US2804175A

US2804175A - Elevator safety apparatus

Info

Publication number: US2804175A
Application number: US402560A
Authority: US
Inventors: Joseph C Phillips
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-01-06
Filing date: 1954-01-06
Publication date: 1957-08-27
Anticipated expiration: 1974-08-27

Description

7, 1957 Y J. c. PHILLIPS I 2,804,175

ELEVATOR SAFETY APPARATUS Filed Jan. 6. 1954 2 Shets-Sheet l f fighi.

INVENTOR.

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Aug. 27, 1957 J. c. PHILLIPS ELEVATOR SAFETY APPARATUS 2 Sheets-Sheet. 2

Filed Jan. 6, 1-954 M W a m W J w United States Patent 2,804,175 ELEVATOR SAFETY APPARATUS Joseph C. Phillips, Baltimore, Md. Application January 6, 1954, Serial No. 402,560 4 Claims. Cl. 187-86) This invention relates to elevators or lifts for carrying persons and material from one height to another through a vertical plane. It is particularly intended for such equipment, used in conjunction with the construction of buildings and serving as a portable or transportable arrangement for the purpose, and the delivery of material needed to the various heights.

While a number of devices have been designed and used in connection with the prevention of elevators from falling and doing damage, when the hoisting cables break such have in most instances proved ineffective because of their tendency to collapse the columns supporting and guiding the elevator platform, as well as slip or break the braking devices involved. In this invention the breaking of the hoisting cables allows braking device to resiliently and powerfully react and work on the supporting columns in such a manner as to avoid collapsing and spreading them apart, while at the same time providing for an effective restraint against further falling of'the platform.

An object of this invention is to provide a new and improved safety control for an elevator that will operate positively and effectively, be installable economically, yet be simple, compact and attractive in design.

Anotherobject of this, invention is. to provide anew and improve safety control for an elevator platform that will act on the supporting columns of the elevator structure without injury to themselves or the control.

A further object of the invention is to provide a new and improved safety control for an elevator platform that will employ an eccentric frictional surface in contact with the supporting columns of the elevator structure immediately operable when the hoisting cables of the elevator break and work efficiently in spite of oil and grease on the contact surfaces.

An additional and important object of the invention is to have a safety control attached to the platform and contactable with the supporting columns of the elevator structure, so arranged that the operation of the control under emergency conditions will not cause the columns to spread ordistort into misalignment or form enough to interfere with the proper action of the device.

Other objects of the invention will become apparent as the details of its construction and the principles of its operative functions are explained.

For a better understanding of the invention and the objects thereof, reference is made to the accompanying drawings. These drawings illustrate a particular form of the construction preferably adopted, while the following description indicate how it is made and the basis of its functioning.

In the drawings:

Fig. 1 is a front elevation of an elevator with safety controls embodying this invention;

Fig. 2 is a perspective view of one spring element; Fig. 3 is a schematic of one spring element in one operative position;

ice

Fig. 4 is a schematic of said spring element of Fig. 3

in a second operative condition; 7

Fig. 5 is a schematic of said spring element of Fig. 3 in a third operative position; f

Fig. 6 is a side elevation of an enclosure with a side thereof broken away;

Fig. 7' is a section along line Fig. 8 is a detail of a pawl.

Similar reference numerals refer to the same parts throughout the drawings. i

In the construction shown in the drawings, an elevator carrier consists of a flat horizontal platform 10, that is supported underneath by a structural member 11. Vertical struts 12 extend from the member 11 upward and terminate in a channel cross beam 14, forming a ridge bar across the carrier and serving as a suspension member to 'which the hoisting cable 13 can be conveniently 7-7 of Fig; 1; and

attached. A thimble 15 at the end of the cable is'held' by a bolt 16 to the beam 14. This single cable 13, is carried to the overhead pulleys and from thence to the winch supplying the power to lift the elevator. This follows conventional procedure and therefore is not shown, as the details are well known to'those skilled in the art.

Coupled to the cable 13 is a clamp 34'bolted securely fulcrum plates 20. When the chains exert a pull on the bars 18 in the angular plane they compress (or extend, as preferred) their individual coil springs 21 and tension them so they induce a resilientforce tending to push the bars '18 downwardly. This is resisted when the cable 13, lifts against them. This force will induce'leverage on the bars and lift up on the short ends 22. The springs 21 are supported on a bolted frame 32 attached to the ridge beam 14. The short ends 22 are attached to oscillatable positioned shackles or saddles 23 holding brake cams24 by part 37. These cams are supported off center by pivots 35 mounted on enclosure 30. The pivots 35 are heldbetween the arms 25 of the saddles which are made bifurcated for the purpose. The front and

rear faces

26 and 27 of the cams respectively are preferably rounded at 27 and serrated at 36 to provide a roughened surface resistance.

U-formed enclosures 30 serve to encompass and support the cams 24 and in definite relation to the ends of the ridge bar 12. This arrangement aligns the cams so their faces 26 can engage the periphery of their respective pipe guiding column 28 on one side and inner surface 29 of the enclosure 30 by the opposite face 27. The inner surface 31 of each enclosure 30 is aligned close to the peripheral surface of the respective column 28, opposite to face 29. The cams are adjusted so that normally they will not contact the surfaces of the encolsures 30 and the pipe columns 28, and thus will not interfere with the free running of the elevator carrier in its usual vertical travel. However, when the hositing rope 13 breaks and loosens up on the chains and release bars 18, the latter allows the coil springs 21 to force the earns 24 upward from the position indicated in Figure 3 or 4 to that shown in Figure 5. The springs 21 push down on a rod 33 and pivots the cams on the fulcrums so that powerful contact effects bring the

faces

26 and 27 against the peripheral faces of the column 28 and face 29 of enclosures 30 respectively. This brakes the carrier and quickly brings it to a stop.

The inner surface 31 of the enclosure is preferably roughened, serrated or faced with welding 134 to add to frictional and wear resistance. When the cams make the emergency contact they exert pressure against the 'Patented Aug. 2'1, 1957 inner surfaces 29 and reacting against the pipe they bring the enclosure-over enough to make the surfaces 31 brace against the opposite side of the pipe. This distributes the effect and prevents the crushing of ,the pipe fcolumn 28 and prevents course to be;understood slightly longer than the jammed against the pipes '28 when the release bars are loosened at the breaking of the hoisting rope. The movement of g the carrier falling and its momentum brings the cams and their serrated ,surfaces into such engagement with the toe. stop. I

The devices are returned tooper-ati-ve conditionaftet repairs have been made,v by replacing thehoistingrope andpulling up on the chains 17 with the release bars into position for emergency tension, and future operation. When the hoisting rope normally holds the carrier in lifting positions, it places theemer-gency braking mechanisms under resilientjtension, ready to actuate when released. 7 7 a *The characteristics. of the device are important because they include plural wearing surfaces for emergency use; a cam-like wedge for positive yet not too abrupt braking effect; the use of the guide columns for braking coordination without danger of their being destructively damaged during the period of braking; components of the braking mechanism made readily accessible for facile inspection, adjustment,; replacement and repair, and designed to operate effectively in spite of grease and other lubricants covering the braking surfaces and components While but one general form of the invention is. shown in the drawings and described in the specification, it is not desired to limit this application for patent to this particular form as it is appreciated that other forms .of construction could, be made that would use the same principles and come within the scope of the appended claims.

Having thusrdescribed the invention, what is claimed is:

1. The combination, with an elevator, of emergency safety mechanism for preventing uncontrolled descent of the elevator; said elevator comprising a pair of oppositely disposed hollow columns, a platform, a cross beam, a pair of struts supporting said cross beam above the platthat the length of each cam is its moving out of alignment; :It is of space .it spans;v They ,become pipe column, as to bring the carrier form and each of said struts embracing one of said colstraddling one of said hollow columns, a second pair of pivot elements each connecting one of said cam members to one ofsaid U-shaped members, means connecting the other end of each of said .levers to said cable and resilient means tending to swing said other ends of said levers toward said cross beam, said U-shaped members and said cam members having serrated portions confronting said columns; the pivots connecting the cam members to the U-shaped members being positioned to cause lifting of the saddles to swing the serrated portions of the cam members into contact with said columns and the length of the cam members being such as to cause such contact to move the U-shaped members to bring the serrated portions thereof into contact with portions of the hollow columns opposite to the portions engaged by said cam members. '2'. A combination of the type set forth in claim 1, in which the means connecting said levers to said cable include a clamp secured to said cable and flexible means connecting said other ends of the levers to said clamp.

3. A combination of the type set forth in claim 2, which includes a pair of frames secured to said cross beam, and supporting said resilient means in position to act on said levers.

'4. A combination of the type set forth in claim 3, in which welding material is applied to a partofeach of the serrated portions of the U-shaped members.

References Cited in the file of this patent UNITED STATES PATENTS 741,481 Fulwider Oct. 13, 1903 1,163,239 Iron Dec. 7, 1915 1,373,944 Boeh'ck Apr. 5, 1921 1,515,452 Webb et al. Nov. 11, 1924 2,629,461

Moyer Feb. 24, 1953