US1842854A - Safety latch-mine skip - Google Patents

Description

Jan. 26,- 1932. R. J. WILLIAMS SAFETY LATCH MINE SKIP JLZ Filed Sept. 27, 1928 banjo/1- We J wzzmma,

Patented Jan. 26, 1932 UNITED STATES Brennan J. WILLIAMS, or VIRGINIA, MINNESOTA sArETY LATCH-MINE (SK-I1 Application filed September 27, 1928. Serial No. 308,679.

This invention relates to safety appliances and is illustrated herein as embodied in a device for use in connection with elevator hoists to prevent falling ,of the car, orlift, upon accidental severance of the hoisting cable 7 In the operation ofvarious elevator hoists, such, for'example, as those employed in mines, the controlling apparatus may for some reason or other fail to operate properly with the result that the liftor' skip, as theyare commonly termed in the mining artdoes not stop when it reaches the limit of its upward travel, but continues .to be pulled vertically until it overtravels the guides upon which it is mounted, and, jams against theframe work of the shaft. Notwithstanding the fact thatthe skip is in such a condition, the hoisting apparatus may still continue to operate, putting more and more tension on the hoisting cable until the latter tears apart and the skip drops downwardly into the mineshaft wrecking itself at the bottom, with apossibility of doing 'greatdamage and possiblycausingloss of life. 1

This undesirable manner of operation on the part of the hoist is commonly termed an overwind, and it'is an important object of the present invention to provide an improved device or mechanism for preventing a skip or hoist fromfalling'if the hoistingcable is parted by'reason of an overwind. It is further anobject of the invention toprovide a device of this character thatiis simple in design and construction and relatively inexpensive to manufacture-and to-install.

A feature of the'invention which leads-to the accomplishment of the recited objects consists in providing'adevice that is normally stationary, but is operable upon contact with the hoist to move into a position in which it prevents the hoist from'falling downwardly in the shaft. It is to be appreciated, of course, that the most accurate manner in which the operation of the safety mechanism could be timed is by its engage mentwith the hoist, or skip, and according- 1y, it is proposed to mount the safety mechanism at the top of the shaft immediately adjacent to the limit oftheupward travel of the hoist, in which condition it remains normally inoperative and out ofthe Way, but will, upon being engaged by the hoist, move nto a position to prevent the latterfrom fall- Still another feature of the invention consists in constructing the safety device in such a manner that when'it has once operated to prevent the skip from falling, it must be reset to reassume an operative position before Other objects and features of the invention will become apparent from a reading of the following specification in the light of the accompanying drawing in which there is shown an elevator hoist suitable for mining use and equipped with a safety mechanism of the improved character.

As shown in the drawing, the elevatorhoist comprises, generally speaking, a plurality of containers, 10, 12, which are known by such terms as skips, cars, buckets, hoists, etc.,

arranged for vertical movement between guideways 14c andldrespectively. A sloping bin '18 is arranged to receive material from the containers 10, 12 and is provided withla track 20, running beneath the bin, in order 1 that dump cars 22may berolled into a position beneath the outlet of the bin to receive materials therefrom. The skips 10 and 12 are provided upon opposite sides with outwardly projecting lugs 2 k, which are arranged to ride in grooves formed in the guideways 14, 16, until the point 26 is reached, whereupon they move inwardly through the guidewa-ys 28, causing the top of the bucket to swing downwardly as the bottom of the bucket is raised. It is during such movement, of course, that the dumping operation betweenthe bucket and the bin takes place.

The mechanism for hoisting the skips 10 and 12, comprises, as illustrated, a hoisting apparatus 30 that is provided with means normally adapted to prevent overwinding of hoisting cables 32 which lead over sheaves 34 and connect, by means of clevises, with the upper cross bar of rectangular bails 36, which carry the skips 10 and 12.

From an inspection of the drawing, it will be seen that if the apparatus should continue to hoist after the skip has reached the limit of its upward travel, then the clevis in the loop end would bind upon and tend to move upwardly in the groove of the sheave 34 until the tension brought about by the bail 36 jamming on the guideways 16, would overcome the tension applied to the hoisting apparatus 30, whereupon the hoisting cable would sever and the bail 86 and container 12 would crash downwardly to the bottom of the shaft where it would wreck itself and, in great likelihood, cause considerable damage.

In order to prevent the skip from falling in the event that an overwind takes place, there is provided a safety device or mechanism which is arranged for movement between an inoperative out of the way posi tion, and an operative skip engaging pos1- tion. As shown in the drawing, a rotatable shaft 40 is mounted at the top of the shaftway or skip-way and is provided with a plurality of arms 42 which extend outwardly in a position to overlie the path of movement of the skips 10 and 12, whereby the outwardly extending arms are engaged by the skips if the latter exceed their respective limits of upward travel, and cause rotation of the shaft 40. Integral arms 44 extend rearwardly from the opposite ends of the shaft 40 and pivotally connect with link connecting rods 46 which, at their lower extremities pivotally connected to safety latch members 48. A supplemental integral arm 50 extends centrally from the shaft 40 and is connected to a plurality of links 52, which are pivotally connected with uniformly operating safety latch members 54, it being observed that both of the safety latches 48 and the latches 54 are pivotally mounted at one extremity upon the frame work of the elevator shaft.

In discussing the operation of the safety device shown in the drawing, it is requested that the reader first turn his attention to the skip 10, which is shown in a lower position than the skip 12, and picture the travel of the skip 10 as it moves upwardly in the shaftway. The arm 42 extending from the shaft 40 overlies the upper member of the bail 36, which carries the skip 10 and if the hoisting apparatus does not operate to stop the upward movement of the bail upon the skip 10 moving into a dumping position, the bail will engage the overlying lever 42 and move it upwardly, thereby rotating the shaft, thrusting the lever 46 downwardly, and moving the safety latch 48 into a position in which it underlies the bail 36, in the manner shown in the drawing in connection with the skip 12, whereby it is impossible for the skip to fall in the event that the cable severs.

When the safety apparatus has once been operated and the latch 48 is underlying the hail of the skip, a lever 60 extending from the opposite ends of the shaft 40 in directions opposite to the levers 44 may be operated manually to movethe safety latch into an inoperative position in which the skip is free to descend. It is to be noted in this connection that such words as skip, hoist, car, etc., are intended to include both the bail and the container mounted within the bail and not merely the container alone.

From so much of the description as appears above, it will be understood that normally the safety latch members 48 occupy an out of the way position which means, of course, that the contact members 42 will occupy a position in which they overlie the skip-ways, whereby the skips 10 and 12, striking the members 42, will cause the latch members to be moved outwardly into engagement with the skips. An important consideration resides in the fact that if by chance the safety latch members 48 should be disposed in an outward, operative position while the skips are beneath them, they will, upon being engaged by the upper edge of the skips, be swung into an inoperative position and the contacting levers 42 will accordingly be moved into an operative position, the result of this being that the safety latch is bound to operate at all times, for if it occupies an inoperative position, the skip itself moves it into an operative position before the limit of upward movement of the skip has been reached and thereafter the safety latch is properly set for operation. It is also to be observed that when the latch is moved from an operative position such as that shown in the drawing to an inoperative position in which it will be disposed out of the path of the skip, the contacting arms 42 must perforce be moved downwardly into a position to overlie the skip-ways. Thus, in releasing the skips, the safety devices are simultaneously reset for a subsequent operation.

While the invention has been discussed herein, with particular reference to mining hoists, it is to be understood that it may be used in connection with elevators and hoists of practically every kind and description, and it is likewise to be understood that the invention contemplates the incorporation therein of modifications and changes such as will from time to time appear to those skilled in the art.

Having thus described my invention, what I claim as new and desire to secure by United States Letters Patent is:

1. An elevator hoist having, in combination, a vertically extending shaft, a lift mounted within the shaft, means for operating the lift, and safety means for preventing the lift from falling upon failure of the operating means, said safety means comprising a pivoted lever adapted to be engaged by the lift, and a pivoted lever adapted to engage a projection carried by the lift, the members being so constructed and arranged that movement imparted'to either of the levers results in movement being imparted to the other.

2. An elevator hoist having, in combination, a vertically extending shaft, a lift mounted within the shaft, a cable operable to impart movement to the lift, a rocker arm located at the top of the shaft and provided with a lever arranged to extend laterally into the shaft for the purpose of being engaged by the lift to oscillate the rocker arm, a second rocker arm located a substantial distance below the first arm and provided with a lever arranged to extend laterally into the shaft restrainingly to engage the lift, a connection extending between the two rocker arms and so arranged that movement of one of the members into a position extending laterally into the shaft causes retraction of the remaining member out of the shaft, and a lever carried by the first named rocker arm for imparting movement thereto.

Signed at Virginia, Minnesota, this 17th day of September, 1928.

RICHARD J. WILLIAMS.

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