US1740460A - Snubber - Google Patents

Description

Dec. 24, 1929. B. B. HOLMES 1,740,460

SNUBBER Filed April 9, 1924 2 sheetsfsheet l INVENTOR r'adfor ZmeS ATTORNEY Dec. 24, 1929.. B. B. HoLMEs 1,740,460

SNUBBER Filed April 9, 1924 2 Sheets-Sheet 2 u* I". n

ATTORNEY Patented Dec. 24, 1929 4,

BRADFDRD B. HOLMES, F NEW YORK, N. Y.

SNUBBER Application filed April 9, 192e. eral No. 305,255

This invention relates to devices for attachgether Whether the vehicle as a Whole be at ment to vehicles for the purpose of modifyrest or in motion.

ino' undesirable vertical oscillations of the Another object is to provide a device for vehicle bodies as the vehicles travel over the the general purposes above mentioned of such road surface. construction that the degree of resistance to ln the particular embodiment of the inrecoil varies according to the extent of deflecvention herein described and illustrated, this tion of the supporting springs.

purpose accomplished by opposing,` a resistiidditional advantages are that a single ance to the normal recoil of the vehicle body device is susceptible of being adjusted to vary lo supporting springs While, at the saine time, its resistance Within reasonable limits so as permitting free compression of these springs. 'l0 adapt 1t for use With vehicles of different Furthermore, consideration is given to the Weights, and that practically all the correfact that it is often desired that the normal S13-@Kling parte of the device are interchangeaction of the conventional supporting springs able to right and left.

15 be not affected unless the compression and @ther advantages and objects will be made 5 consequent recoil exceed a. predetermined to appear in the course of this description. speed, the device being capable of being modil have shown ray invention embodied in a fied in such manner to avoid the objectionsnubber of the type in which the resistanceto able stiii'ening effect on the springs Which frerecoil is largely created by friction. This is quently characte 1zes tie action of devices or for the reason that have found that snube o this character. bers functioning on this principle are in gen- @ne ofthe objects of the invention is to proeral more satisfactory than any others linoWn vide a device for accomplishing the general to me. lt is to be understood, however, purposes above referred to in .vliich the rethat, so far as the inventive feature is consistance opposing` recoil may be varied from cerned, any forin of resist-ance may be used; i point to point in the recoil movement; that is that is to say, either friction, spring,l tension, l' f to say, the instantaneous values of the resistor a combination of both. ance to recoil may, Within liinits7 be lined and Referring; to the drawings: maintained at any desired predetermined Fig. l is a vievv on the line l-l of Fig. 2 Q0 amount. showing' the preferred embodiment of the in- 8G Another object is to provide a device for the vention. l

general purposes above described which will Fig. 2 is a view on the line 2-2 of Figi l.

be cheap and simple to manufacture and in Fig'. 5 is a view of the modified form on the which the necessity for machining and other lines #l of Fig. Ll.

relai" ely expensive processes is avoided. Fig'. 4: is a vieW on the line 3-8 of Fig. 3. 3 5

Another Objectis to provide a device for Fig. is a vievv of a portion of an automothc ocneral purposes hereinbefore referred to bile franje, axle and spring showing my inwl 'ch vfill not oppose substantial resistance vention in association therewith. to recoil unless the normal speed of the recoil Fig. G is a vievv of a drinn similar to that so movement to be resisted exceeds a predetershown in l and 2 but with a modiiied o0 mined amount. form of Winding,` seat or reel.

Another object is the construction of a derlhe operative parte are mounted in a cyvice for the general purposes above described lindrical housing e closed at one end for con c'haracterized by the fact that comparatively venience of assembly and access to the intelittle stress, is exerted to Oppose the supportrior by the cover plate 5 and provided with a 95 ini;- sprine's unless oscillation of the vehicle hollow boss o. The central portion of the bcfl talns place; that is to say, the device so cover plate is provided With an aperture l functions that when the body and aide are to accommodate the washer 87 which is made relatively at rest, or substantially at rest7 ver use of merely be hause it is better able to stand little pull is exerted tending to draw them tothe strain of the connecting bolt lll than 100 would be the thin material ordinarily used as a cover plate. Between the washer 8 and the end of the boss 6, is interposed the plate 9, to which is secured the collar 10 which, with the circular projection 11 on the boss serves to center and lreep in place the helical springs 12 and 18, the construction and functions of which are hereinafter more fully described. F or securing the assembly to the frame of the car the bolt 141: maybe employed, this bolt being passed through the washer 8, the plate 9, the bore 15 of the boss 6, and thence through a hole in the frame of the car and secured by a nut 16. lf desired, spacing plates 17, 17 may be interposed between the housing and the frame. Whether or not these plates are desirable would depend upon the particular conditions under which the device is to be used. Usually, however, the sides of the front springs are not precisely Hush with the 'side of the frame and in order to attain perfect adjustment the spacing plates are ordinarily desirable. F or more rigidly securing the housing to the frame it may further be provided with a lug 18 which lies close to the bottom flange of the frame. By inserting the bolt and assembling the parts as above described and drawing up the nut 16, the housing with its contained parts may be firmly and rigidly secured to the frame of the car.

The interior periphery of the housing serves as a supporting surface for a band of suitable friction material, for instance, ordinary Woven brake lining 19, which is secured by any convenient means such as the rivets 20, ordinarily employed for this purpose. l/Vhile it is not essential to the principle of the invention, l prefer to make use of a lining especially adapted for the purpose,`as a metal to metal friction contact besides being noisy and having well-known disadvantages, does not have the desirable high coellicient of friction of the brake lining. YWhile the friction surface of the brake band covers in actual service a relatively small arc, perhaps 90 degrees, the brake ban-d may, if desirable, be carried entirely, or substantially entirely around the periphery of the housing whereby it will lit the floating drinn, hereinafter nientioned closel enough to -Jrevent substantial i zo l movement or" displacement of the latter.

Under any circumstances, however, it is advisable to leave a small 'a a 21 in the brake e l i liiiin to allow for an stretching and wra 8 e ping'eifect that might take place in the lining. The Jeri aber i of the housinO` is rovided C with a slotted aperture 22 as is likewise the brake lining, the aperture of the latter being indicated by the numeral 23. rThe slots in the housing and lining register with each other and are of sufficient dimensions to permit the cable 24, hereinafter mentioned, to pass through and to have suiiicient freedom of motion in all directions.

The necessary friction for creating resistance to recoil is brought about by the rotation of a floating drum 25 of the brake band. The brake band, in fact, constitutes a bearing which is preferably of a slightly greater radius than the radius of the drum. The slight difference, which is indicated by the numeral 26, is made for the purpose of permitting the drumto rotate freely in the housing when the cable is not put under stress. The cable is not put under substantial stress, as is the case during com-pression of the supporting springs.

rlhe drum' is prcvided with a channel 2T, the bottom 28 of which constitutes a reel or winding seat on which the cable 24; may be coiled through a sufficient arc to taire care of oscillations, of maximum amplitude in the particular case. ln the drawing l have shown the cable coiled on the reel through an aic defined by an angle cf approximately 9G degrees the device being assumed to be in place on a car, the relatively moving parts of which are at rest and the cable being assumed to be under the proper tension.

It is also to be' noted that the drum is supported only by the inner periphery of the brake lining, the bolt ldiand theboss 6 being free from it and not in any way serving a journal on which the drum may rotate. The reel or channel may, as a refinement of construction, be provided with a lining 8O of leather fabric, or other suitable material 'to prevent cutting and excessive wear of the cable. The cable in turn may beV finedly attached to the drum in any convenient way.v such as by means of the stop 81, sw d to it Vand positioned in the aperture 32 which constitutes a brolren away portion of the groove in the drum.

lt is to be noted that the reel or winding seat 28 is of varying radius with respect to the axis of rotation of the drum. In point of fact it is shown in the drawings as circular and eccentric with respect to it. ltis clear, therefore, that as the drum rotates within the housing under any pull exerted on the cable 2a the moment of rotation varies being a minimum when the radius of revolution is shortest and a maximum when the radius of revolution is the longest. On the other hand, the total area of contact, i. e., the friction area between the drum and the brake band remains substantially the same throughout, although, of course, it is slightly varied as the bearing pressure is varied by distortion of the fabric of the lining.

The nature of the variation of the'radius of the reel is, it is to be understood, a matter of selection, to be determined in view vof .the ends to be acomplished. `When the body and axle are at relative rest it is, under most conditions, as l have found, preferable that the moment of rotation be relatively great, which means that the radius of revolution is'lilrewise to be. relatively great. (By the term radius of revolution I refer te the instantaneous radius indicated by O-A. That is, the radius extending from the axis oli rotation et the drum to the point of tangency of the cable 2a with the reel. The length ot the radius et revolution accordingly varies with the anguiar position ot the drum.)

.Vhen, on the other hand, the supporting springs oit the vehicle are compressed, it is usually desirable that the moment ot rotation be relatively small. llhat is to say, that the radius ot' revolution be relatively short. A reel having these characteristics oi'lers comparatively little resistance to the small vibra* tions which are suiiiciently taken care et by the ordinary springs, While, on lthe other hand, it exerts a great resistance the coinmencement of recoil. lt the ra dius oi revolution increases, this resistance accori'lingly decreases as the body and axle appraiach their normal relative positions during recoil. From the latter point on during recoil the amount of resistance may be graduated as desired. In the particular case shown in the drawings, the maximum radius ot the reel is aproxin'iately indicated by the line 0-B, and the radius of revolution at normal relative positions oft body and axle, by the line O-lli- Assuming that the radius -C becomes the radius oi' revolution at the commencement ot the recoil, it is apparent that the resistance to recoil resulting 'from friction alone gradually decreases as the recoil approaches its end until the radius O-B becomes the radius ot revolution when the resistance to recoil begins to increase. lt is, of course, apparent that the character of resistance offered to recoil may be varied, not only by varying the lorin of the reel, but also by varying the anguiar position et a given reel at normal position of body and axle. For bringing about 4variation. ot the last mentioned method it studs. The best methodl however ot adjusting; a given device for a deiinite or conditions would consist in rotating the drum to the desired angular position lor normal position ot' body and axle, securing` the drum in that position, then Winding the spring` to the desired tension and fastening the end ot the cable to the axle. taking up all slack in so doing. A convenient Way in which the drum could be held in position during the Winding of the spring would consist in inserting a pin 29 through a hole 29a in the housing` and brake lining, and thence through a hole 29 in the drum When the cable has been 'fastened to the axle the pin is Withdrawn. il. number of holes similar to that indicated by 291 may be provided for adjustment ot' the drum to varions angular positions. A variation of the last described method would consist in Winding np the spring by turning the drum, alloivance being made in the angular position ot the drum at the beginning tor producing the desired tension ot the springs When the drum had reached the desired angular position for a normal setting.

rl`he means which l have devised for normally inantaining the tension on the cable and tor rotating the drum to its normal angular position following its rotation under recoil comprise, in my preferred term shown in Figures l and 2, tivo helical springs l2 and 18 betere mentioned, which tor convenience are made concentric with each other, one of these springs, `l'or instance, that indicated by nuineral l2, being et a greater diameter than the other.

The springs are anchored at diametrically opposite points in the housing, being hoolred through the apertures 33. rlhe tree ends of the spi fs are c used to engage the drum by f'iein over studs Bel, 34e, projecting lace ot the drum. lt is apparent nin the limits imposed by the capacity sprinas any desired normal tension in he cable may be created by merely ceiling I nn to the desired degree et tension. As soon-'n inthe drawing, variation in the spring t ai can be made only in halt-circle steps v. here are only tivo studs provided over which the :Free ends may be hooked. jrs many however, could be provided as might red tor purposes ot liner adj ustinent.

e cable may be connected with the axle v convenient means such as a clamp cone' et the jaws 35, 36, which by means the bolt SG1 are caused to grip the axle shown in lligurc rlfhe ends of the nav be Wound about the i utton 3T on o and secured in an desired manner. c springs l2 and l" perform a further ion in addition to those that have been l` referred to; nan'iely, that of adding to ano increasing, accordingl to their tension, the friction that is up by the tree ro* ition ot the drum in the housing. Even ivimoiit the springs, it apparent that at least some friction and consequent resistance to rotation is created by mere Weight ot the druiiz, and that even this component of the total friction may be made to oitiler a very high degree ot resistance to rotation if the moment et rotation be made small enough, by sutiiciently reducing` the radius ot the reel.

et the 'i-lmvever, the friction thus produced could depending upon the resistance of the springs to rotation. Y

ln the modiied form shown in Figures 3 i and el, a cylindrical housing consisting of the parts 3S and 39 Which may be assembled in telescopic fashion is provided. lVithin the housing there is mounted on the axle a a drum il of Wood or otherl frictional substance about which is coiled a strap e2, the strap passing around the drum preferably one or more turns and being anchored thereto at a convenient point, such as is indicated by the numeral 4:3. The drum is capable of rotating freely on the axle except restrained by frictional resistance and spring tension as hereinafter further.described. rlli-e part 39 of the housing is provided with a circular concentric depressed portion l31, the only purpose of which is to accommodate the nut del and thus malte it possible to bring the housing` close to the frame lllashers and l? may be used for stilfening the frame to enable it to resist the stresses Which are imposed by the resistance to recoil. `Washer i8 may be also employed, if necessary, to strengthen the housing.

The outer portion of the axle is preferably squared as shoivn in Figure a and passes `with a sliding` tit through a square bore in the bushing 49 Whiz h is merely a convenient way of Vpreventing the axle from turning. The threaded bore 50 in the axle is provided for the purpose of accmnmodating` the screivl. The screw l passes through the star spring` 52, the purpose being to increase the friction of the drum el as hereinafter further' described.

One face of the drum bears against a friction plate 53 consisting of a dish of suitable friction material firmly secured to the part 39 of the housing. The opposite ce of the drum 4l bears against another friction plate which is Welded or 'otherwise secured to the bushing` 49 as shown in Figure 3. The squared portion of the axle l0 is continued for a sufficient distance to allou7 slight clearance indicated by the numeral it is apparent, therefore, that, as the screw 5l isK The drum itself, as is shown in Figure 4:, is

Vof varying radius the periphery serving as a reel or Winding seat, In the particular embodiment of my invention shovvn in Figures 3 and e, the drum is eccentric, but this particular shape is not material it being merely employed because under most conditions it Will satisfactorily eect the objects of the invention. The purpose of the variation in the radius, however, is as inthe case of the forms shown in Figures l and 2 to bring about a corresponding variation in the moment of rotation on the drum and a corresponding variation in resistance to recoil. In other Words, as the drum rotates during a recoil movement, the instantaneous values of the resistance to recoil are graduated to best suit the particular conditions in hand. I find that, under ordinary conditions, it is preferable that the amount of resistance at the commencement of a recoilmovement be comparatively great, di-

ing is provided With a slot 59 of proper dimensions to accommodate and permit free movement of the strap a.

By Way of further reference to the charf the form of Figures l and 2, the housacteristics ofthe modified form of the device shown in Figures 3 and 4l, it should be eX- plained that the angular position of the drum, as is shown in Figure Ll, is assumed to be the normal position; that is to say, the angular position which the drum may take when the vehicle body and axle are relatively at rest. Under these conditi ons the greatest radius is indicated by the line O-B, and since the drum is eccentric the smallest radius is indicated by the line O-D The radius of revolution When the parts are in this position is indicated by the line O-A which is slightly less than the maximum radius. As the drum turns, however, the radius of revolution increases until the maximum radius G-B coincides With it, the result being that there is an increase in the radius of revolution through the are C A B Wit-h a consequent increase in the turning moment and a consequent decrease in the resistance to rotation.

ln Figure 6 is shown a drum similar to the drum of Figures l and 2, but With a modified form of reel or Winding seat. The reel or Winding seat of this figure is indicated by the numeral 60. rlhe reel is shown as of somewhat elliptical shape. The change in resistance to recoil Whensuch a reel is used is, therefore, much more rapid than in the case of the circular eccentric reel of Figures 1 and 2, and this form is adaptable for use When it is desired that the resistance to slight oscillations be reduced to a minimum, While the resistance to recoil be a maximum at the commencement of recoil movement.

l/"Vhile l have shown and described certain practical specilic embodiments of my invention it is to be understood that many of the features described may be varied and yet not depart from the scoje of my claims which are as follows:

l. ln a bralte device a rotatably mounted brake member and. a stationary bralte niember, the rotating` member being provided with a reel of varying' radius, a flexible draft elcinent coiled on said reel and serving as a draf element 'for causing rotation of said reel t produce a braking eii'ect the int as' j o which varies with the angular position of drum.

2. In a brake device comprising tuv relatively rotating brake members having' frio tional contact one With another for producing braking effect, a rcel. of varyi radius connected with one of said member., and a flexible draft element coiled on said reel, the free end of said draft element being adapted for connection With a moving part the motion of Whi ch is to be resisted.

3. ln a brake device a rotatable drum llav ing a peripheral friction braking surf ce, a support for said drum and a complementary friction braking surface therefor, the drum being provided With a peripheral groove the bottom of which is of varyingij radius -with respect to the axis of the d rum and which serves as a reel, and a flexible draft element coiled on said reel and serving when connected to a moving member and put under tension means of causing rotation of said drinn for the purpose of producing frictional braking effect of varying` intensity.

el. In a brake device 'a stationary brake member', a drum rotatably mounted thereon and having a friction surface in frictional contact with a friction surface on the said stationary7 member, a reel carried by said drum, and a flexible draft element coiled on said reel and serving as a means of rotatimgI the drum for braking effect varying moments of rotation.

5. ln a brake device a stationary bral-:e member having an interior cylindrical bralting surface, a drum rotatable in said member, the periphery of said drum serving as a friction surface to produce friction by rotation of the drum in sain stationary member and said drum being also provided with a periplr eral groove to receive a flexible draft element for producing rotation and consequent braln ing effect, the bottom of said groove being of varying radius with respect to the axis of rotation of the drum.

6. In a device for the purpose indicated a rotatable member; a fixed journal bearing member adapted for mounting on one of the tvvo spring-separated members of the vehicle to be served; the rotatable member having` a seat upon Which a flexible connector may be Wound in the rotation of the said rotatable member; a flexible connector attached at one end to the rotatable member and passing over said seat and extending therefrom in direc tion for attachment to the other of said spring-separated members of the. vehicle; a lixedly mounted friction plate and means for stressing said plate and the rotatable member against each other, the parts being formed and dimensioned to render the pressure and area of frictional Contact between the rotatable member and the friction plate, substantially constant throughout the range of rotative movement; the seat for the flexible connector being eccentric With respect to the fixed journal bearing member, whereby the radius of leverage for rotation against the frictional resistance increases in one direction of rotation and diminishes in the opposite direction While the friction remains constant.

7. ln a device for the purpose indicated a rotatable member; a fixed journal bearing member adapted for mounting on one of the tivo spring-separated members of the vehicle to be served; a spring connected with the journal bearing member and with the rotatable member for being tensioned by rotation of the latter in one direction and rotating said latter in the opposite direction by its reaction, the rotatable member having a seat upon Which a flexible connector may be Wound in the rotation of said rotatable member; a flexible connector attached at one end to the rotatable member and passing over said seat and extending therefrom in a direction for attachment to the other of said spring-separated members of the vehicle; a fixedly mounted friction plate and means for stressing said plate and the rotatable member against each other, the seat for the flexible connector being eccentric with respect to the fixed journal bearing member, whereby the radius of leverage in favor of the connector for` tensioning the spring in univinding the connector from the seat, diminishes from a certain point in the univinding which increases the tension of the spring.

BRADFORD B. HOLMES.

Images