US700404A - Door-operating mechanism. - Google Patents

Description

Patented May 20, |902. W. A. BRADEN & J. B. SMALLEY.

000B OPERATING MEGHANISM.

(Application led Nov. 6, 1899.)

4 Sheets-Sheet I.

Patented May 20, |902.

W. A. BRADEN &. J. B. SMALLEY.

DOOR OPERATING MECHANISM.

N0. 700,404.4 Patented May 20, |902. W. A. BHADEN &. J. B. SMALLEY.

DOOR OPERATING MEGHANISM.

(Applicatiop filed Nov. 6, 1899.) (No Model.) 4 Sheets-Sheet 3.

No. 700,404. I

Patented May 20, |902. W. A. BRADEN & J. B. SMALLEY. DOOR OPERATING MECHANISM.

(Application led Nov. 6, 1899.)

UNiTn- STATES ATENT OFFICE.

WILLIAM A. vBRADEN JAMES B. SMALLEY, OF CHICAGO, ILLINOIS, AS-

SIGNORS TO THE ELEVATOR SUPPLY d', REPAIR COMPANY, OF CHICAGO,

ILLINOIS, A CORPORATION.

D'ooR-oPERATaNc' MECHANSM.

SPECIFICATION forming part of Letters Patent No. 700,404, dated May 20, 1902.

I Application ledNovemher 6, 1899. Serial No. 735,888. (No model.)

ro provide improved door-operating mechanism more, particularly designed for the opening and closing of the doors of elevator-hatch- Ways. l v f The invention relates more particularlyl to :'5 that class of door-operating mechanism in which compressed air or other fluid under pressure is employed as the motive power.'` The invention consists in various novel fea- .tures of improvement hereinafter described,

2o illustrated iuthe accompanying drawings,y

and particularly pointed out in the claims at the en d of this specification.

"Figure 1 is a view in .central vertical ,sec`

.. tion througha door-operating mechanism em- 2 5 bodying ournvention, parts being shown in elevation. Fig. 2 is a View in end elevation looking from right to left of Fig. 1.- Fig. 31s

a view in end elevation looking from left to right of Fig. 1. Fig. 4 is a view in vertical 3o cross-section through the upper part of the right-hand block oricasing, the section being taken ou line 4 4 of Fig. 1. Fig'. 4 is a det-ail view in cross-section of the valve shown in Fig. 6. Fig. 4" isa plan view of the trigger ,and connected parts. V

. fractional view,in vertical section,tl1rough the .right-hand end ofthe mechanism, thelsection being taken upon line 5 5 of Fig. 4. Fig. 6

is a view similar to Fig. 5, but is taken upon 4o line 66 of Fig. 2. Fig. V'7 is a detailplan view of the valve-seat. Fig. 8 is a view in central Vertical section through the left-hand end of the apparatus shown in Fig. 1. Fig.9 is a view in vertical cross-section on line 9 9 of Fig. 8. Fig. 10 is a View in vertical section on line 1010 of Fig. 9. Fig. 11 is a view in vertical section on line 11 11 of Fig. 9. Fig.

12 isadiagrammatic view illustrating one way iu which our improved door-operating mech- Fig. 5 is an enlarged,

' the cylinder E is located the .piston G, that is anism may be applied to elevator-hatchway doors. y l

Our improved door-operating mechanism-is shown as mounted upon a supporting-bar A, which bar will be fixed at some convenientpoint above or adjacent the top of the door; of the elevator-hatchway.

In Fig. 12,4A indicates the elevator-well, A2 the elevator-car, and B the sliding elevator-hatchway door.

The door is operated.' through the medium of a lever B2, pivoted at its upper end to the hatchway-wall and having a slotted lower end lengaging a pin B'8 upon the door B'. 4A'bar B (see Fig. l) is pivotally connected to the lever B2 near its upper endand is pvotally or casings C and D, these blocks or casings being shown as heldin position upon thebar A by the screws 2 and 3. To the lower end of the, blockl or casin g C is removably and exteriorly secured in any suitable manner--for example, by screw-bolts C2, (see Fig. 5,)-the valve seat or base C'. The upper part of the Vblock C is formed with a screw-threaded offset c, to which is connected one of the threaded ends of the cylinder E.l In like manner the block or casing D is preferably formed 85 with a threaded odset d, to Whichis connected the corresponding threaded end of the cylinder F. The cylinders E and Fareppositely arranged, as shown in VFig.1, and in xed to the hollow piston-rod 4. The piston G is furnished with a cup-leather g, heldin place by the usual washer g'. In like manner the cylinder F carries a piston G', having a cup-leather gf", held in place by the disk or washer g3, the piston G being attached to the f hollow piston-rod 5. The inner ends of bot-h the piston-rods 4 and 5 are shownv as con- 6s connected at its opposite end, as at b', tothe nected to a head-block 6, the yoke-shaped arm 7 of which spans the transverse tubular rodH.` The screw-threaded ends of the rods H have caps '.8 and 9 attached thereto, the sides f these caps having screw-threaded holes therein to receive the screws 10 and '11, that pass through the laterallyprojecting flanges c2 and d2, formed, respectively, at the upper ends of the blocks or casings C and D;

In the block or casing C is formed an admission-port 15 and a discharge-port 16(see Fig. 2,) these ports being connected with suitable air (or like fluid) admission or discharge pipes., (Not shown.) The admission-port 15 is connected by a channel 15 with a valvechamber 17, within which chamber is located the slide-valve K`,'the under surface of which is formed with the usual exhaust-cavity k. In the removable valve seat orV plate C' (see Figs. 5 to 7) is formed a central exhaust-chan,

nel 18, that connects with the exhaust-port- 16, opening outwardly at the end of the block or casing C. Through the valve-seat C' is also formed a channel 20, that extends downward, (see Fig. 6,) thence diagonally across the base of the seat, (see Fig. 7,) and thence upward (see Figs. 4 and 6)'throughthe block or casing C to a point opposite the'open end of the tubular rod I-I, and by this channel 2 0 air or like Huid under ,pressure will be admitted to and discharged from the cylinder F in manner tobe presently explained. -In the valve-seat C is also formed a channel 22, that leads downwardly from the base of the valve-seat, (see Fig. 6,) thence outwardly, (see Fig. 7,) and thence upwardly (see Fig. 5) to a chamber 2 3, within which is placed a ballv'alve 24, that seats over the top of the chan'- nel 22.- By having the valve-seat C movabl y 4o secured to the exterior of the casing C ready access is afforded to these ports and passages. From. the chamber 23 a channel 25 leads to the cylinder E. The top of the chamber 23 is dshown as closed by a screw-threaded plug 26, this construction serving to permit thev chan- Ilel 22 to be readily drilled. A throttling r snifting needlevalve M intersects the channel 22 and obstructs more or less a small transverse channel 28,lthat Vleads from the cylinder E to the channel 22. (See Fig. 5.)

The threaded portion vof the needle-valve Mv passes through an adjustable Astuffing-boni: m., and by the adjustment of the needle-valve M the discharge of air from the cylinder E to the channel 28 can be accurately regulated. The channel 22 is connected by a cross-channel 29 (see Fig. 4) with an annular chamber 29a, that encircles the chambered plug P, thatpasses through the block or casing C (see Fig. 6) and into the cylinder E, the outer end of the plug P being preferably of polygonal shape to permit it to be conveniently'engaged by a wrench. The interior of the plug'P is connected by holesI p with the annular chamber 29, and the inner end of the plug P is open. Theinner end of the plugis itted with packing-rings p and washer p2 to retain .tion shown.

said rings in place upon the plug, and through the end of the plug is vpassed a wire p3 to prevent the accidental slipping of the rings and washers from the end of the plug in case `they should become loose.

In the block or casing D is formed the ver 'tical channel 30, (see Figs. 8 and 11,) that connects the tubular rod H with the annular lspace- 31, that extends around the screwthreaded hollow plug P', thatpasses through the casing D-and through the end of the cylinder F. From the annular space or channel 31 leads a channel 32, (see Fig. 11,) from which a channel 33 (see Fig. 10) leads into v the cylinder F, and the channel 32 is conndcted by a port 34 with a' chamber 35, in which is located a ball-.valve 36, that seats against the top of the port 34. The upper end of the chamber 35 is closed by a threaded plug 37, and a similar plug 38 closes the outer end of the channel l connected by a channel l39 with the cylinder F. The hollow plug P is`provided with ports 40, that connect the interior of the plug with the annular chamber 3l, and the inner end of the plug P is open, being merely intersected' by a wire 41, that serves to prevent the packing-rings 42 and washers43 slipping off the end of the plug in case they should become loose. A port 44 is shown adjacent the inner end of the plug P', but this is not The chamber 35 is' essential where the end of the plug is open,

asfshown. The outer end of the plug Piis preferably formed with a polygonal portion adapted to receive a wrenchby which the plug cau'be conveniently turned. By refer# ence to Fig. l0 it will be seen that a needlevalve M2 is arranged opposite the outer end of the exhaust-channel 33, the adjustment IOC of this valve M2 being effected byits threaded j portion that passes through a corresponding threaded stuffing-box m2.

From the construction of parts as thus far definedit will be seen that air under pressure' being supplied to the admission-port 15 will passy by the port 15 to the valve-chamber 17. Now when the slide-.valve K is in the position seen in Fig. 6 and the pistons'G IIO and G' are in the position shown in the sevf eral views of the drawings air will pass from the valve-chamber 17 by channel 20 into the tubular rod or pipe H, thence across the chan- .nel 30, (see Fig. 11,) thence through annular -chamber 3l, channel 32, port 34, chamber 35,

(lifting valve 36,) channel 39 to cylinder F, thereby holding the piston G' in the posi- At sueh time all air will have been exhausted from the cylinder E, and the door of the elevator-hatchway may be assumed to be in closed position. desired to open the door, the slide-valve K will be shifted (by the mechanismto be herc inafter described) from the position shown in Fig. 6 until this valve K spans the ports 18 and 20, leaving the port 22 exposed. Air will then pass from valve-chamber 17 through channel 22, lifting ball-valve 24, (shown in lf now it is Fig. 5,) and through channel .into the cylinder E. The pistons G G will then be moved in the direction of the arrow, Fig. 1, and at such time the exhaust from the cylinder F will occur as follows, viz: As the piston G begins .to move the exhaust from cylinder F will occur through the hollow plug P', the air passing thence .by ports 4.0,-channel 30, tubular rod H, and channel 20 into the exhaust- ,cavity 7:. ofthe slide-valve K, (which at such time will span the channels 18 and 20,) thence by channel 18 to exhaust-port 16. So long as the exhaust of air throughthe cylinder F occurs through the plug P', such exhaust will be very rapid; but as the piston G' moves outward the' plug P' will pass into the hollow pistonste'm and the vend of theplug P will thereby be closed, shutting 'olf the exhaust from cylinder F through the' plug P'. haust from cylinder F'will still continue, however, through channel 33, (seeFigs. 10 and 11,) channel 32, annular chamber 3 1, chanvnel, `30`0fv tubular rod H, channel 20, exhaustcavity kl of valve K, and exhaust-channel 18.

Aty such time, however-that is to say, during the final outward movement of the piston,G-the ball-valve 36 willclose the port 34 (seeFig. 10) and will prevent the exhaust of air through the channel 39. Inasmuch as the channel 33 is controlled by the needlevalve M2 it is manifest that the exhaust of air from the cylinder F can be regulated with lchamber 1'Zby channel 20, tubular crss--rodv exactnesswso as to prevent all slammingof the door. If it be assumed that the'door has been opened by the movement of the pistonsI G and G from the position shown in Fig. 1

to the opposite ends f their respective cylinders, it being also assumed that the slidevalvey K has been shifted from, the position shown in Fig. 6, so as to span the channels 1S and 20, and it be now desired to restore the pistons G G to the position seen in Fig. 1 in order to close the door, the slide-valveK will.

be returned (by mechanism to be vpresently described) to the position shown by fulllines in Fig. 6, when air will pass from valve- I. II, channel 30, annular chamber 3.1, (seeFigs.

i l by the tubular piston-stem 4 the exhaust through the plug P willbe cut off and the es cape of air from cylinder E will.1.then occur through channel 2S, around the erd of needlevalve M, through channel 22, exhaust-cavity k of slide-valve K, and exhaust-channel 18 to exhaust-portv 16. The throttling-valve M will enable the exhaust of air to be accurately regulated, so that a quickrv and easy moveoperate in the reverse direction.

The excar A2.

ment of the piston without slamming shall occur. Y

Blocks or casings C and D are provided, as shown, at their lower ends with'ilat bearing-faces on bothsides, Aso that either face may be placed against the flat supporting-bar A in securing the blocks or casings to-said bar. It is possible, therefore, to remove the entire structure from the supporting-bar A by removing the securing- bolts 2 and 3, which hold the blocks of casings C and D in place. The entire structure may then be shifted end for end and secured upon the barA, so as to The snpporting-lugs a6 may be secured 'upon the bar Ain any desired position. Inthis way the door to be shifted may be moved either to the right or to the left. The same object may be obtained by interchanging the removblevalveseat C', so thatthe com-pressed air will flow through the ports in the reverse direction.

The preferred mechanism for shifting the slide-valve K is that shown in Figs. -1 and 6 of the drawings. Upon the supporting-bar A are mounted the brackets a4and a5, through whichpasses the valve-rod R, the rdd being heldin position npon the brackets or bearings c* and a5, preferably by the `retaining plates or caps a6, secured to the brackets.

Upon the valve-rod R are mounted the ad- .justable Stops r 1", that determine the throw of the rod R.l A trigger S will alsobe mounted upon .the valve-rod R, the rod R passing through the trigger, which is held on the rod by the set-screw s., In order to more securely IOO hold the trigger in position, v-it is preferably formed withan arms', extending inwardly therefrom, this arm being guided' by bearing a5, throughwhich the rod R passes, the bearing -S2 being xed to the rod byv a set-screw s2; The trigger S, as-seen in Figs.'2 and 3,

projects outwardly some distance fremthe supporting-plate A,and.this trigger is adapted to be struck by a suitable shifter S, (see Fig.A

12,) which is preferably vertically disposed and provided with cam-shaped ends and may be mounted upon a suitable cross-head S4, arranged to slide in a groove in the -top of the The cross-head is controlled by the car-operator through the medium of a p .ull S5 and an intermediate spring-held bell-crank IIO' S6., It will be understood that the shifter S3 and its operating means for tripping the trigger S as herein set forth are.merely illustrative, and any one of a number of various devices may be employed for the same purpose.

Byreference to'Figs. 1, and 6 of' the drawiugsit will be seen that the valve-rod R passes through to the end of a cylinder T and carries a cup-leather or piston t, that is held in place by a threadednut or Washer "against j the outer end of the circular portion R'of the'valve-rod. This -circular portion R of the valve-rod is formed with a notch or cut-y placement.

locked to the valve K. A leak port or channel 2 connects the interior of the cylinder `T with the valve-chamber 17, so that the pressure of air is at all times within the cylinder T and upon the cup-leather or piston t, tending to force it outward. Hence it will be seen that when the slide-valveK is in position shown in Fig. 6, at which time the elevatorhatchway door will be closed, the pressure of air inthe cylinder T and upon the cup-leather or piston t will hold the valve K against'dis- So, also, after the trigger S has been shifted by the contact device upon ythe elevator-car the air within the cylinder 'I will be temporarilyy forced back into valvechamber 17 but as soon as the contact device in the elevator is disengaged from the trigger S the pressure of air within the cylinder T will -force the piston t outward, thereby automatically shifting the slide-valve K and causing the passage of compressed air to the cylinder E in order to close the door.

Y ment of a supplemental cylinder .'I and a piston for shifting the slide-.valve K avoids the use of springs for this purpose and the use v of a cup-leather t renders the provision of-a Y stuffing-box for the valve-rod R unnecessary.

.from right to left, or vice versa.

This invention will be found of especial advantage, because of the simplicity and effectiveness of the means whereby the slamming of the door when shifted from open to closed position, and ,vice versa, is prevented. 1A further advantage of the inven'-v tion is that the partsare readily interchangeable, so as to facilitate closing a door either By providing means for automatically returning the trigger to the position seen in Fig. 6, which is thel normal position of the trigger when the door isclosed, it will be seen that all springs for this purpose are avoided and the necessity of nsi'nga 'stuffing-box for the cylinder @T does not exist. So, also, the arrangement of the cylinders E and F a's shown not only materially simplifies the'structure, butby employing cup-leatherslfoithe pistons G G i the necessity of using studing-boxes for the piston-rods is avoided. In many other respects also ourinvention will be found to possess advantages over other door-operatin g devices.

It is manifest that without departing from the spirit of the invention the apparatus above described may be modified by the skilled mechanic, and it will be understood also that whilethe linvention is more particularly designed as a means for opening and closing doors of elevator-hatchways -it may be used for other purposes. 4Thus, for eX- ample, while in the preferred form of the invention the lcylinders E and F are formed entirely separate it is manifest that a single The employf 2. In apparatus ofthe character described,

the combination of two oppositely-arranged, open-ended cylinders, pistons within said cylinders rigidly connected together by a common piston-rod, an operating connection for a dooror device to be shifted, secured at one end to said piston-rod intermediate said pistons, an admission and exhaust channel for each of said cylinders and a valve common to both cylinders for controlling the alternate admission and exhaust of fiuid under pressure through said channels. i

3. In apparatus of the character described, the combination with a suitable part, such for example as a cross-head, adapted 'to be connected with the door or device to-be shifted, of oppositely-arranged pistons connected to said part or cross-head, cylinders wherein said pistons are contained, suitable casings at the ends of said cylinders provided with 'admission and exhaust channels and a hollow rod extendingv between said casings, substantially as described.

4. In apparatus of the character described, thecombination with a'suitable part, such for example as a cross-head, adapted to be connected with the door or device to be shifted, of pistons connected to said part or crosshead, cylinders wherein said pistons are contained, suitable channels for delivering fluid ICO' IIO

under pressure to said cylinders, `escape-chf-inand adjustable throttling-valves for regulating` the ow through said exhaust-channels.

5. In apparatus of the character described, the combination of two oppositely-arranged, open-ended cylinders, pistons within said cylinders rigidly connected together by a common piston-rod, an operating connection for a door or device t'obe shifted, secured at one end to said piston-rod intermediate said pisnels for exhausting duid from said cylinders tons, the outer ends of said cylinders being provided with ports for the admission and exhaust of fluid under pressure, a valve-chamber having inlet and exhaust passages, chan- -nels leading from said valve-chamber to the' ports of each of lsaid cylinders, and a valve in said chamber for controlling the ow of fluid under pressure through the said channels. Y

G. In apparatus of the character described, the combination with a suitable part, such for example as a crossh'ead, adapted to be connected with the door `or device to be shifted,

vss

of pistons connected to said partor cross-head cylinders wherein said pistons are contained,

admission and exhaust channels for delivering duid under pressure to said cylinders, hollow piston-rods whereby said pistons are carried, hollowr plugs extending into the cylf inders and adapted to enter the piston-rods and suitable connections between said hollow plugs and the exhaust-chan nels, substantially as described;

. 7. In apparatus of 'thecharacter described, the combination with a suitable part, such for example as a cross-head', adapted to be connectedrwith the door or device to be shifted,

of oppositely-arranged open-ended cylinders, pistons, within said cylinders having pistonrods connected with said part'or cross-head,- a casing at theouter end of each of said cyliuders provided with admission and exhaust channels, a tubular rod'connecting said casings, a valve for controlling the flow of fluid under pressure to and froin said cylinders and a triggerfor operating said val ve, substani tially as described.

8. In apparatus of the characterdescribed, the combination with a suitablepart, such for example as across-head, adapted-to be connected with the door or deviceto be shifted, of.pistoiis on either side of and connected to said part or lcross-head, single-acting cylinders wherein said pistons are contained, admission and exhaust channels for delivering fluid under pressure to and from each of said cylinders, a valve-chamber provided with a seat to which the admission and exhaust channels lead, avalve com-inonto both of'said `cylinders for controlling the flow of fluid under pressure through said channels, and a valve-rod and means for shifting said rod to operate said valve, substantially as described.

0. In apparatus of the character described, the combination witha suitable part, such for example as a cross-head, adapted to be connected with the door or device to be shifted, of pistons connectedto said part or cross-head cylinders wherein said pistons are contained,

admission and exhaust channels for 'delivering duid under pressure toand from said cylinders, a valve-chamber provided with a seat to which theadmission and exhaust-channels lead, a valve for controlling the flow of duid under pressure through said channels,a valve- ,v rod connected to said valve, a cylinderthrougli which said valve-`rod passes, said cylinder'being connected by a suitable channel with the fluid-pressure supply and a piston within said cylinder connected to the valve-rod, substany tially as described.

10. In apparatus of the character described, the combination with a suitable part, such for example as a cross-head, adapted to Abe connected with the door or device to be shifted,

ofpistons on either side of and connected to said part or cross-head, single-acting cylinders whereinsald pistons are contained, ad-

mission and exhaust channelsfor delivering fluid under pressure to and .from said cylin- 'for controlling the flow of fluid under pressure through said channels, a valve-rod connected to said valve, a triggerattached to said valve rod, suitable bearings for said valve-rod and suitable stops upon said rod, substantially as described.

11. In apparatus of the character described, the combination with `a suitable part, such for example as a cross-head, adapted to he connected with the door or device to be shifted, of pistons connected to said part or cross-head, cylinders wherein sa-id pistons are contained, a casing at the outer end of each of said cylinders provided with admission and exhaust channels for delivering fluid under pressure to and from said cylinders, one of said casings being provided with a valve-chamber having a valve therein and 'a removable valve-seat attached to said casing, substantially as described. l I

12. In apparatus ofthe characterdescribed, the combination with a suitable part, such for T example as :across-head, adapted to be connected with the door or device to be shifted, of pistons connected to said part or cross-head, hollow rods whereby said pistons are carried,

cylinders wherein said pistons are contained,

casings at the outer ends of vsaid cylinders provided with admission and exhaust channels and hollow plugs extending through said I casings and adapted to enter said hollow piston-rods, said hollowplugs beingprovided 4 with ports communicating with the exhaustchannels, ysubstantially as described.

13. In apparatus of the character described,

the combination with a cylinder and a piston `therein adapted to operate a door or other device to be shifted, of channels for the admission land exhaust of fluid under pressure to and from said cylinder, a valve-chamber, a valve therein for controlling the flow through l'said channels, and a valve-seat removably secured to said valve-chamber, said valve- 'seat having passages therein connecting said' Valve-chamber to said channels'.-

1l.. In a door-operating device, the combination of a cylinder, a piston therein for ac, tuating a door or other device tobe shifted, two ports opening into one'end of said cylinder, means for closing onev of said 'ports during the exhaust-stroke of the piston and an adjustable throttling-valve for the other of said ports, Wliereby the movement of the shifted part will be cushioned.

15. In aldoor-operating device, the combination of a cylinder, apiston therein for actuating a door or other device to be shifted, two ports opening into one end of said cylin- TIO der, outwardly-closing check-valve for one of for actuating a door or other device to be shifted, of two ports opening into said cylinder through which the motor fluid escapes during the exhaust-stroke of said piston, one of said ports arranged to be closed before the piston has completed its exhaust stroke,

whereby the movement of the shifted part will be cushioned.

17. In a door-operating device, the combination with the cylinder and apiston therein for actuating a door or other device to be shifted, of two ports opening into said cylinder through which the motor Huid escapes during the exhaust-stroke of said piston, one of 'said ports opening into said cylinder intermediate its ends and arranged to be closed by the piston before it has completed its exhaust-stroke, the other of said ports opening into the end of the cylinder and an adjustable throttlin,f.,'valve` for controlling the opening of said port, whereby the movement of the shifted part will be cushioned.

1S. In a door-operating devicethe combination with the cylinder and a piston therein for actuating a door or other device to be shifted, of two ports opening into said cylinder through which the motor fluid escapes during the exhaust-stroke of said piston, one of said ports being mounted on the end of a tubular extension Within said cylinder, a hollow piston-rod for said piston into which said extension enters, the other of said ports opening into the vend of said cylinder and pro-v vided with an adjustable throttlingvalve, wherebythe movement'of the shifted part will be cushioned.

19. In a shifting device for doors and the like, the combination with a cylinder and a piston therefor, o f threeports openinginto one end of said cylinder, one of said ports provided with an outwardly-closing check-valve for closing the latter during the exhauststroke of the piston, means for closing another of said ports before the piston has completed its exhaust-stroke, whereby the escape of the motor Huid during the last part of the exhauststroke will only take place through the remaining port.

20. In a shiftingvdevicefor doors ,and the like, the combination withduplicate cylinders and pistons therefor, of three ports opening into the outer ends of each of said cylinders, one of the ports of each of said cylinders being provided with an outwardly-closing check-valve for closing the latter during the exhanst-stroke of the piston therein, another of said ports in each of said cylinders being located intermediate to epds thereof and arranged to be closed by the piston therein before it has completed its exhaust-stroke, and the remaining port in each cylinderbe'ing provided with a'n adjustable throttling-valve, whereby the movement of the part to be shifted in each direction will be cushioned.

21. In a shifting device for doors and the like, the combination with duplicate, singleacting cylinders and pistons therein rigidly connected together by a common hollow piston-rod, of three ports opening into the outer ends of each of said cylinders, oneof the ports in each cylinder being provided with'an outwardly-closing check-valve, another of said ports being mounted upon the inner end of tubular extensions within said cylinders, said extensions being adapted to enter said hollow piston-rod, and the remaining ports in each cylinder being provided with an adjustable throttling-valve, whereby the movement of the part to be shifted in both directions will be cushioned. f

22. In a shifting device for doors and the like, the' combination with a cylinder and a piston therein, a valve-chamber, a valve therein controlling the admission and exhaust of fluid under pressure to and from said cylinder, a valve-rod therefor, a cham'bersurrounding said rod,^and a piston within said chamber secured to said rod, there being an openj ing leading from said valve-chamber to said piston-chamber, whereby the valve is automatically operated in one direction by the fluid-pressure.' i j WILLIAM A. BRAD'EN. JAMES B. SMALLEY.

Witnesses:

GEO. P. FISHER, Jr., ALBERTA ADAMICK.

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