US294905A - Pneumatic door-check - Google Patents

Description

(No Model.)

G. S. PERKINS.

' PNEUMATIODOOR CHECK.

vN0. 294,905. Patented Mar. 11, 1884.

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N. PETERS. Phnlwlilhngnpher. Washington. 0.x;

UNITED STATES GUSTAVUS S. PERKINS, OF

PATENT Er ca.

HARTFORD, CONNECTICUT.

PNEUMATIC DOOR-CHECK.

SPECIFICATION forming part of Letters Patent No. 294,905, dated March 11, 1884. I

a Application filed August 21, 1882. (No model.)

To all; whom it may concern.-

Be it known that I, GUSTAVUS S. PERKINS, of Hartford, in the county of Hartford and State of Connecticut, have invented a certain new and useful Improvement in Door-Checks, of whichthe following is a description, reference being had to the accompanying drawv ings, where Figure 1 is a top view of my device as ap plied to a door. Fig. 2 is a view of same in longitudinal central section, showing the door open. Fig. 3 is a detail view of one end of the cylinder, the thumb-nut and washer removed to show the adj ustable vent.

My invention relates to the class of devices for preventing the slammingof doors by the use of an-air-cushion, and known as pneumatic door-checks.

The invention consists in the new and improved combination of parts that'renders the pressure of the spring practically uniform, whether the door is open or shut, gives a compact arrangement of operating parts, and renders the adjustable vent of the air-chamber easily accessible when the door is closed.

In the accompanying drawings, the letter a denotes a cylinder, preferably of metal, as brass. 1) denotes a piston, usually leather-packed, and so fitted to the cylinder as to be air-tight; c, a piston-rod fast to the piston at one end,vand pivoted to the standard d, appurtenant to plate 6, at the other. The cap f is recessed, as shown in Fig. 2, so that the cylinder fits closely upon the plate 6, to which is pivoted the guide-rods g, which are pivoted at their outer end to the cap h of the cylinder. To the same cap, h, is pivoted the lever-arm c, which is also pivoted to the stand or bracket 70, adapted to be secured to a door. The cap h is ordinarily fastened to the cylinder by a screw-thread, and holds between them a leather disk, Z, slitted for the admission of air to the cylinder,

- as through the opening 7r, when the piston is drawn outward. Another opening, if, is provided in cap h, closed by a thumb-nut, m, and this latter opening is used to adjust the outflow of air under pressure of the piston, which is impelled in closing the door by a coiled spring, a, arranged within the cylinder about the rod, and bearing upon the cap and back of the piston. I

My device is readily applicable to either a right or left hand door, with no change in the parts herein shown, the plate e being fastened to the jamb over the door at a point near the hinge side, and the stand or bracket in to the upper edge of the door at a point farther removed from the hinge side.

By means of dotted lines in Figs. 1 and 2, I have illustrated the operation of the device considered as a lever, the spring being the power applied between the pivot e on the plate 0 and the pivot k on the bracket k. The short arm of the lever, from eto 9:, remains almost constant, as the door is swung open, while the longer arm increases rapidly in length as the door is opened, as illustrated in Fig. 2, and the weight and friction of the door upon its hinges is also constant. At the same time the compression and resiliency of the coiled spring have increased,with the result of a practicallyuniform pressure upon the door at all points of its path between the extremes of open and shut-a desirable feature in many places.

- By arranging the cylinder in the manner shown, the air-ch amber and its openings to the outer air are located on the outer end of the cylinder, with the adjustable vent covered by the thumb-nut in a position easy of access.

I am aware that pneumatic door-checks consisting of the combination of the aircylinder, levers, and brackets, and also having adjustable vents for governing the speed and force of closing the door, are not new, and these I do not .broadly claim.

Iclaim as my invention 1-. I11 a pneumatic door-check, a cylinder, a, pivotally connected to guide-rods g, lever z, and bracket k, in combination with piston Z1, spring a, and rod 0, pivoted to stand e, whereby the'cylinder is reciprocated'on the piston in opening and closing the door, all substantially as described, and for the purpose set forth.

2. In a pneumatic door-check, the combination of the cylinder a, having recessed head f and cap 71, with vent 7L2 and adjustable thumbnut m, piston b, rod 0, plate 6, having standard d, guide-rods g, lever 75, and bracket 7:, all substantially as described.

GUSTAVUS S. PERKINS.

W'itnesses:

O. L. BURDETTE, U. H. MARsH.

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