US2481796A - Safety grip for hoists or elevators - Google Patents

Description

p 1949. E. THOMAS 2,481,796

SAFETY GRIP FOR HOISTS OR ELEVATORS Filed April 14, 1947 I 2 Sheets-Sheet 1 I INVENTOR. aw- CHARLES E.THOMAS o M M "mm Attorney:

Sept. 13, 1949. c. E. THOMAS 2,431,795

SAFETY GRIP FOR HOISTS on ELEVATORS Filed April 14, 1947 2 She'ts-Sheet 2 "IIIIIIII a H i i: h l' l H ['41 l ::l L- I I I 34 Z4 U"- (E I 'uumnuumuu i l I 3 25 (g. 4 Z INVENTOR.

CHARLES E. THOMAS BY MM Attorneys mmmm.

Patented Sept. 13, 1949 UNITED STATES PATENT OFFICE 2,481,796 SAFETY GRIP FOR HOISTS on ELEVATORS Charles E. Thomas, Los Angeles, Calif. Application April 14, 1947, Serial No; 741,164

This invention relates to improvements in elevators or hoists.

A primary object of the invention is to provide a device applicable to a conventional type of elevator or hoist which will automatically arrest the descent of the carriage whenever the car,- riage starts to fall freely.

More specifically, an object of the invention is to provide a construction wherein the carriage is provided with grips and engageable with the guides or runners that guide its vertical movement, and to provide means for normally holding these grips out of engagement with the guide to enable the carriage to be lifted or lowered as long as. the carriage is suspended, either loaded or unloaded. By means of this construction, in the event that the suspending cable should break to allow the carriageto fall freely, the grips are automatically advanced into engagement with the guides or runners to arrest the descent of the carriage.

Another object of the invention is to provide a carriage for hoists wherein there is a lower deck on which variousmaterials may be positioned that are to be hoisted and also an upper deck which may be similarly loaded, the upper deck being so arranged that after it has been unloaded it may be conveniently positioned to facilitate unloading of the lower deck.

With the foregoing and other objects in view, which will be made manifest in the following detailed description and specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Figure 1 is a view in side elevation of the carriage embodying the present invention;

Fig. 2' is a partial view in front elevation of the same;

Fig. 3 is a vertical section taken substantially upon the line 33 upon Fig. 2; and

Fig. 4 is a horizontal section taken substantially upon the line 44 upon Fig. 3.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, the improved carriage may be constructed in any conventional or preferred manner and has a lower deck, generally indicated at Ill, with uprights II extending upwardly therefrom adjacent the sides of the lower de'ck. Horizontal members l2 may connect these uprights and braces l3 may be used to connect them. At the top of the carriage there is a transversely extending beam generally indicated at M and through this beam a pair of vertical members 2 Claims. (01. 187-86) [5 are vertically slidable These vertical members are connected together by means of a clevis 16 to which a suspending cable, not shown, -may be secured. The lower ends of the vertical members are connected by a fitting I'l consisting of vertically spaced plates connected to each other by means of a central stud l8. A compression spring I9 is seated at its lower end upon the upper plate ofv the fitting I8 and is seated at its top on the underside of the upper portion of the beam l4. When the carriage is suspended fromthe clevis Hi the compression spring I8 is compressed due to the load imposed thereon either bythe unloaded or loaded carriage.

Levers 20 are pivoted on fulcrums 2| on the beam l4 and have their inner ends slidably disposed in the spaces between the upper and lower plates of the fitting Il. These levers in turn have their outer ends bent downwardly as at 22 and apertured to receive the outwardly bent upper ends of actuating rods 23. The rods 23 extend downwardly adjacent the sides of the carriage to a point adjacent the jaw housings 24. The lower ends ofthe actuating rods 23 have spaced plates 25 between which arms 26 are slidably disposed. These arms are rigidly secured to opposed jaws '21 arranged on opposite sides of a guide or runner 28 that forms a part of a surrounding scafiolding or other structure that provides an elevator shaft for the carriage. Inclined slots 29 are formed in the jaws and pins 30 extend through these inclined slots and connect the sides of the jaw housmgs.

When the loaded or unloaded carriage is suspended from the clevis It the compression of the spring 19 enables the fitting I! to move upwardly with relation to the carriage. This moves the inner ends of the levers 20 upwardly and forces the outer ends of the levers 20 downwardly forcing the actuating rods 23 downwardly and thus shift- 7 ing the grips or jaws 21 downwardly with relation to the pins 30. In this manner, the grips or jaws are normally held out of engagement with the guides or runners 28. When the grips or jaws are thus held out of engagement with the guide or runner 28 the carriage may be freely raised or lowered by means of the suspending cable. However, if the suspending cable should break or the carriage otherwise be allowed to fall freely, the load imposed on the compression spring IS on being removed enables the compression spring to expand, thus forcing the inner ends of the levers 2i} downwardly and elevating the actuating rods 23. When the actuating rods are thus elevated the grips or jaws 21 are carried upwardly thereby.

It will be appreciated from the above-de ii scribed construction that the actuatingof the jaws is entirely automatic and is dependent entirely upon whether or not the load of thecarriage is at least partially suspended from the suspending cable.

3| indicates an upper deck that is pivotally mounted as at 32 upon supporting legs 33, These supporting legs in turn are pivoted on the carriage as at 34. On .the underside of the upper deck there are pins 35 receivable in recessed keepers 36 on the framework of the carriage or hoist. On the opposite side of the upper deck there are slidably mounted latches 31 urged out.- wardly by means of a compression spring 38 but which can be retracted inwardly by means of handles 39. The outer ends of these latches are receivable in keepers 40 mounted on the framework of the carriage. As the legs 33 are preferably telescopic in form the upper deck 3 I may assume a position eitheras indicated in full lines "on Fig. 1 or a position as indicated in, dotted lines .wherein the pins 35 are engaging the keepers 36 andthe latches 39 are engaged with the keep- .ers 40. .In this positionthe carriage provides two decks both of which may be loaded. When the upper deck has been unloaded the latches3lcan be retractedv by means of the handles 39 to disengage the keepers 4D and theupper deck tilted into the position shown in full lines on Fig. 1 to iacilitate the unloading of the lower deck..

Itwill be appreciated by this construction that 'theimproved carriage enables two decks to be loaded and raised or lowered to the desired elevation and that when the upper deck has been unloaded it may be tilted to assume a position that and scope of the invention. as, defined by the appended claims.

I claim: V V 1. An elevator or hoist comprising a carriage, at least one longitudinal guide member at either side of the carriage for guiding the carriage,

means connectable to cables for supporting the carriage slidably receivable by the carriage, spring means positioned between the first means and the carriage compressible by relative movement of the first named means and the carriage when the first named means supports the carriage, a pair of paws for each guide member, the jaws for each guide member sandwiching the guide member therebetween, jaw housings fixedly mounted on the carriage at the sides thereof for carrying the jaws, the jaws providing angular slots therein slanted upwardly and inwardly toward the guide members, means on the jaw housings receivable in the slots in jaws whereby the jaws are guided in their movement toward and away from the guide members, and means connecting the first named means and the jaws whereby when the carriage is suspended by the first means, the spring means are compressed and the jaws are urged .away from the guide members but when the carriage is free, the spring means urges the jaws upwardly and inwardly toward the guide members.

2. An elevator or hoist comprising a carriage, at leastv one'longitudinal guide member at either side of the carriage, means connectable to cables for supporting the carriage, slidably receivable by the carriage, resilient means associated with the'first named meansand the carriage so as to be stressed when the carriage is supported by the first named means and urging the first named means to move relative to the carriage, a pair of jaws for each of the guide members, the laws for each guide member sandwiching the guide member therebetween, guide means on the carriage carrying the jaws for guiding the paws in-.

wardly and upwardly toward the guide members and downwardly and outwardly from the guide members, and means connecting the first named means and the jaws whereby when the carriage is supported by the first named means the resilient means are stressed and the jaws' urged away from the guide members but when thecar- V riage is free'the resilient means urges the jaws upwardly and inwardly toward the guide mem- CHARLES E. THOMAS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED sTATEs PATENTS Number Name H Date 762,398 Froussard June 14, 1904 803,425 4 Mater Oct. 31, 1905 1,252,737 Tanner Jan. 8, 1918 1,541,144 Holmes June'9, 1925 2,133,621 Klein Oct. 18, 1938

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