of said holes of said said carrier. .Iaddend.