US546979A - Railway-gate - Google Patents

Description

(N0 Model.) 2 Sheets-Sheet 1.

J. W. MURRAY. RAILWAY GATE.

No. 546,979. Patented Sept. 24, 1895.

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(No Model.)

2 Sheets-Sheet 2. J. W. MURRAY. RAILWAY GATE.

No. 546,979. Patented sept. 24, 1895.

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JOHN W. MURRAY, OF CHICAGO, ILLINOIS.

SPECIFICATION forming part of Lett ers Patent No. 546,979, dated September 24, 1895. Application ledNovember 27, 1894. Serial No. 530,125. (No model.)

To @ZZ whom t may concern:

Be it known that I, JOHN W. MURRAY, a citizen of the United States, residing at Ohicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Railway-Gates, of which the following is a specification.

My invention relates to improvements in railway-gates of the class comprising swinging arms, which are actuated to rise and fall by means of mechanism operated by air-pressure.

My object is to provide a gate of this class with improved pneumatic operating mechanism of a simple, durable, and easily-operative construction, whereby the movement of the barrier-arm will be steady and certain, and whereby, in the case of a double gate, the barrier-arms will, without being tied together, rise and fall evenly.

It is also my object to provide automatic locking mechanism for the barrierarms, which shall operate to hold them rigidly in position, when raised, against movement under the force of the wind.

My invention consists in the general construction of my improvements, as well as in details of construction and combinations of parts, all as hereinafter set forth and claimed.

In the drawings, Figure 1 is a broken view in sectional elevation of a gate-post upon which a swinging barrier-arm is pivotally supported, and which is provided with my improved gate actuating and locking mechanisms, the section being taken on line l of Fig. 3 and viewed in the direction of the arrow; Fig. 2, a section taken on line 2 of Fig. 3 and viewed in the direction of the arrow; Fig. 3, a cross-section of the gate-post, taken on line 3 of Fig. 2 and viewed in the direction of the arrow; Fig. 4, a broken diagrammatic view of adouble gate of myimproved construction; and Fig. 5 an enlarged longitudinal section of an air-retarding valve, of which several are employed.

A is a hollow gate post or casing. Journaled loosely in the opposite walls of the gatepost in the upper part thereof is a transverse shaft B, to which the barrier-arm B is rigidly secured beyond the casing. Above the shaft B and extending at right angles thereto across the post-chamber are parallel guiderods t t,

Extending across the center and lower part of the casing, parallel with the shaft B, is a bearing-rod C, and mounted at its lower end upon the said rod is an upward-extending swinging lever Ov. On the upper end of the lever O is a head C2, provided at its upper end with teeth forming a segmental rack p. The shaft B is provided with a segment-gear p', engaging the rack p.

D is a frame consisting of two parallel side braces n n and parallel plates or platens m m. The side braces n are provided at their centers with bearing-openings n', which receive pins p2 on opposite sides of the head O2. The frame D is thus pivotally supported by the pins p2 at the upper end portion of the swinging lever C. Mounted in the casing just below the shaft B and extending parallel therewith is a bearing-rod Z, and pivotally supported upon the said rod is a block or plate Z', having a segmental edge Z2. The block Z ts tightly between the rod Z and shaft B, and its segmental edge describes the arc of a circle, of which the rod Z is the center. The office of the block Z is to afford an autifrictionbearing for the shaft B, and for this purpose two such blocks are provided, one near each end of the shaft B, close to the casing-walls.

E E are collapsible and inflatable tubes formed of rubber or other iexible material impervious to air. The tube E is passed over and hangs at its center from the yoke o, extending down opposite sides of the diaphragm q and between the platens sm. The tube E is passed over and hangs at its center from the yoke r', extending down opposite sides of the diaphragm q and between the platens s m. Each tube is closed at one end by means of a cap or fastener Zr. The opposite end Zr. of the tube E is connected to a pipe F, extending from a compressed-air supply, (not shown,) and the end k of the tube E is con- IOO nected with a pipe G, extending from the compressed-air supply. Interposed in the pipe F is a valve device F', containing a checkvalve z', which seats in the direction of the compressed air-supply. Through the checkvalve is a small passage i'. In the pipe G is a valve casing G', formed in every way like the valve F described and containing a check-Valve like the valve t', provided with a passage like the passage i'.

The operation of the mechanism so far described is as follows: lVhen the barrier-arm B is raised, as shown in the figures, the tube E is inflated and the tube E' is collapsed, as indicated. To lower the barrier-arm a threeway cock h, interposed in the pipe F, is turned to open the said pipe to the outside air, and a three-way cock h', interposed in the pipe G, is turned to open the pipe G to the compressedair supply. Air under pressure passing through the pipe G enters the tube E to eX- pand the latter, and at the saine time the air in the tube E exhausts through the pipe F and cock h. In the expansion of the tube E', caused by the entrance to it of air under pressure from the pipe G, it bears against the platens s m', and in its expansion forces the diaphragm q, with the yoke-piece r', along the guide-rods fand forces the frame D toward the platen s. In the movement of the frame D the lever C' is swung in the same direction, and the rack p turns the segment p' to rock the shaft B and swing the barrier-arm B' from the vertical to the horizontal plane. At the same time that the tube E' expands, the tube E collapses and permits the frame D to move against it and force the diaphragm q and yokepiece r to the left until the tube extends col lapsed and Hat between the platens m s. During the operation described the air entering the tube E' lifts the valve t' in the valve-casing G and flows freely to said tube, while the air escaping from the tube E presses the valve z' in the valve-casing F to its seat and escapes only through the small open passage z". Thus the speed of movement of the parts is limited by the escape of air through the passage t" of the respective retarding-valve, and there is always what may be termed a head of pressure during operation in the tube which is being inflated. lVhen it is desired to raise the barrier-arm B', the cock h is turned to vent pressure from the pipe G to the outside air and to open the pipe F to the compressed-air supply. This causes the tube E to be expanded by air passing freely through the valve-casingF' and the tube E' to contract slowly by the venting of air through the small passage in the retarding-valve casing G', whereby the diaphragm q, yoke-piece fr, and frame D are moved to press the tube E flat between the platens m' s', move the yoke-piece r' and diaphragm q' to the position shown in the Igures, and turn the lever C to rock the shaft B and swing the barrier-armB' to the vertical plane. Pivoted in the casing A at g is a bell-crank lever I-I, having an upper armf, provided with a notch f', and a lower arm e,presenting at its lower end a platen e' and provided with a weight@ 2. On the wall of the casing adjacent to thelower end of the lever is a platen d, and between the platens d e' is an expansible and contractible tube c, closed at its upper end and there fastened against the casing and communicating atits lower end with a pipe G2, leading to the pipe G. On the rock-shaft B is a finger B2 in the relative position indicated in Fig. l. The tendency of the weight e2 on the lever H is to swing the platen c' in the direction of the platen d and to swing the upper end of the levcrf, with its notch f', into the path of the end of the finger B2. Thus when the barrier-arm is raised to the position shown in Fig. l the notched end of the leverj", extending across the path of the finger B2, will lock the barrier-arm against movement in the downward direction under the action of the wind. Vhen to lower the barrier-arm air from the compressedair supply is turned into the pipe G,it enters the pipe G2 and iniiates the tube c, causing the latter to swell between the platens c d and press the lower weighted arm of the lever H in the forward direction, which carries the upper end of the leverfout of the path of the linger B2, whereby the inflation of the tube F.' lowers the barrier-arm, as before described. When the barrierarm is raised to the vertical plane, the finger B2 in its' rise wipes against the armf of the le ver and swings it back against the resistance of the weight e2 until the finger reaches the notchf', when the lever will swing and engage the finger, as shown in Fig. 1.

It is usual at railway-crossings to provide two casings A and barrier-arms B at oppo site sides of the thoroughfare at each side of the track, the barrier-arms Working in pairs to lower in the direction of each other and rise in the direction away from each other. In Fig. 4, I show what is termed a double gate consisting of two casings A and barrier-arms B', both constructed alike and containing the mechanism described. I'Iitherto, in order to cause the companion arms B to lower and rise with equal speed, mechanism has been provided to tie the arms together, either through the medium of underground pipes or otherwise. In my improved construction the ynecessity ot' tying the arms together is obviated by the valves F' G', which by limiting the speed at which pressure from the tubes may escape, and thus creating a preponderance of pressure in the other tubes during the operation, cause the barrier-arms to rise and fall with approximately equal speed, and in all events to complete their movements in each operation.

Constructed as described my improved mechanism is simple, positive in action, and eminently durable, and while the details of construction shown are the best known to me IOO IIC

they may be modied without departing from the spirit of my invention as defined by the claims.

What I claim as new, and desire to secure by Letters Patent, is-

l. In combination with a hollow casing forming a gate-post, and a swinging arm thereon, of stationary platens on opposite sides ot' the casing, a lever in the casing geared to the axis of the arm to operate it by turning on its fulcrum, platens on opposite sides of and carried by the lever, sliding carriers mounted at opposite sides of the lever, collapsible and expansible tubes suspended from the carriers and extending and coniined between the said platens on the lever and the respectively adjacent stationary platens, airpressure mechanism for directing air into said tubes, and means for venting the air from said tubes, substantially as and for the purpose set forth.

2. ln combination with a hollow casing forming a gatepost, and a swinging arm thereon, of stationary platens at opposite sides of the casing, a lever in the casing geared to the axis of the arm to operate it by turning on its fulcrum, platens on opposite sides of and carried by the lever, sliding yokepieces on opposite sides of the level', diaphragms suspended from said yoke-pieces, collapsible and expansible tubes suspended between their ends from the said yoke-pieces and extending across opposite sides of the said diaphragxns between the platens on the lever and respectively adjacent stationary platens, and air-pressure mechanism for directing air into said tubes, and means for venting air from said tubes, substantially as and for the purpose set forth.

3. In combination with a hollow casing forming a gate-post, shaft B,swinging arm B thereon, compressed air-supplier and means for turning the shaft to raise and lower the arm B actuated from the said air-supplier, of a stop-projection B2 on the shaft, and means for locking the shaft against rotation when the arm B is raised, comprising a lever H pivotally mounted between its ends in the casing and having an arm e provided with a weight, and an arm f extending normally into the path of the said stop-projection, a platen e ou the arm e, a platen d adjacent thereto on the casing, an expansible and collapsible tube c supported between the said platens and communicating with the said air-supplier, and means for directing air from the supplierinto said tube and for exhausting the air from said tube, the armfoperating to engage the stopprojection B2 when the arm B is raised, and the tube c operating when expanded to bear against the platen e and swing the lever out of the path of the said stop-projection, substantially as described.

JOHN W. MURRAY. In presence of-- M. J. FROST, J. H. LEE.

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