US2705659A

US2705659A - Locking type tongs

Info

Publication number: US2705659A
Application number: US311033A
Authority: US
Inventors: Barchoff Abraham
Original assignee: Eastern Brass & Copper Co Inc
Current assignee: Eastern Brass & Copper Co Inc
Priority date: 1952-09-23
Filing date: 1952-09-23
Publication date: 1955-04-05
Anticipated expiration: 1972-04-05

Description

Apnl 5, 1955 A. BARCHOFF LOCKING TYPE TONGS 2 Sheets-Sheet .1

Filed Sept. 25, 1952.

INVENTOR ATTORNEY April 5, 1955 A. BARCHOFF 2,705,659

LOCKING TYPE TONGS Filed Sept. 23, l952 2 Sheets-Sheet 2 ATTORNEY United States Patent I O LOCKING TYPE TONGS Abraham Barchotf, New York, N. Y., assignor to Eastern Brass & Copper Co., Inc., New York, N. Y., a corporation of New York Application September 23, 1952, Serial No. 311,033

1 Claim. (Cl. 294118) This invention relates to lifting and lowering tongs and more particularly to tongs capable of being locked in the operative position thereof to maintain engagement with the load being handled thereby.

It is the object of the present invention to provide a tong device which is rugged and simple in construction and reliable in operation.

It is a further object of the invention to provide for the locking of tongs of the crossed-lever type in the operative position thereof, in order to maintain the grip of the object being handled while the tongs are manipulated into different positions, and which would normally result in the release of the object therefrom. The adaptation of conventional tongs to locking type tongs in accordance with the instant invention requires but the addition of a few simple parts which may be added to existing tong devices or which may be incorporated as parts of new tong assemblies.

The invention proceeds upon the principle of adding to a tong device of the crossed-lever type a cross-arm or bracing arm extending between the pivotal mountings of the crossed levers remote from the gripping jaws. The cross-arm may be provided with an opening at one end which fixes the location of one of the pivotal mountings and is provided with a longitudinal slot at the opposite end thereof to permit the tong levers to execute the necessary" movements attendant the gripping and releasing of objects by the gripping jaws in dependence upon the degree of opening of the jaws. The end of the cross-arm adjacent to the longitudinal slot is provided with threads along opposed edges thereof for the guidance of an interiorly threaded locking nut which cooperates with the threads on the cross-arm to permit the locking npt to be brought into juxtaposition with the relativelyfnovable pivotal mounting of the tongs in the operative, position of the tong device. Thus, the locking nut pre'yents a spreading movement of the tongs while the tongs and the load engaged thereby are manipu lated in the course of diverse transporting and handling operations.

Other objects and purposes will appear from the following detailed description of the invention taken in conjunction with the accompanying drawings, wherein Fig. 1 is a front elevation of the tong device in accordance with the present invention;

Fig. 2 is a left end view of Fig. 1;

Fig. 3 is a front elevation of the tong device illustrating its manipulation in the course of engagement thereof with a crate of metal;

Fig. 4 is a sectional view along line 44 of Fig. 3; and

Fig. 5 is a vertical sectional view along line 5-5 of Pi 4.

The drawings illustrate a tong device of the crossedlever type which may be of conventional design by its provision of crossed levers 1, 1 having gripping jaws or points 3, 3' seated in the opposed adjacent ends 2, 2', respectively. The levers are pivotally mounted to each other at intermediate parts thereof by bolt assembly 4, 4. The ends of levers 1, 1 remote from the gripping jaws are pivotally mounted to the lower ends of crossed bars 6, 6', respectively, at pivotal mountings 5 and 15, respectively. The upper ends of bars 6, 6' are pivotally joined together by the common pivotal mounting 7, 7 which also carries the hook 9 for engagement with a chain hook H extending from a hoist, crane or the like.

2,705,659 Patented Apr. 5, 1955 \s is well known in the art, the levers generally described above may be formed of dual assemblies of congruous levers. For example, levers 1 may be formed of companion levers which pivot between the more widely spaced congruous levers 1 and the pivot bolt assembly 4 includes the spacing sleeve 4 between the levers 1'. Likewise, the congruous straight bars 6 extend between levers 1 while bars 6' are disposed on the outside of bars 6 as well as on the outside of congruous levers 1 with the spacing sleeve 7' on the pivot assembly 7 spanning the distance between the innermost bars 6.

The distance between the bars 6 at their lower ends and between the levers 1' at their upper ends in Figs. 1 and 2 is spanned by a cross'arm 10 which is provided with an opening at one end thereof to accommodate the bolt 5 which pivotally integrates the levers 1 and 6 and lever 10. The opposite pivotal mounting of the levers, including the bolt 15, may move relatively to bolt 5 by virtue of a slot 12 provided in the cross-arm 10 at the end thereof remote from the fixed pivotal mounting 5. The movement of pivotal mounting 15 along the slot 12 of arm 10 enables the tong device to operate in the conventional manner as the pivotal mountings 5 and 15 approach each other when the jaws approach each other and recede from each other as the jaws are spread apart. In this case the cross-arm 10 merely functions as a bracing arm for the tong assembly.

In order to attain the advantages of the invention, the arm 10 is provided with screw threads 11 on the upper and lower edges thereof adjacent to the slot 12 and an interiorly threaded locking collar 20 is threaded upon the arm for rotary movement thereon in order to bring the locking or blocking edge 22 of the collar into engagement with the pivotal mounting 15 of the tong device.

The arm 10 is preferably provided with a stop disk 13 which may be detached from the arm in order to mount the locking collar 20 on the arm 10. The disk 13 may be attached to the arm by means of screw bolt 14 cooperating with a threaded opening in the end of arm 10 to fix the stop 13 at the end of arm 10, which prevents a complete disengagement of the locking collar from the arm after the collar has been mounted thereon.

With the locking arm 20 in its fully withdrawn position as shown in Fig. 1, the tongs may execute its normal movements as controlled by the lifting; of the tongs at hook 9 and the engagement of any object with the gripping jaws 3, 3'. In order to prevent a release of the object by the gripping jaws following the grasping thereof, if the object requires additional manipulations around a plant, as might be the case in the handling of heavy crates of sheet metal, the locking nut 20 is advanced upon the arm 10 until the edge 20 is forced into close abutting relation with the pivotal mounting 15. This prevents an opening movement of the crossed-lever system and correspondingly of the gripping jaws, despite a release of the book 9 by the hoisting cable or other granigulations executed with the load as indicated in The rotation of the locking nut is facilitated by making the same of substantial diameter and by providing circumferential cutouts 21 therein for the purpose of facilitating a convenient hand-hold thereof.

Following the positioning of the load L, as shown in Fig. 3, in any desired position, the locking nut 20 may be retracted along the arm 10 in order to permit the spreading of the jaws and the release of the load.

The objectives of the instant invention may be attained by the provision of a more complex assembly in which the cross-arm may be provided with a pair of slots for guiding the relative movements of the pivotal mountings and which embodies a screw threaded locking nut at each end for blocking the levers against spreading movement in the operative position of the tong device.

While I have described my invention as embodied in a specific form and as operating in a specific manner for purposes of illustration, it should be understood that I do not limit my invention thereto, since various modifications will suggest themselves to those skilled in the art without departing from the spirit of my invention, the scope of which is set forth in the annexed claim.

I claim:

A tong device comprising a pair of crossed pivoted levers terminating in gripping jaws at opposed adjacent ends thereof, intersecting pivoted bars connected to the opposite ends of said levers forming pivotal mountings therebetween which are relatively movable with respect to each other, an arm interconnecting said pivotal mountings, one of which is fixedly disposed at one end of said 10 arm, said arm having a slot for accommodating the instantaneous movement of the other one of said pivotal mountings during the contracting and distending movements of said jaws, screw threads disposed on the exterior -thereon for engagement with and blocking said lastmentioned pivotal mounting in the contracted position 5 of said jaws.

References Cited in the file of this patent UNITED STATES PATENTS 1,877,975 Robb Sept. 20, 1932 2,476,169 White et al. July 12, 1949 FOREIGN PATENTS 43,589 Norway Jan. 17, 1927