US1916571A

US1916571A - Doorcheck

Info

Publication number: US1916571A
Application number: US590884A
Authority: US
Inventors: Laurence N Hoffman
Original assignee: SHELBY METAL PRODUCTS Co
Current assignee: SHELBY METAL PRODUCTS Co
Priority date: 1932-02-04
Filing date: 1932-02-04
Publication date: 1933-07-04
Anticipated expiration: 1950-07-04

Description

L. N. HOFFMAN July 5 1933a DOORCHECK Filed Feb. 4. 1932 M m T M z m Q U a L i A ZTORN Patented July 4, 1933 UNITED STATES PATENT OFFICE LAURENCE N. HOFFMAN, OF SHELBY, OHIO, ASSIGNOR TO THE SHELBY METAL PRODUCTS COMPANY, OF SHELBY, OHIO, A CORPORATION OF OHIO DOOR-CHECK Application filed February 4, 1932. Serial No. 590,884.

The present invention relating as indicated to a door check, has more particular reference to a pneumatic cylinder type of door closing device designed primarily for application to doors of lighter construction, such as screen doors. It is particularly desirable in screen door installations to provide a form of door check which may be conveniently attached and removed due to the fact that the door it- "1 self is not a permanent fixture, but is reu to provide means for regulating the rate of flow of the compressed air from the interior of the'pneuinatic cylinder and to provide means for producing var'able velocity of the door closing motion. Further advantages shall become apparent as the description proceeds. To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims. r

The annexed drawing and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of vaious mechanical forms in which the principle of the invention may be used.

In said annexed drawing:

Fig. 1 is an elevational assembly view of the pneumatic door check embodying the principle of my invention; Fig. 2 is a plan view of Fig. 1, showing the door check device in position upon the door and door casing and with the cylinder and piston in section; Fig. 3 is a section taken substantially upon the line 33 of F ig. 1; Fig. 4c is a section taken substantially upon the line i4 of Fig. 1; Fig. 5 is an enlarged fragmentary sectional view of the compression end of the pneumatic cylinder; Fig. 6 is a sectional view of the door closing tension spring; Fig. 7 is a matic cylinder 1 having the piston rod 2 and piston 3 positioned therein for reciprocal operation. The piston 3 may be of any suitable construction satisfactory for pneumatic operation. The cylinder 1 is carried upon its open or non-compression end by thc threaded cap 4, which has a laterally proiecting stud 5 pivotally mounted with in the sleeve 6 of the door bracket 7. -The bracket 7 may be permanently secured to the door by means of wood screws, bolts, clamps, or similar fa tening means.

As best illustrated in Fig. 1, the door casing bracket 9 has a pair of p rallel horizontally projecting

plates

10 and 11 which are adapted to removably receive the transversely bent portion 12 of the piston rod 2. The coilcdtension spring 13 having the tangentially extending end portions let and 15 is adapted to be carried between the

bracket plates

10 and 11 and to engage the piston rod 2. The bracket 9 may be permanently secured to the door casing 16 by suitable wood screws 17 It will be seen, however, that although the bracket 9 itself is a. permanent installation, that the projection 12 of the piston rod 2 and the tension spring 13 are in removable engagement with the bracket. Likewise directing attention. more particularly to Fig. 3, it will be seen that the pneumatic cylinder 1 is in removable engagement with the door bracket 7.

Referring to Fig. 4,. the tension in the door casing spring 13 may be variably. adjusted by means of. positioning the vertical projection 18 of the tangential spring extension 15 in any one of theholes 19 to 22 inclusive drilled in the bracket plate 11.

In order to variably control the rate of flow of the air from the interior of the pneumatic cylinder and, consequently, to vary the pneumatic pressure resistance, there is provided in the compression end 25, the tapered screw 26 threadedly engaging therewith. It will thus be seen that varying positions of threaded engagement of the tapered screw 26 in the end wall 25 will correspondingly produce a larger or smaller escape opening for the compressed air. A compression spring 27 is positioned between the head of the tapered screw 26 and the exterior of the piston wall 25 in order to maintain the screw in adjusted position.

In order to impart a closing movement to the door, which is characterized by relative rapid motion toward closed position during the first part of the closing arc, and then substantial retardation for the last foot or so, followed by final rapid closing movement; there are provided a pair of by-

passes

31 and 32. The by-pass 32 consists of an enlarged portion of the cylinder wall of the pneumatic cylinder 1 and is adapted to temporarily relieve the pneumatic pressure while the piston is moving in that particular portion of the cylinder. When the door arrives substantially at half closed position, the piston 3 will correspondingly arrive at the portion 33 of the cylinder at which point the pneumatic pressure will again become substantially increased so that the door closing motion will undergo deceleration.

The purpose of the smaller lay-pass 31 positioned in the compression end of the pneumatic cylinder 1 is in order to impart a final rapid closing action to the door movement. Such a rapid final action is particularly desirable where snap latches are installed on the door.

A coiled spring 30 is positioned in the nonrompression end of the cylinder 1 and is adapted to engage with the piston 3 and the cylinder cap 4 in order to absorb any shocks caused by too forcible opening of the door, and likewise to aid in an initial closing ac tion.

In the light of the foregoing description it will thus be seen that I have provided a unique form of construction of door closing means which is applicable and adjustable to various conditions of installation. The adjustable features found to reside in the closing spring 13 and in the adjustable screw 26 are of particular advantage when the device is to be applied to doors of varying weight and size.

By means of the expedient of pivotally supporting the pneumatic cylinder at its noncompression end, it will become apparent that the cylinder itself will always be located in a position parallel to the door when the door is closed, so that, as well as offering an attractive appearance, no unnecessary space will be occupied.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a door check, the combination of a pneumatic cylinder, a piston operably positioned within said cylinder, a central portion in the wall of said cylinder raised out of contact with said piston and adapted to serve as a fluid by-pass, and a portion adjacent the compression end of the wall of said cylinder raised out of contact with said piston.

2. In a door check, the combination of a pneumatic cylinder, a piston operably positioned within said cylinder, a central portion in the wall of said cylinder raised out of contact with said piston and adapted to serve as a fluid by-pass, a portion adjacent the compression end of the wall of said cylinder raised out of contact with said piston, means for regulating the rate of flow of air from the interior of said cylinder consisting of a tapered screwthreada-bly positioned in the compression end of said cylinder, and bracket means removably attached to the 0pposite end of said cylinder for pivotally securing said cylinder to the door.

3. In a door check, the combination of a pneumatic cylinder, a piston operably positioned within said cylinder, a piston rod, a central portion of the wall of said cylinder raised out of contact with said piston and adapted to serve as a fluid by-pass, a portion adjacent the compression end of said cylinder raised out of contact with said piston, a bracket secured to the door casing adapted to removably engage said rod, a tension spring associated with said bracket and rod, and a plurality of holes in said bracket to receive one end of said spring and to forcibly adjust the tensional resistance thereof, means for regulating the rate of flow of air from the in terior of said cylinder, and bracket means removably attached to the non-compression end of said cylinder for pivotally securing said cylinder to the door.

LAURENCE N. HOFFMAN.

Signed by me this 3rd day of February,