US2177553A - Safety trip device - Google Patents

Description

@cft. 24-, 1939. J C) SPEED 5 AL 2,177,553

SAFETY TRIP DEVICE Filed Feb. 11, 1938 Sniaentors JAMES 0. SPEED BE NAMES 1.. SHORES SAMUEL R. POWERS W 7 (Ittornegs Patented Oct. 24, 1939 PATENT OFFIQE SAFETY TRIP DEVICE James 0. Speed and James L. Shores, Birmingham, and Samuel R. Powers, Clanton, Ala.

Application February 11, 1938, Serial No. 190,000

1 Claim.

Our invention relates to safety trip devices, and is particularly, though not exclusively, designed and adapted for use in connection with the releasable securing of poles, logs, and the like, in piles on cars or similar conveyances. In the particular application for which our invention is more especially designed, our safety trip device is employed as a means for securing chains, cables, ropes or the like, used to bind and secure poles and the like in a pileupon a railway car, truck, or the like, toa suitable anchorage wherein, as a matterof safety, it is important to provide means which will enable these safety devices to be tripped from a position where the operator will not be endangered by the fall of the poles or the like, and yet which will make proreleasable hook which engages the pole binding I are adapted to be locked positively in this posi-- tion by a retainer, itself independent of the trip vision for a positive means to prevent the accidental tripping of the safety devices.

To the foregoing endour invention contemyplates an organization of parts comprising a frame with provision at one'end for attachment to an anchorage, and atthe other end with a cable or chain andis held in operative position by members that are held in set position against the frame by the action ofthe load on the hook and release means. The frame itself carries a trip adapted, by a cam action, to force the hook retaining members past dead center where the load on the hook will automatically effect its release andfree the binding cable it held.

Our invention is characterized by forming the,

35 frame of spaced members between. which, at op- 46?: frame sides, and adapted to rock into engage ment with the frame'in both open and closedv posite ends, thehook and one retaining element are pivotally mounted,.the adjacent ends of said hook and retaining member being pivotally connected by a pair of links lying in the plane of the positions of the safety trip device. Our invention further contemplates the pivotal mounting between the frame sides of a trip lever normally dependent from its pivot and associated -with a pull cable or chain, by means of which it can be, drawn into a position in which, acting as a cam, it will force the hook retaining members to released position beyond dead center relation 9- outwardly from their set position beyond dead center inwardly when in .locked position.

Our invention further contemplates mounting usage to which it is subjected without liability to injury or breakage from the severe usage to which it is subjected. 7

Our invention further comprises the provision of aligning holes in the frame members and in a retaining member which register when the device is set in operative position and which receive an outwardly releasable lock pin disposed apart from the trip lever and in position to require detachment by movement in a direction normal to the plane of movement of the trip lever.

Our invention further comprises the novel details of construction and arrangement of parts which, in their preferred embodiment only, are hereinafter more particularly described, reference being had to the accompanying drawing, in

which:

Fig, 1 is a partial view of a car of poles showing our safety trip device in service;

Fig. 2 is an enlarged view in side elevation of the safety trip device in corresponding position to that shown in Fig. 1, the full lines showing its operative position, and the dotted lines showing the displacement of parts requisite to affect its release;

Fig. 3 is an end view of Fig. 2; and

Fig. 4 is a view corresponding to Fig. 2, showing the parts in released position.

Similar reference numerals refer to similar parts throughout the drawing.

In the illustrated embodiment of ourinvention, we have shown the safety trip device employed as a means for binding and securing poles 3 upon a fiat car 5. In practice these poles are shipped in piles on cars and held in position between side stakes 5 until they reach their destination. To unload these poles, the practice has been to apply suitable binding or retaining means, such as chains, cables, or the like 6, which are made fast at one side of the car and, after being drawn tightly over the pile of poles, are secured at the other side of the car. The problem is to devise a retaining means for these chains or cables which can be tripped from a point of safety and thus release chainsso that the poles can fall .freely from the car on to skids or the ground, as may be desired. To this end it has been the practice to make fast each binding chain or cable by what is known as a safety trip device, and in our present invention this device comprises, in its preferred embodiment, a frame formed by the parallel spaced side bars 7 which, at their upper end,

receive a pivot pin 8, by means of which the hook arm 9 is pivotally mounted between them, said arm comprising a short undercut hook formed by the end overhanging to the right of the frame (Fig. 2).

At its lower end the frame bars receive a pivot pin 10, by means of which there is mounted between them the lower single retaining link ll.

is flexibly connected by any suitable means to the side of the car, in position for the hook to drop j and carry the safety trip device with it out the path of the falling poles.

The link H is coupled to the hook 9 by meansof a pair of links M which lie in common planes with the pair of side bars I of the frame, pins I5 and [6 being employed to connect pivotally the links M and the interposed members 9 and I I.

The links I4 are preferably rounded at their ends, and the frame bars I are .recessed at I! to receive the lower rounded ends of the links [4' when locked in their operative relationship (Fig. 2), in which it will be noted that they are set with their joint to the lower link I4 shifted past dead center toward the frame so that the load on the hook will hold the links powerfully in this position. Opposite the notches I! we mount in the frame a pivot pin i8, upon which the upper end of a trip lever I9 is pivotally mounted so as to form a cam disposed in position to engage the link ll opposite pin I6.

The trip arm normally hangs downwardly against the link H so as to permit the upper links I4 to seat themselves in the frame notches IT. A hole 28 is provided in the free end of the trip I lever to receive a pull rope or chain 2I which is long enough for the operator to hold it and, by a pull thereon, trip the lever while in a position of safety clear of the adjacent end of the pile of poles. It will be understood that any desired number of binding elements 6, as thus described, may be applied to' hold the pile of poles until ready to be unloaded, and all will be provided with pull ropes 2| long enough to be manipulated from points of safety.

It is an important feature of our invention that the safety trip devices are positively locked against accidental release by a simple means, capable of resisting any shearing stresses or accidental contacts that might displace the links II, M from their operative position and trip the device. As shown, the link II in its operating position stands between and almost parallel with the frame bars I so that its upper end is received in part between said bars. There we provide a hole 22 in this link I I and aligning the holes 23 in the frame bars I which register with the link hole 22 when the links assume operating position.

A look pin 24 is fitted into these holes so as to be demountable in a direction normal to the plane of manipulation of the trip lever l9 but so'as to be entirely disassociated from the latter, so that the release of the lock pin can have no effect upon the trip lever, nor can any accidental blows against, or movement of, the trip lever serve'to dislodge the lock pin. A- cord or chain 25 is connected to a cotter key 26 in pin 8 and serves to hold the lock pin assembled with the device. The lock pin is of the cotter key type to take a springgrip in said holes.

An examination of the device will make it readily apparent that when the trip device is set in its operating position (Fig. 1) no appreciable shearing strain can come on the lock pin by reason of the load on the hook '9, because the thrust of the links M is transmitted directly to the recesses I! of the frame, in which position it will exert no thrust or shear strain on the lock pin. Further, the angle between the set links I4 and II can be made very slight, when this safety lock pin is used, so that no appreciable shearing strain can be brought in any manner upon the lock pin by forces working in any direction upon the device.

It will be noted that the trip leveris preferably full line toward dotted line position, Fig. 2.

In operation, having secured by our safety trip devices the requisite number of binding chains or cables 6 about the load of poles, and having cut away the stakes 5 on the side toward which the poles are to be dumped, the lock pins 24 are first drawn by an outward pull on them, or on their hanger chains 25,- thereby releasing the safety devices for the tripping operation. The pull cords or cables 2| are then carried to points of safety beyond the ends of the car and are pulled laterally, drawing their respective trip levers [9 to the dotted position shown in Fig. 2, which causes their cam ends, by pressure against the joint between the retaining elementsl l and I 4', to shift same outwardly beyond dead center position, thus freeing the lock holding the hooks 9 in position. whereupon the load on the hooks snaps the parts to the position shown in Fig. 4, releasing the binding chains 6 and permitting the safety trip devices to swing down below the car into a position of safety clear of the falling poles.

While we have shown our invention in but oneform, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of Various changes and modifications, without departing from the spirit thereof, and we desire,

therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth inthe appended claim.

What we claim is:

In a safety trip device of'the character described, a frame comprising a pair of spaced rigid bars, an arm having at one end a hook which is pivoted adjacent to said hook between said bars at one end of the frame, articulated links flexibly connecting the non-hook-bearing end of said arm to the other end of said frame and comprising a single linkpivotally mounted between the latter end of the frame bars, and a pair of links pivotally connecting said single link to the hook arm, the joint connecting the said links being arranged and adapted-tobreak in wardly toward and bear against the frame immediately after passing dead center position to lock said hook arm, a trip cam lever pivotally mounted between the frame bars opposite the link joint in position for its cam element to en-' gage and thrust said joint outwardly from the frame past dead center position to release said hook arm, and an anchor element connected to-

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