US1015809A - Cable-clamp for electric-elevator circuit-breakers. - Google Patents

Description

A. H. LOWE.

CABLE CLAMP FOB. ELECTRIC ELEVATOR CIRCUIT BREAKERS.

APPLICATION FILED NOV. 12, 1909.

1,015,809. Patented Jan. 30, 1912.

ag- 2 WITNESSES: INVEN TOR.

ALBERT H. LOWE, OF ST. LOUIS, MISSOURI.

CABLE-CLAMP FOR ELECTRIC-ELEVATOR CfIRGIJ'I'D-IBIRJEAKEIlZtS.

Specification of Letters Patent.

I Patented Jan. 30, 1912.

Application filed November 12, 1909. Serial N 0. 527,674.

To all whom it'may concern:

Be it known that I, ALBERT H. LOWE, citizen of the United States, residing at St. Louis, State of Missouri, have invented certain new and useful Improvements in Cable- Clamps 'for Electric-Elevator Circuit- Breakers, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part hereof.

My invention has relation to improvements in cable-clamps operating in conjunction with circuit-breakers on electric elevators; and it consists in the novel details of construction more fully set forth in the specification and pointed out in the claims. In the drawings, Figure 1 shows a crosssection of the cable securing beams at the top of a conventional elevator car showing my invent-ion applied to the circuit-breaker controlling cable; Fig. 2 is an enlarged side elevation of the upper end of thecircuitbreaker lever with the cable and my attachment passed through the stirrup or loop of the lever; Fig. 3 is a view at right angles to Fig. 2; Fig. tie a view similar to Fig. 2 with one of the clamp sections and circuitbrea'ker lever omitted; Fig. 5 is a cross-section on the line 55 of Fig. 2; and Fig. 6 is a cross-section on line 66 of Fig. 2.

The object of my invention is to provide a clamp or protecting sleeve for that portion of the supporting cable of an electric elevator which passes through the terminal loop or stirrup of the circuit-breaker lever with which the majority 'of elevators are equipped, said clamp preventing the cable from direct contact with 'suchstirrup and hence preventing any possible wear of the cable at that point. The point referred to is generally the weakest in the cable, and

' necessitates not only constant watchingj but is a source of danger on account of weakening the cable.

A further object of my improvement is to provide a clamp which will guide a slack cable back into the stirrup in' the event of displacement resulting from a sudden stoppage of the car on its descending trip; a

further object is to provide a clamp which will grip the cable uniformly throughout the length of the clamp; one which may be applied to the cable without the necessity of disturbing any of the parts identified with the circuit-breaker; and one possessing further and other advantages better apparent from a detailed description of the invention, which is as'follows:

Referring to the drawings, 0 represents the upper portion of an elevator car, and B, B, the usualbeams surmounting the roof thereof, and to which the hoisting cables at are attached. Pivoted between a pair of lugs 1, 1, on the top of the car, is the base 2 constituting the short arm of the bent circuit-breaker lever 3, the free end of the long arm of which terminates in a loop or stirrup 4 through which one of the cables freely pass, the particular cable thus identified with the circuit-breaker lever being for convenience designated by the reference letter a.

The free end of the short arm or base 2 of this lever carries a spring-controlled contact disk 5 which normally engages the ends of the wires w, w, included in the circuit of the current that operates the motor or engine by whichthe car is driven. The contact disk 5 is forced into contact with the wire elec trodes w, w, by the cable a which so long as it is stretched taut, will oscillate and hold the lever 2, 3, in proper position to force the disk 5 into contact with the wires; but should the cable at any time become slack, so as to lose control over the lever 2, 3, then the expanding action of the strong spring 6 (interposed between the. hinge axis of the lever and the disk 5, with opposite ends bearing respectively in "the depression 0r pocket 8 in the base 2 and against the beam B), will assert itself and oscillate the lever in areverse direction or so as to force the disk 5 'out of engagement with the wires 20, w, thereby breaking the circuit, which will have the effect of stopping the motor and the car C will come to a stop. The slacking of the cables at, a naturally arises when for any reason the car while descend ing comes to a su ddenstop, as for example in emergency cases where the gripping dogs arrest the car against sudden precipitation in cases of accident. When the descending car therefore, for any reason'comes to a sudden stop, it is absolutely necessary that the circuit be broken, otherwise the motor would continue to run and unwind the cables which would then be twisted out of shape, and damage to the machinery result. In the slackening of the cable a under the conditions referred to, it will slip more or less through the stirrup or loop 4:; and, under normal conditions the constant pressure which inevitably results between the cable a and the stirrup 4: (brought about by the expansive force of the spring 6), in time causes the cable to wear and become weak at the point where it passes through the stirrup, the cable even cutting through the bushing with which the stirrup is usually provided. The weakening of the cable a at this point is dangerous and consequently undesirable, and it is the object of my invefntion to protect the cable and prolong its li e.

The features above described are all well understood in the art and I make no claim thereto, their description being however, necessary to abetter understanding of my invention which is as follows :Where the cable a passes through the stirrup 4, I secure thereon a sectional clamp or sleeve, said clamp being preferably made of two halves or sections 7, 7, united together below the stirrup by bolts 6 passed through the lugs 8, 8, the outer peripheral formation of one of the sections opposite the lugs being in the form of a rib 9, the ends of which form shoulders (1 against which the nuts n are first placed before the bolts are screwed thereinto, these shoulders serving as nutlocks, and preventing the nuts from unscrewing when once the parts are assembled. It will be seen that the upper terminal of the clamp is provided with a conical or tapering end 10, the purpose of which is to guide the clamp back into the stirrup 4 should the slack in the cable permit the stirrup to pass beyond the clamp. Preferably, (though, not necessarily) a layer of fiber e is first wrapped about the cable, before the clamp is secured thereto.

It is obvious of course, that, but for a detail to be now referred to, the greatest grip of the clamp on the cable would be opposite the-bolts b which are located near the base of the clamp below the stirrup 4. This 'leaves the upper portion of the clamp or that passing through the stirrup &, of greater length than the lower portion or that below the lugs 8, 8, and this excessive length would naturally not hug the cable as tightly as the parts in the region of the bolts. To equalize therefore, as nearly as possible, the grip of the sections on the cable, I form at the base of the inner bore or surface of each section an offset or shoulder 11 which first contacts with the cable,,said olfset serving as a fulcrum about which the sections are drawn toward the cable when the screw-bolts are applied. In this way the grip on the cable is substantially equalized at the top and bottom of the clamp, actual contact with the cable taking place at substantially all points along the length of the clamp, except perhaps just a trifle above the shoulders 11. The clamp once in place on the cable forms a protecting sleeve therefor, and as it is preferably made of bronze or equivalent composition the wear will come on it rather than on the stirrup, and so far as the cable is concerned, it will be fully protected. When the clamp is worn it may be readily replaced with a new one, the individual sections being slipped through the stirrup from the bottom, and then bolted together and clamped to the cable. The upper extension of the clamp, or that above the fastening lugs 8, 8, as compared with the lower portion or that below the lugs, should be of sufficient length to allow for the necessary play of the cable through the stirrup under all circumstances, and the upper terminal bevel or conical tip 10 should be of the proper pitch to easily guide the cable back into the stirrup should the slack, in cases of sudden stoppage of the car, force the clamp out of the stirrup. Obviously, the object of making the protecting clamp or sleeve in sections, is to facilitate the application of the clamp for purposes of renewal. So far as the invention is concerned, however, its sectional character may be ignored.

It may be stated in passing that in the event a slack in the cable occurs, but the cable should fail to slip through the stirrup as a result of such slack, the spring 6 will nevertheless force the lever 2, 3, to break the circuit, the necessary oscillation to effect such result being possible by reason of the fact that the lugs 8, 8, are sufficiently removed from the bottom of the stirrup as not to interfere with the oscillation of the lever.

I-Iaving described my invention, what I claim is I 1. In combination with an oscillating circuit-breaking lever for electric elevators, provided with a terminal loop, a controlling cable secured at one end to the car and extending through the loop, a protecting clamp on the cable normally fitting loosely within the loop, and means on the clamp positioned below the loop for securing the clamp to the cable.

2. In combination with an oscillating circuit-breaking lever for electric elevators, provided with a terminal loop, a controlling cable secured at one end to the car and extending through the loop, a protecting clamp In testimony whereof I aflix my signature, on the cable normally fitting loosely within in presence of two witnesses. the loop, said clamp comprising two sections adapted to jointly envelop the cable and ALBERT H LOWE form a sleeve about the same, and means on the respective sections positioned below the Witnesses: loop for securing the sections together and EME STAREK, clamping them securely to the cable. FANNIE E. WEBER.

Copies 01' this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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