US360042A

US360042A - Pneumatic door-check

Info

Publication number: US360042A
Authority: US
Publication date: 1887-03-29
Anticipated expiration: 1904-03-29

Description

l (N0 Model-J 2 Sheets-Sheet I.

V G. S. PERKINS.

PNEUMATIG DOOR CHECK. No. 360,042. K Patented Mar. 29, 1887.

N. PETERS, mammal. wnnmgm. uA c.

'(No Model.) 2 Sheets-Sheet 2.

G. S. PERKINS.

PNEUMATIG DOOR CHECK.

Patented Mar. 29, 1887.

1.1 h/y/A Ntra STATES lArnNr einen.

GUSTAVUS S. PERKINS, OF HARTFORD, CONNECTICUT.

PN EUMATIC DOOR-CHECK.

SPECIFICATION forming part of Letters Patent No. 360,042, dated March 29, 1887.

Application filed August 2, 1886. Serial No. 209ml. (No model.)

.To all whom, 'it may concern:

Beit known that l, GUsTAvUs S. PERKINS, of Hartford, in the county of Hartford and State of Connecticut, have invented a certain new and useful Improvement in Pneumatic Door-Checks, of which the following is a full, clear, and exact description, whereby a person skilled in the art can make and use the same.

My improvement relates to that class of door-checks in which the elasticity of air when confined in a chamber is made use of as a buffer or cushion to prevent the slamming of a door in closing under the impulse of a spring.

The object of my improvement is mainly to provide a device of this class with a peculiar valve or vent that automatically regulates and controls the movement of the air out of and into the chamber in a cylinder' in front of the piston.

To this end my improvement consists in a cylinder having practically air-tight head in combination with a piston that bears the au` tomatic seltregulating valve; and it further consists in the combination ot' a cylinder with contained piston, and the peculiar' levers that connect a door and its frame to such parts, as more particularly hereinafter described, and pointed out in the claims.

Referring to the drawings, Figure lis a front view of one form-of my improved device as adjusted in position for use. Fig. 2 is a view in horizontal section through the door-check on the plane denoted bythe line x a: of Fig. l. Fig. 3 isa detail view in section on the same plane, sh owing the part-s extended by the opening ofthe door. of the piston. Fig. 5 is a detail rear View of the piston. Fig. G is a detail view in crosssection through the piston and valve on plane denoted byline y i/in Fig. 4. Fig. 7 is a detail'view ofthe front end of a modified form of piston and valves. Fig. S is a detail view in cross-section through the latter form of piston and valves, showing comparative views illustrating` the operation of the valves.

In the accompanying drawings, the letter a denotes a door-i'rarne; Z), a door, and c the cylinder of the door-checlr. rIhis cylinder is preferably a metallic tube having iirmly screwed or fastened to one end the back head, which is pivotally connected to a stand, c, the latter having the foot e', through which screws are driven to fasten the stand to the jamb of the Fig. et is a detail front view door or to the door. In the drawings the cyl inder is pivotally connected at the back head to the door-jamb.

rl`he letterf denotes the front head of the cylinder, that is firmly secured thereto, as by means of ascrew-thread, and through the center of this front head passes the piston-rod g, on the inner end ot which is screwed the piston g. Vithin the cylinder, and between the back oi" the piston and the front head, is arranged a spiral spring, h, seated with one end pressing against the piston and the other against the follower 7i', that is seated on the ends of screws that are bornein threaded sockets in the front head, and preferably extend through it, so that their outer ends are accessible for the purpose of adjusting the position of this follower with relation to the fronthead, so as to increase or decrease the tension of the spring 7i without removing the head from the cylinder. The outer end of this piston-rod g is pivotally connected to the lever k, that is a bent lever pivotally connected at ils angle to the stand l, and at its other end to the tie-rod m. In the form shown this tie rod is pivoted to the guiderod n, and, to the connecting-arm o by a common pivot at the meeting point of these parts, the guiderod being pivoted to lugs l on a stand, Z, at a point between the points ot' connection of the stand l and bent lever 7a and the bent lever and tie rod m, these three points being about in line with cach other when the parts are in their normal position, as seen in Fig. l.

The connecting-arm ois pivoted to theY bracket 1), that is secured to the door b, and when the latter is opened the arm pushes tle tie-rod at its outer end, which in turn pullsl on and rocks the bent lever, and thus draws the piston forward in the cylinder, compressing the closing spring, whether the latter is inclosed in the cylinder or is attached to the door at some other point.

By means ofthe bent lever, the guide-roda, and tic-rod m the travel of the piston in a given sizeof cylinder is reduced to a minimum. (An examination of the position of guide-rod n and tie-rod min Fig. 3 will show this.) The force of the compressed spring when the door is opened is thus used to the best advantage, and the door is prevented from traveling faster in closing than the piston travels in the cylinder, and it also more eli'ectuallyprevents the door from slamming'than when the pistonrod is pivoted directly to the tie-rod. It has been found by experiment and somewhat ex tended use of this device that the force required to first move the door in opening in creases to about twice that amount until the door reaches an angle of sixty degrees and then the force decreases, but not to a degree to prevent the spring from starting the door very forcibly in closing.

At no time in the movement of the several levers and connecting parts does the pull of the spring upon the piston-rod lie in a line' through the pivots or over the center/7 as is the case in several prior devices, and thus there is no pause in the closing movement of the door. The decreased play of the piston enables the cylinder to be made much shorter and cheaper than in prior devices having a spring ofthe same power and a cylinder of the same diameter.

The follower h', that is arranged between one end of the spring and the front head of the cylinder,is supportethpreferably, on screws h,that are adjustable in sockets in the follower, and have shoulders bearing against the inner side of the front head,f. The tension of the spring may be easilycontrolled by this device.

There is no provision made for the passage of air into or out ofthe cylinder c. In fact, the latter is substantially air-tight; but the piston g is provided with a valve, q, that provides for the passage of air from one side to the other of the piston as it moves forward and back in the cylinder. This valve q has a broadened head, q', lying on' the front side of the piston, and held with its stem q within the chamber 1 by the pressure of theI spring r. Vithin the chamber ,.r, that is open through'to the back of the piston, is seated a spiral spring, 1', with one end thrusting against a shoulder or lug within the chamber and the other against the valve, so as to hold it in its normal condition between the two springs and slightly raised from its seat. In this condition, when the door to which this device is connected is opened, the piston moves toward the front head of the cylinder, the air passing quite freelyv through the valve in the piston, and offering practically no resistance to such forward movement of the piston. As soon as the return movement of the piston is begun,

as under the impulse oi a spring, any quick movement of the piston causes the valve q to close upon its seat and prevent the passage of air from the front to the back side of the piston.

The valveseat is preferably provided with a relief-opening, S2, which consists of avery small channel in the face of the valve or seat, that allows asufcient quantity of air to leak through to relieve the pressure on the back of the valve, due to the compression of the air in front of the piston, and as soon as this pressure of the compressed air is less than the pressure of the spiral spring in the chamber the valve opensand allows the air to pass more freely through it to the other side of the pis ton, which then continues its movement, and the door closes quietly.

Instead of providing the valve q or its seat with the relief-opening described, I may use a separate relief-valve, s, located at another point in the piston, and thismay consist of' a valveseat formed on the back of the piston, into which the valves is seated under the pressure of the spring s. The office of the reliefvalve is the same as that of the relief-opening. In order to provide for thetight packing of the piston, I use a cup-packing, t, of suitable material, as leather, secured to the piston by a disk-shaped clamp that is screwed upon an extension of the pistonrod, that is perforated for the free passage of the air. p

The piston may obviously be packed in any other convenient way and the clamp secured by other means than screwing it onto the eX- tension of the piston-rod; but the latter is preferable.

I claim as my'i-nvention- 1. In a door-check of the within-described class, the combination of the cylinder with pivot-bearings on its back head, the cylindersupporting stand e, the piston and connected piston-rod, the bent lever and its supportingstand, with one end ofsaid lever pivotally connected to the piston-rod and the other to a tie-rod, the guide-rod n, and connectingarm with its supportingstan'd, the tie-rod, guiderod, and connecting-arm being united by a common pivot, all substantially as described.

2. In a door-check of the within-described class, in combination with the cylinder andits connected piston and rod, a bent lever pivotally attached to the frame or casing of a door,to which part the cylinder is also connected, and having its outer ends pivotally connected to the piston and a tie-rod, respectively, and a guiderod, also pivoted to a stand, all substantially as described, and for the purpose se forth.

43. In a pneumatic door-check, in combination, a cylinder with closed end, and a piston movable within the cylinder,with its outer1 edge having an air-tight packing, and the balanced valve borne by said piston to permit `the passage of air through the piston, all substantially as described.

4. In a pneumatic door-check, a cylinder, c, and a piston, g, bearing the valve q, having a relief-opening, all substantially as described.

5." In a pneumatic door-check,y in combination, a cylinder, c, and a piston, g, having the valve g balanced between the springs r and r2, and having a relief-opening, all substantially as described.

6. In a pneumatic door-check, in combination, a cylinder, c, and a piston, g, having the IOO rio

balanced valve q, and a reliefvalve, s, all substantially as described.

GUSTAVUS S. PERKINS.

lVitnesses:

Guns. L. BURDETT, H. It. WILLIAMS.