US3828895A

US3828895A - Self-energizing and self-aligning double-acting brake assembly

Info

Publication number: US3828895A
Application number: US00334564A
Authority: US
Inventors: E Boaz
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-02-22
Filing date: 1973-02-22
Publication date: 1974-08-13
Anticipated expiration: 1991-08-13

Abstract

A double-acting brake assembly comprising a drum mounted on a rotary shaft, a brake band with looped ends surrounding the drum, and actuator means to displace ends of the band toward one another, is provided with a mounting bracket having spaced reaction surfaces which cooperate with the ends of the band to permit the band to wrap onto the drum for braking the drum when rotating in either the clockwise or counterclockwise directions. The reaction surfaces extend widthwise of the band adjacent the periphery of the drum, and a pair of guide surfaces extend alongside the ends of the band for aligning the band axially of the drum. In one embodiment, the bracket has an L-shaped crosssection with a flange overlying the drum and the reaction and guide surfaces are provided by the edges of an aperture in the flange. Other forms of brackets, including a bracket combined with a dust cover, are also disclosed. A preferred form of actuator includes a flexible sheath and cable assembly having one end connected to an operating lever and the other end connected to the ends of the band. The actuator draws the looped ends of the band together to engage the band with the drum, but allows lost motion between the end loops and the reaction surfaces of the mounting bracket. The end loops are free to move against either reaction surface, so that no matter which direction the drum is rotating, it will be the end loop at the leading end of the band which engages a reaction surface, and the trailing end of the band will in every case be free to wrap about the drum to provide a servo or self-energizing braking action. This will provide self-energizing braking on both forward and reverse rotation of the drum.

Description

United States Patent [191 Boaz [ Aug. 13, 1974 SELF-ENERGIZING AND SELF-ALIGNING DOUBLE-ACTING BRAKE ASSEMBLY [76] Inventor: Edward G. Boaz, PO. Box 60,

Ottsville, Pa. 18942 22 Filed: Feb.22, 1973 21 Appl.No.:334,564

[52] US. CL... 188/77 R, 188/2 D, 188/26 [51] Int. Cl. Fl6d 51/04 [58] Field Of Search 188/26, 77, 2 D; 192/80 [56] References Cited UNITED STATES PATENTS 1,947,823 2/1934 Brey 188/77 R 2,048,420 7/1936 Babel 188/77 R 3,240,293 3/1966 Ferguson'et al. 188/2 D 3,495,690 2/1970 Otten 192/80 Primary Examiner-Trygve M. Blix Assistant Examiner-Sherman D. Basinger Attorney, Agent, or Firm-Howson & Howson 5 7 ABSTRACT A double-acting brake assembly comprising a drum mounted on a rotary shaft, a brake band with looped ends surrounding the drum, and actuator means to displace ends of the band toward one another, is .provided with a mounting bracket having spaced reaction surfaces which cooperate with the ends of the band to permit the band to wrap onto the drum for braking the drum when rotating in either the clockwise or counterclockwise directions. The reaction surfaces extend widthwise of the band adjacent the periphery of the drum, and a pair of guide surfaces extend alongside the ends of the band for aligning the band axially of the drum. In one embodiment, the bracket has an L- shaped cross-section with a flange overlying the drum and the reaction and guide surfaces are provided by the edges of an aperture in the flange. Other forms of brackets, including a bracket combined with a dust cover, are also disclosed. A preferred form of actuator includes a flexible sheath and cable assembly having one end connected to an operating lever and the other end connected to the ends of the band. The actuator draws the looped ends of the band together to engage the band with the drum, but allows lost motion between the end loops and the reaction surfaces of the mounting bracket. The end loops are free to move against either reaction surface, so that no matter which direction the drum is rotating, it will be the end loop at the leading end-of the band which engages a reaction surface, and the trailing end of the band will in every case be free to wrap about the drum to provide a servo or self-energizing braking action. This will provide self-energizing braking on both forward and reverse rotation of the drum.

13 Claims, 13 Drawing Figures SELF-ENERGIZING AND SELF-ALIGNING DOUBLE-ACTING BRAKE ASSEMBLY The present invention relates to brakes, and more particularly, the present invention relates to doubleacting band-type brake assemblies.

Some recreational vehicles (such as all-terrain vehicles) and utility vehicles (such asv ridingmowers and light tractors) presently on the market are provided with single-acting braking systems. Such systems usually include a brake drum, a band surrounding the drumand having one end fixed to the frame of the vehicle, and actuator means to displace the other or free end of the band toward the fixed end. As long as the periphery of the drum is rotating in a direction which carries its surrounded surface, from the fixed end toward the free end of the band, the band wraps onto the drum when actuated and the band is self-energizing. However, when the drum rotates in the other direction, the band tends to unwrap from the drum, resulting in only a minimal braking action. This type of brake is normally employed to stop a vehicle moving in a forward direction; it is not capable of providing a satisfactory braking action for stopping the same-vehicle when traveling in the reverse direction, for example to prevent the vehicle from moving backward when stopped on an incline. As a result, vehicles having single-acting braking systems are not as safe to use as desired.

Double-acting braking systems are known. Examples of such braking systems are disclosed in U.S. Pat. Nos.: 2,304,646; 1,673,211; and 2,703,155. Although these patented brake assemblies may be satisfactory for their intended purposes, none is of such simple construction as to be capable of being manufactured inexpensively. In addition, none is capable of being used in conjunction with a conventional brake band in a manner which permits single acting systems to be converted in the field into double-acting systems.

In US. Pat. No. 1,673,211 there is disclosed a double-acting brake assembly which comprises a band surrounding a brake drum and having ends displaceable toward one another by means of an actuator assembly for causing the band to engage the drum to effect a braking action. The ends have elongated slots for receiving pins which provide stops against which the ends engage, depending on the direction of rotation of the drum when the brake is activated. The pins are mounted to move toward or away from one another to permit the band to be adjusted relative to the drum. In addition, there is provided means for supporting the band at a location diametrically opposed to the ends so that the band is normally spaced from the drum when the brake is de-activated. Although this brake may operate satisfactorily, the activating mechanism is complex and expensive to manufacture. and has a number of moving parts which are subject to wear, particularly in severe service conditions where foreign matter is likely to permeate the assembly. Moreover, since the activating mechanism is relatively bulky, it may not be used in vehicles where spatial limitations require compact brake assemblies. This brake possesses a further limitation in its inability to be used to convert an existing single-acting system into a double-acting system without requiring substantial modifications.

With the foregoing in mind, it is a primary object of the present invention to provide a novel double-acting 2 brake assembly which is relatively inexpensive to manufacture and use.

It is another object of the present invention to provide a unique double-acting brake assembly which possesses both self-energizing and self-aligning capabilities.

As a further object, the present invention provides an improved double-acting brake assembly which possesses a minimum of moving parts.

It is still another object of the present invention to provide a double-acting brake assembly with an actuating mechanism which is relatively compact to permit the assembly to be installed in vehicles having spatial limitations.

As a still further object, the present invention provides a double-acting brake assembly which is resistant to wear even when utilized under severe service conditions.

It is an important object of the present invention to provide a durable, one-piece bracket which is capable of being employed in conjunction with a brake band and a sheathed cable to provide a double-acting brake.

As an additional object, the present invention provides a bracket which is capable of being installed in vehicles having single-acting band-type braking systems to convert the single-acting systems into doubleacting systems with a minimum of labor and/or modifications to the vehicle.

More specifically, in the present invention a brake assembly comprising a brake drum surrounded by a band having looped ends spaced from one another and an actuator connected to the ends to draw them together is provided with a mounting bracket having a pair of spaced reaction surfaces which embrace the looped ends of the band for limiting rotation of the band relative to the drum when the ends are drawn together to effect a braking action. A pair of guide surfaces extend in spaced parallel relation alongside of the ends of the band and between the reaction surfaces for aligning the band axially of the drum. A preferred actuator includes a flexible cable assembly having a cable element telescopically mounted inside a slack sheath. One end of the cable element is connected to an operating lever, and the other end of the cable element passes slidably through a pin in one looped end of the band and is fixed in a pin in the other looped end of the band. The cable sheath is arranged to abut the first pin, so that as the cable is drawn into the sheath by the operator, the two band ends will be forced toward each other to draw the band into braking engagement with the drum. The cable and sheath are free to move relative to the mounting bracket, and thus. permit lost motion between the drawn-together band end-loops and the bracket reaction surfaces. This leaves the end loops free to move against either reaction surface as the direction of drum rotation dictates. Hence, regardless of the direction of drum rotation it will always be the loop at the leading end of the band (relative to the direction of drum rotation) which will engage the reaction surface, and the trailing end of the band will always be free to wrap onto the drum with a servo or self-energizing action. Accordingly, the brake assembly is double acting and a self-energizing braking action is provided so that the brake assembly may be employed in vehicles where both forward and reverse braking actions are desired. In one embodiment, the bracket has an L-shaped 3 cross-section with a reaction flange, and the reaction and guide surfaces are provided by an aperture in the reaction flange. In other embodiments, the surfaces are provided by bolts and wire forms, and by a cover enclosing the band and drum. The L-shaped bracket is also capable of being installed in a brake assembly in which a rigid rod is employed as an actuator.

These and other objects, features and advantages of the present invention should become apparent from the following description when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a double-acting brake assembly embodying the present invention;

FIG. 2 is an enlarged partly sectioned side elevational view of the brake assembly of FIG. 1, the view illustrating the brake assembly in an inactive position with both ends of a brake band engaging reaction surfaces provided by a bracket;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a sectional view illustrating the position of the ends'of the band relative to the reaction surfaces of the bracket when the brake is activated and the drum is rotating in the clockwise direction, the looped end at the right being the leading end in this situation;

FIG. 5 is a view similar to FIG. 4 but illustrating the position of the ends of the band relative to the bracket when the brake is activated and the drum is rotating in the counterclockwise direction, the looped end at the left being .the leading end in this situation;

FIGS. 6 and 8 are side elevational views of modified embodiments of the present invention;

FIGS. 7 and 9 are plan views'of the modified embodiments illustrated in FIGS. 6 and 8, respectively;

FIG. 10 is a side elevational view of another modified embodiment of the present invention wherein the brake drum and band are substantially enclosed by means of a cover;

FIG. 11 is a plan view of the embodiment of FIG. 10;

FIG. 12 is a side elevational view of still another modified embodiment of the present-invention wherein the mounting bracket is utilized in conjunction with a brake assembly actuated by a rigid actuator rod; and

FIG. 13 is a plan view of the embodiment illustrated in FIG. 12.

Referring now to the drawings, there is illustrated in FIG. 1 a double-acting brake assembly 10 embodying the present invention. The brake assembly 10 is illustrated in conjunction with a rear axle 12 of a vehicle such as an allterrain vehicle having ahandle bar 11. An operating lever 13 is mounted on the handle bar 11, and the lever 13 is connected through a flexible sheathed cable assembly 14 to the brake assembly 10 to cause the brake assembly 10 to be activated when the lever 13 is depressed toward the handle bar 11. Although the assembly 10 is illustrated in conjunction with a rear axle of an all-terrain vehicle, it should be apparent that it may be employed effectively in other ve-' hicles where a double-acting brake is desired. For instance, the brake assemblies of the present invention may be associated with the drive trains of such vehicles as tractors, riding mowers, snowmobiles and the like. In place of the operating lever 13 a foot pedal may be provided to activate the brake assembly 10.

' As best seen in FIG. 2,'the brake assembly 10 comprises a cylindrical brake drum l5 fixedly secured to the axle or shaft 12, a brake band 16 surrounding substantially the entire periphery of the drum l5, and actuator means indicated generally at 20 for causing the band 16 to engage the drum 15. In the present instance, the band 16 is of conventional construction, comprising an inner layer of friction material 17 confronting the drum and an outer strip of steel 18 bonded to the outside of the friction material 17. The steel strip 18 has ends which are reversely turned and fastened to form closed loops 18a and 18b which are spaced from one another at the top of the drum 15. As may be seen in FIG. 3, each end, such as the left and 18b, has an upwardly-open slot 18c. Brake bands of this construction are presently in service in conventional single-acting braking systems.

A braking action is effected when the actuating means 20 displaces the looped ends 18a and 18b toward one another to cause the friction material 17 to engage the drum 15. Depending on the direction of rotation of the drum 15, however, the ends 18a and 18b will tend to rotate with the drum 14 as the friction material 17 begins to engage the drum 15. In order to limit rotation of the band 16 relative to the drum 15, the present invention provides a bracket 19 having a pair of reaction or limit surfaces 21a and 21b engageable by the looped ends l8aand 18b respectively.

In the present instance, the vehicle has a frame member 23 which'overlies and extends transversely to the rear axle l2, and the bracket 19 is fastened to the frame member 23. As best seen in FIG. 3, cross-section bracket 19 has an L-shaped corss-section with a horizontally-disposed reaction flange 24 overlying the brake drum 15 in closely-spaced relation therewith and a vertically-disposed mounting flange 25 secured to the frame member 23 as by bolts, welding or the like. In the embodiment illustrated in FIGS. l-5, the reaction or limit surfaces 21a and 21b extend widthwise of the band 16 (FIG. 3) and engage the looped ends 18a and 18b along their entire widths so that contact stresses on the looped ends 18a and 18b as well as on the reaction surfaces 21a and 21b are minimized for rendering the brake assembly 10 resistant to wear.

In order to align the band 16 axially with the drum 15, the bracket 19 has a pair of guide surfaces 26a and 26b extending in parallel relation alongside the looped ends 18a and 18b of the band 16. In the present instance, the guide surfaces 26a and 26b are provided by

webs

27 and 28 which remain after a rectangular aperture 29 (FIG. 1) is punched in the reaction flange 24. It is noted that the limit surfaces 21a and 21b are provided by the widthwise-extending edges of the aperture 29 and the guide surfaces 26a and 26b are provided by the lengthwise-extending edges of the aperture 29.

As best seen in FIG. 2, the limit surfaces 21a and 21b are spaced from one another a distance which is less than the diameter of the drum 15, and as best seen in FIG. 3, the guide surfaces 26a and 26b are spaced from one another a distance which is slightly greater than the width of the band 16 as to provide a clearance. The reaction flange 24 is located in a plane which is disposed substantially tangential to the top of the drum 15 and adjacent the bases of the looped ends 18a and 18b, respectively, of the band 16. Thus, the looped ends and 18b are contained by the aperture 29 and are prevented from being displaced beyond the reaction surfaces 2la and 21b when the band 16 engages the drum 15. It is noted that the steel strip 18 of the band 16 possesses a sufficient amount of elasticity as to bias both of the looped ends 18a and 18b against their respective reaction surfaces 21a and 21b when the brake assembly is deactivated. As a result, the band 16 is normally spaced a slight distance from the periphery of the drum and is thereby prevented from rubbing on the drum 15.

As noted above, when the actuator means displaces the looped ends 18a and-18b toward one another, the ends 18a and 18b tend to rotate in the direction of rotation of the drum 15 until one or the other of them engages its associated reaction surface. The end which engages the reaction surface may be termed the leading end, and the end which wraps onto the drum may be termed the trailing end. For instance, as illustrated in FIG. 4, the right end 18a engages the right limit surface 21a when the drum 15 is rotating clockwise; hence it is the leading end and the left end 18b is the trailing end. As seen in FIG. 5, the left end 18b engages the left limit surface 2lb when the drum 15 is rotating counterclockwise; hence, it is the leading end and the right end 18a is the trailing end. When'one of the looped ends, such as the right end 18a engages its limit surface 21a, rotation of the portion of the band 16 adjacent the end 18a is arrested and the remainder of the band 16 tends to wrap onto the drum 15 as long as the band ends 18a and 18b are urged toward one another by the actuator 20. In wrapping, the left or trailing end 18b tends to move'rightward toward the right or leading end 18a and the band thus has a selfenergizing action which greatly enhances the braking effect. This progressively increases with increased actuating pressure on the operating lever, and may increase until the band 16 wraps tightly onto the drum 15. The same action occurs when the drum 15 is rotating in the opposite direction; however, the left end 18b engages its limit surface 21b and the right end 18a tends to move leftward toward the left end 1812 as the band 16 wraps onto the drum 15. r

In the present invention, a compact actuating mechanism is provided to urge the ends 18a and 18b of the band 16 toward one another. To this end, the actuator mechanism is provided by means of a conventional sheathed cable assembly 14 which has a fixed end portion 14a connected to the operator lever 13 and which has a freely movable end portion 14b connected to the ends 18a and 18b of the brake band 16. The cable assembly 14 comprises an outer sheath 30 which slidably encloses an inner cable 31. At the fixed end portion of the assembly, the sheath 30 is fixed to a collar 13a mounted on the handle bar and the cable 31 is connected to an eccentric anchor 13b on the operating lever 13.

As best seen in FIGS. 2 and 3, the free end 14b of the cable assembly 14 is disposed substantially tangential to the drum 15 and overlies the reaction flange 24 in closely spaced relation. The cable element 31 is connected to the left-end 18b of the band 16 by means of a pin 32 which is carried in the looped end 18b. In the present instance, the pin 32 has a transverse bore 32a in registry with the slot 180 in the left end 18b of the band 16, and the cable element 31 is secured to the pin 32 by means of a threaded fastener or set screw 35 which is threaded into an axially extending bore in the pin 32 and which bears against thecable element 31 when tightened. It is noted that the cable element 31 engages the slot 180 to prevent the pin 32 from moving axially in the loop 18b.

The cable element 31 is secured to the right end 18a of the band 16 by means of a free sliding connection. In the present instance, the sliding connection is provided by a pin 33 which is mounted in the right loop 18a and a transverse bore 33a which slidably receives the cable 31. The sheath 30 terminates in an abutment surface 30a which normally engages the outside of the right end 18a but which is slightly spaced therefrom for illustration purposes in FIG. 2. With this structure, depression of the lever 13 pulls the cable 31 into the sheath 30 to cause the band ends 18a and 18b to move toward one another until the friction material 17 of the brake band 16 engages the periphery of the drum 15. The free end 14b of the cable assembly is free to move relative to the bracket 19. Accordingly, if the drum is rotating clockwise as indicated in FIG. 4, the tightened band 16 tends to move in that same direction to engage the right end-loop 18a against its associated reaction surface 21a, with the left end-loop 18b tending to move rightward also. The band 16 thereby wraps itself on the drum 15 to produce a self-energizing braking action. Conversely, if the drum is rotating counterclockwise as indicated in FIG. 5, the left end-loop 18b engages its associated reaction surface 21b to initiate the braking action, and the right end 18a of the band 16 tends to wrap around the drum 15 to produce a self-energizing action. Thus, in both directions of rotation, a selfenergizing action is obtained, and a double-acting braking effect is provided with a compact and simple structure. It is noted that in order to prevent the cable element 31 and/or its sheath 30 from binding, the

pins

32 and 33 are dimensioned so as to permit them to pivot slightly relative to their mounting loops 18a and 18b, and if desired, a slight amount of lubricant may be provided around the

pins

32 and 33 to further reduce any tendency for binding.

The brake assembly 10 of the present invention provides a braking action even as the friction material on the band wears in use. When installed initially, the cable 31 is pulled through the left looped end 18b of the band 16 untilthe abutment surface 300 of the 32 when the set screw 35 is tightened as by an allen wrench. Since the band ends 18a and 18b are spaced from one another without any intervening structural element, they are capable of moving toward one another whatever distance is required to cause the band 16 to brakingly engage the drum 15. Preferably, when the brake is deactivated, the ends 18a and 18b are spaced from one another a distance less than the diameter of the drum 15, and the thickness of the friction material 17 is selected to cause the steel back 18 of the band 16 to engage the drum before the ends 18a and 18b engage one another. As a result, some braking action is always provided regardless of the amount of friction material remaining on the band 16.

The brake assembly 10 possesses other advantages. For instance, in the event that the band 16 should tend to wear unevenly, it may be readily reversed. Moreover, should it become desirable for the travel of the lever 13 to be adjusted to compensate for wear, such adjustment may be readily effected by loosening the set screw 35, pulling the cable element 31 through its mounting pin 32 and retightening the screw 35. Since 7 many existing vehicles have single-acting braking systems with brake bands and sheathed cablesof the type illustrated, it should be apparent that such systems may be readily converted into a double-acting system simply by installing the mounting bracket 19 in place of the mounting mechanism of the single-acting system.

In using the mounting bracket 19, the looped ends 18a and 18b of the band 16 are inserted upwardly through the aperture 29 of the reaction flange 24, and the ends 18a and 18b are engaged at their outer concave faces against the end edges 21a and 21b of the aperture 29. The looped ends lie between and are located axially by the side edges 26a and 26b of the aperture 29. The cable assembly 14 is connected to the loops, and the band 16 is located about the drum 15, in the relationship shown in FIGS. 1 and 2.

v In operation, displacement of the lever '13 toward the handle bar 1 1 causes the cable element 31 to telescope into the sheath 30, thereby drawing the looped ends together. If the drum 15 is rotating in the clockwise direction as indicated in FIG; 4, the right or leading end 18a engages its reaction surface 21a and the band 16 wraps onto the drum 15 causing the left or trailing end 18b to move closer to the right end 18a. When the drum 15 is rotating in the counter-clockwise direction as indicated in FIG. 5, the slack in the cable assembly 14 permits the free end 14b of the cable assembly to move leftward as pressure is applied to the right looped end 18a through the sheath 30, and the band again wraps onto the drum 15. When pressure on the lever 13 is relieved, the steel back 18 of the band 16 acts through the cable assembly 14 to displace the lever 13 away from the handle bar 11 and returns the band 16 to its inactive position with the ends 18a and 18b engaged with the reaction surfaces 210 and 21b and the band 16 spaced from the drum 15.

If desired, modified forms of brackets may be provided for use in the brake assembly of the present invention. For example, as illustrated in FIGS. 6 and 7, a modified brake assembly 110 has a bracket 119 pro vided by a U-bolt having legs 121a and 121b which are bolted to a frame member 123. The legs 121a and 121b provide reaction or limit surfaces for engaging the looped ends 118a and 118b of the brake band 116. A bar 127 connecting the legs 121a and l2lb and a side plate 126a cooperate to provide guide surfaces for permitting the band 116 to align itself with its drum 115. A sheathed cable assembly 114 is connected to the band 116 in a manner similar to the embodiment of FIGS. land operates similarly to activate and deactivate the brake assembly 110.

Another embodiment of the present invention is illustrated in FIGS. 8 and 9. As seen therein, a brake assembly 210 has a bracket 219 which includes a pair of bolts 221a and 221b extending in spaced relation away from a frame member 223 to provide reaction surfaces for engaging the ends 218a and 2l8b of a brake band 216. The outer ends of the bolts 221a and 221b are connected together by means of a wire form 227 and the inner ends carry a side plate 226a. The wire form 227 and side plate 226a provide guide surfaces for aligning the brake band- 216 with the drum 215. A flexible sheathed cable actuator 214 similar to the actuators 14 and 114 is provided. Operation of this brake assembly is similar to the aforedescribed assemblies.

invention. In this embodiment, a relatively wide frame member 323 is disposed alongside a brake drum 315, and a bracket 319 is provided to shroud the drum 3 15. The bracket 319 has a cylindrical portion 319a which surrounds the periphery of the brake band 316 and a planar portion 31917 which is disposed parallel to the frame member 323.-The cylindrical portion 319a is provided with an aperture 329 defined by a pair of spaced edges 321a and 321b which operate to engage the ends 318a and 318b, respectively of the band 316 when the brake 310 is actuated by means of a sheathed actuator cable 314 as described heretofore. A circular mounting flange 325 extends at a right angle away from the cylindrical portion 319a of the bracket 319 for mounting to the frame member 323 as by

screws

350, 350. It is noted that, in this embodiment, the cable assembly 314 is disposed vertically, and a compression spring 351 is provided between the ends 318a and 318b of the brake band 316, and surrounds the inner cable 331 of the cable assembly 314. With this structure, the brake assembly 310 is protected from foreign matter such as dirt, water and the like. Moreover, the spring 351 operates to provide a positive biasing action to en- In FIGS. 10,.and11 there is illustrated yet another modified brake assembly 310 embodying the present sure separation of the brake band 316 from the brake drum 315 when the brake is deactivated.

The embodiments of FIGS. 1-5, FIGS. 6 and 7, FIGS. 8 and 9, and FIGS. 10 and l 1 all employ a common actuator mechanism and operate basically on the same principle. All of them provide a double-acting brake having self-aligning and self-locking features. Moreover, all are compact and relatively inexpensive to manufacture.

If desired, a braking system 410 (FIGS. 12 and 13) may be provided by utilizing a bracket 419 similar to the bracket 19 of the embodiment of FIGS. l-5. The brake assembly 410 is generally similar to the assembly 10 illustrated in FIGS. 1-5; however, in the assembly 410, the actuating mechanism includes a rigid rod 431 which is fastened at one end to a pin 432 carried in the left looped end 418b of a brake band 416. The rod 431 is slidably received by another pin 433 carried in the right looped end 418a of the band 416. It is noted that in this embodiment, the rod .431 is unsheathed. Thus, when the drum 415 is rotating in the clockwise direction and the rod 431 is displaced axially in the rightward direction, the right band-end 418a engages a reaction surface 42la on the bracket 419 and the band 416 wraps onto the drum 415 to brake the same. However, when the drum 415 is rotating in the opposite direction, the band 416 may not have the same selfenergizing action as the other modifications and the braking action may not be of the same magnitude as when the drum 415 is rotating clockwise. It is noted that the guide surfaces 426a and 426b permit the band 416 to align itself with the drum 415 as in the brake assembly 10 of FIGS. 1-5.

In view of the foregoing, it should be apparent that an improved double-acting brake assembly has now been provided. The brake assembly is of simple but durable construction and is compact, permitting usage in environments in which there are severe spatial limitations. The present invention provides a low-cost mounting bracket which is capable of being used to convert existing single-acting braking systems into double-acting systems and which is also capable of use with a rod-actuated braking system.

While preferred embodiments of the present invention have been described in detail, various modifications, alterations and changes may be made without departing from the spirit and scope of the present invention as defined in the appended claims.

I claim:

1. For use in a brake assembly including a drum rotatable on an axis, a band disposed around the periphery of said drum, said band having ends with portions spaced from one another and extending away from said periphery, and actuator means for displacing said ends in a direction to cause said band to engage said drum, including an elongated element slidably received by one end and secured to the other, a mounting bracket for reacting with said ends to limit rotation of said band in opposite directions about said axis when engaged with said drum, said bracket having a reaction flange with an aperture having edges defining a pair of reaction surfaces spaced apart a distance greater than the corresponding spacing of said end portions for loosely receiving said end portions therebetween and defining a pair of guide surfaces extending between said reaction surfaces for engaging laterally of said end portions to limit movement of said band axially of said drum, said bracket also having a mounting flange extending along one side thereof at an angle away from said reaction flange for securement adjacent said drum, and including clamping means carried by said other band end and displaceable transversely to said element for releasably connecting said element to'said other band end to afford longitudinal adjustment of said element, said clamping means being exposed opposite said mounting flange so as to be operable from the side of the reaction flange opposite the mounting flange.

2. Apparatus according to claim 1 wherein said mounting flange is integral with said reaction flange and extends outwardly of said axis beyond said end portions of said band.

3. In a brake assembly including a brake drum, a band operatively associated with said drum and having ends disposed in spaced relation, and actuator means for displacing said ends in a direction to cause said band to engage said drum, including a cable element connected to one of said ends, a sheath telescopically receiving said cable element and having a movable abutment surface confronting the other of said ends, and means providing a slidable connection between said cable and said other end to slidably receive said cable element, the improvement comprising: bracket means having a reaction flange providing a pair of reaction surfaces extending widthwise of said band and spaced apart to receive said band-ends therebetween,

said reaction flange also having a pair of guide surfaces extending laterally of said band-ends between said reaction surfaces, each reaction surface being coextensive with the widthwide dimension of its associated band-end, and said reaction and guide surfaces loosely embracing said band-ends, said bracket means further having a mounting flange extending away from said reaction flange for securing the bracket means adjacent said drum periphery, so that when said cable element is telescoped into said sheath, said ends are drawn together and said, cable and sheath move freely therewith for causing the band to engage the drum.

4. Apparatus according to claim 3 including means carried by said one end of said band for mounting said cable element to pivot relative to said band and means 6. Apparatus according to claim 5 wherein said pin carried by the loop on said one end has a transverse bore for receiving said cable element, and clamping means displaceable axially of said pin for securing said cable element in said pin.

7. Apparatus according to claim 6 wherein said clamping means includes a threaded bore extending axially in said pin and a threaded fastener mounted in said axial bore.

8. Apparatus according to claim 3 wherein said bracket means includes a cover portion surrounding the periphery of said band and extending in a plane transverse to the rotational axis of the drum for enclosing substantially the entire periphery of the band and the drum.

9. Apparatus according to claim 3 including elastic means normally urging said ends into engagement with said reaction surfaces to space said band from said drum.

10. Apparatus according to claim 9 wherein said elastic means includes a compression spring engaging between said band-ends and surrounding said cable element.

11. In a vehicle having a frame element, a shaft mounted to rotate relative to the frame element, a drum fixedly mounted to the shaft, a brake band surrounding said drum and having ends disposed in spaced relation adjacent said frame element, the improvement comprising: bolt means extending away from said frame element and providing a pair of reaction surfaces extending widthwise of said band-ends in spaced relation for engaging said ends loosely therebetween to limit rotational of said band relative to said drum, guide surface means carried on said bolt means a spaced distance from said frame and extending laterally of said band-ends for positioning said band axially relative to said drum, and actuator means for urging said ends toward one another including a flexible sheath having one end fixedly connected to said frame and another end engageable against one end of said brake band, a flexible cable within said sheath, said cable having one end connected to an operator displaceable relative to the frame and having another end connected to the other end of said brake band, said sheath and cable being disposed relative to the frame to permit the unconnected end of the sheath to engage its associated end of the brake band and to move therewith relative to said frame when said operator is energized to telescope said cable into said sheath with said cable and sheath moving freely relative to said frame substantially tangentially to said drum.

12. Apparatus according to claim 11 wherein said bolt means includes a U-bolt having parallel legs providing said reaction surfaces and nut means connecting said legs to said frame element.

13. A mounting bracket for use with a brake assembly including a drum rotatable on an axis, a resilient brake band disposed around the periphery of said drum and having reversely-turned ends forming loops at the ends of the band with said loops projecting outwardly from the periphery of the band, and actuator means engaged with said loops for drawing the same toward each other to cause the band to engage the drum in braking relation therewith, said mounting bracket having a reaction flange with an aperture providing a pair of reaction surfaces extending widthwise of the band and providing a pair of guide surfaces extending between said reaction surfaces, said reaction surfaces being spaced apart a distance to receive said loops and loosely embrace them therebetween and to be resiliently engaged by said loops when the band is in a deactivated condition, said reaction flange being spaced radially from the drum a distance sufficient to receive the ends of the band loosely between the reaction surfaces but less than the maximum outward projection of the loops,

said actuator means including a sheathed cable connected to the loops above said reaction flange and extending alongside said reaction flange closely-adjacent thereto in a manner providing free movement of the loops between the reaction surfaces, said bracket also having a mounting flange for securing the reaction flange at said distance, so that whenthe band is engaged with the rotating drum the loops move between the reaction surfaces in a direction corresponding to the rotational direction of the drum with one loop leading the other and being carried forwardly in the direction of drum rotation against its associated reaction surface, whereby the other end of the band wraps onto the drum to provide a self-energizing braking action.

Claims

1. For use in a brake assembly including a drum rotatable on an axis, a band disposed around the periphery of said drum, said band having ends with portions spaced from one another and extending away from said periphery, and actuator means for displacing said ends in a direction to cause said band to engage said drum, including an elongated element slidably received by one end and secured to the other, a mounting bracket for reacting with said ends to limit rotation of said band in opposite directions about said axis when engaged with said drum, said bracket having a reaction flange with an aperture having edges defining a pair of reaction surfaces spaced apart a distance greater than the corresponding spacing of said end portions for loosely receiving said end portions therebetween and defining a pair of guide surfaces extending between said reaction surfaces for engaging laterally of said end portions to limit movement of said band axially of said drum, said bracket also having a mounting flaNge extending along one side thereof at an angle away from said reaction flange for securement adjacent said drum, and including clamping means carried by said other band end and displaceable transversely to said element for releasably connecting said element to said other band end to afford longitudinal adjustment of said element, said clamping means being exposed opposite said mounting flange so as to be operable from the side of the reaction flange opposite the mounting flange.

3. In a brake assembly including a brake drum, a band operatively associated with said drum and having ends disposed in spaced relation, and actuator means for displacing said ends in a direction to cause said band to engage said drum, including a cable element connected to one of said ends, a sheath telescopically receiving said cable element and having a movable abutment surface confronting the other of said ends, and means providing a slidable connection between said cable and said other end to slidably receive said cable element, the improvement comprising: bracket means having a reaction flange providing a pair of reaction surfaces extending widthwise of said band and spaced apart to receive said band-ends therebetween, said reaction flange also having a pair of guide surfaces extending laterally of said band-ends between said reaction surfaces, each reaction surface being coextensive with the widthwide dimension of its associated band-end, and said reaction and guide surfaces loosely embracing said band-ends, said bracket means further having a mounting flange extending away from said reaction flange for securing the bracket means adjacent said drum periphery, so that when said cable element is telescoped into said sheath, said ends are drawn together and said cable and sheath move freely therewith for causing the band to engage the drum.

4. Apparatus according to claim 3 including means carried by said one end of said band for mounting said cable element to pivot relative to said band and means mounting said slidable connection to pivot relative to the other end of said band.

5. Apparatus according to claim 4 wherein said ends of said band have reversely turned loops with slots extending lengthwise of the band, and said cable mounting means include pins rotatably mounted in said loops.

6. Apparatus according to claim 5 wherein said pin carried by the loop on said one end has a transverse bore for receiving said cable element, and clamping means displaceable axially of said pin for securing said cable element in said pin.

13. A mounting bracket for use with a brake assembly including a drum rotatable on an axis, a resilient brake band disposed around the periphery of said drum and having reversely-turned ends forming loops at the ends of the band with said loops projecting outwardly from the periphery of the band, and actuator means engaged with said loops for drawing the same toward each other to cause the band to engage the drum in braking relation therewith, said mounting bracket having a reaction flange with an aperture providing a pair of reaction surfaces extending widthwise of the band and providing a pair of guide surfaces extending between said reaction surfaces, said reaction surfaces being spaced apart a distance to receive said loops and loosely embrace them therebetween and to be resiliently engaged by said loops when the band is in a deactivated condition, said reaction flange being spaced radially from the drum a distance sufficient to receive the ends of the band loosely between the reaction surfaces but less than the maximum outward projection of the loops, said actuator means including a sheathed cable connected to the loops above said reaction flange and extending alongside said reaction flange closely-adjacent thereto in a manner providing free movement of the loops between the reaction surfaces, said bracket also having a mounting flange for securing the reaction flange at said distance, so that when the band is engaged with the rotating drum the loops move between the reaction surfaces in a direction corresponding to the rotational direction of the drum with one loop leading the other and being carried forwardly in the direction of drum rotation against its associated reaction surface, whereby the other end of the band wraps onto the drum to provide a self-energizing braking action.