US 2875658 A
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March 3, 1959 H. BENJAMIN? INSULATED LEVER-MEANS FOR A RATCHET WRENCH Filed Dec. 12, 1957 INVENTOR. HOWARD BENJAMIN FIG.3
, ATTORNEY United States Patent 2,875,658 INSULATED LEVER-MEANS FOR A RATCHET WRENCH Howard Benjamin, Ithaca, N. Y.
Application December 12, 1957, Serial No. 702,409
4 Claims. (Cl. 81-63) This invention relates to an insulated wrench for linemen working on high voltage electrical lines. It may be used to loosen or tighten nuts on any live electrical apparatus where there is danger in working with ordinary insulated wrenches, and it has been found to be particularly useful to loosen or tighten nuts holding the insulator clamps on post type insulators generally found on high voltage transmission lines which may carry many thousands of volts. Such clamping nuts, being exposed to the weather, tend to rust or corrode so as to be hard to turn. Insulated wrenches have been used, but it is dangerous for one man to use them since in applying them to the nut he comes rather close, and in straining the wrench may slip so that he may touch a live wire with fatal results.
The present invention is best handled by two men standing at a safe distance, one of whom holds the wrench socket on the nut while the other man works the ratchet of the wrench thru a system of insulated levers permitting both men to stand at a safe distance from the high voltage. The leverage obtained is such that a powerful force may easily be applied to the nut, so that the wrench will work even with badlyrusted or frozen nuts. The device may also be used in other than electrical work, where because of the size or arrangement of arnachine it is not convenient for a workman to get close to it with an ordinary wrench.
Referring now to the drawings forming part of this specification,
Fig. 1 is a general view of the wrench mechanism in elevation, showing the links and levers by which the forces are applied.
Fig. 2 is a detail view partly in cross-section on the line 2-2 of Fig. 1, showing the socket wrench head and turning ratchet collar, with one wrench socket in a fixed axial position and the other wrench socket driven thru a universal joint so that it may reach a nut at various angles to the plane of the operating linkage levers.
Fig. 3 is a modification having an adjustable leverage.
Similar reference numerals refer to similar parts throughout the various views.
Referring now to Fig. 1, the primary wrench element with its operating arm 1 is provided with a socket wrench head 2 as will be described more in detail later. In order to operate this socket wrench 1 at a safe distance there is provivded an approximate parallelogram with three other levers, the arm 4 serving as a holding handle by which one of the two men can hold the socket wrench on the nut to be tightened or loosened at the electrical equipment or other machine being worked on. This arm 4 is principally made of insulating material such as wood, hard rubber, plastic or other good non-conductor of adequate strength and stiffness; and is provided at its free end with a suitable handle or grip 5. The arm 4 is generally about three or four feet long, though it can be made any suitable size.
Near the grip 5 is pivotally attached at 6 an operating handle 7 terminating in a grip 8. This is the handle by 2,875,658 Patented Mar. 3, 1959 which the socket wrench 2 is operated to tighten or loosen a nut being worked on by a second man while the first man holds the wrench in place on the nut. The force of the second man is transmitted from the handle 'I to a link 9 extending from the pivot 10 on the handle 7 to a pivot 11 at the other end of the link 9 connecting it to a point near the free end of the wrench handle 1, so that the wrench 1 can be operated from a safe distance. The socket wrench head 2 is of the usual type with a control provided havingthe customary direction setting lever 14 by which it can be set to either screw or unscrew a nut as desired by simply oscillating the wrench handle lever 1.
The operating levers 7 and 9 are constructed of insulating material as was the arm 4 described. The handle of the wrench 1 may also be wholly or partly of insulating material, though that is not strictly necessary since the levers 4 7 and 9 give adequate protection to the two workmen.
Referring now to the socket wrenchmechanism shown in Fig. 2 more in detail, the wrench head 2 contains the usual ratchet which can be set for either direction of rotation by the control lever 14 so that, when the head 2 is oscillated by the lever arm 1 it will drive an inner square shaft 15 accordingly. in Pig. 2 there is shown fitting directly on the upper end of the shaft 15 a suitable wrench socket 16 of a size for the work contemplated, which can be interchanged at will to fit whatever size nut is being operated on. This socket in is fixed laterally relative to the holding handle 4, and can be used when the nut is in such a position that it is not too diihcult to reach, as when the handle 4 extends at right angles to the axis of the bolt or stud on which the nut is screwed.
However, when the handle must be at an oblique angle to reach the nut, the wrench socket 2 3 is employed. This socket is connected to the ratchet head by a universal joint 21 which permits such nuts to be easily reached at an angle and turned. The plane of the general ap paratus need not then be dependent onjthe position of the nut. The man holding the positioning handle 4 may select whatever position is best for holding the socket wrench in place on the nut, while the other man can operate the handle 7 to deliver the operative torque to the nut by way of the universal connection.
In general a parallelogram of levers as shown in Fig. l is the simplest and cheapest construction and might be termed the preferred form. However, other quadrilaterals can be used with opposite sides not parallel if desired, such as shown for example in Fig. 3, and such modifications have certain advantages.
in Fig. 3 an arm 7 is used in place of the arm 7 previously described, and this arm '7' is provided with a number of pivot holes 10 extending along it, into any of which the pivot of the link 9' may be inserted. By thus using a variable number of pivotal locations 10' the connecting link 9' may be given various positions not necessarily parallel to the arm 4, and the power of the leverage may thus be changed.
When the link 9' is in the position shown by solid lines in Fig. 3, the speed of the wrench motion is reduced but the force of the leverage system is greatly increased over what it would be for a parallelogram. On the other hand, if the arm 9' is shifted to the position 9 as shown in broken lines the force of the wrench is reduced while the speed of the wrench motion is correspondingly increased. In either event the principal advantages of the device are retained, in that the wrench can be safely held on the nut by one man while another man works the ratchet wrench, all at a safe distance from the high voltage electric lines. It is possible for one man to hold and operate both the handle 5 and the handle 8 at the same time, but it is safer and much more the particular forms shown but is susceptible to various modifications and adaptations in different installations as will be apparent to those skilled in the art, without departing from the scope of the invention as stated in the following claims.
1. In a safety wrench, the combination of a ratchet ing handle pivotally attached near the other end of the holding handle remote from the wrench socket, and an insulated connecting link arm pivotally attached between the operating handle and the operating arm of the socket wrench for transmitting force from the operating handle to the socket wrench, whereby a nut on electrical apparatus may be turned without danger.
2. In a safety wrench, the combination of a ratchet type socket wrench having an operating arm, an insulated holding handle arm pivotally secured at one end to the socket wrench by which an operator standing at a safe distance may hold the wrench socket on a nut, an operating handle pivotally attached near the other end of the holding handle remote from the wrench socket, and an insulated connecting link arm between the operating handle and the operating arm of the socket Wrench for transmitting force from the operating handle to the socket wrench, a number of selective terminal pivot locations for said connecting link, whereby the efiective leverage between the operating handle and the wrench may be changed, both the holding handle and the operating handle being sufiiciently remote from the socket wrench so that a nut may be turned without danger.
, 3. In a safety wrench, the combination of a ratchet type socket wrench having an operating arm, a wrench socket and a universal joint connecting said wrench socket to the ratchet type wrench, an insulated holding handle arm pivotally secured at one end to the socket wrench by which an operator standing at a safe distance may hold the wrench socket on a nut, an operating handle pivotally attached near the other end of the holding handle remote from the wrench socket, and an insulated connecting link arm pivotally attached between the operating handle and the operating arm of the socket wrench for transmitting force from the operating handle to the socket wrench, whereby a nut on electrical apparatus may be turned without danger.
4. In a safety wrench, the combination of a ratchet type socket wrench having an operating arm, a wrench socket and a universal joint connecting said wrench socket to the ratchet type wrench, an insulated holding handle arm pivotally secured at one end to the socket Wrench by which an operator standing at a safe distance may hold the wrench socket on a nut, an operating handle pivotally attached near the other end of the holding References Cited in the file of this patent UNITED STATES PATENTS 1,005,815 Doolittle Oct. 17, 1911 1,897,465 Coon Feb. 14, 1933 2,095,137 Johnson Oct. 5, 1937 2,574,212 Huss Nov. 6, 1951 2,582,442 Lapp Jan. 15, 1952 2,737,839 Paget Mar. 13, 1956 2,834,237 Renoux May 13, 1958 1 FOREIGN PATENTS 653,477
France Nov. 9, 1928