CA1058532A - Mechanical type disc brake - Google Patents
Mechanical type disc brakeInfo
- Publication number
- CA1058532A CA1058532A CA310,706A CA310706A CA1058532A CA 1058532 A CA1058532 A CA 1058532A CA 310706 A CA310706 A CA 310706A CA 1058532 A CA1058532 A CA 1058532A
- Authority
- CA
- Canada
- Prior art keywords
- adjusting bolt
- disc
- nut member
- movable pad
- pad
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D55/00—Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes
- F16D55/02—Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes with axially-movable discs or pads pressed against axially-located rotating members
- F16D55/22—Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes with axially-movable discs or pads pressed against axially-located rotating members by clamping an axially-located rotating disc between movable braking members, e.g. movable brake discs or brake pads
- F16D55/224—Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes with axially-movable discs or pads pressed against axially-located rotating members by clamping an axially-located rotating disc between movable braking members, e.g. movable brake discs or brake pads with a common actuating member for the braking members
- F16D55/225—Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes with axially-movable discs or pads pressed against axially-located rotating members by clamping an axially-located rotating disc between movable braking members, e.g. movable brake discs or brake pads with a common actuating member for the braking members the braking members being brake pads
- F16D55/226—Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes with axially-movable discs or pads pressed against axially-located rotating members by clamping an axially-located rotating disc between movable braking members, e.g. movable brake discs or brake pads with a common actuating member for the braking members the braking members being brake pads in which the common actuating member is moved axially, e.g. floating caliper disc brakes
- F16D55/2265—Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes with axially-movable discs or pads pressed against axially-located rotating members by clamping an axially-located rotating disc between movable braking members, e.g. movable brake discs or brake pads with a common actuating member for the braking members the braking members being brake pads in which the common actuating member is moved axially, e.g. floating caliper disc brakes the axial movement being guided by one or more pins engaging bores in the brake support or the brake housing
- F16D55/227—Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes with axially-movable discs or pads pressed against axially-located rotating members by clamping an axially-located rotating disc between movable braking members, e.g. movable brake discs or brake pads with a common actuating member for the braking members the braking members being brake pads in which the common actuating member is moved axially, e.g. floating caliper disc brakes the axial movement being guided by one or more pins engaging bores in the brake support or the brake housing by two or more pins
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D65/00—Parts or details
- F16D65/38—Slack adjusters
- F16D65/40—Slack adjusters mechanical
- F16D65/42—Slack adjusters mechanical non-automatic
- F16D65/46—Slack adjusters mechanical non-automatic with screw-thread and nut
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D55/00—Brakes with substantially-radial braking surfaces pressed together in axial direction, e.g. disc brakes
- F16D2055/0004—Parts or details of disc brakes
- F16D2055/0037—Protective covers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D2125/00—Components of actuators
- F16D2125/18—Mechanical mechanisms
- F16D2125/20—Mechanical mechanisms converting rotation to linear movement or vice versa
- F16D2125/34—Mechanical mechanisms converting rotation to linear movement or vice versa acting in the direction of the axis of rotation
- F16D2125/36—Helical cams, Ball-rotating ramps
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Braking Arrangements (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A mechanical type disc brake comprising a calliper slidably supported in the axial direction of a disc and straddling a peripheral portion of the disc, a stationary pad secured to the calliper for engaging with one surface of the disc, a movable pad disposed opposite to the stationary pad and being slidably mounted only in the axial direction, a nut member mounted in the calliper and adapted to be rotated by means of a brake arm, an adjusting bolt threadingly extending through the nut member, with one end thereof abutting the movable pad for urging it against the disc, a mechanism for converting the rotation of the nut member into the axial movement thereof, and a rotation control member which is mounted on the movable pad and which is modified to act as a pawl or a ratchet for cooperating with a ratchet or pawl formed or mounted to the adjusting bolt for controlling the relative rotation between the adjusting bolt and the movable pad.
A mechanical type disc brake comprising a calliper slidably supported in the axial direction of a disc and straddling a peripheral portion of the disc, a stationary pad secured to the calliper for engaging with one surface of the disc, a movable pad disposed opposite to the stationary pad and being slidably mounted only in the axial direction, a nut member mounted in the calliper and adapted to be rotated by means of a brake arm, an adjusting bolt threadingly extending through the nut member, with one end thereof abutting the movable pad for urging it against the disc, a mechanism for converting the rotation of the nut member into the axial movement thereof, and a rotation control member which is mounted on the movable pad and which is modified to act as a pawl or a ratchet for cooperating with a ratchet or pawl formed or mounted to the adjusting bolt for controlling the relative rotation between the adjusting bolt and the movable pad.
Description
~5~53Z
This is a divisional of our copending Canadian Patent Application, Serial No. 245,911 filed on February 17, 1976 entitled "Mechanical Type Disc Brake".
This invention relates to a mechanical type disc brake in which an input force given by a cable and the like in the circumferential direction of a disc is converted into ` ` an axial force for urging a friction pad against the disc, the disc brake having an automatic brake clearance adjusting function, which is attained by modifying the rotation control 1o member so as to act as a pawl or a ratchet cooperating with a ratchet or pawl formed or mounted to the adjusting bolt.
In general, it has been a common practice to build in the disc brake of the type described a brake clearance adjusting means for ad~usting to a given range the brake clearance between the disc and the fric-tion pad. However, the brake clearance adjusting means hithertofore proposed is complex in construction and consists of a great number of parts, so that the size of the disc brake, when such means ls built therein, will be increased, resulting difficult~ in 23 handling and an increase in cost.
~ n object of the present invention is to provide simple, effective and economical brake clearance adjusting means adapted for use in the above mentioned type disc brake.
According to the present invention, there is provided a mechanical type disc brake comprising a calliper slidably supported in the axial direction of a disc and straddling a peripheral portion of the disc, a stationary pad secured to the calliper for engaging with one surface of the disc~ a movable pad disposed opposite to the stationary paa and being 3~ mounted for sliding movement in the axial direction only for engaging a second surface of ~he disc, a nut member mounted in ~Si3532 1 the calliper and adapted to be rotated by means of a brake arm, and adjusting bolt threadingly extending through the nut member, with a first end thereof directly abu-tting the movable pad for urging it against the second surface of the disc, a mechanism for converting the rotation of the nut member into the axial movement thereof, and a pawl and r2tchet means, disposed between the first end of the adjusting bolt and the movable pad, the pawl and ratchet means comprising ratchet teeth formed in the first end of the adjusting bolt, an annular resilient washer secured to a backing plate of thç movable pad, and at least one pawl cooperating with the ratchet teeth and formed in an inner circumference of the washer, for allowing rotation of the adjusting bolt relative to the nut member only in a direction of the adjusting bolt moving outwardly of said nut member toward the disc.
The features of the present invention will be apparent from a reading of the ensuring part of the specification in conjunction with the accompanying drawing, in which:
Fig. 1 is a longitudinal cross-sectional view of a mechanical type disc brake exemplifying the present invention, Fig. 2 is a cross-sectional view taken along the line X-X of Fig. 1, Fig. 3 is a cross--sectional view taken along the line Y-Y of Fig. 1, Fig. 4 is a longitudinal cross-sectional view of an essential portion of the disc brake of a modified form, Fig. 5 is a view taken along the line Y'-Y' of Fig. 4, Fig. 6 is an enlarged view showing the portion C in Fig. 5, and ~58S32 1 Fig. 7 iS a modified form of the rotation limiting member of the second embodiment.
In the drawing, shown at 1 is a calliper of generally C-shaped with leg portions la and lb extending along the opposite surfaces of a disc D. The calliper 1 is supported on a supporting member 2 secured non-rota-tably to a body of a vehicle in a manner to slidingly move in the axial direction, by means of two bolts 3 (one of which is omitted in Fig. 1).
A stationary pad 4 is secured to the leg portion la of the 19 calliper 1 by means of a mounting plate 5 and a screw 6.
A hole 7 is formed in the supporting member 2 for receiving a movable pad 8 slidably in the axial direction.
The movable pad 8 is oppositely disposed relative to the stationary pad 4 and is of such a shape ihat the upper (radially outer~ portion and the lower portion af a circle are cut off, and the hole 7 is complementary shaped so that the rotation of the movable pad 8 in the hole 7 is prevented.
A cavity 9 having different diameter portions or a stepped configuration is formed in another leg portion lb of the calliper 1. Disposed within the cavity 9 is a ramp member 10 having a projection lOa which is fitted in a small recess 9a formed in the end wall of the cavity 9 for preventing rotation of the ramp member 10 within the cavity 9.
- In the surface of the ramp member 10 on the side opposite to the aforesaid end wall of the cavity 9, there are provided three circumferentially spaced inclined grooves 11, one of which is shown in Fig. 2 which is a cross-sectional view taken along the line X X in F~g. 1.
Shown at 12 is a nut member disposed adjacent to the ramp member 10 having three circumferentially spaced inclined 1 grooves 13 in the surface opposing to the ramp member 10, as shown in Fig. 2. Each of the inclined grooves 13 has a sloped por-tion extending generally in parallel with a sloped portion of each of the grooves 11. Interposed bet.ween the grooves 11 and 13 are three balls 14 each for each pair of the inclined grooves 11 and 13. Normally, the balls 14 are positioned at the deepest portions of the grooves 11 and 13, but when the nut member 12 is rotated relative to the ramp member 10 in the arrow ~ direction in Fig. 2, the balls 1~
1~ ride up the inclined surface portions of the grooves 11 and 13 and the nut member 12 is separated from the ramp member in the arrow B direction in Fig. 3.
A brake arm 15 is secured to the nut member 12, and a cable or the like (not shown) is connected to a hole 15a provided in the brake arm 15. Thus, the nut member 12 is rotated upon braking action. Shown at 16 is an adjusting bolt, with a male thread portion formed thereon being in meshing relation to a female thread portion provided in the nut member 12. One end 16a of the adjusting bolt 16 is sup-ported by a backing plate 8a of the movable pad 8~ Adjacent to the end 16a, a hexagonal cross-section portion 16b is formed on the adjusting bolt 16 as shown in Fig. 3. Secure to the backing plate 8a of the movable pad by means of pins is a rotation controlling member 17 for cooperating with the he.xagonal portion 16b of the adjusting bolt 16. As shown in Figs. 1 and 3, the rotation controlling member 17 is formed by punching and press-forming a steel plate or the like. A hole for passing through the hexagonal portion 16b of the adjusting bolt 16 is formed in the member 17 and opposing inner edges of the hole define locking or engaging portions 17a which are adapted to ~;13S3Z
engage with ~wo opposite surfaces of the hexagonal portion 16b therehy controlling the rotation of the adjusting bolt 16.
On the other hand, the other end 16c of the adjusting bolt 16 extends into a hole 10b provided in the ramp member 10, and is accessible from outside of the calliper through an access hole 9b in the leg portion lb.
Shown at 18 is a wave washer, which is retained in position by means of a retainer 19 and a retaining ring 20~ The wave washer 18 engages with the stepped portion of the nut member 12 so as to urge the nut member towards the ramp member 10.
- Shown at 21 and 22 are seals and at 23 is a rubber plug, which prevent ingress of water, mud and the like from the outside.
In operation, when a driver o~ the vehicle depresses a brake pedal or pulls a brake lever, a cable associated there-with is pulled so as to apply a torque on the brake arm 15 which,, in turn, rotates the nut member 12 in the arrow A direction as shown in ~ig. 2. The inclined grooves 13 and 11 and the balls 14 act to convert the torque applied to the nut member 12 into a . thrust and move the nut member 12 axially in the arrow B direction.
The axial movement of the nut mem'ber is transmitted through the adjusting bolt 16 to the movable pad B, thereby urging the pad 8 against the disc D.
At th.is time, the adjusting bolt 16 is maintained in threading engagement with the nut member 12, while the rotation o~ the adjusting bolt 16 is normally prevented by means of the rotation control member 17. As a result, the rotation of `
the nut member 12 will not cause rotation of the adjusting bolt 16 in the initial stage. But, when the nut member 12 is,turned to a further extent so that the movable pad abuts with the disc D to transmit the thrus~, then the calliper 1 will slidingly ~L~S853Z
1 move on the supporting member 2 accordiny -to a reaction Eorce created thereby, so as to urge the stationary pad 4 against the opposite surface of the disc D, thereby effecting a braking action.
At ~his stage, a large thrust is exerted on the adjusting bolt 16, thus increasing the frictional force between the nut member 12 and the adjusting bolt 16, with the result that the adjusting bolt 16 will rotate jointly with the nut membex 12.
However, the rotation angle of the nut member 12 which is required for obtaining an ample braking force, after such a thrust has been applied to the adjusting bolt 16 is as small as 5 - 10, in general. This range, however, is not inconsistent with the acceptable engagement of the rotation control member 17 with the two opposite surfaces of the hexagonal portion 16b of the adjusting bolt 16. As a result, when the cable is released for releasing the brake, then the brake arm 15, jointly with the nut member 12, will be rotated in a reverse direction, by means of a return spring (not shown), so that the nut member 12 is urged by means of the wave washer 18 to return to its home position shown, while the adjusting bolt 16 will return to its home position assumed prior to the actuation of the brake. In this respect, the position relationship in the circum~erential direction between the adjusting bolt 16 and the rotation control member 17 will be maintained unchanged.
In case the stationary pad 4 and movable pad 8 cause wear, resultiny in an increase in rotating stroke of the arm 15 r then the dust cover 23 is removed to make access to the adjusting bolt 16 for turning the adjusting bolt 16 so as to move forth, thereby adjusting the gaps between the pads 4, 8 and disc D.
~L~58532 1 Meanwhile, with this embodiment, the engaging portion of the adjusting bolt 16 with the rotation control member 17 is hexagonal in its cross section. However, the present invention is by no means limited to this instance, and thus the aforesaid engaging portion may be octagonal or of other shapes, as ~ar as the adjusting bolt 16 may be returned to its home position assumed prior to the actuation of the brake, when the adjusting bolt 16 rotates with the nut member 12. In addition, the movable pad is supporte~ on the supporting member, but ma~ be supported 1~ on the calliper itself.
Fig. 4 shows a second embodiment of the present invention, in which, the rotation control mechanism 17, 16b for the adjusting bolt 16 of the first embodiment is substituted by a mechanism for attaining automatic bralce clearance adjustment.
The construction of this embodiment is otherwise the same as that of the first embodiment and corresponding reference numerals have been given to corresponding parts.
Shown at 16' is an adjusting bolt having a ratchet teethed portion 16'b as shown in Figs. ~ and 6. A rotation control member 17' is securea to the backing plate 8a and has locking or en~aging portions 17'a which act as pawls cooperating with the ratchet teeth portion of the adjusting bolt 16' so as to restrict the rotation of the adjusting bolt 16' in one direction only, namely, in such direction that the adjusting bolt 16' escapes out from the ~ut member 12 so as to compensate wear of the pads 4 and 8.
In this embodiment, the seal rin~ 22' disposed between the nut member 12 and the adjusting bolt 16' acts to apply suitable resistance therebetween when the nut member 12 is rotated in applying brake.
1(~585~2 1 Similarly to the first embodiment, the adjusting bolt 16' is rotated by the frictional resistance of the SGreW thread engagement with the nut member 12 in the last stage of brake application.
Normally, the range of rotation of the adjusting bolt 16' in brake application is within the range o~ one tooth o the ratchet teeth 16'b and the pawls 17'a will not ride over the ratchet teeth 16'b. But, in case the pads 4 and 8 cause wear, resulting in an increase in rotating range of the adjusting bolt 16' in brake application, the pawl will ride over one tooth of the ratchet teeth 16'b thus effecting automatic brake clearance adjustment.
Fig. 7 shows a modified form of the rotation control member 17l of the second embodiment, in which, a generally flat rotation controL member 17" having two pawl portions 17"a cooper-ates with the ratchet teeth portion 16'b of the adjusting bolt 16'.
The member 17" is movably connected to the backing plate 8a of the movable pad 8 by pins 24, and the pawl portions 17"a are connected with each other by relatively thin walls 17"b. Thus, in this embodiment, the member 17l' deforms in the plane of'the plate or in circumferential direction when the pawl portions 17"a ride over the ratchet teeth.
In the second and the third embodiments, the ratchet teeth are formed on the adjusting bolt and the pawl cooperating with the ratchet teeth is mounted on the movable pad, but it will be noted that it is possible to form the ratchet teeth on the movable pad and the pawl on the adjusting bolt, for restricting the rotation of the adjusting bolt in one direction only.
Further, the movable pad 8 may be mounted on the leg portion lb of the calliper 1.
853~
1 As is apparent from the foregoing description of the construction and operation of the mechanical -type disc brake according to the present invention, the rotat.ion control means for the adjusting bolt is not positioned within the calliper as in the prior art, but in the pad which is adapted to be displaced by the ad]usting bolt in the axial direction, thereby simplifying the construction of the brake clearance adjusting means, while shortening the axial length of the disc brake itself, thus allowing easy attachment of the disc brake which presents a lowered manufacturing cosk. Further, an automatic brake clearance control means can be easily incorporated.
_ 9 _
This is a divisional of our copending Canadian Patent Application, Serial No. 245,911 filed on February 17, 1976 entitled "Mechanical Type Disc Brake".
This invention relates to a mechanical type disc brake in which an input force given by a cable and the like in the circumferential direction of a disc is converted into ` ` an axial force for urging a friction pad against the disc, the disc brake having an automatic brake clearance adjusting function, which is attained by modifying the rotation control 1o member so as to act as a pawl or a ratchet cooperating with a ratchet or pawl formed or mounted to the adjusting bolt.
In general, it has been a common practice to build in the disc brake of the type described a brake clearance adjusting means for ad~usting to a given range the brake clearance between the disc and the fric-tion pad. However, the brake clearance adjusting means hithertofore proposed is complex in construction and consists of a great number of parts, so that the size of the disc brake, when such means ls built therein, will be increased, resulting difficult~ in 23 handling and an increase in cost.
~ n object of the present invention is to provide simple, effective and economical brake clearance adjusting means adapted for use in the above mentioned type disc brake.
According to the present invention, there is provided a mechanical type disc brake comprising a calliper slidably supported in the axial direction of a disc and straddling a peripheral portion of the disc, a stationary pad secured to the calliper for engaging with one surface of the disc~ a movable pad disposed opposite to the stationary paa and being 3~ mounted for sliding movement in the axial direction only for engaging a second surface of ~he disc, a nut member mounted in ~Si3532 1 the calliper and adapted to be rotated by means of a brake arm, and adjusting bolt threadingly extending through the nut member, with a first end thereof directly abu-tting the movable pad for urging it against the second surface of the disc, a mechanism for converting the rotation of the nut member into the axial movement thereof, and a pawl and r2tchet means, disposed between the first end of the adjusting bolt and the movable pad, the pawl and ratchet means comprising ratchet teeth formed in the first end of the adjusting bolt, an annular resilient washer secured to a backing plate of thç movable pad, and at least one pawl cooperating with the ratchet teeth and formed in an inner circumference of the washer, for allowing rotation of the adjusting bolt relative to the nut member only in a direction of the adjusting bolt moving outwardly of said nut member toward the disc.
The features of the present invention will be apparent from a reading of the ensuring part of the specification in conjunction with the accompanying drawing, in which:
Fig. 1 is a longitudinal cross-sectional view of a mechanical type disc brake exemplifying the present invention, Fig. 2 is a cross-sectional view taken along the line X-X of Fig. 1, Fig. 3 is a cross--sectional view taken along the line Y-Y of Fig. 1, Fig. 4 is a longitudinal cross-sectional view of an essential portion of the disc brake of a modified form, Fig. 5 is a view taken along the line Y'-Y' of Fig. 4, Fig. 6 is an enlarged view showing the portion C in Fig. 5, and ~58S32 1 Fig. 7 iS a modified form of the rotation limiting member of the second embodiment.
In the drawing, shown at 1 is a calliper of generally C-shaped with leg portions la and lb extending along the opposite surfaces of a disc D. The calliper 1 is supported on a supporting member 2 secured non-rota-tably to a body of a vehicle in a manner to slidingly move in the axial direction, by means of two bolts 3 (one of which is omitted in Fig. 1).
A stationary pad 4 is secured to the leg portion la of the 19 calliper 1 by means of a mounting plate 5 and a screw 6.
A hole 7 is formed in the supporting member 2 for receiving a movable pad 8 slidably in the axial direction.
The movable pad 8 is oppositely disposed relative to the stationary pad 4 and is of such a shape ihat the upper (radially outer~ portion and the lower portion af a circle are cut off, and the hole 7 is complementary shaped so that the rotation of the movable pad 8 in the hole 7 is prevented.
A cavity 9 having different diameter portions or a stepped configuration is formed in another leg portion lb of the calliper 1. Disposed within the cavity 9 is a ramp member 10 having a projection lOa which is fitted in a small recess 9a formed in the end wall of the cavity 9 for preventing rotation of the ramp member 10 within the cavity 9.
- In the surface of the ramp member 10 on the side opposite to the aforesaid end wall of the cavity 9, there are provided three circumferentially spaced inclined grooves 11, one of which is shown in Fig. 2 which is a cross-sectional view taken along the line X X in F~g. 1.
Shown at 12 is a nut member disposed adjacent to the ramp member 10 having three circumferentially spaced inclined 1 grooves 13 in the surface opposing to the ramp member 10, as shown in Fig. 2. Each of the inclined grooves 13 has a sloped por-tion extending generally in parallel with a sloped portion of each of the grooves 11. Interposed bet.ween the grooves 11 and 13 are three balls 14 each for each pair of the inclined grooves 11 and 13. Normally, the balls 14 are positioned at the deepest portions of the grooves 11 and 13, but when the nut member 12 is rotated relative to the ramp member 10 in the arrow ~ direction in Fig. 2, the balls 1~
1~ ride up the inclined surface portions of the grooves 11 and 13 and the nut member 12 is separated from the ramp member in the arrow B direction in Fig. 3.
A brake arm 15 is secured to the nut member 12, and a cable or the like (not shown) is connected to a hole 15a provided in the brake arm 15. Thus, the nut member 12 is rotated upon braking action. Shown at 16 is an adjusting bolt, with a male thread portion formed thereon being in meshing relation to a female thread portion provided in the nut member 12. One end 16a of the adjusting bolt 16 is sup-ported by a backing plate 8a of the movable pad 8~ Adjacent to the end 16a, a hexagonal cross-section portion 16b is formed on the adjusting bolt 16 as shown in Fig. 3. Secure to the backing plate 8a of the movable pad by means of pins is a rotation controlling member 17 for cooperating with the he.xagonal portion 16b of the adjusting bolt 16. As shown in Figs. 1 and 3, the rotation controlling member 17 is formed by punching and press-forming a steel plate or the like. A hole for passing through the hexagonal portion 16b of the adjusting bolt 16 is formed in the member 17 and opposing inner edges of the hole define locking or engaging portions 17a which are adapted to ~;13S3Z
engage with ~wo opposite surfaces of the hexagonal portion 16b therehy controlling the rotation of the adjusting bolt 16.
On the other hand, the other end 16c of the adjusting bolt 16 extends into a hole 10b provided in the ramp member 10, and is accessible from outside of the calliper through an access hole 9b in the leg portion lb.
Shown at 18 is a wave washer, which is retained in position by means of a retainer 19 and a retaining ring 20~ The wave washer 18 engages with the stepped portion of the nut member 12 so as to urge the nut member towards the ramp member 10.
- Shown at 21 and 22 are seals and at 23 is a rubber plug, which prevent ingress of water, mud and the like from the outside.
In operation, when a driver o~ the vehicle depresses a brake pedal or pulls a brake lever, a cable associated there-with is pulled so as to apply a torque on the brake arm 15 which,, in turn, rotates the nut member 12 in the arrow A direction as shown in ~ig. 2. The inclined grooves 13 and 11 and the balls 14 act to convert the torque applied to the nut member 12 into a . thrust and move the nut member 12 axially in the arrow B direction.
The axial movement of the nut mem'ber is transmitted through the adjusting bolt 16 to the movable pad B, thereby urging the pad 8 against the disc D.
At th.is time, the adjusting bolt 16 is maintained in threading engagement with the nut member 12, while the rotation o~ the adjusting bolt 16 is normally prevented by means of the rotation control member 17. As a result, the rotation of `
the nut member 12 will not cause rotation of the adjusting bolt 16 in the initial stage. But, when the nut member 12 is,turned to a further extent so that the movable pad abuts with the disc D to transmit the thrus~, then the calliper 1 will slidingly ~L~S853Z
1 move on the supporting member 2 accordiny -to a reaction Eorce created thereby, so as to urge the stationary pad 4 against the opposite surface of the disc D, thereby effecting a braking action.
At ~his stage, a large thrust is exerted on the adjusting bolt 16, thus increasing the frictional force between the nut member 12 and the adjusting bolt 16, with the result that the adjusting bolt 16 will rotate jointly with the nut membex 12.
However, the rotation angle of the nut member 12 which is required for obtaining an ample braking force, after such a thrust has been applied to the adjusting bolt 16 is as small as 5 - 10, in general. This range, however, is not inconsistent with the acceptable engagement of the rotation control member 17 with the two opposite surfaces of the hexagonal portion 16b of the adjusting bolt 16. As a result, when the cable is released for releasing the brake, then the brake arm 15, jointly with the nut member 12, will be rotated in a reverse direction, by means of a return spring (not shown), so that the nut member 12 is urged by means of the wave washer 18 to return to its home position shown, while the adjusting bolt 16 will return to its home position assumed prior to the actuation of the brake. In this respect, the position relationship in the circum~erential direction between the adjusting bolt 16 and the rotation control member 17 will be maintained unchanged.
In case the stationary pad 4 and movable pad 8 cause wear, resultiny in an increase in rotating stroke of the arm 15 r then the dust cover 23 is removed to make access to the adjusting bolt 16 for turning the adjusting bolt 16 so as to move forth, thereby adjusting the gaps between the pads 4, 8 and disc D.
~L~58532 1 Meanwhile, with this embodiment, the engaging portion of the adjusting bolt 16 with the rotation control member 17 is hexagonal in its cross section. However, the present invention is by no means limited to this instance, and thus the aforesaid engaging portion may be octagonal or of other shapes, as ~ar as the adjusting bolt 16 may be returned to its home position assumed prior to the actuation of the brake, when the adjusting bolt 16 rotates with the nut member 12. In addition, the movable pad is supporte~ on the supporting member, but ma~ be supported 1~ on the calliper itself.
Fig. 4 shows a second embodiment of the present invention, in which, the rotation control mechanism 17, 16b for the adjusting bolt 16 of the first embodiment is substituted by a mechanism for attaining automatic bralce clearance adjustment.
The construction of this embodiment is otherwise the same as that of the first embodiment and corresponding reference numerals have been given to corresponding parts.
Shown at 16' is an adjusting bolt having a ratchet teethed portion 16'b as shown in Figs. ~ and 6. A rotation control member 17' is securea to the backing plate 8a and has locking or en~aging portions 17'a which act as pawls cooperating with the ratchet teeth portion of the adjusting bolt 16' so as to restrict the rotation of the adjusting bolt 16' in one direction only, namely, in such direction that the adjusting bolt 16' escapes out from the ~ut member 12 so as to compensate wear of the pads 4 and 8.
In this embodiment, the seal rin~ 22' disposed between the nut member 12 and the adjusting bolt 16' acts to apply suitable resistance therebetween when the nut member 12 is rotated in applying brake.
1(~585~2 1 Similarly to the first embodiment, the adjusting bolt 16' is rotated by the frictional resistance of the SGreW thread engagement with the nut member 12 in the last stage of brake application.
Normally, the range of rotation of the adjusting bolt 16' in brake application is within the range o~ one tooth o the ratchet teeth 16'b and the pawls 17'a will not ride over the ratchet teeth 16'b. But, in case the pads 4 and 8 cause wear, resulting in an increase in rotating range of the adjusting bolt 16' in brake application, the pawl will ride over one tooth of the ratchet teeth 16'b thus effecting automatic brake clearance adjustment.
Fig. 7 shows a modified form of the rotation control member 17l of the second embodiment, in which, a generally flat rotation controL member 17" having two pawl portions 17"a cooper-ates with the ratchet teeth portion 16'b of the adjusting bolt 16'.
The member 17" is movably connected to the backing plate 8a of the movable pad 8 by pins 24, and the pawl portions 17"a are connected with each other by relatively thin walls 17"b. Thus, in this embodiment, the member 17l' deforms in the plane of'the plate or in circumferential direction when the pawl portions 17"a ride over the ratchet teeth.
In the second and the third embodiments, the ratchet teeth are formed on the adjusting bolt and the pawl cooperating with the ratchet teeth is mounted on the movable pad, but it will be noted that it is possible to form the ratchet teeth on the movable pad and the pawl on the adjusting bolt, for restricting the rotation of the adjusting bolt in one direction only.
Further, the movable pad 8 may be mounted on the leg portion lb of the calliper 1.
853~
1 As is apparent from the foregoing description of the construction and operation of the mechanical -type disc brake according to the present invention, the rotat.ion control means for the adjusting bolt is not positioned within the calliper as in the prior art, but in the pad which is adapted to be displaced by the ad]usting bolt in the axial direction, thereby simplifying the construction of the brake clearance adjusting means, while shortening the axial length of the disc brake itself, thus allowing easy attachment of the disc brake which presents a lowered manufacturing cosk. Further, an automatic brake clearance control means can be easily incorporated.
_ 9 _
Claims (2)
1. A mechanical type disc brake comprising:
a calliper slidably supported in the axial direction of a disc and straddling a peripheral portion of said disc;
a stationary pad secured to said calliper for engaging with one surface of said disc;
a movable pad disposed opposite to said stationary pad and being mounted for sliding movement in the axial direction only for engaging a second surface of said disc;
a nut member mounted in said calliper and adapted to be rotated by means of a brake arm;
an adjusting bolt threadingly extending through said nut member, a first end of said adjusting bolt direatly abutting with said movable pad for urging said movable pad against said second surface of said disc;
means for converting the rotation of said nut member into axial movement thereof; and pawl and ratchet means, disposed between said first end of said adjusting bolt and said movable pad, said pawl and ratchet means comprising ratchet teeth formed in said first end of said adjusting bolt, an annular resilient washer secured to a backing plate of said movable pad, and at least one pawl cooperating with said ratchet teeth and formed in an inner circumference of said washer, for allowing rotation of said adjusting bolt relative to said nut member only in a direction of said adjusting bolt moving outwardly of said nut member toward said disc.
a calliper slidably supported in the axial direction of a disc and straddling a peripheral portion of said disc;
a stationary pad secured to said calliper for engaging with one surface of said disc;
a movable pad disposed opposite to said stationary pad and being mounted for sliding movement in the axial direction only for engaging a second surface of said disc;
a nut member mounted in said calliper and adapted to be rotated by means of a brake arm;
an adjusting bolt threadingly extending through said nut member, a first end of said adjusting bolt direatly abutting with said movable pad for urging said movable pad against said second surface of said disc;
means for converting the rotation of said nut member into axial movement thereof; and pawl and ratchet means, disposed between said first end of said adjusting bolt and said movable pad, said pawl and ratchet means comprising ratchet teeth formed in said first end of said adjusting bolt, an annular resilient washer secured to a backing plate of said movable pad, and at least one pawl cooperating with said ratchet teeth and formed in an inner circumference of said washer, for allowing rotation of said adjusting bolt relative to said nut member only in a direction of said adjusting bolt moving outwardly of said nut member toward said disc.
2. A mechanical type disc brake as claimed in claim 1, wherein said ratchet teeth are formed in the outer periphery of said first end of said adjusting bolt, said washer is mounted on said backing plate of said movable pad by means of two pins, and two pawls cooperate with said ratchet teeth.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA310,706A CA1058532A (en) | 1975-02-17 | 1978-09-06 | Mechanical type disc brake |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP50019627A JPS5749775B2 (en) | 1975-02-17 | 1975-02-17 | |
| JP50019997A JPS583132B2 (en) | 1975-02-18 | 1975-02-18 | hard disk brake |
| CA245,911A CA1052298A (en) | 1975-02-17 | 1976-02-17 | Mechanical type disc brake |
| CA310,706A CA1058532A (en) | 1975-02-17 | 1978-09-06 | Mechanical type disc brake |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1058532A true CA1058532A (en) | 1979-07-17 |
Family
ID=27425894
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA310,706A Expired CA1058532A (en) | 1975-02-17 | 1978-09-06 | Mechanical type disc brake |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1058532A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2865916A4 (en) * | 2012-09-28 | 2015-12-02 | Honda Motor Co Ltd | Brake caliper |
-
1978
- 1978-09-06 CA CA310,706A patent/CA1058532A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2865916A4 (en) * | 2012-09-28 | 2015-12-02 | Honda Motor Co Ltd | Brake caliper |
| US9440705B2 (en) | 2012-09-28 | 2016-09-13 | Honda Motor Co. Ltd. | Brake caliper |
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