US425802A - John johnston - Google Patents

Description

No Model.)

- J. JOHNSTON.

SAFETY LATOH FOB. ELEVATOR DOORS. No. 425,802.

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JOHN JOHNSTON," OF NEW YORK, N. Y.

SAFETY- LATCH FOR ELEVATOR-DOORS.

SPECIFICATION forming part of Letters Patent No. 425,802, dated April 15, 1890.0

To all whom, it may concern:

Be it known that I, JOHN JOHNSTON, of New York city, in the county and State of New York, have invented a new and Improved Safety-Latch for Elevator-Doors, of which the following is a full, clear, and exact description.

My invention relates to a safety-latch for elevator-doors, and has for its object to provide a means whereby an elevator-car, in ascending or descending, upon reaching a floor will automatically unbolt the shaft-door and permit the same to be opened; and also wherein, before the elevator-car leaves the floor, if the shaft-door is closed said door will be automatically locked.

A further object of the invention is to provide a device of simple and durable construction capable of accomplishing the above results and of attachment to any shaft.

The invention consists in the novel construction and combination of the several parts, as will be hereinafter fully set forth, and pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar figures of reference indicate corresponding parts in all the views.

Figure 1 is a vertical section through the elevator-car and a partial vertical section through the shaft, illustrating the said shaft and car as fitted with my improvement; and Fig. 2 is an enlarged section of a portion of the shaft and door and a portion of the car.

The door of the elevator-shaft 11 may be either a sliding or a swing door, and is provided at any point between its top and bottom on one edge, preferably at its center, with a keeper 12. Upon the inner face of the doorjamb 13, near the keeper 12 when the door is closed, a strap 14 is vertically secured, within which strap the inner end of a latch 15 is cocentrically pivoted. The latch 15 is provided with a suitable head adapted to engage with the keeper 12 of the door, and the inner or pivotal end is somewhat circular in general contour and provided below the fulcrum upon its under side with a series of teeth 16. These teeth are adapted to mesh with teeth 17, formed in the upper edge of a bar 18, which for convenience I term a rack-bar, the said rack-bar being adapted to slide in the strap 14, and also in a second strap 19, attached to the jamb at or near its inner edge.

The rack-bar '18 extends beyond the inner strap 19, and a spring bears at its upper end against the inner extremity of said rackbar, whichspring is secured at its lower end in any suitable or approved manner to the inner edge of the jamb 13, the central portion of the spring being bowed or curved to project within the elevator-shaft, the spring employed being usually a strap-spring.

The elevator-car 21 is provided with a bar 22, attached to its front at one side, which bar preferably extends from top to bottom of the car, and its extremities are beveled, as best illustrated at 23 in Fig. 1. The bar 22 may be made entirely of metal, or it may be made of wood provided with a metal facing.

The bar 22 extends a sufficient distance from the face of the car to contact with the bow portion of the spring 20 and compress the same when the car is passing a floor.

In operation when the car is out of contact with the spring 20 the weight of the latch 15 at its head is sufficient to cause it to drop by gravity into engagement with the door-keeper 12, and thereby-force the rack-bar 18 outward to a contact with the upper front end of the spring. When, however, the bar 22 of the car, when the latter is ascending or descending, contacts with the spring 20, as shown in dotted lines in Fig. 2, it compresses the said spring, and thereby forces the rack-bar 18 in the direction of the door,-which movement of the rack-bar, by reason of its engagement with the latch 15, elevates the latter, taking it out of engagement with the door-keeper, thus permitting the door to be opened, and the latch will stand in this position (shown in dotted lines, Fig. 2) until the car is carried out of contact with the spring.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. The combination, with a latch consisting of a headed latch-bar eccentricallypivoted, and having teeth produced below its pivotal point upon the under edge, of a' rack engaging with the teeth of the latch-bar, and a bowspring contacting with one end of said rack, substantially as and for the purpose specified.

2. The combination, with a latch-bar eccentrically pivoted at one end and having teeth produced upon its under edge below the pivot, of a rack-bar engaging with the teeth of the latch-bar, a bow-sprin g rigidly secured at one extremity and bearing against the rack-bar at its other end, and means, substantially as shown and described, for compressing the said spring, as and for the purpose specified.

3. In a latch for the doors of elevator-shafts, the combination, with a door provided with a keeper, having attached to its face an out wardly-extending bar, of a latch secured to the door-jamb of the elevator-shaft, consisting of a headedlatch-bar eccentrically pivoted at one end and provided with a series of teeth in the under face of its pivotal end, a

rack-bar held to slide upon the jamb and en-.

J OHN JOHNSTON.

' WVitnesses:

J. F. ACKER, J r., (J. SEDGWICK.

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