WO2015125132A1

WO2015125132A1 - Device for inserting electrical cables through tubing

Info

Publication number: WO2015125132A1
Application number: PCT/IL2015/050136
Authority: WO
Inventors: Yehezkel TAL; Gil TAL
Original assignee: Tal Yehezkel
Priority date: 2014-02-18
Filing date: 2015-02-05
Publication date: 2015-08-27

Abstract

A device for the insertion of electrical or communication cables through tubing or conduits using fish tape or draw wire of the present invention provides a tool allowing one electrician to do the job. The battery operated power tool is directly mounted on the electrical box or on a bare conduit. The device can be remotely controlled so that the technician can stay in the cable entrance end of the conduit and guide the cable into the conduit while putting lubricant on the cable. The technician can obtain visual as well numerical information that helps him in the control of the tool.

Description

DEVICE FOR INSERTING ELECTRICAL CABLES THROUGH TUBING

FIELD OF THE INVENTION

[0001] The invention relates to installation of electrical cables and more specifically it relates to inserting electrical cables through tubing or conduits.

BACKGROUND OF THE INVENTION

[0002] Electrical and communication cables within a building are enclosed in tubing or conduits. The conduits are installed in the building during construction, sometimes with a drawing rope there within, and sometimes without a drawing rope. In cases where the conduits do not contain a drawing rope, a fish tape is pushed along the conduit. Usually the each end of the conduit terminates either in an electrical box or in a distribution box.

[0003] The cable to be inserted is coupled to one end of either the drawing rope or the fish tape, and the installer pulls the drawing rope or the fish tape and the coupled cable from the other end.

[0004] Pulling the drawing rope or the fish tape is physically demanding, time consuming and labor intensive. Usually two workers are needed for the operation, one at each end of the conduit. One worker pulls the drawing rope or the fish tape and the other worker pushes the cable. When the cable is pushed into the conduit, the pulling operation becomes easier.

[0005] Although many tools to solve the problem of cable pulling were invented, they were not accepted by the market because they did not provide an acceptable solution to the problem. The unsolved problems are universal solution to the use of either fish tape or drawing rope, ease of use,

[0006] GB 1201566 describes a motor driven apparatus. It has to be inserted into the conduit, and thus, a special adaptor is required for each conduit type and size. A tear shaped slider has to be located on each end of the fish tape, thus its use is confined to specific fish tapes. The unit requires mains supply for its operation. In many cases the conduit is within an electrical box and it is difficult to make a firm connection to it as required by the apparatus.

[0007] US patent 4,917,362 by Wilson, discloses an automatic wire puller. This apparatus can use only standard fish tape reels. It can be used only if at least one side of the conduit is within an electric box. Although it is attached to the electric box, the connection requires screwing of the tool interface spacer to the screw webs or tangs existing on the electric box. The tool can be remotely controlled by a remote control box which is connected by wire cable to the apparatus.

[0008] US patent 6,409,154 by Quinn discloses a fish tape feed battery-operated apparatus. It is a pistol shaped, hand held apparatus, whose main objective is to alleviate the physical demanding effort required to pull the cable through the conduit i.e. it only adds muscles to the technician. It cannot be remotely operated, thus the operator has to stay on the pulling end. It can be used only with fish tape, and does not support the use of draw wires. Hence two workers are needed for insertion of cable through a conduit.

[0009] US patents 6,513,791 by Yate and 6,361,021 by Brennen disclose power driven fish tape, where an external drill unit applies the power. The driven fish tape is either a standard fish tape reel or a fish tape wound on the unit's reel. Both are hand held tools, without remote control, and practically reduce the physical effort of pulling the cable through a conduit.

[0010] US patent application 6,003,842 by Hug and patent publication 2012/0168699 by Rachminov et al. describe electrically powered device for insertion of cable into a conduit. The devices are mounted on the floor and a special conduit coupler is used to connect the device to the conduit through which the cable is inserted. The installation of the conduit coupler is a difficult job to accomplish, and in some cases the coupling, when attached to the inner side of the conduit, blocks the path of the cable. In addition, both inventions do not supports the handling of a draw rope already inserted in the conduit. [0011] There are many patents for the insertion of electrical or communication cables into conduits. However, the mere fact is that it is impossible to find such devices in the market suggests that no existing solution satisfies the requirements. Hence, there is a need for a flexible, easy to use device for the threading of electrical or communication cables into tubing or conduits.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a conduit between two electrical boxes. FIG. 2 shows the fish tape within the conduit. FIG. 3 shows the main components of the device.

FIG. 4 shows preferred embodiment of adaptor unit to for connecting to electric box.

FIG. 4A shows preferred embodiment of clamping mechanism of adaptor unit for electrical box.

FIG. 4B shows adaptor unit for connecting to bare conduit. FIG. 5 shows cross section A-A of FIG. 3.

FIG. 6 shows one embodiment of the drive unit, cross section B-B of FIG. 3.

FIG. 7 shows another embodiment of the drive unit, cross section B-B of FIG. 3.

FIG. 8 presents the path of fish tape in the drive unit.

FIG. 9 shows one embodiment of the pulling-pushing wheels.

FIGS. 10a and 10b show a pulling-pushing wheel attachment for drawing rope. SUMMARY OF THE INVENTION

[0012] The present invention is a power tool device for the insertion of electrical cable or communication cable through tubing or conduits using fish tape or draw wire. The invented tool enables one electrician to do the job. The rechargeable battery operated power tool is directly mounted on the electrical box or on a bare conduit, using special interchangeable adaptors. An external charging unit can recharge the battery.

[0013] The fish tape is passing between three special V grooved pulling-pushing wheels or U shaped rough grooved pulling-pushing wheels driven by motors via a gear unit. A special attachment is connected to a pulling-pushing wheel for pulling draw wire.

[0014] The direction of rotation, the speed of rotation can be remotely controlled via a wireless communication channel. Visual as well as numerical information can be displayed to the operator on the remote control unit.

DETAILED DESCRIPTION

[0015] Full description of the invention is given hereinafter with reference to the accompanying drawings, in which a preferred embodiment of the invention is shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein; rather this embodiment is provided so that the disclosure will be thorough, and will fully convey the scope of the invention to those skilled in the art.

[0016] It is the object of the present invention to provide a flexible device for the insertion of electric or communication cable in a conduit installed in the structure of a building. The device supports the pulling of drawing rope as well as of fish tape. [0017] In FIG. 1 a wall 100 of a building is shown in which a conduit 130 for electric cable is installed. The conduit connects two electrical boxes 110 and 120. There are cases where at least one side of the conduit does not end in a small electrical box such as those used for switches and outlets. For example, many conduits end in the main electrical or communication box of an apartment from where they are distributed all over. Thus it is important for the invented device to be able to support cable insertion when no small electrical box are at the ends.

[0018] FIG. 2 shows the wall and conduit of FIG. 1 in which a fish tape 210 is inserted. The fish tape is inserted from one electrical box, through the conduit 130 to another electrical box. The fish tape has an eye 212 used to connect the cable to the fish tape. Sometimes, a drawing rope is already inserted in the conduit.

[0019] FIG. 3 displays the structure of the device. The device is comprised of a drive unit 320 and an adaptor unit 310. The two units are firmly connected to each other by a two-way axis 330, which enables to flexibly position the drive unit 320 with respect to the adaptor unit 310. When connected, the two units form one integrated device. The drawing rope or the fish wire 210 passes through the adaptor unit 310 and is inserted into the drive unit 320. The drive unit has a door 322 which is opened when the draw rope or the fish tape are inserted. The drive unit pulls the draw rope or the fish tape in the direction indicated by arrow 342. A remote wireless control element 380 is used to control the operation of the drive unit. For insertion of fish tape the drive unit pushes the fish tape into the conduit. The adaptor unit can be replaced with one designed to hold a bare conduit, as will be explained later on.

[0020] FIG. 4 shows an example of adaptor unit for electrical boxes. The adaptor unit 310 has plurality of static clamping pins 420 and plurality of adjustable clamping pins such as 424 and 426. The clamping pins are inserted into the electrical box 110 and are pressed against its walls. There are at least three clamping pins, although in FIG. 4 four clamping pins are shown. The pins are arranges so that they can fit in any type of electrical box, a square box or around box. The two-way axis 330 can rotate around axis 432. When in the proper position, the two-way axis 330 is firmly fixed to the adaptor unit 310. The drive unit 320 in FIG. 3 has a connection pin 324 used to fix it into the slot 436 in two-way axis 330. This enables the drive unit 320 to move around the axis 434. The freedom in placing the drive unit relative to the electrical box reduces the bending of the fish tape when it enters or exits from the conduit.

[0021] Adjustable clamping pin 424 is clamped by rotating a screw 425. In another embodiment, as shown in FIG 4A, the clamping pin uses a special mechanism that is mounted on a post 426 in FIG 4 to fasten it to the electrical box. The clamping mechanism shown in FIG 4A is comprised of two metal plates 442 and 444 held in place by two springs 443 and 445 respectively. Pressing the handle 460 downward, in the direction pointed by arrow 462, causes the pin 440 to move downwards relative to post 426. Metal plate 442 prevents the pin 440 from moving up. Only when pushbutton 450 is pressed against the spring 443, the pin 440 can be moved up.

[0022] Example of an adaptor unit for bare conduits is shown in FIG 4B. It is comprised of two half cylinders, a static one 460 and moving one 462. The static one is part of a rigid block 470 that includes a post 468 and an axis 466 similar to axis 330 in FIG 3 used to attach the pulling-pushing element. The moving cylinder 462 can be moved up and down relative to the static cylinder 460 using the same mechanism as described in section [21] above. In the inner side of each cylinder there are thorns 472 that firmly grip the conduit.

[0023] FIG. 5 shows cross-section A-A of FIG. 3. The drive unit 320 has a connection pin 324 that is inserted into groove 436 of the two-way axis 330. The hole 522 in the connection pin 424 enables a pin to be inserted through the two-way axis and through it. Three pulling-pushing wheels 510 are under the door 322.

[0024] In FIG. 6 cross-section B-B of FIG 3 is presented. It shows the internal modules of the drive unit 320. In this embodiment the three pulling-pushing wheels 510, are driven by a single motor 630 connected to the wheels by a gear module 620. The drive unit includes a rechargeable battery module 640 and remotely operated control module 650. Via openings 610 and 620 the draw rope or the fish tape are entering and leaving the pulling-pushing element. The battery module 640 can be a detachable unit that can be charged by a separate charging unit. [0025] In FIG. 7 another cross-section B-B of FIG 3 is presented. It shows the internal modules of the driving element 320. In this embodiment each the three pulling- pushing wheels 510a, 510b and 510c is driven by its own driving motor, 710a, 710b and 710c respectively. The drive unit includes a rechargeable battery module 640 and remotely operated control module 650. The fish tape 210 enters the drive unit 410 via opening 620, passes on top of pulling-pushing wheel 510a, beneath pulling - pushingwheel 510b and on top of wheel 510c, and exits the drive unit through opening 610.

[0026] In FIG. 8 side view of the pulling-pushing wheels is displayed. The center of middle wheel 510b is offset from the line connecting the centers of the two outer pulling-pushing wheels 510a and 510c. This arrangement increases the friction between the fish tape and the pulling-pushing wheels by the increase in the contact area between the fish tape and the wheels. Pins 810 are used to guide the fish tape to the proper path. I another embodiment one of the pins 810 can be replaced by a passive wheel connected to rotation counter. This enables to measure the length of the fish tape inserted into the conduit. The user can reset the counter from the remote control or by local switch. The counter can be displayed on the remote control unit.

[0027] FIG. 9 presents a typical cross section C-C of a pulling-pulling wheel in FIG. 8. The groove 910 in which the fish tape is passing in this embodiment has a V shape. It may have a U shape. The plane of the groove 910 is not perpendicular to the axis of rotation of the pulling-pushing wheel. This causes the fish tape to further bend and as a result, the friction between the fish tape and the wheels is increased. In another implementation, the pulling-pushing wheel is perpendicular to the axis of rotation but the groove is rough to increase the friction between the fish wire and the pulling- pushing wheel.

[0028] In order to pull drawing rope, an extension element 1010 is connected to the last pulling-pushing wheel 510c, as shown in FIGS 10a and 10b. The extension 1010 has an axis 1012 with a disk 1014 on the far end. In the disk, 1014 there is a groove 1016 used to insert the draw rope. The draw rope is wound on the axis 1012. After the electric cable is in place, the drawing rope is taken off the extension element. [0029] The drive unit can be equipped with the camera that can send the picture, via radio communication to be displayed on the remote control unit. Thus, the operator can be in the other end of the conduit and monitor the fish tape or drawing rope movement.

[0030] The remote wireless control element 380, includes control switches for controlling the direction and speed of the pulling-pushing operation. It can also contain video display as well as display of the counter of the fish tape. A pedal may be connected to the remote control with which the speed of the pulling-pushing can be controlled. That allows the operator to insert the cable into the tubing or conduit with both hands.

[0031] While one embodiment of the invention has been shown, it is to be understood that many modifications may be made thereon within the spirit of the invention.

Claims

CLAIMS is claimed is:

1. A device for the insertion of electrical or communication cables through tubing or conduits using fish tape or draw wire, the device is comprised of: a) a drive unit capable of pushing and pulling a fish wire, the drive unit is comprised of;

i plurality of pulling-pushing grooved wheels;

ii plurality of motors for driving said pulling-pushing wheels; iii a gear unit connecting said motors to pulling-pushing wheels; iv control electronics for controlling said motors; v electricity supply means for supplying energy to said motors and control electronics;

b) detachable adaptor unit for attaching the drive unit to electrical box; said adaptor unit is rigidly coupled to the drive unit on one end and has clamping means to attach it to electrical box; and c) a remote wireless control unit for remotely controlling the operation of the drive unit.

2. The device for the insertion of electrical or communication cables as defined in claim 1 wherein the pulling-pushing wheels have a V shaped groove whose plane is not perpendicular to the axis of rotation.

3. The device for the insertion of electrical or communication cables as defined in claim 1 wherein the pulling-pushing wheels have a U shaped groove.

4. The device for the insertion of electrical or communication cables as defined in claim 1 wherein electricity is provided by a detachable rechargeable battery.

5. The device for the insertion of electrical or communication cables as defined in claim 1 wherein wireless camera is attached to the driving unit, transmitting picture to the remote control unit.

6. The device for the insertion of electrical or communication cables as defined in claim 1 further including a fish tape distance counter.

7. The device for the insertion of electrical or communication cables as defined in claim 1 where the control electronics can get commands and display information from local switches and displays on the drive unit or from the remote wireless control unit.

8. The device for the insertion of electrical or communication cables as defined in claim 1 where an extension element can be attached a motor driven pulling-pushing wheel for pulling draw wire.

9. The device for the insertion of electrical or communication cables as defined in claim 1 wherein a pedal can be connected to the remote control unit to control the speed of the drive unit motors.

10. A device for the insertion of electrical or communication cables through tubing or conduits using fish tape or draw wire, the device is comprised of: a) a drive unit capable of pushing and pulling a fish wire, the drive unit is comprised of;

i plurality of pulling-pushing wheels;

ii plurality of motors for driving said pulling wheels; iii a gear unit connecting said motors to pulling -pushing wheels; iv control electronics for controlling said motors;

v electricity supply means for supplying energy to said motors and control electronics;

b) adaptor unit for attaching the drive unit bare conduit; said adaptor unit is rigidly coupled to the drive unit on one end and has clamping means to attach it to electrical box; and

c) a remote wireless control unit for remotely controlling the operation of the drive unit.

11. The device for the insertion of electrical or communication cables as defined in claim 9 wherein the pulling-pushing wheels have a V shaped groove whose plane is not perpendicular to the axis of rotation.

12. The device for the insertion of electrical or communication cables as defined in claim 9 wherein the pulling-pushing wheels have a U shaped groove.

13. The device for the insertion of electrical or communication cables as defined in claim 9 wherein electricity is provided by a detachable rechargeable battery.

14. The device for the insertion of electrical or communication cables as defined in claim 9 wherein wireless camera is attached to the driving unit, transmitting picture to the remote control unit.

15. The device for the insertion of electrical or communication cables as defined in claim 9 further including a fish tape distance counter.

16. The device for the insertion of electrical or communication cables as defined in claim 9 where the control electronics can get commands and display information from local switches and displays on the drive unit or from the remote wireless control unit.

17. The device for the insertion of electrical or communication cables as defined in claim 9 where an extension element can be attached a motor driven pulling-pushing wheel for pulling draw wire.

18. The device for the insertion of electrical or communication cables as defined in claim 1 wherein a pedal can be connected to the remote control unit to control the speed of the drive unit motors.