US1637071A

US1637071A - Draft gear

Info

Publication number: US1637071A
Application number: US61717A
Authority: US
Inventors: Edward F Carry
Original assignee: Individual
Current assignee: Individual
Priority date: 1925-10-10
Filing date: 1925-10-10
Publication date: 1927-07-26
Anticipated expiration: 1944-07-26

Description

2 Sheets-Sheet 1 INVENTOH E. F. CARRY DRAFT GEAR Filed Oct. 10, 1925 July 26, 1927.

dwamd .7: Carr 2 Sheets-Sheet 2 E. F. CARRY DRAFT GEAR Filed Oqt. 10. 1925 INVENTOR award ace/y 3. Car v fns (lav-1167' Patented July 26, 1927.

UNITED STATES EDWARD I. CARRY, OI CHICAGO, ILLINOIE.

nm'r em;

Application filed October 10, 1825. Serial R0. 81,717.

The invention relates to draft gears designed to absorb the energy exerted by the drawbars of railway cars,-and has for its principal object to dampen the shocks of recoil incident to the pull .and'thrust of the drawbar upon the s rings of .the gear through the medium of a liquid agent operating to supplement the springs in their resistance to. draft and bufling movements.

The invention further consists in certain other novel details of construction andcombinations and arrangement of parts, preferred embodiments of which are shown on the accompanying drawing, in which- Fig. 1 is a longitudinal sectional view of the gear with the several parts in their normal positions taken on line 1 -1 of Fig. 2. Fig. 2 is a horizontal plan view showing portions of the underframe in section and 20 the gear in assembled position withthe draft lugs on the center sills; I

Fig. 3 is a view similar to Fig. 1, but showing the port closing position of the piston during a bufiing operation with the front spring expanded and the rear spring in compression;

Fig. 4 is a dual view showing at the left a front end view of the gear assembled with the underframe ofthecar and at the right a vertical transverse sectional view through gear and underframe taken on line 4-4 of Fig. -1 looking in the direction indicatcd by the arrows;

Fig. 5 is a vertical section taken on line 5-5 of Fig. 3 looking in the direction indicated by the arrows showing the combined air and liquid chamber and the piston chamber below it; and I Fig-6 is a rear view :taken on line 6-6 of Fig. 1 showing the gear supported in position between the draft castings on the underframe, looking in the direction indicated by the arrows.

In the drawings, 10 represents an underframe having the usualcenter sills 11 to which are secured the customary. draft castings 12. Between and in engagement with the draft castings is the draft gear 13 of my invention, comprising a s ring and liquid casing 14 and a re'nova le cross head portion 15. The casing 14. is rovided at its rear end with a head 16 pre erably integral therewith, the-front portion of the casinsr being open to permit access to the interior thereof. The removable head portion 15 covers the opening in the casing to eonfine therein movable gear elements hereinafter to be described, and is held to the casing in any a roved fashion, preferably by stud bolts 1% threaded into the casineg above the bottom thereof and by' head bolts 18 taking the casing flange 19 and the head 15, all of said bolts being held against rotation in any a proved manner.

The gear as a whole is su ported in position by a tie late 20 spanning the distance .between the raft castings 12 and a supplemental plate 23 shaped to the contour of the underside of the gearcasing14. Each of these plates is secured to the outwardly extending flanges 21 of the draft castings 12 by means of bolts 25, arranged along the respective margins of said plates. The tie plate 20 engages the front head 15 and adjacent portion of the casing 14, while the supplemental plate 23 supports the rear end 16 of said casing, by virtue of which the whole gear is held'in operative position between front and

rear lugs

26 and 27 of the draft castings 12. To insure efiective trans- ,mission of draft and bufling stresses to the underframe and to avoid possible lost motion between the draft gear and the front and

rear lugs

26 and 27 of the draft castings v12, I provide a wed e key.28 designed to compensate for possi le variation in length of draft gear unit or distance between the

lugs

26 and 27 of the draft castings. A wedge key is positioned preferably between the front lug 26of each draft casting 12 and adjacent face 31 of cross head 15 and is held from dis lacement by a rib or ribs 32 on the incline face 30 of the key interlocking with similar ribs 33 on the correspondingly inclined contiguous face 31- of the cross head 15. These wedge keys function to establish and maintain positive draft and bufiing relation between the draft gear, unit and underframe since by the operation of gravity they automatically adjust themselves to the space between the ugs 26 of ment in one direction on the rodby shoul-f ders 42 on the rod and in the opposite direction by; retaining-nut 41 roviding abutments for the iston head. he? piston head 37 divides the cylindrical chamber 36 into front compartment- 39 and. rear compartment 40 containing respectively the flat Volute springs 43 and 44 arranged on opposite sides of the piston head and seated against the respective sides of the piston head and front and

rear ends

15 and 16 of the casing. Above chamber 36 of the casing 14 is a combined liquid and air chamber 34 separated from compartments 39 and 40 by a partition 29 having front and

rear ports

45 and 46 communicat- I ing respectively with said compartments and plu Tfiie piston rod 35 has a sli COIltttlDlIlg, if desired, needle valves 47 adjustably mounted in the upper wall 48 of the The valves are manually operable endently adjustable'to control the ow ofthe liquid from one comcasing. and inde rate of partment of the chamber 36 to the other and thru the liquid and air chamber and are provided with thickened shank portions 49 threaded into supporting bushings 50 se' cured in the upper wall 48 of the casing and reduced stem portionsregistering with operation; a

port openings

45 and 46 in partition 29'. An opening in the upperwall 48 of the easing provides ready access to the liquid and air chamber 34 for the introduction of air and liquid to the casin and is closed by 51 threaded into te o ening.

ding bearing in acking screw 53 and bushing 52 respectivey let into the front and rear portion of the cross head 15, suitable packing 69 being interposed to provide a liquid tight joint where the piston rod passes out of the casing 14. The packing screw head 54 is shaped to provide a series of spaced lugs 55 on the periphery of the head adapted to accommodate a spanner wrench (not shown) for use in tightening the packing screw 53 upon the packing 69. The packing screw is held from reverse rotation by means of a looking iece 56 having a lug 57 projecting upwar ly from the base of the piece and adapted to be lodged between a pair of the peripheral lugs 55 on, the head of the packing screw. The locking, piece 56 is removably fixed in position by means of a stud bolt or cap screw 58 threaded into the underside of the cross head 15 as-best shown in Fig. 1. The piston rod 35 is also provided with drawbar coupling59 for connection with the usual drawbar 60 by coupling pin 61 having the upper wallof'the cross head 15.

The drawba-r coupling'59 is guided in its movements within the cross-head 15 to insure against distortion in the piston rod and prevent injury to the packing screw 53 caused by side thrusts from thecou ler when positioned at an angle to line or raft. To facilitate movement between drawbar coupling 59 and top, bottom and side walls. 63, 64 and 65; it may be desirable to rovide for the lubrication of these members t rough the medium preferably of oil grooves 67 in the'top and side walls to distribute the flow of oil issuing from drain hole 68 of the oil and waste pan 66' formed in the top wall of the cross head.

With the gear mounted in position on the underframe access to the needle valves 47 and to casing plug 51 may be had thru opening 8 in the car floor 9, and the casing may be drained by removing drain plugs 7 closing openings in the bottom of chamber 36, as best shown in Fig. 1.

Assuming the parts to be in the normal osition shown in Fig. 1 of the drawing,

iquid is poured into the casing thru opening in the top wall of the casing to till compartments 39 and 40 and as much more liquid as may be required to only partially fill the liquid and air chamber 34 in order to provide for a substantial volume of air above the liquid level for a purpose to be described. y w

bailing shock will, cause the piston to move in the direction indicated by the arrows in Fig. l. The speed and extent ofthis movement will depend upon the energy applied at the drawbar and the resistance offered by the liquid and spring contained in compartment 40 and by the compression of the air in chamber 34. The piston movement will result in the displacement of the liquid in compartment 40 and cause it to be forced through port 46 at a rate of flow proportioned to the magnitude of the energy driving the piston. This flow of the liquid under pressure will meet with a resistance commensurate with the s eed of the piston and the acceleration of the ow of liquid thru said port will increase that resistance until the energy driving the piston is spent. During such movement of the piston, the liquid displaced will flow into the chamber 34 and the liquid in said chamber will be forced thru a second port 45 into the expanding front compartment 39 to further increase the resistance to the flow of the liquid and therefore to piston movement. Continued movement of the piston will bring the piston head 37 within the area of port 46-and in thejpath of the liquid passing thru it; causinga progressive reduction of the port opening and consequent. throttling of the liquid flowing thru that port, ultimately checking further movement of the iston.

It Will be noted that in the present embodiment of the invention the volume of liquid displaced in compartment l0 exceeds to beexpelledfrom compartment 40 is about equal to that contained in the space between the retaining nut 41 and the rear head 16 of the casing, and as this space is not diminished by any piston rod volume as in the case of the othercompartment, it is evident that a given movement of the piston and'a corresponding increase in the length of compartment39 will cause a greater amount of liquid to be forced thru port 46 into chamber 34 than would be drawn from said chamber into compartment 39. the excess accumulating in the chamber 34; to build up a flexible resistance thru the increasing compression of the air confined in said chamber. Continued movement of the piston will cause an additional length of piston rod volume to enter compartment 39 thus further reducing the capacity of that compartment to accommodate all of the liquid expelled from com partment 40, causing further accumulation of excess liquid in the air and liquid chamber 34 and a proportionate increasein the comression of the air volume in said chamber.

his operation maybe continued until the piston head 37 completely covers the port 46 of compartment 40 when the entrapped liquid in said compartment will check further movement of the piston. Untilthe piston completely closes the port 46 and communication between chamber 34 and com partment 40 is interrupted, the'compressed air volume in the liquid and air chamber will operate to cushion the piston to prevent the too sudden checkingof its movement as it approaches the port closing position. 7

With the piston in the port closing position indicated. in Fig. 3, and with spring 44: compressed under the stress of piston movement, the expansive force-0f the spring will start the piston back to its normal balanced position but since the piston can moveas fast only as the liquid drawn into expanded compartment 39 and expelled from compartment 40 can flow thru the respective ports, the spring will release its energy Without recoil and the gear parts will be restored to their original position without shock or other disturbing vibrations.

It will be noted that the gear functions to afford a high resistance to butting operations and lesser opposition to draft strains, thereby greatly increasing the starting torque of the train power unit by reducing the force required to take up the slack between the cars of the train, but in either direction of movement the gear parts will becontrolled by the rate of flow of the liquid from one compartment to the other through the air and liquid chamber 34, whether induced by forces appliedat the drawbar or the released energy of the comn'essed spring elements within the gear. and the rate offlowmay be regulated and established by the manipulation and setting of thence le valves in the air and liquid chamber, their proximity to the liquid ports in the path of, they liquid stream regulating the speed of the liquid thrii said ports or, if Vvalves'ar'e' not desired,

such rate of flow may be regulated by the size, shape or number .of the port openings communicating partments. I

In the construction described the impact of balling operation will be resisted by the spring, liquid and compressed 'air elements found in the gear, but under draft movements only the spring and liquid elements will funct on to absorb the'st resses of operation.- This condition is brought about by the difference in the capacities of the comp'artments at opposite sides of the piston head due to the presence in one of them (compartment. 39) of the piston rod 35 the bulk of which displaces'an appreciable quantity of the liquid contained in said. compartment, and since, a given movement of the piston in a direction opposite to that indicated by arrows in F ig. 1' will caus'e a smaller volume of liquid to be forced out of the contracting compartment 39 into air and liquid chamber '34 than the quantityfdrawn from said chamber into the expanding-compartment 1-0 the level of the liquid in chamber 34 will fall and the air trapped in said chamber with the "respective comwill expandand berendered inefl'ective to restrain movement of the piston in that direction, leaving, the burden of the pulling strain to be resisted, by the springand liquid elements alone-T From the foregoing disclosure it will be evident that provision is made for the proper absorption of the forces created bythe swift initial movements of the piston in both draft andbuifing operations with means for progressively increasing the resistance to piston movement as the piston'approaches a port closing position. From this'itis obvious that to cushion the or draft the

liquid ports

45 and 46 should be of such size or number as to permit the instantaneous transfer of the liquid in either compartment 39 or 40 to the air and liquid chamber 34 and to the other compartment. It will also be evident that due to the use of asingle combined air and liquid chamber common to both compartments 39 and 40. it is'possible to equalize the resistance to both draft and butting 'movements of the piston and compensate for the piston rod volume in compartment 39 by increasing the capacity of said compartment or reducing thatoof the other compartment, as desired.

What I claim is 2- 7 1. A draft gear comprising a housing containing a piston chamber, a piston reciprocable in said chamber, sprin s on opposite sides of said piston, an air an liquid ,chamber, ports connecting both chambers and in communciation with opposite sides of said piston, and manually operable valve means within said liquid and air chamber'adapted to control one of said ports. 2. A draft gear comprising a taining a piston chamber,

housing cona piston reciprocable in said chamber, springs on opposite sides of said piston, an airand'liquid chamber, ports connecting both chambers and in communication with opposite sides of said piston, and manually and severally operable valves within said iquid and air chamber adapted to control said ports.

3. A draft gear com rising a housing containing .a piston cham er, a piston reciprocable in .said chamber and dividing the chamber into compartments, springs in said compartments on opposite sides of said piston, an air and liquid chamber, ports'connecting both chambers and in communication with said compartments, and port controlling .valves supported within said air and liquid'chamber adapted for manipulation outside said chamber.

4. A draft gear comprising a housing containing' a piston chamber, a piston reciprocable in said chamber, a liquid and air chamber, ports connectin both chambers and in communication with opposite sides of said piston, and manually operable needle valves adapted to control said ports.

5. A draft gear of the class described comprising a iston chamber, a piston reciprocable in said chamber, a combined liquid and 'air chamber above and in communication with the opposite sidesof the piston in the piston chamber, and airchamber adapted to control the flow of liquid in either direction of piston movement. 7

. 6.. A draft gear comprising a piston chamber, a piston reciprocable in said chamber and dividing the chamber into compartments, springs in said compartments on opchamber in communication wit posite sides ofsaid piston operable to normally hold the piston in its balanced position, and a single combined liqgiid and air said compartments, the air volume in said last mentioned chamber being in excess of that required to provide for piston displacement.

7. In a draft gear the combination comprising a pistonchamber and a piston movable thereln and dividing said chamber into compartments a single chamber vcontaining liquid and an air volume and communicating air volume ineffective and ,valves in said liquid with said compartments opposite sides of said piston, the air volume in said last mentioned chamber being in excess of that required to provide for piston displacement, said air volume being adapted for compression'to oppose movement of the piston in one directlon and rendered ineffective to restrain movement thereof in the opposite direction. V Y

8. A draft mechanism comprising a i ton chamber, a'piston dividing the chain r into compartments, a single chamber containing liquid and an air volume and'communicating with said compartments thru ports arranged on opposite sides of said piston, the air volumein said last mentioned chamber being in excess of that required to provide for piston displacement, and means for progressivel increasing compression of the air volume y piston movement in one direction and rendering said air volume ineffective to oppose movement of said piston in the opposite direction.

through ports on 9. In a draft gearcomprising a piston chamber, a piston reciprocable in said chamber and divlding the chamber into compartments, a single chamber containing liquid and an air volume and having port connection with said compartments, the air volume in said last mentioned chamber being in excess of that required to provide for'piston displacement, and means adapted to compress the air in said chamber during piston movement in one direction and render said to oppose movement of said piston in the opposite direction.

10. A draft gear comprising a piston chamber, a iston reciprocable therein and dividing sai chamber into compartments, a single chamber containing ,liquid and an air volume and having port connection with said compartments, the air volume in said last mentioned chamber being in excess of that required to provide for piston displacement, and means adapted to increase the flow of liquid to said chamber to compress the air in said chamber during piston movement in one direction and cause the recession of the liquid in said chamber to render said air inefiective to oppose movement of said piston in the opposite direction.

11. A draft gear comprising a chambered casing and a front crosshead portion reciprocable insaid casing andprovided with a drawbar coupling slidably mounted in said crosshead, shock-absorbing elements within said casing, and wedge key elements between said crosshead and the draft castings of the underframe-whereby draftand buifing stresses applied at the drawbar coupling are transmitted thru the gear assembly 'to said underframe.

13. A draft gear comprising a chambered casing and a front crosshead portion removably secured to said casing, a piston reciprocable in said casing and provided with a drawbar coupling slidably mounted in said crosshead, and coupling lubricating means in said crosshead comprising an oil and waste pan formed on said crosshead, oil grooves in the top and side walls of the crosshead, and an oil drain communicating with said grooves and pan.

14. The combination with'the underframe of a railway car, of a draft gear assembly, and wedge key elements between said under.- frame and draft gear assembly whereby draft and bufling stresses are transmitted thru the gear assembly to said underframe, said wedge key and draft gear assembly having interlocking engagement one wit the other to prevent displacement of said keys.

15. A draft gear comprising a piston chamber, a piston reciprocable in said chamber and dividing the chamber into compartments, and a combined liquid and air chamber common to said'compartments, the air volume insaid last mentioned chamber being in excess of that required to provide for piston displacement.

16. In a draft gear the combination comprisinga piston chamber and a piston movable therein and dividing said chamber into compartments, of a combined liquid and air chamber communicating withand overlying said compartments, the air volume in said last mentioned chamber being in excess of that required to provide for piston displacement.

17. In a draft gear the combination comprising a piston chamber and a piston movable therein and dividing said chamber into compartments, a combined air and liquid chamber in communication with and overlying said compartments, the air volume in saidlast mentioned chamber being in excess of that required to provide for piston displacement, and a liquid in said chamber and compartments, the liquid in said chamber constituting aliquid head common to the liquid in said compartments.

18. A draft gear of the class described comprising a piston chamber, a piston reciprocable in said chamber, a combined liquid and air chamber above and in communication with the opposite sides of the piston in the piston c amber, and valves operable valves adapted adapted to control the flow of liquid in either direction of piston movement.

19. A draft gear comprising a housing containing a piston chamber, a piston reciprocable in said chamber, a liquid and air chamber, ports connecting both chambers and in communication with opposite sides of said piston, and valves adapted to control said ports.

20. A draft gear comprising 'a housing containing a piston chamber, a piston reciprocable in said chamber and dividing the chamber into compartments, springs in said compartments on opposite sides of said pis ton, an air and liquid chamber, ports connecting both chambers and in communica tion with said compartments, and port controllin valves. l

21. draft gear comprising a housing containing a piston chamber, a piston reciprocable in said chamber, springs on opposite sides of said piston, an air and li uid chamber, ports connecting both chain rs and in communication with opposite sides of said piston, and manually and severally to control said ports.

22. A draft gear comprising a housingcontaining a piston chamber, a piston reciprocable in said chamber, springs on opposite sides of said piston, an air and liquid chamber, ports connecting both chambers and in communication with opposite sides of said piston, and manually operable valve means adapted to control one of said ports. 23. A draft gear comprising a housing containing a piston chamber, a piston reciprocable in said chamber, springs on op posite sides of said piston, an air andliquid chamber, ports, connecting both chambers, and in communication with opposite sides of said piston, and valve means controllin one of said ports,

24. g .draft gear comprising a housing containing a piston chamber, a piston reciprocable in said chamber, springs on opposite sides of said piston, an air and liquid chamber, ports connecting both chambers and in communication with opposite sides of said piston, and valves presenting deflecting surfaces to oil entering the air and liquid chamber through the ports.

25. A draft gear comprising a housing. containing a piston chamber,a piston reciprocable in said chamber, springs on opposite sides of said piston, an air and liquid chamber, ports connecting both chambers and in'communication with opposite sides of said piston, and means ad acent said ports for deflecting entering oil currents. 26. A draft gear comprising a housing containing an air and liquid chamber, ,a piston chamber, a piston reciprocable in said chamber, ports connecting both chambers and in communication with opposite nectmg 10 sides of 'said piston, and needle valve means adapted to' control said ports. 5 27. A draft gear comprising a housing containing apiston chamber, a iston reciprocable in said chamber and ividing the chamber into compartments, springs in said compartments on opposite sides of said piston, an air and liquid chamber, ports conboth chambers and in communication with said compartments, and port controlling valve means mounted for manipulation outside of said chamber.

28. The combination with the underframe' of a railway car, of a draft gear assembly, and wedge key elements between said underframe and draft gear assembly, said wedge key and draft gear assembly having interlocking engagement one with the other to prevent displacement of said draft gear assembly.

29; The combination with the underframe and draft castings of a railway car, of a draft gear assembly including a front crosshead portion, and Wedge tween said cross head and the draft castings of the underframe, said Wedge key and key elements befront crosshead portions having complemental ribs interlocking one with the other to connect said draft gear assembly and underframe.

In witness whereof I have hereto set my hand this 6th day of October, 1925.

EDWARD F. CARRY. i