Patent Application
20090056079
This invention relates generally to a rope pulling device or handle; and, more particularly, to a device that one or two people may manually hold and pull to assist in pulling electrical wires and cables through conduit or pipe.
In the past, numerous devices have been developed and used to pull ropes, cables, lines or wires through conduits or passageways. These devices range from simple hand-held items to more complex equipment such as power-driven winches and windlash machines. However, the need still exists for a simple, hand-held tool whereby one or two people can quickly secure the loose end of a rope and pull the rope through a passageway. Accordingly, it is a general object of the present invention to provide such a device.
In particular there is a need for a device where rope does not have to be manually gripped and can be secured to a handle for pulling without being tied in a knot that may slip or become so tight under pulling tension that it cannot be untied easily. Thus, it is another object of the invention to provide a rope pulling device that does not require that a knot be tied.
One example of a prior art hand pulling devices is that shown in U.S. Pat. No. 2,736,532 that issued on Feb. 28, 1956 to E. V. Hughes and which requires that the fish tape be threaded through a wedging cam or locking mechanism to hold the fish tape. Similar arrangements are shown in U.S. Pat. No. 5,423,517 which issued on Jun. 13, 1995 to James E. Rausch and in U.S. Pat. No. 7,152,846 B1 which issued on Dec. 26, 2006 to Jeffrey Jue. Accordingly, it is another object of the present invention to provide a rope pulling device which does not require mechanical clamping jaws or tedious threading of the rope end.
These and other objects are accomplished by my invention which is described below.
It has been surprisingly discovered that a rope puller that includes a bar or handle with a V-shape slot milled on one side of the bar center with a post mounted adjacent the bottom of the V-slot will provide a quick and easy method of securing a rope to be pulled. The loose end of the rope is guided through the V-slot, looped around the post, and then guided under the rope portion that extends through the V-slot as it comes from a conduit. Alternately, the rope is looped around the post with the upper run of the looped portion being the pulling portion and the lower being the loose end. The upper portion is positioned in the V-slot and crosses over the lower portion. This assembly is then in the pulling position when the rope in the V-slot turns at a right angle as it leaves the slot under pulling tension. On the other side of the bar the rope is pulled and clamps the loose end against the handle as it leaves its lower run around the post.
The ends of the bar on either side of the slot act as handles and may be provided with finger grips, and the post may be provided with a retainer head or cap. When gripped and pulled, and with the tension in the rope clamping down the loose end looped around the post, the rope can be pulled by either horizontally positioning the bar or vertically positioning the bar. One person may pull the bar or when in horizontal position the hurdle may be readily pulled by two people, one person pulling on the handle on one side of the notch and the other person pulling the handle on the other side of the notch. When a pulling operation has been completed, such as pulling a wire cable that is fastened to the rope through a conduit, the release of pulling tension allows the quick removal of the bar from the rope end without having to release any clamps or undo any knots. The rope during the pulling operation surprisingly does not slip and retains its position. Thus, the rope pull bar of the present invention requires no maintenance and can be readily carried in the tool box of an electrician.
In a further aspect, the rope pull bar of the invention comprises an elongated handle having a flat, central surface with a V-slot formed in one edge of said surface so that the bottom of the V-slot extends into the surface; and a post is mounted on the handle adjacent the bottom of the V-slot. The distance from the edge of the post to the bottom of the V-slot is preferably about ¼″ but can be in the range of ⅛″ to 1″ or more. The depth of the V-slot is preferably about ⅜″ but may vary from about ¼″ to about 1″ in depth.
The central surface which is preferably flat and in which the post is located may have flat or round or other shaped handles extending outwardly therefrom. The pull bar may be formed of wood, plastic, or metal, preferably, aluminum or an aluminum alloy. The post may be a bolt with a cap and extend through the handle or the post may be screwed into a threaded hole or socket formed in the surface of the bar.
In still another aspect, the invention is a rope pull bar comprising an elongated handle having a flat, central surface with a V-shaped notch or slot formed in one edge of said surface with a post mounted in the surface adjacent the bottom or the point of the V, the post having a cap to retain the rope and the lateral surface of the post shaft being knurled to provide a friction surface; and a rope positioned in the V-slot and looped around the post and under the lower run of rope extending from the V-slot. When pulled by a user by placing his hands on each side of the pull bar and exerting force, the tension of the upper loop of the rope will clamp the loose lower end and prevent it from sliding so that a secured rope end is provided and the rope is readily pulled with the handle when fastened to a line or wire in a conduit. It is preferred that the post be mounted so that it is at right angles or orthogonal or perpendicular to the surface. The handle preferably should be positioned so that it lies in a vertical plane that is at a right angle or perpendicular to the direction to the rope pull. The handle position may be vertical or horizontal or at other comfortable angle for the user.
In a still further aspect the invention is a method of pulling line or rope through a conduit by providing a pull bar or handle as described above and looping the rope around the post so that the rope segment that goes through the notch and to the conduit is on top or upper run and the loose end on the lower run where it is clamped against the handle by the upper rope segment. When held vertically, at the end of one pulling stroke, the bar may be held by one hand of a person doing the pulling and as the rope becomes slack the other hand can pull the loose end to tighten the rope for another pulling stroke without removing the rope from the post. Thus, the rope may be pulled from the conduit and the person doing the pulling need not move backwardly to a great degree or may even stay at the same location.
The invention may be better understood by reference to the drawings described below:
The drawings which are attached hereto and made a part of this disclosure are for illustration and not for limitation. In the drawings:
Looking first at
Pulling can be done in strokes. When the tension on the rope 2 is relaxed, the clamping action is relaxed and one hand of the operator or puller can pull the loose end 3 downward to take up slack after each pulling stroke. Then, by applying pulling force the rope 2 again clamps loose end 3 against bar 4 for the next stroke.
The position of the rope in the slot or notch can be seen more clearly in
In
In
For optimum operation, it is preferred that the post 5 be located with its upper edge at about the same depth D as the bottom of the V-shaped slot. The preferred location is the distance X or about ¼″ to the right and a distance Y of about ¼″ below the bottom of the notch. These distances X and Y are measured from the vertical and horizontal centerlines V and H of the cap 5. This distance is a preferred and optimum distance for ease of handling and looping and unfastening of the looped rope. Referring back to
Turning now to
The bar 4 of rope puller 1 is preferably made of aluminum or an aluminum alloy but it may be formed of steel or other metal, plastic, or wood. The preferred thickness T of the bar is about ¾″ in a preferred range from about ½″ to 1½″. The preferred width W is about 1½″ and may be in the range of about 1″ to about 3″. A preferred length of the bar is about 14″ and the length may vary from 10″ or less to 18″ or more. This provides a readily usable rope puller which can be used in the manner as shown in
The preferred embodiment with the dimensions and materials described above is the best mode of the invention. Other embodiments and modifications may become apparent to those skilled in the art upon reading this disclosure and observing the drawings but it should be understood that the scope of the invention is defined and limited only by the following claims.
