US1755392A

US1755392A - Secret-door latch

Info

Publication number: US1755392A
Authority: US
Inventors: Carl J Hagstrom; Carl G Hagstrom
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-12-23
Filing date: 1927-12-23
Publication date: 1930-04-22
Anticipated expiration: 1947-04-22

Description

AprilZZ, 1930. C, J, HAGSTRQM ET'AL 1,755,392

SECRET DOOR LATCH v Filed Deo. 25, 19,27

lili", l ll'illllfllll//lf fig Patented Apr. 22, 1930v CARL J'. HAGSTROM AND CARL G. I-IAGSTROM, OF GLEN COVE, NEW YORK SECRET-DOOR LATCH 'Application filed December as, 1927( serial ne. 242,047.

This invention relates to builders hardware and has particular reference to latches or analogous fasteners for doors, panels, shutters, or other building details that are calculated to be held iny closed or locked position, but which may be unlatched orv opened readily at any time by one who-knows the naturevofsuch door, panel,ror the like, and

Y its fastening means, it being contemplated that these latches or fasteners shall be used without keys and without disclosing by eX- ternal appearance the presence of the fasteners, hinges, or other hardware. Any suitable concealed hinges may be employed and hence they are not made a part of this specification.

Among theV objects, therefore', of this invention is to provide a latch for a secret door so constructed that the door may be 2,0 pushed to closed position and coincidentally be securely latched, and for its unlatching and opening a slight firmer push and then release bythe operators hand will cause the latch mechanism to be opened and the door to be started toward open position.

With the foregoing and other objects in view the invention consists in the arrangement and combination of partsfhereinafter described and claimed and while the invention is not restricted to the exact details of construction disclosed or suggested herein, still for the purpose of illustrating apractical embodiment thereof reference is had to the accompanying drawings in which like reference characters designate the same parts in the several views, and in which- Figure 1 is la plan View of the latch with parts of the door and door frame in horizontal section. v l y Fig. 2 is a vertical section on the line 2-2 of Fig. 1, the face plate of thelatch being removed, and the door being in latched position.

Fig. 3 is a similar view showing the action while the door is being unlatched.

Fig. 4: is a similar view with the door starting toward open position.

Fig. 5 is a vertical section on theline 5 5 of Fig. 2.

Fig. 6 is a face view of the strike carried by the inner face of the door.

Fig. 7 is an outer edge view of a modified form of latch Vmechanism as shown in Fig. 8.

Fig.l 8 is a face view of a modified form of latch, the face plate thereof being removed and with the door approaching its latched position.

Fig. 9 is a similar view showing the posi'- tion of the parts when the door has reached its limit of closing movement but with the catch not yeteffective. f y

Fig. 10 is a similar view indicating the CII position of the parts of the latch after the y door is released from the position of Fig. 9 and with the catch retained in idle position.

Fig. 11 is a side elevation of a further modiiication.

Referring now more specifically to the drawings we show atl a door, panel, or the like,'which will be referred to hereinafter as a door irrespective of its nature or construction, but it is to be understood as swinging shut as per large arrow on Fig. 1, the door carrying on itsinner face aplate or strike 16 having a lipl' struck inward and downward in the upper portionv thereof and having 'a cavity 18 adjacent to the lip formed in the plate.

rlhe door frame 19 is recessed at 20 tol receive a latch casing 21 of relatively small and flat formation and mainly rectangular inform as viewed from the side, the casing being set back as shown at 22 from the front edge 23 ofthe frame. A clearance 2l is thus provided between the effective edge 23 of the frame and the normal inner surface of the door as shown in Fig.V 2. The door, however, may be pushed inward slightly from this normal position as shown in Fig. 3 due to this clearance at 24, and when so pushed the lip 17 approaches the front edge of the latch casing 21.

25 indicates a catch' pivoted at 26 within the casing and projecting forward approximately horizontally therefrom through an opening 27. -A spring 28 bears constantly upon the catch tending to hold the outer end thereof downward and in position to co- TTI operate with the lip 17 to catch and hold the door latched.

29 indicates a plunger guided siidably in a hole 30 formed in the lower portion of the front edge of the casing and guided along a lug 31 struck inward from the side wall of the casing. rThis plunger is urged forward by means of a compound spring 32 having a bow 32a and an extension 32b connected directly with the inner end of the plunger.

The two parts of the spring are normally spaced from each other as in Fig. 2, the latter part 32b acting with a moderate degree of force to resist the injard movement of the plunger as it approaches the position shown in Fig. 2. During the subsequent movement, however, of the plunger both arms 32at and 32b of the spring combinepto resist with a greater degree of force such inward move- ;nent as shown in Fig. 3. The extreme outward movement of the plunger is limited by a lug 33 Coming into contact with the front wall or edge of the casing. Adjacent to this lug is formed a wide notch 34 in which plays the lower shorter arm 35 of an actuator in the nature of a first class lever 36 pivoted at 37. The upper longer arm of the actuator' 36 cooperates with a downwardly projecting lug or cam 38 formed on the catch 25 adjacent to its pivot. With the door in latched position as inFig; 2, to open it the operator presses inward firmly against the door, thereby moving the plunger to the position of Fig. 3, swinging the actuator towardv the left and causing the lifting of the catch 25 through the co-operation between the upper end of the actuator and the cam 38. As soon as the catch 25 is so lifted from the lip 17, the combined force of the spring 32, acting on the plunger 29,7throws the door toward the open osition bringing the li 17 outward toward,

3 D C) p and beyondA the position shown in Fig. 4 so that it is out of the way of the catch which immediately thereafter returns to normal position under the force of its spring 28, at which time the plunger 29 will be in its eX- treme forward position and the actuator will have been returned thereby to its normal position as in Fig. 2, The spring 28 is moderately light and acts only to hold the catch downward in position to snap over the lip 17 when the door is returned to its position of Fig. 2. Y

y In the form shown in Figs. 7 to 10, the catch 25a pivoted at 26 acts somewhat as already described and is urged normally downward by means of a spring 28a. The actuator 36a is a slidable member pivoted at 39 to the catch and has a downward projection 40V offset somewhat rearward from an angular shoulder 41 between theends thereof. The act-uator i'sguid'ed at its lower ends between a pair of pins 42 and is so held from lateral movement. Y Instead of a slidable plunger actuated by the door we provide in this form a dog 43 pivoted at 44 at its lower end and urged normally by a spring 45 to project at its upper end forward through the hole 30a. rlhe upper rear or inner corner of the dog is beveled off at 46 for wiping co-operation with the aforesaid shoulder 41 when the door goes shut and whereby the actuator and catch are lifted into the position of Fig'. 9 for unlatching the door. When the catch is so lifted a detent 47 takes over the rear endof the catch at 48 and holds the catch in open or lifted position, the detent being held in this position by means of a spring 49 acting-upon the detent. This element 47 is pivoted at its lower end at 50 and adjacent to this lower end is-pivoted thereto a trigger 51 which extends thence forward and is urged upward toward the shoulder 41 by means of 'a spring 52. The force of the spring 28FL is superior to that at 52 and hence the rearward extension of the main portion of the actuator 36a bearing downward upon the trigger holds it in normal position as in Fig. 8. TWhen, however, the catch is liftedby the co-operation between the dog and the actuator as in Fig.. 9, the detentacts to hold the catch in elevated position even after the door is opened and the dog'is thrown forward by the spring 45 as in Fig. 10. TWhen, however, the door is pushed firmly subsequently to closed position for latcliing it, the dog strikes squarely against the front end of the trigger as will he seen in Fig. 10, with the result that the detent 47 is thrown rearward against the force of its spring 49, releasing the catch 25a and allowing it to snap downward to catch and hold the door. rlhis action of the trigger takes place early enough in the closing movement of the door to render it unnecessary for a substantial movement of the door to take place in order to release the trigger or remove it'from obstructing position. That is to saye when the dog` is moved inward or rearward against the trigger as shown in Fig. 10, it causes the release of the detent yand catcl early enough for the door to be latched by the catch and yet allow the trigger to be moved downward by action of the actuator.

In Fig. 11 we show a catch 25b pivoted at 26 and provided with an upwardly projecting lug 53 Clo-acting with a spring 28", the rear end of which is connected to the upper end of a slide 54 movable along the rear edge of the casing and provided at its lower end with forwardly projecting foot 55 positioned normally just below the rear end of the plunger 29 similar in construction and action to the plunger first described and with which co-operates an actuator36 substantially similar to that one first described. The catch has a downwardly projecting cam 38 cor-operating with the upper end of the actuator. The plunger is actuated rearward against the force of a spring 32F. When the Vdoor is closed the catch 25b is lifted by riding over the lip 17 of the strike and at the same time the plunger moving inward and rearward throws the actuator to the left, wiping against the cam 38. The slide 54 is held down by the plunger taking over the foot 55 of the catch and the catch is held elevated by the spring 28h acting against the lug 53. When the door is released the spring 32C acts forward upon the plunger restoring it to the position shown in Fig. l1. At the time the rear end of the plunger clears the foot 5v5, the force of the spring 28h lifts the slide 54, bringing it back of the plunger, and at this time the catch 25b is set free to swing into catching position.

We claim:

1. A door latch comprising a casing, a strike, a catch carried by the casing, said catch being movable bythe strike on entering the same to engage the strike, a plunger in the casing 'projecting therefrom, and means operated by the plunger to move the catch to release the same from engagement f; with the strike, the plunger being actuated on moving the door closely to the jamb, said means retaining the catch in released position while the plunger moves outward of the casing to normal position.

2. A door latch comprising a casing, aV

strike, a catch carried by the casing, said catch being movable by the strike on entering the same to engage the strike, means in the casing to move the catch out of engaging ya position, said means projecting from the casing to be actuated on moving the door closely to the jamb, and a resilientmember to move the door away from the jamb, said means re` taining the catch in released position until f, the same clears the strike, with the door moving under actuation of said member.

3. A door latch comprising a casing, a strike, a catch carried by the casing, said catch being movable by the strike on entering the same to enGaO'e the strike means in the f D D 7 casing to move the catch out of engaging position, said means projecting from the casing to be actuated on moving the door closely to the jamb, said means retaining the catch in released position for a predetermined length of time until the catch clears the strike, to permit opening of the door.

In testimony whereof we aflix our signatures.

CARL J. HAGSTROM.

CARL Gr. HAGSTROM.