US1532737A - Safety latch for doors - Google Patents

Description

April 7, 1925. 1,532,737

I A. c. DOHRMANN SAFETY LATCH FOR DOORS Filed March 13, 192;

raisin carries.

ALBERT C. DOHRMANN, OF CHICAGO, ILLINOIS.

. SAFETY LATCH nos. noons.

Application filed March 13, 1922. Serial No. 543,172.

To all whom it may concern Be it known that E, MANN. a citizen of the United states and a resident of the city of Chicago, in the county ofCook and State of Illinois, have invented certain new and useful Improvements in Safety Latches for Doors, of which the following is a specification.

This invention relates to improvements in safety latch'es for open doors, in which the latch bar is secured and hinged to the door frame and adapted to be detachabiy connected with opposing open hooks secured to the door and with which the latch bar has a sliding engagement, and is detachable therefrom.

Among the objects of my invention is t provide a means by which, in closing the door, the latch bar is automatically locked in its operative position to the door against accidental detachment.

A further object of my invention-is o provide a means by which, when the door is open, the force resisting its further opening is shifted from the hooks and the shank thereof and may be directly to the door, and in the absence of the possibility of bending or breaking eitherof the hooks.

With these ends in view, my invention finds embodiment in certain features of novcity in the construction, combination. and arrangement of parts by which the said objects and certain other objects are attained, all as hereinafter fully described with reference to the accompanying drawings and more fully pointed out in the claims.

in said drawings,

Fig. 1 is a front elevation showing the automatically locked position of the strap on the closing of a door.

Fig. 2 is a section taken on the line 22 of Fig. 1.

Fig. 3 is a. front elevation of the position of the strap relative to the hooks when the door is open.

Fig. 4 is a vertical section taken on the line l of Fig. 3; and

Fig. 5, a front elevation showing the position of the strap on being disconnected from engagement with the hooks therefor.

Similar characters of reference indicate the same parts in the several figures of the drawings.

6 indicates a door to which is secured the hook member of my device, which latter that the surface consists of a 31%.t0 7, provided with 'longi} tndinal flanges 8' and'a rear end flange 9, which plate, with its flanges, is secured to the door 6 by means of set screws 9, 9, so"

of't'he plate projects ontwardly frcni the door and substantially in a plane with the face 10 of the door frame 11, said pl 5 L being provided with a slight opening at one side formed by integrally opposing hooks 12, 12, bent tl'iere'from with their ends spaced apart, as indicated at 13, which plate and the hooks therefor are preferably formed from sheet steel.

eemed to the edge of the frame of the door and preferably by means of screws 14, preferably recessed therein, is a plate15, to which is hinged, by' means of a pintle16, a strap 17, bent upon itself at its free end, as indicated at 18, and terminating'in a narrower portion or tongue 19, which tongue is adapted to project through a slot 20 in the plate Z -when the strap is in the position shown inv Fig. 3; that is to say,.

when the door is wide open as the strap will permit it to be. The strap 14, adjacent the hinge, is narrowed, as indicated at 21, suff ciently for the passage of the strap between the ends of the hooks 12, but this cannot be until the door is closed, in order that, as the door begins to move towards an open position, the wider portion of the strap will prevent its passage between the ends of the hooks.

As indicated by dotted lines 22 in Fig. 4:, the tongue 19 may be of sutficient length that when the door is open, the bearing of the tongue may be and is directly against the door, so that, in any attempt to forcibly open the door, that force will be removed in its entirety from both the hooks and their shank and be resisted by the door.

My invention also provides, for the first time, so far as I am aware, a simple and effective means for automatically locking the strap against accidental detachment from the door when closed, and which, as shown in the drawings, consists of a catch pawl 23 secured by a pivot 2 1 to the side flanges of the door plate 7, around which is coiled a spring 25, one end of which presses against the catch pawl and the other against the plate, for normally maintaining the catch pawl in its locking position.

The strap 17 is provided with a slot 26, with which the catch pawl may be moved against the resistance of the springs to a position registering therewith for the detachment of the strap.

From this construction it will now be seen that when the door is closed with the strap, on being moved to the position shown in Figs. 1 and 2, the catch pawl will yield until it is moved to position registering with the slot 26, the force of the strap being sufficient to produce this movement, and so that as soon as the catch pawl is projected through the slot, its spring will move it and lock the strap against accidental detachment.

The raising of the flanges of the plate for the pawl provides a means avoiding the otherwise necessity for swinging the strap to engagement with the pawl and for the location of the hinge therefor in aplane permitting the strap to swing to a parallel position against the surface of the frame of the door.

Having described my invention, what I claim anddesire to secure by Letters Patent 1s:

1. A safety latch for doors, consisting of a plate secured to the door, provided with an open hooklike slot, the hooks on which are outwardly curved, a hinged strap secured to the door frame passing through said slot adapted to be removed therefrom between said projections when the door is closed and means projectalole through said strap for locking the door.

2. A safety latch for doors, consisting of a plate secured to the door, provided with a slot open at one side, a hinged strap cured to the door frame passing throng said slot, projecting through said plate and adapted to automatically lock the strap when the door-is in its closed position and a pawl adapted for locking said strap to the door.

A safety latch for doors, consisting of a plate secured to the door, provided with a slot open at one side, a perforated hinged strap secured to the door frame projecting through said slot, a pawl pivoted to the plate and adapted to register with and be automaticall ro'ected throu h said erforation and lock the strap against movement in the slot.

a. A safety latch for doors, comprising a flanged plate located in a plane ith and secured to the surface of the door, and having a slot therein, a pawl pivoted to said plate adapted to be projected through said slot, a strap hinge provided with a slot for opposing said pawl, and means for automatically projecting said pawl through the hinge'slot for and thereby locking the strap to the plate and door when the latter is in its ALBERT C. DOHRMANN.

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