US1886213A - Elevator safety appliance - Google Patents

Description

Nov. 1, 1932. J. B. MURPHY 1,886,213

ELEVATOR SAFETY APPLIANCE Filed Oct. 17, 1929 2 Sheets-Sheet 1 Nbv. l, 1932. J. B. MURPHY ELEVATOR SAFETY APPLIANCE Filed Oct. 17, 1929 2 Sheets-Sheet 2 glwomioz .Mwr ok fwd/94 Patented Nov. 1 1 9 32 UNITED STATES JOHN B. MURPHY, OF GOTTONWOOD, ALABAMA ELEVATOR SAFETY APPLIANCE- Application filed October 17, 1929. Serial No. 400,286

The object of the invention is to provide an appliance for use in connection with elevators, whether they be passenger or freight that will automatically operate to hold the car at a fixed position in the shaft in the event of damage or rupture to the hoisting cable or hoisting apparatus; to provide a construction which may be readily applied to elevators now in use without any material modification 10 thereof; and to provide a construction which, while extremely eflective, is of simple form and therefore susceptible of cheap manufacture and low marketing cost.

With this object in view the invention consists in a construction and combination of parts of which a preferred embodiment is illustrated in the accompanying drawings, wherein:

Figure 1 is a view partly in elevation and 20 partly in section, showing an elevator equipped with the invention, the latter being in the released position or that in which the elevator is permitted to move.

Figure 2 is a view similar to Figure 1 but 25 showing the invention in operative position to prevent dropping of the elevator.

Figure 3 is a cross-sectional view on the plane indicated by the line 33 of Figure 1.

Figure 4 is a perspective view of one of the grippers.

Figure 5 is a central longitudinal sectional view of the structure of Figure 4.

In the application of the invention, the car traverses the usual guides 11, being ele- 5 vated and lowered through the instrumentality of the cable 12 actuated by a suitable hoisting apparatus.

In the illustrated embodiment, the guides 11 are shown at diagonally opposite corners 0 of the shaft and at the remaining diagonally opposite corners are the safety rails 14 which constitute elements of the invention. These safety rails are preferably standard steel sections of cross-sectionally H-shaped form, one flange being used for stationing them in their upright positions and the remaining flanges being embraced by the gripper feet 15 of the safeties 16, the latter being of the general form of bell crank levers pivoted, as at 19, on the car 10. Preferably the pivots 19 are carried by corner posts 20 formingelements of the car. a

The force arms of the safeties 16 are pivoted to bars 21 which at their upper ends are pivotally connected to links 22 which have pivotal connections 23 with the upper ends of the corner .post 20. The two levers 22 extend towards each otherand are connected with the hoisting cable 12 by means of links 24 which engage .an eye 25 carried at the lower end of the cable.

The bars 21 extend through openings'in the car bottom and are formed with heads 26 below the bottom of the car, combination springs 27 surrounding the bars and having their ends bearing respectively on the car bottom and on the heads 26.

The springs tend to effect relative movement between the bars 21 and corner posts 20 in one direction but this tendency is op posed by the levers 22 when the cable 121 is under tension, as when hoisting and lowering the car. With the cable 12 under tension, the force arms of the grippers are elevated and the work arms depressed and the car may move freely up and down since the gripper feet will then slide readily over the safety rails. Should the cable 12 break, however, or anything happen to the hoisting apparatus resulting in a slack in the cable, the springs 27 would immediately function to force the bars 21 downwardly, swinging the force arms of the grippers downward and elevating the work arms when'they would effect gripping action on the safety rails and retain the car at its point of location at the time of the slack in the cable 12.

The gripper feet 15 are of a form to embrace the free flange and a part of the web of the safety rails, the T-shaped slot thus formed in the feet having its walls parallel with the free flanges of the safety rails when i the work arms of the grippers are depressed or in a released position. In the operative or gripping position of the work arms of the safeties, however, the walls of the T- shaped slot in the gripper feet are swung out of parallelism when the safety rails flanges and the edges of the slot bite into the flanges to retain the car at the point where it happened to be at the time of slack or breaking of the cable 12.

The invention having been described what is claimed as new and useful is:

In combination with an elevator, safety rails disposed on opposite sides of the elevator and arranged in parallelism with its line of travel, said rails being formed with spaced parallel flanges and a connecting web portion joined with the flanges 011 an inter mediate longitudinal line, grippers'pivotally mounted on the elevator and consisting of levers the work arms of which are formed with gripper feet provided with T-shaped slots of a form to embrace one flange of the safety rails and the adjacent. web portion thereof, and means connected with the force arms of the levers to normally hold them in a position where the walls of the T-shaped slotsparallel the flanges of the safety rails, and additional means connected to the force arms of the levers to swing the gripper feet to a position where the edges of the T-shaped slogs will bite into the flanges of the safety rai s.

In testimony whereof he affixes his signature.

JOHN B. MURPHY.

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