Патент USA US2120917код для вставки
-June 14, i938; - @KHAVUS‘E _ 2,120,911 BRAKE MECHANISM Filed June 3, 1936 www Í ` Patented June 14, 1938 2,120,917 à PATENT OFFICE UNITED STATES Y 2,120,911 v BRAKE MEcHANlsM Gilbert K. Hause, Dayton„-0hio, assignor to Gen eral Motors Corporation, Detroit, Mich., a cor poration of.Delaware Application June 3, 193s, serial No; 83,185 ' .5 claims. (criss-_152) This invention relates to brakes and particu larly to internal expanding brakes for use on ve hicles. . , ‘ chor pin 2i. At its head, yokeli is recessed at , 43’ _to rotatably receive a nut 45 threaded upon > a screw ¿I1 forked at its end to engage the web of shoe 21. The nut has external teeth 49. Ac An object of the invention is to provide brake 5 mechanism associated with a rotating drumV snapped into plate 49 isI5. hadRotation by removing of theanut cap ad5I. whereby much the larger part of the annular cess to'teeth ,drum surface is frictionally engaged to retard ‘justs the shoe clearance since the nutremains drum rotation. ' in contact with the yoke. \~ . “A further object is to provide the same effec-` Adjacent the anchor l pin I9, shoe 21 is provided with articulating links -10 tive retarding action for' either direction of drum` 53 resembling in structure and function the links 10 33 and 35. Also adjacent anchor pin I9, shoe 25 - As a further object the invention aims to mini- _ has a similar- provision for adjustment and for mize manual _effort through the instrumentality anchoring on the pin I9. This is constituted by of servo shoes adapted to be brought into drum yoke 55, nut 51 and screw 59. A fiat plate 6I has an elongated opening 63 15. 15 contact by manual effort and to themselves actu ate the main shoes. surrounding hub I3 and having a shorterdiam Still further the main shoes are designed to eter of such length that yit may be guided for ' readily accommodate themselves to the. drum axial> movement by said hub, and alsoto be free contour by means o'f an articulated form of an to rotate about the hub. This plate 5I has an .;0 chorage. ' opening 65 freely surrounding pin I9 and is ter- 20 ‘ ' Other objects and advantages will be under-A minally provided with a servo shoe 61 adapted to stood from the following description. engage the drum when projected radially into The invention is illustrated by the accompanyf- contact with the latter. AA second iiat plate 63 ing drawing in which Fig. 1 is a sectional view has a servo shoe -1I diametrically opposite shoe rotation. 25 through the drum, showing in'elevation, partly in section, the shoes and the operating mecha nism. l '- Fig. 2 is a section on 'line 2-2 of Fig. 1. Fig. 3 is Ia section on line 3-3 of Fig. 1. 30 Fig. 4 is a section on line 4-4 of Fig. 1.l Y Referring by reference characters to the draw ing, numeral 1 is used to designate a conven tional brake drum, such a drum asis usually car-` ried by each of the Wheels of a motor vehi le. The drawing shows the .invention applied to o e of the rear Wheels, the similar application to the `front wheels not being illustrated. To the axle housing 9 at~ the rear wheels is secured by fas tening means I2 an anchor plate II to which is 40 secured a pivot hub I3. 4A light backing plate I5 and a -dust and splash shield I1 complete the closure of the drum. Diametrically opposite an chor pins I9 and 2| are carried by the anchor plate I I.> , Within the drum and positioned to fric 61. The two servo shoes are therefore between ’25 the adjacentfends of main shoes 25 and 21. It will be observed that the flat plates (plate 69 -in Fig. 3) straddle. the anchor pins Within the arms of the yoke and also between the links 33 and 35. These plates on either side of the 30 anchor pins have welded thereto reinforcements 13 and 15 atA their edges. plates' with reinforcement 13 engages the head of ‘ the yoke 4l between its arms 43. The other edge with its reinforcement 15 engages the end of the 35 y web of the shoe (shoe 25gin Fig', 3).~ Plate 39 in wardly adjacent the hub I3 is formed with forked ends 11 and 19 turned over the' adjacent edges of plate 3l so the plates 3l and 39 may reciprocate axially relative to each other but rotate together ‘n as a unit. Between thefend wall 3l Iof plate 3| and the region 33 between the forked ends of plate 39 is located what corresponds to the wheelcylinder of a hydraulic brake applying means. v45 tionally engage its annular Surface ‘23 are main » Tii'ere is a cylinder 35 within which is a hollow 45 shoes 2,5 and 21, each `having suitable frictional piston 31. A cap 39 closes the open end of the~ lining 29. Pivoted upon opposite faces ofthe piston and contacts the wall 3i on one side and web of shoe 25 at 31 are links 33 and 35. Limited - the ends of the cylinder 35 and piston 31 on its vmovement about pivot 31 is afforded by a fric other side. There is a seal29| carried by the 50 'tion pin 3| carried by the links and extending cylinder and engaging the 'piston to preventleak through an enlarged opening 33 in the shoe. The age. Suitable hydraulic medium from a onven ends of links 33 and 35 are recessed to engage tionall master cylindennot shown passe hrough anchor pin 2l as seen in \Fig. l'and Fig. 3. _ One edge of these A y a conduit 93 in the cylinder 35 through an open yoke 4I. has arms 43 overlapping linksl 33 and 35 ing 35. It will be understood that a conventional `and-having similar recessed ends to engager an brake pedal serves as the instrumentality by l, 2 2,120,917 ’ which the master cylinder actuates the wheel is to move the plates 6| and 69 diametrically cylinders. The cylinder 85 is iìxed by fastening into drum contact. Also there is no need to ad just the servo shoes `because the travel of lthe wheel cylinder to accommodate the lining wear of the servo shoes- is always within the range of means 91 to the reciprocable plate 69 and to ac commodate itsV motion a suitable opening in the anchor plate is shown in Fig. 2. Springs lSil are attached to the main shoes and to the sliding movement at thel master cylinder provided by fiat plates and operate to draw the plates 6|A and . one stroke of the brake pedal. ` 69 together and to release the shoes from con tact with the drum. 10 i 4 Y « ' 1. In a brake, a drum, oppositely located main shoes, means to anchor either end of each main 10 shoe, servo shoes between the adjacent ends -of 'I'he operation is as follows: The parts may be assumed to be in the positions shown when the brake is not operated. When ñuid is forced into the cylinder 85 the plates 6| and 69 are forced the main shoes, means to' force said servo shoes into contact with the drum whereby the servo shoes apply the main shoes in either direction of drum rotation, said anchoring means includ 15 apart, the movements being equalized, shoes 81 15 and 'Il engaging the rotating drum. If the drum is rotating counterclockwise, the direction corre sponding to forward travel, shoes B1 and 1l are - similarly rotated With and by the drum. The upper edge of plate 69 and the lower edge of plate 6I with their reinforcements engage the yokes 4I between their arms and push the main shoes against the drum, these shoes having an ing anchor pins and articulating links pivoted to said shoes and engaging said pins. 2. In a brake, a drum, oppositely located 'main shoes, means to anchor either end of each main shoe, servo shoes- between the adjacent ends of the main shoes, means to force said servo shoes into contact with the drum whereby the servo shoes apply the main shoes in either direction of articulated anchorage through the instrumen tality of links 33 and 35 whereby the shoes may 25 accurately conform tothe drum surface. If the drum is rotating in the opposite directiomboth shoes aresimilarly applied, but in this case, the plates 6I and 68 engage the webs of the shoes and drum rotation, said means comprising oppositely reciprocable plates carrying said servo shoes and a hydraulic cylinder and piston assembly between said plates. 3. In a brake, a rotatable drum, a fixed the shoes anchor by means of the articulated adjustable yokes. I claim: anchor ‘ plate, Y anchor ` pins carried by said anchor plate, a centrally disposed hub carried by said anchor plate, main shoes, articulating links By these provisions a single hydraulic wheel cylinder only is required. In either direction of rotation both shoes engage the drum throughout their complete arcuate surfaces. All the advan35 tages of an articulated anchorage is present. The manually applied eil‘ort need be only enough between the ends of said shoes and said anchor pins, oppositely reciprocable plates guided by and ‘ ' jointly rotatable upon said hub, servo shoes car ried by said plates, means to reciprocate said re ciprocable plates .and spread' said servo shoes to oppositely reciprocate the plates 6| and 89, whereby the servo shoes apply said main shoes whereupon the rotating-drum will serve to rotate as the rotating drum rotates said plates in unison the two plates as a unit 'about the central hub, about said hub. ' 40 to apply the two main shoes. The construction iscomparatively simple and relatively inexpensive y . 4. The invention defined by claim 3, said means 40 comprising a hydraulic cylinder between said re , although exceedingly emcient.l It will withstand ` ciprocable plates. severe treatment _since so large an area of the v drum is engaged that distortion of the drum is 45 avoided. Preferably the drum is provided with , 5. In a brake, a drum, main shoes therein, servo shoes between the ends of the main shoes, anchors cooling ribs as shown in Fig. 2 to prevent the vfor said main shoes at either Vend and means to 45 heat, under the influence of severe frictional en . spread said servo shoes. to contactl the drum whereby the drumV as it rotates «rotates the servo gagement, from expanding the drum and lessen ing the braking vemciency. ` shoes which apply the main shoes for either di-~ Another advantageous characteristic is found rection of drum rotation, said means comprising ' 50 in this brake in that.A it avoids the necessity forl ' a hydraulic cylinder rigid with one of said servo ~ adjustment. A_s the lining on the main shoes shoes and a piston therein movable relatively wears away, a somewhat greater rotation of the thereto and engaging a part rigid with 'the other servo shoestakes place with no sacrifice in pedal servo shoe. 55 travel, since >the only purpose of pedal travelI GILBERT K.`HAUSE.