US2203542A - Cushioning mechanism - Google Patents

Description

2 Sheets-Sheet 1 H. p. PAGE CUSHIONING MECHANISM Filed April 4, 1.935

June 4, "1940;

ELM/5 June 4, 1940.y

H. D. PAGE CusHIoNING MEGHANISM Filed April 4, 1936 2 Sheets-Sheet 2:

ATTORNEYS Patented June 4, 1940 CUSHIONING MECHANISM Harold` D. Page, Flushing, N. Y., assignor to Waugh Equipment Company, New York, N. Y., a corporation of Maine Application April 4, 1936, serial No. 72,102

12 Claims.

This invention relates to coupling and draft mechanism for use on railway vehicles and is concerned more particularlywith novel appa- -ratus for connecting together the units of a 5 train, so constructed that, under normal operating conditions of the equipment,'free or uncontrolled relative movement of the parts of the apparatus, resulting from looseness or lack of contact commonly known as free slack, is prevented.

l The new apparatus may be employed, with suitable chages necessary to meet the different con.- ditions of operation, on vehicles for either freight or passenger service, but for purposes of explanation, an application of the principles of the inl vention to passenger cars will be described in deand the motive power unit, is highly objectionable since it results in shocks which cause discomfort to passengers or damage to lading and also frequently do damage to the equipment. 3o free slack may be the result of wear, breakage, or misalignment of parts or it may be inherent in the construction Aor assembly of the various l, elements of the connecting mechanism, and for 'these reasons the objectionable results which it 35 produces occur even though the motiveA power for the train is handled most carefully by skilled operators. 'I'he shocks which are transmitted to the car structures through the connecting mechanism are more intense during the periods when the train is being .accelerated or decelerated, and when the train "consist or make-up is being altered, either as to number of cars or as to their relative positions in the train, or the locaA @tion of the .train is being changedv relative to 4'5 station `or other facilities, than during 'theltimes ,when the train'is running at relatively uniformspeeds between station stops. `But even during running, the shocks and disturbances referred to occuras a result of undulations and other 50 irregularities in the track surface,changing resistances, Vnecessary -changes in the power output from the motive power units,` oscillations and vibrations from the motive power unit, brake applications and releases, and other causes.

The amount of free slack' has a constant tendency to increase and decrease lengthwise of the train throughout the connections, and such slack develops even though the connections are made up of new and well designed devices of modernl construction and there is no slack in the cou- 5 plers, yokes, draft gears, draft gear pockets, and related parts, when the devices are in Vnormal position and notsubjected to the forces applied during operation. The reason for this is that present devices are so constructed that the forces applied to the couplers are transmitted to the draft gears or shock absorbing devices of the assembly by means of contacting metallic parts, and whenl a draft gear is subjected to such a force, spaces develop in the connections,and l5 upon the removal or reversal of the force', the spaces so created constitute free slack which produces the objectionable results above mentioned. f

The development of such free slack, during normal operation, in the connections now in 'common use takes place, in one instance, as follows. When the coupler with its draw bar is subjected to a tensional force, that is, is under draft, the coupler yoke tends to move forward with its rear end bearing against the rear end of the draft gear housing either directly or through a follower. The forward end of the draft gear housing then engages, either directly or through a follower, front draft gear stops which are attached to a portion of the car structure. When the force in draft exceeds the initial compression of the gear, the gear isfurther compressed and its length is shortened, and, since the forward end'of the housing is held im- 35 movable by the stops and the yoke moves forward,` a space develops between the forward end of the yoke and the forward end of the housing or front follower, if one is used. At the same time, a corresponding space develops between 40 the rear end of the housing or follower and the rear draftv gear stops, the two spaces referred4 to constituting free slack. If with the mechanism in this condition, the application of the forcein draft ceases or' changes toa compressive 45 force, that is, one in buff, the coupler yoke moves back and this movement is not controlled until the front portion of the yokeha's again engaged the forward end of the draft gear housing or front follower and the rear end of the draft gear housing or rear follower has engaged the rear draftgear stops. This uncontrolled movement results from the free slack and the amount of the movement depends on the magnitude of the force originally applied to the mecha.- 5o

nism. l The eifect of the free slack is to produce the dynamic shocks and resulting disturbances referred to, and such shocks and disturbances may be of considerable intensity, particularly if the force in draft suddenly changes to a force in buff, and both forces are substantial.-

The conditions above described which result in the development of free slack when a force in draft is applied to the connections, likewise occur upon the application of a force in buif, but in this case, the spaces or clearances occur between the rear end of the yoke and the rear end of the draft gear housing or follower, and between the front end of the housing or front follower and the front draft gear stops. Here again when the force in buff changes to a force in draft, the yoke has a free and uncontrolled movement until its rear portion has again engaged the rear end of the draft gear housing or rear follower, and the .forward end of the housing or front follower has engaged the front stops.

As the direction of the forces applied to the connecting mechanism in a train 'varies almost constantly during operation, slack is always present in the connections to a greater or less degree,

and this condition is at its worst when a heavy train is being accelerated or retarded and the parts of the connecting mechanism are brought into sudden contacts with the development of severe dynamic shocks. This condition exists with connecting mechanism of modern construction even when the devices forming the mechanism are new and in good condition, and when these devices become worn, broken, or misaligned, slack develops inproportiona'tely greater amounts and its effect, namely. the production of dynamic shocks, is correspondingly increased.

The present invention is accordingly directed l to the provision of novel apparatus for use on railway vehicles for connecting together the units of a train, the new apparatus being' so constructedrthat the development vof free slack with its objectionable results is prevented under normal conditions of operation. v

According to the invention, each railway car is equipped at each end with a coupler and yoke,

and each yoke is connected to the car str-ucture through a cushioning apparatus which includes a pairof cushioning mechanisms or units. These units are interposed between a rigid part of the car structureV and parts of the yoke, and they operate in alternation to oppose movements of the yoke and coupler in opposite directions. The cushioning units are installed under a relatively high compression and each unit has an expansivity as great as the amount by which its normal overall length was reduced during installation.

The relatively high in stallationcompression referred to is imposed upon the units inrorder to make available an expansion of the units which is effective to prevent the development of free slack between the yoke and the'rigid part of the car structure referred to, and when installed under such compression, both units are, under normal operating conditions, in continuous contact "with l thecar structure and with the yoke and'feflective to perform the desired cushioningffunction..

For convenience, I shall refer to vthe compression under which the cushioning units are installed and maintained in the apparatus as their effective compression,` and that effective compression is not to be confused withthe "initial compression of an ordinary draft gear; such initial compression is imposed on the 'gear' in its the manner in which such a gear is installed between stops at its ends makes it impossible to prevent the development of free slack in the connections, whenever a force in excess of the initial compression is imposed upon the gear.

Since the two units of the new apparatus opcrate alternately and are under effective compression, it is apparent that when the coupler is subjected to a force in buff, for example, one cushion unit resists the movement of the coupier and yoke and is thereby compressed, and at the same time the other unitv freely expands. T'he units are so constructed that the resistance which they offer to the movement of the yoke limits the amplitude of that movement to an l extent such that the forces applied to the coupler under normal operating conditions are insufficient to produce a yoke movement greater than the expansivity of either unit. Accordingly, upon the application of a force in buff, the expansion of the unit, which `is ynot resisting movement of the coupler and yoke, is at least as great as thenormal amplitude of the movement of the yoke against the resistance of the other unit, and the expanding unit is therefore always in operative engagement with the yoke. As a consequence, if the application of the force in draft ceases or changes to a force in buff, the expanded unit becomes immediately effective to resist and control the return movement of the yoke. The' result is that no spaces-or clearances develop between the contacting parts of the connecting 4apparatus, so that there is no free slack and all movements of the yoke are against the resistance and under the control of `a cushioning unit.

With the arrangement thus described, the application of a force in draft, for example, to the coupler is transmitted to and stored in one of the units, and when theforce in Idraft on-the coupler ceases, the stored force tends to return the coupler to its original position. As this return movement is always resisted and controlled by the second unit, it does not result in dynamic shocks and no considerable problem of recoil in the apparatus is thus presented. The cushioning units employed may therefore be of. various constructions, as, for example, the units may resemble commercial friction draft gears,'which include friction elements, such as wedges or shoes extent necessary to prevent the development of free slack under normal operating conditions. Since the amount of expansion required depends on the amplitude of yoke movement, which is in turn determined by the resistance to such movement offered by a cushioning unit, it follows that paratus-to the forces applied to the yoke under normal operating conditions, and the effective compression of the units must be deflnitely correlated to one another. Each unit is therefore selected to have operating characteristics necessary in view of the weight of the car on which it is employed and with reference to the forces to which the unit is subjected under normal operating conditions. When cushioning units which include rubber are employed, a further condition `should be fulfilled, namely, the effective compression on the units should be less than that which would detrimentally affect the resilient material. Such units should, therefore, offer a resistance sufficient to limit the amplitude of movement of the yoke to a value not greater than the expansion of the units corresponding to' an effective compression which does not cause the rubber to take a permanent set.

So longas the units have the operating' characteristics above referred to, the details of their construction are relatively unimportant, but since cushioning elements which include rubber are preferred, particularly for passenger service, an embodiment of the invention which includes cushioning mechanisms including rubber is illustrated in the' accompanying drawings. In these drawings,

Figure l is a plan view, partly in section, of one l form of the new apparatus installed on a railway car; i

lFigure 2 is a view, partly in longitudinal section and partly in elevation, of the apparatus illustrated in Figure 1;

Figures 3 and 4 are sectional views on the lines 3-3 and 4 4, respectively, of Figure 2;

Figures 5 and 6 are diagrammatic longitudinal sectional views indicating the positions of the different parts ofthe apparatus when it is subjected to forces in draft and buff, respectively;

Figure 7 is a sectional view through one of the resilientelements of the cushioning mechanism, and

Figures 8, 9,v and ld are diagrammatic sectional views showing modified forms of the apparatus.

In the construction illustrated in Fig. 1 of the drawings, the connecting mechanism' on a car is shown as including a draftpocket III which lies between the longitudinal sills II of the car, although, if desired, this pocket may be formed by other members attached tofthe sills or any other convenient part of the car structure. Associated with the pocket are abutment members I2, here shown as extending transversely within Athe pocket and cooperating to form transverse abutment means. This abutment is immovable relative to the walls of the pocket, and the abutment members may be formed as integral parts of the walls of the pocket or as integral extensions from plates I3 secured byv rivets, or the like, to the inner faces of the walls of the pocket, each such abutment member preferably being formed with side faces which convergetoward the longitudinal axis of the pocket-. Each plate I3 may also be formed with a longitudinal rib I3a for protecting the heads of the rivets from contact with the units and preventing lateral displacement of the units or parts-thereof.

The cushioning mechanisms or units, generally designated I5 and I5a, lie within the pocket, one

. on each side of the abut-ment, and in the form illustrated, each mechanism includes a follower block IG, I6a in contact with the abutment. When the abutment member is provided with inclined lateral surfaces, as above mentioned, the

oval shape, is applied to-opposite faces of the plate and is held in position by portions thereof which extend through the openings, each plate illustrated having three such rubber rings on each face. Between adjacent resilient members are at metal separator or divider plates I9, and at the outer end of each group of resilient members and divider plates of each mechanism I5, I5a, there is an outer follower 2i), 20a.

The car is equipped with a. coupler 2| which is preferably of tight-lock construction, the i coupler illustrated being one of the present commercial couplers of that type. The coupler is connected by a shank or draw bar 2Ia to a yoke 22, which lies between the sills, and, in the construction illustrated, encircles the cushioning mechanisms in the draft pocket. These mechanisms are introduced into the pocket under effective compression as previously described, and the followers of each mechanism are accordingly forced into close contact with the abutment and one portion of the yoke, respectively. At each end of the pocket is a pair of safety stops or lugs, 23, 23a, these stops coming into action only in the event of damage to the central abutment, to f prevent unlimited free movement of the cushioning mechanisms relative to the car. These stops or lugs may also serve as guiding vmeans for the lyoke to limit lateral movement thereof.

The car is equipped `with the usual platform plate 2l carrying the diaphragm plate 25 to which one end of the collapsible diaphragm 26 is attached. The plate 24 is supported by means of hinge members 21 pivotally attached to the 4 ends of a pair of stems 28 which pass through an end sill 29 forming part of the car structure, and the rear end of each stem is encircled by a spring 30, the springs permitting relative movement of the stems necessary when the platform plates lare swung at an angle during operation of the car on a. curve.

The platform plate is continuously urged forward by a stem 3i. which passes through the end sill 28 andA engages a follower 32 in a pocket device bears against a filler block 31 which vcontacts with the rear end of the pocket.

The operation of the new apparatus is illus- 'tx-ated in Figures 5 and 6, the first figure showing the parts in the positions which they assume when subjected to a forc'e in draft, and the second showing the positions of the parts following the application of a force in buff.

As shownin Figure 5, a force in draft applied tothe coupler causes the coupler, the coupler 7 ward. In this movement, the rear end of the yoke compresses the rear cushioning mechanism I5a against the draft pocket abutment, and the for` ward end of the yoke, movingv away from the abutment, permits the forward cushioning mechanism I5 to expand. Since the cushioning mechanisms are -under effective compression and have such absorptive capacity that ythe greatest am force in buff, the coupler,-. draw bar, and yoke move toward the rear, and, as a result, the forward mechanism I5. `is compressed, and the rear mechanism I5a is allowed to expand. Since the .forward mechanism has been in continuous engagement with the yoke and abutment, the return movement of the yoke is at once resisted and controlled by that mechanism, and there is no lfree slack in the apparatus.l The removal of the forcein draft, therefore, does not'produce shocks which are transmitted to the car structure and cause discomfort to the passengers.

When under normal operating conditions a force in buff is applied to the coupler, the cushioning mechanisms assume the conditions illustrated in Figure 6, the mechanism I5 being compressed and the mechanism I5a expanding so that no free slack develops in the apparatus. Here again, when the applied force is removed or re versed, the mechanism I 5a comes at once into action to resist and control the return movement of the yoke and cushipnthe applied forces.

' As previously explained, it is important,when

cushioning mechanisms including rubber compounds as the resilient material, are employed, that the effective compression thereon be less than that which would cause the resilient material to take a permanent set. 'I'he effective compression required is that whichiivill give the cushioningl mechanisms an expansion at least as,

great as the greatest amplitude of movement of the coupler and yke from normal position under ioning unit includes 4resilient material insuchquantity,` shape, and form that the resistance I offered thereby 'to the movement of the coupler limits that movement to a value not greater. than the normal or free expansionof the units corre- A sponding to an effective compression which does not have a detrimental effect on the resilient ma;

'n terial. The effect referred to varies with dierentY types of rubber compounds and is to some extent dependent on time, but the construction of the units is such that the effective compression permissible thereon can be readily determined for each particular type of compound.

The cushioning mechanisms employed in th new apparatus are preferably of equal capacity and travel and, when the mechanisms include rubber, the desired result` may be obtained by in# cluding in both units a similar number of plates carrying like masses of rubber in like arrangeul 2,208,542 Y shank or drawba'r, and the yoke to move for- A ment. 'I'he use of mechanisms of such characteristics is not necessary so long as both mechanisms can expand sufficiently to avoid the-development of free slack. Accordingly, if desired, the cushioning mechanism at the forward end of the pocket, which absorbs force in buff, may be of greater capacity than the mechanism at the rear end of 'the pocket which absorbs the forces in draft, or vice versa.

While the p'ocket has been illustrated as provided with stop lugs 23, 23a, it is to be understood that these lugs are placed at a `distance from the abutment at least as great as the expansion of the adjacent cushioning mechanism. The lugs serve to limit lateral movement of the yoke but never contact with the outer followers of the cushioning mechanisms, except in the event that through accident, the abutment members are broken. If that occurs, the coupler could force the cushioning mechanisms out of the pocket if there were nothing to prevent, and the lugs are safety devices which become operative only in that situation. Accordingly, under normal with the walls I I of the draft pocket or as ex tensions from plates I3 lsecured to the Walls. The abutment members39 are formed with parallel faces extending transversely of the draft pocket instead of the inclined faces with which the abutment members I2 are provided. When abutment members 39 are employed, the followers 40 and 40a of the cushioning mechanisms I5 and I5a have flat faces which engage the outer faces of the abutment members.

In th'e construction shown inv Figure 9, the transverse abutment is provided by a member 4I which is seated in recesses 42 in the walls of the draft pocket. When such an abutment is employed, followers similar to those designated I6, I6a, 01'40, 40a may be dispensed with.

lIn the construction illustrated in Figure 10, the

abutment is in two parts lying at the ends of the pocket, and ,theV rear transverse portion of the yoke'lies between the followers at the middle of the pocket 'I'he parts of the abutment consist of pairs of projections 43, 43a formed as integral parts .of the walls of the pocket or'as extensions from plates similar to the plates I `3, or these parts may take the form of abutment members, similar to that designated 4I, seated in recesses of the pocket walls. 'I'he yoke employed with-this construction encirclcs the front cushioning mechanism' I5 only, and the rear transverse portion of -the' yoke lies between the two mechanisms I5 and I5a and in contact with followers I6 and Iia if such followers are used, while the forward transverse -portion a of the yoke is spaced from `nisms by the rear traverse portion 44 of the yoke lying between the followers I6 and IGa. Thus, u'

when a force in buff is applied to the coupler, the rear cushioning mechanism I5a is compressed and the front mechanism I5 expands, and when` anapparatus in which the abutment lies between the mechanisms, instead of at the ends thereof; thus, in the apparatus shown in Figure 1, a force in buff applied to the coupler causes the front mechanism I5 to be compressed, and the rear mechanism I5a is permitted to expand.

In the apparatus in the form illustrated in Figure 10, the cushioning units are under effective compression such that, under normal operating conditions, each mechanism has an expansion at least as great as the greatest amplitude of movement of the yoke. Since the forward transverse portionMa of the yoke is spaced from the front follower 20 of mechanism I5, this portion of the yoke never contacts With that follower. As a consequence, the followers 20 and 20a, and the followers I6 and 16a, remain in continuous contact, respectively, with the abutment and the rear transverse portion of theyoke and, under normal operating conditions, no free slack develops in the apparatus.

In the constructions shown in Figs. 1, 8, and 10, `the abutments are formed by aligned projections extending inwardly from the walls of the draft pocket and spaced apart a distance greater than the width of a longitudinal member of the yoke. Accordingly, in installing the new cushioning device, the rubber-bearing and spacer plates and the followers may be placed in the yoke under the desired compression with adjacent followers I6, I6a held apa-rt by temporary means a distance greater than the thickness of the abutment. Theyoke with the units in place is then raised into position from beneath with the top longitudinal member of the yoke passing through the space between the projections forming the abutment and the temporary holding means are next removed to let the followers engage opposite faces of the abutment. With the Fig. 9 construction, the abutment member 4I is mounted in the yoke with the rubber-bearingv and spacer plates and the end followers 20, 20a, the rubberv being under the desired compression. The yyoke thus loaded may again be raised into position with the ends of the member 4I entering the recesses 42.

In all constructions illustrated, the yoke is an open center frame, preferably of unitary construction, and since the rubber-bearing and spacer plates and the followers are confined only at top and bottom by the yoke, lateral displacement o'f the plates and followers byy movement` in a.` horizontal plane must be prevented. If the abutment is formed by means of plates riveted to the draft pocket walls, as in the-Fig. l construction, displacement of the cushioning plates and followers laterally may be prevented in various ways, as by forming the abutment plates only slightly less than the spacing of the walls.v

`In all forms of the apparatus, the two cushioning mechanisms act on the yoke in opposition to one another so that when the apparatus is not in operation, the yoke assumes a neutral position in which the cushioning mechanisms balance one another. As a consequence, only a slight force need be applied to the coupler to start the cushioning action and the apparatus is therefore more sensitive and comes into action more quickly than the cushioning devices now employed. With most modern cushioning apparatus, the cushioning mechanism is under initial compression and does not begin to perform a cushioning action until a force in excess of the initial compression of the device is applied to the coupler. As a con-v sequence, the` cushioning mechanism does not begin to function at once and manyforces appliedfto the coupler are transmitted direct to the car structure.

Another advantage of the new apparatus as illustrated is that the maximum travel of the coupler and yoke controlled by the new apparatus maybe materially less than that of the coupler and yoke connected to the car structure through the cushioning devices of the type now in common use. When the coupler travelis thus lessened, much less force need be applied to the diaphragm and platform plates to maintain them in contact with those of the adjacent car. This reduces the friction between the contacting plates on adjacent cars, and thus contributes to smoother action of the train, and reduces noise. Also, since 1esspressure on the diaphragm and platform plates is required, the operation of coupling cars iS facilitated.

The advantages of the new connecting mechanism are obtained to the greatest degree when ployed, there is slack betweenthe faces of the coupler knuckles, but under normal operating conditions, the new cushioning devices will cushion the shocks arising therefrom, and prevent their transmission to the vehicle structures. On infrequent occasions, however, the slack in such couplers may result in the transmission of forces to the cushioning devices so great as vto develop some free slack therein, and it is for that reason that tight-lock couplers are preferred.

In the foregoing, the new apparatus hasfbeen described in a form suitable for passenger equipment, but it is to be understood that with sultable changes, such as the use of cushioning mechanisms of greater capacity, the apparatus may be used to advantage in freight service. In both cases, it will be desirable to eguip not only the cars, but also, the rear end of the motive power unit with the new mechanism.

In the foregoing,the means by which the coupler shank or draw bar is operatively connected to the cushioning apparatus has been referred to as a yoke and a yoke of the vertical type, such as is used in present standard rolling stock, is illustrated in Figures 1 and 2. It is to be understood, however, that with 'suitable changes in the installation, a horizontal yoke could ,be employed and other forms-f connecting means could also be used. The'term fyoke as used in this specication, therefore, is intended to refer to any suitable means for connecting the coupler and cushioning mechanism. Also, the abutment against which the cushioning units of thenew apparatus sisr 6 are seated may be located either within the draft pocket between the cushioning units or at the ends of the pocket and beyond the outer ends of the cushioning units. Accordingly, in `the appended claims, the term abutment is intended to refer to both these constructions unless the contrary is clearly indicated.

In describing the construction and operation of the new cushioning apparatus, I have pointed tions and that the development in the train connections of free slack may thereby be prevented.

I have also stated that by using rubber-bearingA plates in the units and providing those plates with proper amounts of rubber in proper arrangement, it is possible to maintain the rubber under the desired effective compressionwithout detrimentally affecting the rubber.

An embodiment of the invention that fullls the specified conditions and has operated satisfactorily in regular railroad service includes six rubber-bearing plates in each unit with separator plates between them. Each rubber-bearing element includes a metal plate which is about 9" by 12%" overall and-1%" thick and on each face, the plate carries three lsimilar concentric rubber rings of flattened oval shape similar to those shown in Fig. 4. The rings are thick and the faces vary in width from 1" to 11/8". The outer ring has'straight portions having outer surfaces parallel to the end and side edges of the plate and spaced therefrom by 1/2", the straight portions being connected by' curved portions. 'Ihe outer surface of the intermediate ring is spaced from the inner surface of the outer-ring, While the spacing between/the intermediate and inner rings is 1%". 'I'he rubber used is a compound containing various usual ingredients., I

In the specific installation mentioned, each cushioning unit is installed between the abutment and yoke under a total pressure of 7000 pounds and the cushioning devices constructed and installed as describedfhave functioned so succesfully in improving train operation and riding conditions, that, since the first installation, many similar devices have been installed in the equip- -mentin use on passenger trains of the highest type;

I- claim: l

1. The combination in a railway vehicle, .such

. as a car or motive power unit, of a. draft pocket on thel vehicle structure, a transverse abutment having parts disposed at opposite ends of said" `pocket, a pair of cushioning mechanisms lyingl in line within said pocket with their remote ends h i contacting only with the parts of the abutment, a yoke encircling one mechanism only and having one direction and undergoing compression while the other mechanism expands, and saidmeicha.- nisms being under effective compression such i ,i that, under normal operating conditions.. the expansion of each mechanism is at least as great as the greatest amplitude of that movement of the coupler and yoke during which expansion of said mechanism takes place, whereby both mechanisms ar'e in continuous engagement with lsaid yoke and the development of free slack between the yoke and vehicle structure is prevented.

2. The combination in a railway vehicle, such as va car or motive power unit, of a draft pocket on thevehicle structure, a transverse abutment in said pocket between the ends thereof, a pair o f cushioning mechanisms in said pocket, one on each side of said abutment, each mechanism contacting at one end with said abutment, a connecting element, the other ends of'said mechanisms contacting with said element only, a coupler attached to said element, said coupler and element being moved lengthwise in opposite directions from normal position by forces in buff and draft, respectively, applied to said coupler, each lmechanism resisting lengthwise movement of the coupier and element in one direction and undergoing compression while the other mechanism expands, and said mechanisms being under effective compression such that,under normal operating conditions, the expansion of each mechanism is at least as great as the greatest amplitude of the movement ofthe coupler and element against the resistance of the other mechanism, whereby both mechanisms are in continuous engagement with said element and the development of'free slack between the element and vehicle structure is prevented, and stops beyond said other ends of said mechanisms and each lying at a distance from said abutment at least as great as the expanded length of its adjacent mechanism, said stops preventing free lengthwise movement of said mechanisms only when said abutment becomes inoperative.

3. 'I'he combination in a railway vehicle, such as' a car or motive power unit, of a draft pocket on the vehicle structure, a transverse abutment in said pocket between the ends thereof, a pair -of cushioning mechanisms in said pocket, one

- operating conditions, the expansion of each mechanism is at least as great as the greatest amplitude ofv that movement of the coupler and ele- `ment during which expansion of said mechanisms takes place, whereby both mechanisms are in continuous engagement with said element and the vdevelopment of free slackbetween the element and vehicle structure is prevented, and means beyond said other, ends of said mechanisms for limiting lateralmovement of said element during the lengthwise movements thereof, each means lying at a distance from said abutment at least as great as the expanded length of its adjacent mechanism and preventing free lengthwise movement of said Ymechanism only when said abutment becomes inoperative.

` 4. The combination in a railway vehicle, such as a car or motive power unit, of a draft pocket l quantity of rubber in each of said mechanisms and on the vehicle structure, abutment means in said pocket, a pair of cushioning mechanisms in said pocket, each mechanism contacting at one end with said abutment means', a connecting element, the other ends of said mechanisms contacting with said element on1y, and a coupler attached to said element, said mechanisms containing resilient elements including rubber and being under effective compression, each mechanism resisting lengthwise movement oi the coupler and element in one direction and undergoing compression while the other mechanism expands, such movements of the coupler and element being restricted only. by the unit undergoing compression, the

the effective compression of said mechanisms being such that the resistance offered thereby to the movementsof the coupler, and element produced by forces occurring underl normal operat-` ing conditions restricts said movements to an extent such that the expansivity of said mechanisms is at least as great as the greatest amplitude of lengthwise movement of said coupler and element from normal position, and the effec- .tive compression of said, mechanisms is insufficient to affect said rubber detrimentally.

5. The combination in a railway vehicle, such` as a car or motive power unit, of a draft pocket on the vehicle structure, transverse abutment means having parts disposed at opposite ends of said pocket, a pair of cushioning mechanisms in said pocket, the mechanisms contacting at their remote ends with parts of said abutment means, and a yoke encircling one of said mechanisms and having a part lying between and in contact with the adjacent. ends of said mechanisms, the remote end of said encircled mechanism being out of contact with the yoke, and said mechanisms being under effective compression such that, under normal operating conditions, both mechanisms maintain continuous contact at,l one end with parts of said abutment means and at `the other end -with the part of the yoke lying between them.

6. The combination in a railway vehicle, such as a car or motive power unit, of a draft pocket on the vehicle structure defined in part by opposed walls, a pair of platesJ attached to the inner faces of the walls, each plate having an inwardly extending projection, the projections cooperating' to form an abutment, a pair of cushion/ingl units in the pocket on opposite sides of the abutment with their adjacent ends in contact with the abutment, a coupler, a yoke attached to the coupler and encircling the units and contacting with their remote ends, the units being longitudinally confined only by the yoke and abutment and being compressed in alternation im resistingjnove` ments of the coupler and yoke produced by forces in `buff and draftapplied to the coupler, and

stops secured to the .inner faces of the walls in engagement with the ends of the plates, said stops preventing free lengthwise movement of the units only when the abutment becomes inoperative.

'7, In a railway vehicle, such as a car or motive power unit, the combination of a pair of spaced,

vparallel walls, a transverse abutment between the walls, a pair of cushioning units of equal capacity and travel lying between the walls, one on each lside of the abutment, with the 'adjacent ends of the units in contact with opposite faces of the abutment, each unit comprising alternately arranged rubber-bearing Aand spacer plates of a. transverse dimension not substantially less than that of the free space between the walls on `either side of the abutment, the rubber-bearing plates of each unit carrying like masses of rubber in like .nation to resist longitudinal movements of the coupler and yoke with one unit undergoing compression and the other free to expand, such movements of the coupler and yoke being limited only by that unit which is undergoing compression, the units being under such effective compression between the yoke and abutment that, under normal operating conditions, each unit has an expansivity at least as great as the greatest amplitude of the movement of the coupler and yoke against the resistance of the other unit, whereby a continuously effective cushion is provided between the coupler and vehicle structure and the development of free slack is prevented, the plates being prevented by the walls from being laterally displaced relative to the yokeand abutment.

8. In a railway vehicle, such as a car or motive power unit, the combination of spaced abutments attached to the car structure and extending transversely'thereof, a pair of cushioning units lying in line in the space between the abutments with the remote ends of the cushioning units contacting only with the abutments, 4a coupler, and .a yoke attached to the coupler and encircling onecushioning unit only, the yoke having a part movable therewith which lies between the adjacent ends of the cushioning units and is normally in contact with both said ends, the cushioning units acting in alternationto resist and cushion buff and draft movements of the coupler and yoke, such movements being restricted by one of the cushioning units which undergoes compression in performing its cushioning function and the Aunitbeing compressed constituting the sole -restriction upon the movements of the coupier and yoke in which such compression occurs, the cushioning units being installed between said part of the yoke and the abutments under compression such that as one cushioning unit is compressed, the other expands.

19. In a railway vehicle, such as a car or motive power unit, the combination of a pair of spaced, parallel walls, a pair of plates attached to the opposed faces of the walls and provided with aligned projections' cooperating to form a transverse abutment between the walls, the ends of the projections being spaced apart, a pair of cushioning units between the walls, one on each side oi the abutment with the adjacent ends of the units contacting witl" opposite faces ofthe projections and spanning the space between them, each unit .comprising alternately arranged rubber-bearing and spacer plates, an open center yokeencircling ,both units, the remote ends of the units contacting only with end portions of the yoke, a coupler attached to the yoke, the units operating in alternation to resist longitudinal movements of the coupler and yoke with one unit undergoing compression and the other free to expand, such movements of the coupler and yoke being limited only by that unit which is undergoing compression, the units being under such effective compression between the yoke and abutmentthat, under normal operating conditions, each unit has an expansivity at leastas great as the greatest amplitude of the movement of the coupler and yoke against the resistance of the other unit, whereby a continuously effective cushion is provided between the coupler and vehicle structure andthe 1'5 developmentof 'free slack is prevented, and means projecting inwardly from the opposed faces of the plates attached to the walls for holding the rub# spacer plates'. 1 against: lateral ber-bearing and movement. -f

10. In a railway vehicle, such as a car orrnotive l power unit, the combination of a pair of spaced, parallel walls having aligned integral projections cooperating to form an abutment, a pair of cushioning units between the walls. one on each side of the abutment, with the adjacent ends of the units in contact with opposite f aces of the abutment, each unit comprising alternately arranged rubber-bearing and spacer plates, the rubberbearing plates carrying like masses of rubber in like arrangement, an open center yoke encircling both units, the remote ends of the units contacting only with end portions of the yoke, and acouplerV attached to the yoke, the units operating in alternation to resist longitudinal movements of the coupler and yoke with one unit undergoing compression and the other free to` expand such Amovements of the coupler and yoke being limited only by that unit which is undergoing compression, the units being under such eiective compression between the yoke and abutment that, under normal operating conditions, each unit has an expansivity at least as great as the greatestv amplitude of the movement of the coupler and yokev against the resistance of the other unit. whereby a continuously effective cushion is` provided between the coupler and vehicle structure and the development of free slack is prevented,

the plates being prevented by the walls on either side of the abutment from being laterallyl displaced relative to the yokerand abutment.

11, In a railway vehicle, such as a car or motive power unit, the combination of a .pair of spaced, parallel walls, a pair of plates mounted o nrthe opposed faces of the walls and provided with projections extending toward one another and cooperating to form an abutment, rivets securing the plates to the walls, a pair of cushioning units between the walls, one on each side of the abutment, with the adjacent ends Yof the units in contact with opposite faces of the abutments, each unit "comprising alternately arranged rubber- :Lacasse bearing and spacer plates, a-yoke encircling both units, the remote ends of the units contacting only with end portions of the yoke, a coupler at# .tached' .to the yoke,the units operating in alternation to resist longitudinal movements of the coupler and yoke with one unit undergoing compression while the other is free to expand, such movements of the coupler and yoke being limited only by that unit which is undergoing compres-I sion, the units being under such effective compression between the yoke and abutment that,

under normal operating conditions, each unit has an expansivity at least as great as the greatest amplitude of the movement of the coupler and yoke against the resistance of the other unit, and a pair of longitudinal ribs on each abutment plate on opposite sides of the projection thereon, said ribs extending 4inwardly from said plates beyond the heads of said rivets and preventing lateral displacement of the rubber-bearing and spacer plates units.

12. In a railway` vehicle, suchas a car or motive power unit, the combination of a pairof spaced, parallel walls secured to the vehicle structure and during operation of the cushioning extending longitudinally thereof, spaced abutments attached to the inner faces of said walls and extending transversely thereof, a pair of cushioning units lying in line between said walls and having their remote ends contacting only with the abutments, acoupler, a yoke attached to the coupler and encircling one cushioning unit only, the yoke having a part movable therewith which lies between the adjacent ends ofthe units and is normally in contact with both said ends,

`the cushioning units acting in, alternation Ato resist and cushion buff and Ydraft movements of the coupler and yoke,. such movements being resisted by one of the cushioning units which undergoes compression, the unit thus being compressed constituting the sole restriction upon the movements of the coupler and yoke in which such compression occurs, the cushioning units being installed between said part of the yoke and the abutments under compression such that as one cushioning unit is compressed, the other expands. HAROLD D. PAGE.

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