PARTS AND TOOL FOR OBTAINING CONDUCTION FOR USE AT ELECTRICAL CONNECTION

Abstract: Parts and a tool for providing electrical connections with good conduction by removing insulating materials such as paint and rust from conductor surfaces when they are connected. A flexible metal strip like a band saw, which can be formed into a small cylinder, is used as a cutter for removing insulator from desired areas on conductor surfaces. Next, parts to be interposed between insulated conductor surfaces are provided to improve the electrical conduction between the conductors. The parts include a conductive screw having a file to act on an insulated surface, a washer having a similar file, and a combination of the washer and screw. Alternatively, the screw is fastened to an extension of a connecting member on a conductor and is connected to another conductor. Still alternatively, the above tool can be provided with a file.

Description: BACKGROUND OF THE INVENTION Field of the Invention: This invention generally relates to devices for providing efficient electrical conduction with a generally planar conductor covered with an insulating layer such as paint, rust or stain. Description of Background Art: There can be various types of electrical connections between conductors. An earthing code is often connected with an enclosure of a switchboard. A linear conductor is connected with another linear conductor by corresponding terminals. A conductor is connected to a terminal base of a distributor or a planar terminal of an electrical appliance. A large capacity transformer utilizes surface contact between two plate bars. Cords are connected to terminals of a battery. There are a numerical other connections between conductors. Such electrical contacts or connections are often hindered by insulating hazards covering contact portions such as paint, dust or rust. Mere connection with a conductor surface painted with insulating paint for pleasing appearance or rust inhibition often renders the connection electrically insufficient. Dust or rust may also inhibit sufficient electrical connections. To provide an electrically sufficient connection with a planar conductor covered with an insulation layer, an appropriate portion or area on a conductor surface need be pretreated or scraped with a file or screwdriver. It is very time consuming to provide sufficient scraped areas on a large or complicated appliance, especially if there are many portions to be treated. Some members of a complicatedly designed appliance cannot be easily or properly earthed partly due to their relative inaccessibility. It is often wishfully expected that unearthed members of an electric device will provide indirect earthing by the mere fact that they somehow contact earthed members, which is often proved to be a misbelief. A similar problem arises between a cable pipe and electric cables housed therein. A cable pipe is often made of a conductive material such as a metal, which is generally indirectly earthed or expected to be earthed through a conductive portions of an electric apparatus to which the cables in the pipe are connected. However, such earthing is not actively contrived, thus often proved to be insufficient. There exist a number of makeshift ways to provide earthing where such electrical connections are not originally contrived such as by utilizing frames or bodies of electric appliances. Of course, originally contrived electrical connections can be made between electric codes and terminals of electric appliances, between two flat bars where large current is involved, or between batteries and cords. Those originally contrived contact areas are generally prepared of copper or aluminum, which are prone to rusting, staining or dusting, possibly adversely affecting electrical conduction therewith. To provide reliable electrical conduction, it is often required to remove such insulating substances from the contact areas before electrical connections are made. JP-A-54-98955 describes a bolt device having a head and a threaded shaft. The head includes a flange that extends outwards from the shaft. Slits are provided in the periphery of the flange forming teeth that are bent downwards. FR-A-2675859 describes a washer with anchorage teeth. The washer is dish-shaped and has a plurality of sharp teeth that extend from the periphery of the washer on the concave side thereof. Accordingly, it is an object of the present invention to provide devices and tools with which to provide efficient and easy removal of insulating substances from portions of conductor surfaces, preferably concurrently with operation for electrical connection therewith. Other objects of the present invention will become apparent from the description below. SUMMARY OF THE INVENTION The foregoing object and other objects of the present invention will be accomplished when a device and/or tool prepared according to the present invention is appropriately utilized. A device of the present invention is generally a conductive thread device having a serration portion which scrapes or clear a generally planar surface portion of a conductor plate. This invention additionally provides conductive intermediate members to further efficiently provide electric conduction with a planer conductor. Such a thread device may be a bolt device having a serration portion. The serration portion scrapes a surface portion of a conductive material or conductor plate covered with an insulating substance as the bolt device is further fastened into a threaded hole provided in the conductor plate to clear or remove the insulating substance from the surface portion. Such a thread device may be a nut device having a serration portion. The serration portion scrapes a surface portion of a conductor plate covered with an insulating substance as the nut device is tightened and turned with a bolt to remove the insulating substance from the surface portion. Alternatively, such a thread device may be a washer device. The serration portion scrapes a surface portion of a conductor plate covered with an insulating substance as the washer device is pressed against the surface and turned on the surface to remove the insulating substance from the surface portion. Such a thread device may be a combination of a thread device and a washer device having a serration portion. The serration portion scrapes a surface portion of a conductor plate covered with an insulating substance as the washer device is pressed and turned on the surface by the thread device when the thread device is further screwed through a threaded hole provided in the conductor plate to remove the insulating substance from the surface portion. A tool or scraper device with a serration portion may also be provided to directly and conveniently provide scraping of a conductor surface portion. A variety of tool members are additionally provided to provide easier and improved scraping of a conductor surface portion. Such conductive devices and tools as well as other member devices of the present invention are first described corresponding to the attached claims for easier initial understanding of the present invention. Serration Member: A conductive serration member according to claim 1 is provided as a bendable metal plate such as a copper plate having a serration portion along a longitudinal edge, which is made into a single-layered or multi-layered cylindrical ring having a serration along an edge. The serration portion may advantageously be a plurality of A -shaped teeth. The serration member should be hard enough to efficiently scrape and clear paint or rust from a conductor surface portion when pressed and turned against the surface portion. It is not essential but advantageous that the serration member is also deformable and flattened to provide efficient electric conduction after the scraping operation by providing a large contact area with the conductor surface portion. When a cylindrical serration member is utilized, it is advantageous that all such deformation of the serration is provided toward the inside of the cylinder. The serration member as claimed in claim 2 is made of a shape memory alloy. Such a serration member when deformed through a use can be restored and utilized again by appropriate heating of the deformed serration body. Thread Device: A conductive thread device according to claim 3 may be a bolt device having a serration member according to claim 1 or claim 2 provided around its bolt shaft under its bolt head to form a serration device. The serration device is pressed against a surface of a conductor plate covered with an insulation substance as the bolt device is further screwed into a threaded hole provided in the conductor plate, scraping a surface portion to remove the insulation substance from the surface portion and provide efficient electric conduction therewith. The thread device may alternatively be a nut device having a serration member as a serration device on its surface contact face. A thread device uses a serration device which will gradually crash or deform on a conductor surface covered with an insulation substance as the thread device is pressed or fastened on the conductor surface to remove the insulation substance from a surface portion for providing improved electric conduction with the conductor plate by providing a wide contact area with the surface portion. A thread device of claim 4 is a bolt device having a serration device thereon, further having a screw hole on its bolt head for connection with an electric terminal to provide electrical conduction between the terminal and a conductor plate covered with an insulating substance. A thread device according to claim 5 is another bolt device having a serration device. The bolt device has an additional thread formed around the side wall of its bolt head to be engaged with a nut. A thread device according to claim 6 utilizes the bolt device of claim 5, which engages a nut device provided with an elastic member or packing on its conductor contact face to provide a securer contact with a conductor surface for prevention of a scraped area on the conductor surface from contacting moist air. A thread device of claim 7 is a modification of the thread devices claimed in claims 4-6. This thread device has a serration device protruding from the distal end of its bolt shaft, which provides scraping on a surface of a second conductor plate covered with an insulation substance which is located beyond a first conductor plate to provide efficient electrical connection or conduction between those two conductor plates. A thread device of claim 8 is a nut device having a serration device according to claim 3. This nut device is applied on an under surface of a conductor plate covered with an insulation substance. The serration device scrapes a portion of that under surface as pulled and turned against the under surface by a bolt inserted through an opening provided in the conductor plate from the other or upper surface, which engages the nut device. A thread device according to claim 9 is a bolt device having serration plates protruding from the lower end of the bolt device, which is biased by a coil spring. The serration plates can gradually retreat into the bolt body as the bolt device further approaches a conductor surface and are completely housed within the bolt body in the end so as to provide sufficient electrical conduction between the flat bottom of the bolt device and the conductor plate covered with an insulating substance. A thread device of claim 10 is another nut device having a serration device, which is a nut version of a thread device. Its serration device is partially housed in holder cuts and biased by a coil spring, which can clear an insulation substance from a surface portion of a conductor plate and provide efficient electrical conduction with the conductor plate. Washer Device: A conductive washer device according to claim 11 has a serration device on a face. The serration device on the washer device can be turned with a bolt engaging the washer device and scrapes a conductor surface portion covered with an insulation substance. The serration device is eventually deformed substantially "flat" on the cinductor surface. The washer device can be independently used as a file if so desired. A washer device of claim 12 additionally has a stop means to provide securer engagement with a bolt so that the washer device and its serration can securely turn together with the bolt. A washer device according to claim 13 is further provided with means to engage with a tool such as a screwdriver or a wrench to facilitate an easier use of the washer device as a file. For example, a "+"-shaped or "-"-shaped screwdriver groove is provided on the washer device to facilitate use of a screwdriver. A washer device of claim 14 has a serration means according to claim 1 or 2 provided around the washer device. A washer device according to claim 15 has a serration means directly formed on the washer body in a unit. A washer device of claim 16 has a cylindrical serration device made from a washer device as claimed in claim 11, 12, 13, 14 or 15 which has threads around the cylinder wall and through its axis. A nut having an elastic packing member provided on its conductor contact face is to be engaged with the outer thread of the washer device. A washer device of claim 17 is similar to the washer device of claim 16. The axial hole of this washer device is not threaded. This washer device having an elastic packing member is applied onto a conductor surface portion which has been treated or cleared of an insulating substance to prevent the scraped surface portion from corrosion by preventing contact with air or moisture. Washer-Incorporated Thread Device: A conductive washer-incorporated thread device according to claim 18 incorporates a washer device according to any one of claims 11 - 17. The thread device can be a bolt device or a nut device. This washer-incorporated thread device provides easier and more efficient operation on a conductor surface covered with an insulating substance. A washer-incorporated thread device according to claim 19 has a bolt shaft provided with a longitudinally extending engagement groove, which is to be engaged by a protrusion provided on a washer device for securer engagement between the washer and the bolt shaft. Connector Device and Terminal Plate: A connector device claimed in claim 20 is mainly used to earth a cable pipe by electrically connecting the cable pipe with the body portion of a switchboard or distributor. A connector device of claim 21 utilizes a terminal plate to detachably mount a nut device to provide flexibility in size adjustment as cable pipes generally come in a variety of sizes. Scraper Device: A scraper device according to claim 22 provides scraping of a conductor surface portion covered with an insulating substance, including a serration portion and a grip handle. The scraper device provides handy and quick scraping of a conductor surface portion for securer electrical conduction. The serration portion is gradually deformed, providing a constant and secure scraping on the conductor surface. A scraper device of claim 23 is used where a conductor plate has a threaded hole. The scraper device engages the threaded hole with its shaft and comparatively easily and stably provides surface scraping, even where there is not much room for operation. Another scraper device as claimed in claim 24 is also used where a conductor plate has a hole. The shaft portion of the scraper device engages the hole and the scraper device provides scraping on the conductor surface easily when pressed and turned against the conductor surface. A scraper device according to claim 25 utilizes a sucking disk to stably hold the scraper device on a conductor surface where there is no hole in the conductor surface. In a scraper device of claim 26, a serration device according to claim 1 or 2 is utilized for improved scraping of a conductor surface. In a scraper device of claim 27, a spring is additionally utilized to constantly press the serration device against a conductor surface to provide a constant pressure on the serration device for smoother surface scraping. In a scraper device of claim 28, serration plates are provided on the distal end of the scraper device such that the serration plates can be pressed back inwardly into a serration base to provide a flat bottom so as to provide improved electrical conduction with a conductor plate covered with an insulation substance. In a scraper device of claim 29, a serration device is provided replaceably so that a new serration device can be mounted as desired. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a serration member of claim 1; FIG. 2 shows the serration member of Fig. 1, which is wound in layers into a cylinder to provide serration device; FIG. 3 shows a single-layered serration device; FIG. 4 shows another single-layered serration device; FIG. 5 shows a thread device, which is a bolt device according to claim 4; FIG. 6 is an exploded view of the serration device of Fig. 5; FIG. 7 is a perspective view showing an embodiment use of the thread device of Fig. 5; FIG. 8 is a sectional view of the thread device shown in Fig. 7 as mounted on a conductor surface; FIG. 9 shows another thread device additionally having a ring; FIG. 10 shows another thread device; FIG. 11 shows another thread device with a coil thereon; FIG. 12 is a perspective view of a thread device as claimed in claim 5; FIG. 13 is a partial sectional view of the thread device of Fig. 12; FIG. 14 shows an embodiment use of the thread device of Fig. 12; FIG. 15 shows a use of a skirt on the thread device of Fig. 12; FIG. 16 shows an embodiment use of a thread device according to claim 6; FIG. 17 is an exploded view of the thread device of Fig. 16; FIG. 18 shows the thread device of Fig. 16 engaged with a nut; FIG. 19 shows an embodiment use of the thread device of Fig. 16 on a conductor surface; FIG. 20 shows a thread device of claim 7; FIG. 21 is an exploded view of the thread device shown in Fig. 20; FIG. 22 is a sectional view of the thread device of Fig. 20; FIG. 23 shows another thread device according to claim 7; FIG. 24 shows an embodiment use of the thread device of Fig. 20 on a double-decked conductor; FIG. 25 shows the thread device of Fig. 20, where the serration device is completely deformed; FIG. 26 shows the thread device of Fig. 20 as attached on the double-decked conductor shown in Fig. 24; FIG. 27 shows an assembly of a switchboard; FIG. 28 shows another embodiment use of the thread device of Fig. 20; FIG. 29 is a perspective view of a thread device according to claim 8; FIG. 30 is an exploded view of the thread device of Fig. 29; FIG. 31 shows an embodiment use of the thread device of Fig. 29; FIG. 32 shows an embodiment use of a nut device as claimed in claim 9; FIG. 33 shows an embodiment use of a nut device as claimed in claim 10; FIG. 34 shows another nut device according to claim 9; FIG. 35 shows a washer-incorporated thread device of claim 18 incorporating a washer device of claim 12; FIG. 36 shows another washer-incorporated thread device of claim 18 incorporating a washer device of claim 14; FIG. 37 shows another washer-incorporated thread device of claim 18 incorporating a washer device of claim 15; FIG. 38 shows the washer device shown in Fig. 37; FIG. 39 shows an embodiment use of the washer-incorporated thread device of Fig. 37 having a cover thereon; FIG. 40 shows a washer-incorporated thread device of claim 18 incorporating a washer device of claim 16; FIG. 41 shows a washer-incorporated thread device of claim 18 incorporating a washer device of claim 17, FIG. 42 shows a connector device according to claim 20; FIG. 43 shows an embodiment use of the connector device of Fig. 42; FIG. 44 is a sectional view showing a use of the connector device of Fig. 42; FIG. 45 shows a nut device on which a spring is mounted; FIG. 46 shows a use of the spring of Fig. 45; FIG. 47 shows another connector device; FIG. 48 shows another connector device; FIG. 49 shows another connector device; FIG. 50 shows a use of bolt devices according to claim 7; FIG. 51 shows a scraper device according to claim 23; FIG. 52 shows a serration portion of the scraper device according to claim 23; FIG. 53 shows a scraper device according to claim 24; FIG. 54 shows a serration portion of the scraper device of claim 24; FIG. 55 shows an exploded view of a scraper device according to claim 28, and FIG. 56 shows a scraper device according to claim 25. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Various embodiments are described hereinafter in detail using the accompanying drawings. (Embodiment 1) In Fig. 1 is shown a serration member 1 of the present invention, which is made from a copper plate or serration body 4 of about 0.8 mm in thickness, about 1 cm in width and about 9 cm in length. The serration member 1 has a V-shaped serration 2 of about 5 mm in depth at about 5 mm intervals along a longitudinal edge, and a stop member or projection 4a on the other edge to engage a hook member or end portion 4b provided on an end of the serration body 4. This serration member 1 is rolled into a cylindrical serration device 3 as shown in Fig. 2(a) and held firmly there by hooking engagement between the projection 4a and the end portion 4b as shown in Fig. 2(b). The serration 2 on the serration device 3 can function as a rasp and scrapes an insulating substance such as paint, rust or dust on a portion of a metal conductor plate when pressed against the conductor surface and turned thereon. The serration device 3 may be used as an independent file on the surface if so desired. The serration portion 2 should be hard enough to work as an effective file. It is advantageous that the serration portion 2 is also soft enough to be deformed and flattened as it scrapes a surface portion of a conductor plate to provide a wide contact area with the conductor plate so that the serration device 3 itself can provide improved electrical conduction when the removal of the insulating substance from the conductor surface portion is over. Advantageously, the serration 2 of the serration device 3 is deformable all inside, which can be provided by slightly bending the distal end of the serration portion inside as a dome. The serration body 4 may be rolled and fixed in any other appropriate way. A serration device 3 shown in Fig. 3 has end portions R and T, which are fixed together. Fig. 4 shows another single-layered serration device 3, whose ends fixedly engage each other by engagement between a catch 5 formed near an end and a catch window 6 formed near the other end of the serration device 3 as shown in Figs. 4(a) and 4(b). Spot welding of both ends or between appropriate portions of a serration member 1 may be utilized to provide such fixing. A serration member 1 may be made from a shape memory copper alloy to allow its repeated use. (Embodiment 2) Figs. 5-8 show a thread device 10a and its modifications as claimed in claims 3-4 The thread device 10a is a thread bolt or bolt device 10a. The bolt device 10a is screwed into a screw hole (not shown) formed in its attachment surface. A cord terminal 50 shown in Fig. 7 is to be connected to the bolt device 10a by means of another bolt 53 via a washer 52. The bolt 53 is screwed into a thread hole 18 provided in the bolt head 11 of the bolt device 10a as shown in Fig. 7. The bolt device 10a has a bolt neck 12 having a stop cut 15 on the bolt neck 12 under its bolt head 11. From the bolt neck 12 extends a bolt shaft 13. A serration member 1 is wound around the bolt neck 12 and fixed thereon by means of engagement between the stop cut 15 and a first end R and a second end T of the serration member 1. The serration member 1 is advantageously made of copper having serration 2 along a longitudinal edge. A coil 51 is mounted around the serration device 3 to prevent the serration member 1 from opening outside when the serration device 3 is pressed against a conductor plate 90 as shown in Fig. 8. The coil 51 also provides secure attachment of the bolt device 10a on the conductor surface by constantly applying pressure between the conductor surface and the thread device 10a. The top face 16 of the bolt device 10a has a diametrical screwdriver groove 17 in addition to the thread hole 18 for working with a screwdriver. This thread device or bolt device 10a can be fastened onto a frame portion of a switchboard or distributor for earthing. Its serration portion 14 deforms and flattens as shown in Fig. 8 to provide improved electrical conduction with a conductor plate. The washer 52 is provided above the thread hole 18. The screwdriver groove 18 can be replaced by a plus-shaped groove or any other appropriately shaped groove for engagement with a corresponding fastening tool. Alternatively, the thread device 10a can be formed so as to be turned with a wrench or spanner. Fig. 9 shows a modified thread device 10a having a serration member 1 around its bolt neck 12 as shown in Fig. 9(a). The coil 51 is replaced by a ring 19 shown in Fig. 9(b), which is deformed inwardly with an appropriate tool at appropriate portions or deformation points A shown in Fig. 9(c) to prevent the serration member 1 from independently turning, and to fix the ring 19 on the bolt neck 12, eliminating need of a stop cut 15. Fig. 10 shows a modification of the thread device 10a having a ring or cylindrical member 20 mounted on its serration member 1 under its bolt head 11. The cylindrical member 20 is deformed inwardly at a deformation point P on its side wall instead of the deformation points A previously described so as to be fixed onto the bolt neck of the thread device 10a and the serration device 3. Fig. 11 shows another thread member 10a having a coil 51 provided on its serration device 3. A spring cover 54 made of a rubber or other resilient material is provided over the coil 51 under its bolt head 11 to prevent corrosion of a scraped portion on a conductor surface (not shown) by preventing entry of moist air onto the scraped portion. (Embodiment 3) Figs. 12 to 14 show another thread device 10b according to claim 5. The thread device 10b has a bolt head 11, a bolt neck 12, and a bolt shaft 13. A serration member 1 is wound around the bolt neck 12 to provide a serration device 3 or serration portion 14. The bolt head 11 has a thread 21, on which a nut 55 is mounted to fixedly mount the thread device 10b on a conductor plate 90 as shown in Fig. 14. A cord terminal 50 is attached to the thread hole 18 provided on the top face 16 of the bolt neck or head 12 for electrical conduction with the thread device 10b as shown in Fig. 14. Fig. 13 shows a sectional view of the thread device 10b. As shown in Fig. 15, a skirt may be additionally provided over the serration device 3 to protect a scraped portion (not shown) on the conductor plate 90 from corroding by preventing entry of moist air onto the scraped portion. (Embodiment 4) Another thread device 10c or bolt device 22 which is substantially identical with the bolt device claimed in claim 5 is shown in Figs. 16 to 19, having a bolt shaft 13 and a serration device 14 under its bolt head 11 or bolt 21 provided with a screwdriver groove 17 and an axial thread hole 18 on its top face 16. The bolt 21 is screwed into a nut 23 and the bolt shaft 13 is screwed into a conductive hole in a conductor plate 90. A packing washer 24 made of a rubber material in this embodiment is provided on the under portion of the nut 23 to protect a scraped portion or area 92 on the conductor plate 90 from corrosion, as claimed in claim 6. The packing washer 24 may be of any resilient material. Its thickness is preferably about 1mm. Fig. 17 shows how the serration member 1 is attached on the thread device 10c. Fig. 18 shows how the thread device 10c looks from under, while Fig. 19 is a sectional view of the thread device 10c, showing how the thread device 10c is mounted into the conductive hole 91 in the conductor plate 90 (Fig. 19(a)) and its final appearance (Fig. 19(b)) after providing scraping around the conductive hole 91. (Embodiment 5) Figs. 20 to 22 show a thread device 10d having a serration device 3 around its neck 12 according to claim 7. The serration device 3 is fastened to the neck 12 by means of point pressing or deformation at a deformation point P against the neck 12. This thread device 10d has a serration portion 14 at the distal end of the bolt head 11 having a thread 21 on its outer wall. The bolt head 11 has on its top face 16 a diametrical screwdriver groove 17 and an axial thread hole 18. This thread device 10d is for providing scraping on a second surface under a first surface (not shown here). Fig. 21 shows how the serration 2 having a first end R and a second end T is mounted on the neck 12. The first end R and the second end T are inserted into a stop cut 15 prepared in the neck 12 having a deformed point 25 to receive the deformation point P as deformed inwardly. Fig. 22 is a sectional view of the thread device 10d. Fig. 23 shows another thread device 10d, which has a serration portion 14 at the distal end of its bolt shaft 13 in a unit. This serration portion 14 can be provided directly from the bolt shaft 13 by appropriate cutting process. Such a serration portion is advantageously hardened by a hardening treatment. This thread device 10d is provided with a polygonal bolt head 11 so that a spanner (not shown) is used instead of a screwdriver (not shown) to fasten the thread device 10d into a first conductor plate and provide scraping on a second conductor surface behind the first conductor plate. Fig. 24 shows how such a thread device 10d is used. The thread device 10d is screwed into a conductive hole 91 in a first conductor plate 93. Its serration portion 14 reaches a second conductor plate 90 provided beyond the first plate 93. The first plate 93 and the second plate 90 may be those mounted in a switchboard 94 as shown in Fig. 27 for attaching various electric devices. The first plate 93 is generally apart from the first plate 93 by about 5-10 mm. Accordingly, the thread device 10d is generally given a dimension which appropriately fits in this gap. The thread device 10d scrapes a portion of the second plate 90 and removes an insulation substance from the surface portion, providing electrical conduction between the two plates 90 and 93 through the thread device 10d. Fig. 25 shows how the serration device 3 is deformed in the end on the second plate 90. Fig. 26 shows the thread device 10d mounted on the plates 90 and 93, which is connected with a cord terminal 50 by a screw 53. Fig. 28 shows another use of the thread device 10d to electrically connect an electric device with a conductor plate 93 covered with an insulating substance through the thread device 10d. (Embodiment 6) Figs. 29 to 31 show a thread device 10e as defined in claim 8, having a plurality of serration plates 28 engaged in holder cuts 29 provided in its bolt neck 12. These serration plates 28 have serration portions 14 along an edge, which partially protrude from the holder cuts 29. A coil 27 is additionally provided on the bolt neck 12 between a bolt head 11 and the serration plates 28 to resiliently press the serration plates 28 against a surface of a conductor plate 90. The bolt head 11 has a screwdriver groove 17 and an axial screw hole 18. The serration plates 28 will resiliently retreat further into the holder cuts 29 when pushed back by the conductor plate 90 as the bolt shaft 13 of the thread device 10e advances through a conductive hole 91 prepared in the conductor plate 90, while providing a scraped area 92 on the conductor plate 90. The serrations 30 of the serration plates 28 will completely enter the holder cuts 29 when the conductor contact face 31 of the thread device 10e contacts the conductor plate 90. Fig. 31 shows a state of the thread device 10e mounted on a first plate 93 having electrical connection therewith, whose bolt shaft 13 is screwed into a screw hole (not shown) of a second plate 90 under the first plate 93, providing electrical connection between the two plates 90 and 93. (Embodiment 7) Fig. 32 shows an arrangement of a thread device 10f as claimed in claim 9, which is a nut device 10f having a hexagonal head with an axial threaded hole, a nut neck 12 and a serration portion 14 provided around the nut neck 12. A coil 51 is provided over the serration portion 14 to bend the serration inwardly when pressed on a conductor surface. As in other embodiments utilizing such a coil, the coil 51 shrinks as the serration device 3 is deformed. This nut device 10f is often used on an angled conductor frame 95 having through holes or openings 96 as shown in Fig. 32. A receiver bolt 56 is inserted into the opening 96 from an inner face B of the angled frame 95 and receives the nut device 10f on an outer face F. The thread device 10f scrapes a portion of the upper face F of the frame 95 and removes an insulation substance from the portion. A cord terminal 50 may be fixed on the nut head with a bolt (not shown) screwed into the nut hole. (Embodiment 8) Fig. 33 shows another nut-type thread device 10g or nut device 33 as defined in claim 10, which is a modification of the thread device 10f. This thread device 10g uses serration plates 28 instead of a serration device 3 received in holder cuts 31 formed in its nut neck 12 as previously defined. The nut device 33 is received by a receiver bolt 56 inserted into a through hole provided in a conductor plate from under as shown in the figure. The serration plates 28 remove an insulation substance from a conductor surface portion. Fig. 34 shows a modification of the nut device 10g. The serration portion 14 of this embodiment is provided directly on its head portion in a unit by appropriately cutting out the serration from the head portion. (Embodiment 9) Fig. 35 shows a washer-incorporated thread device 100a according to claim 18 incorporating a washer device 200a of claim 11 or 12 on a bolt 110a. The washer device 200a is provided by pressing and deforming a serration member 201 having a circumferential serration 202 and an engagement hook 204 onto a serration base 203. The engagement hook 204 is formed around its center opening to engage a stop hole 112 provided in the bolt head 111 of a bolt 110a or thread device 100a having a bolt shaft 113 when the center opening of the washer device 200a engages the bolt shaft 113 to provide a synchronous movement of the bolt 110a and the washer device 200a. Fig. 35(c) shows a completed washer-incorporated thread device 100a as claimed in claim 18, also having a diametrical screwdriver groove. (Embodiment 10) Fig. 36 shows another washer-incorporated thread device 100b according to claim 18, incorporating a washer device 200b of claim 17 on a bolt 110b. The washer device 200b has a head 211 and a neck 212 having a serration member 1 around. The head 211 has a pin receiver hole 213 to engage a pin hole 114 provided in the bolt head 111 of the bolt 110b through a pin 115 to synchronously turn the bolt 110b and the washer device 200b. The bolt head 111 has a diametrical groove and an axial hole. (Embodiment 11) Fig. 37 shows a washer-incorporated thread device 100c according to claim 19 incorporating a washer device 200b of claim 11, 12 or 15 on a bolt 110b. The bolt 110c has a longitudinal stop groove 116 formed on its bolt shaft 113 as shown. The washer device 200c has serration cuts 214 formed such that the serration cuts 214 can scrape a surface portion of a conductor plate 90 to remove an insulating substance from the surface portion. The washer device 200c has a center hole 217 having a center stop 218 as clearly shown in Fig. 38, which engages the stop groove 116 when the bolt shaft 113 is inserted into the center hole 217. The bolt shaft 113 is inserted into a conductive hole 91 prepared in the conductor plate 90. A cord terminal 50 is mounted on the bolt shaft 113 for electrical conduction with the conductor plate 90, and a generally transparent plastic cover 60 having a cover mark 61 thereon such as an indication of earthing may be provided on the thread device 100c for convenience and protection of the thread device 100c. The cover 60 is provided with hooks 60a on its inner wall to engage projections 219 formed on the washer device 200c. Fig. 39 shows the thread device 100c as attached on the conductor plate 90, which is covered by the plastic cover 60. The cover 60 is provided with an opening on its side wall to allow the cord extending from the terminal 50 to extend outwardly from the thread device 100c. (Embodiment 12) Fig. 40 shows another washer-incorporated thread device 100d according to claim 18 incorporating a washer device 200d of claim 16 on a bolt 110d. This device 100d comprises a bolt 110d having a bolt head 111 and a bolt shaft and a washer device 200d. The washer device 200d comprises a washer member 221 having a threaded center hole 225 and a thread 226 on its outer wall, a nut 223 and a packing plate 224. Its washer member 221 has a neck 212 on which a serration member 1 is fixedly wound. The bolt 110d is screwed into the threaded hole 225 of the washer member 221, which is screwed into the nut 223 and the packing plate 224. The bolt 110 reaches and screwed into a hole provided in a conductor plate 90 and the serration member 1 provides scraping on a surface portion of the conductor plate 90 and provides a scraped area 92 on the surface portion. The packing plate 224 about 1mm thick provides protection of the scraped area. A cord terminal 50 is provided on the bolt 110d for providing electrical conduction with the conductor plate 90. (Embodiment 13) Fig. 41 shows another washer-incorporated thread device 100e according to claim 18 incorporating a washer device 200e of claim 17 on a bolt 110e, which is similar to the washer-incorporated thread device 100d. This device 100e is used so that the thread device 100d can protect the scraped area from degrading. (Embodiment 14) Figs. 42 to 50 show a connector device 300 according to claim 20 and various types of terminal plates 301 according to claim 21. Such a connector device 300 is connected to a connection 81 of a cable pipe 80 through a plate hole 97 of a conductor plate 90 as shown in Fig. 43 to provide electrical connection between the cable pipe 80 and the conductor plate 90. This embodiment connector device 300 comprises a terminal plate 301, a nut 10d having a serration and a nut device 333. The terminal plate 301 has a holder ring 330 having a hole for fixedly engaging the connection 81 and an attachment portion 334 having a raised opening 335. In this embodiment, the opening 335 is of a track shape to unturnably hold the nut device 333 having a correspondingly shaped nut body 336 therein as shown in Fig. 42. A thread device 10d having a serration is screwed into the nut device 333 through the opening 335 to provide scraping on the conductor plate 90. A nut ring 82 engages the connection 81 and fastens the cable pipe 80 on the conductor plate 90 as shown in Fig. 44. A nut device 333 shown in Fig. 45 is further provided with a spring groove 339 to engage a spring 340 and hold the thread device 10d resiliently as shown in Fig. 46 so that the thread device 10d screwed into the nut device 333 does not loosen within the nut device 333. It is possible to replace the raised opening 335 of the terminal device 301 with a nut portion 332 as shown in Fig. 47. It is also possible to provide a step 338 on the terminal device 301 instead of raising the opening 335. The terminal device 310 may have a step 338 and a cut portion instead of a hole as shown in Fig. 49. Fig. 50 shows another embodiment. In this embodiment, a lock nut 82 is used to link the cable pipe 80 through the plate hole 97 of the conductor plate 90. A plurality of thread members 10d each having serration are screwed into threaded holes formed in the lock nut 82 and respectively scrape surface portions of the conductor plate 90 to provide efficient electric conduction between the conductor plate 90 and the cable pipe 80. (Embodiment 15) Various embodiments for scraper devices as claimed in claims 22, 23, 26 and 29 are shown in Figs. 51 and 52. Fig. 51 shows a scraper device 400a comprising a shaft 401, a grip handle 403, and a scraper portion 402. The scraper portion 402 comprises a cylindrical holder 404 enclosing a serration device 405 having a threaded shaft 409. The serration device 405 is fixed inside the cylindrical holder 404 with a pin or pins. The threaded shaft 409 is engaged with a threaded hole 91 provided in a conductor plate 90 and the grip handle 403 is turned with a hand such that the serration device 405 provides a scraped area 92 on the conductor plate 90. This scraper device 400a can provide very secure scraping on a conductor plate where other serration devices according to the present invention do not, easily. The serration device 405 of this embodiment is prepared as shown in Fig. 52, having a dome-like serration over the threaded shaft 409 under its head portion 407. (Embodiment 16) Figs. 53 and 54 show another scraper device 400b according to claim 22, 24, 26 or 29 which is similar to the scraper device 400a. In this embodiment, the shaft 410 is not threaded as shown in Fig. 54 and engages a hole provided in a conductor plate. Therefore, its handle need be pressed and turned with a hand to provide an appropriate scraped area on the conductor plate. (Embodiment 17) Fig. 55 shows another scraper device 400c according to claim 28, which is similar to the previously described scraper devices 400a and 400b. In this embodiment, a different type of scraper member 411 is provided. This scraper member 411 comprises a serration device having a head 414, a neck 412 and a threaded shaft 413. In the neck 412 is provided cuts 415 to receive serration plates 416. A spring 417 is additionally provided on the neck 412 to press and resiliently receive the serration plates 416. The serration plates 416 gradually retreat into the neck 412 as they provide further scraping on a conductor surface as set forth. The serration device is received within a cylindrical holder of the scraper device 400c. (Embodiment 18) Fig. 56 shows still another scraper device 400d claimed in claim 22 or 25, which is substantially different from those described in the above. This device 400d utilizes an absorber disk 425 and can be used where there is no hole provided in a conductor plate as the absorber disk 425 can stably hold the scraper device 400d. The scraper device 400d comprises a handle 424 and a thread member 422 having a cylindrical threaded wall 423 and a serration 421 which is held within the threaded wall 423 by means of pins. The threaded wall 423 engages the threaded inner wall of the absorber disk 425 to be tightly held therein. The handle 424 is turned with a hand and the serration 421 removes an insulation substance from a surface portion of the conductor plate 90. A magnet (not shown) may be appropriately utilized instead of such an absorber disk 425. Those serrations can be made from a shape memory alloy to allow their repeated use. Though not shown, a spring may be additionally utilized as claimed in claim 28 to press the serrations against a conductor surface for an improved scraping operation.

Claims: A conductive serration means (3) comprising a cylindrical ring having a serration along an edge thereof for providing scraping on a conductive plate to provide electrical conduction therewith, the serration means being made of a bendable metal plate (4) having a serration portion (2) along a longitudinal edge. A serration means according to claim 1, wherein said plate is a conductive shape memory alloy plate having a memory of its original shape so that said serration portion (2) can restore its original shape after use. A conductive thread device having a serration means according to claim I or claim 2. wherein said serration means (3) is deformable and capable of providing a substantially planar contact face when the thread device is firmly mounted on a conductor surface. A thread device according claim 3, wherein said thread device is a bolt device (10a) comprising a head (11) and a shaft (13), said head having an axial threaded hole (18) and said serration (3) means provided on said head over said shaft. A thread device (10b) according to claim 4 wherein said head (11) is further provided with an outer thread (21). A thread device according to claim 5, further comprising a nut (55) to engage said head (11) and a packing member (24) to be provided on said nut on its conductor surface contact face to provide protection of a scraped area. A thread device according to claim 3, wherein said thread device is a bolt device (10d) having a shaft (12) and said serration means (3) is provided on the distal end of said shaft. A thread device according to claim 3, wherein said thread device is a nut device (10f). A conductive thread device having a serration means, wherein said thread device is a bolt device (10e) having a head (11) and said serration means comprises at least one serration plate (28) mounted in a serration holder (29) provided under said head, which is biased by a coil (27), said serration plate (28) being resiliently provided in said serration holder (29) and being retreatable into said serration holder when pressed back on a conductor surface. A conductive thread device having a serration means, wherein said thread device is a nut device (10g) and said serration means comprises at least one serration plate (28) mounted in a serration holder (29) provided on said nut device, which is biased by a coil (27), said serration plate being resiliently provided in said serration holder and being retreatable into said serration holder when pressed back on a conductor surface. A conductive washer device (200a) for scraping a conductor surface to provide electrical conduction therewith, comprising a washer body (203), a serration means (202) protruding from said washer body, and means (204) for engaging a rotatable tool or thread device for rotation therewith, so that rotation of the serration means scrapes the conductor surface, said serration means being deformable in use to provide a substantially flat surface against the conductor surface. A washer device according to claim 11, wherein said means for engaging a tool or thread device comprises stop engagement means (218) to engage a bolt (110c) so as to synchronously turn with said bolt. A washer device according to claim 11, wherein said means for engaging a tool or thread device comprises engagement means to engage a fastener tool. A washer device according to any one of claims 11 to 13, wherein said serration means is provided by a serration means (3) of claim 1 or 2. A washer device according to any one of claims 11 to 13, wherein said serration means (214) is provided on said washer body by punching means. A washer device according to any one of claims 11 to 15, wherein said washer body is a cylindrical body (221) having an outer thread (226) and an axial inner thread (225), further comprising a packing means (224) to provide protection of a scraped area on a conductor surface. A washer device according to any one of claims 11 to 15. wherein said washer body is a cylindrical body having an axial hole (225) and an outer thread (226); said washer device further comprising: a nut (223) to engage said outer thread; and a packing means (224) to be provided on said nut to provide protection of a scraped area on a conductor surface. A conductive washer-incorporated thread device for scraping a conductor surface to provide electrical conduction therewith, comprising a thread device (110c) having a shaft (113) and a washer device (200c) according to any one of claims 11 to 17, which includes a hole (217) to receive said shaft. A washer-incorporated thread device according to claim 18, wherein said shaft is provided with a longitudinal engagement groove (116) and said hole is provided with a projection (218) to engage said engagement groove. A conductive connector device for providing electrical conduction between a cable pipe (80) and a conductor plate (90), comprising: a holder ring (301) to hold said cable pipe on said conductor plate through a hole (97) provided on the conductor plate; a nut means (333) connected to said holder ring to be applied on said conductor plate; and a conductive bolt device (10d), that includes a conductive serration means, wherein said conductive bolt device is to be screwed into said nut means to provide scraping on said conductor plate for providing said electrical conduction. A connector device according to claim 20, further comprising a nut mounting means (334) connected to said holder ring to detachably mount said nut means. A scraper device for scraping a conductor surface, comprising a turn handle (403), a shaft (401) connected to said turn handle and a serration means (405) attached to the distal end of said shaft, said serration means being deformable in use to provide a substantially flat surface against the conductor surface. A scraper device according to claim 22, further comprising a threaded shaft (409) protruding from said serration means to engage a threaded hole (91) provided in a conductor plate. A scraper device according to claim 22, further comprising a shaft (410) protruding from said serration means to engage a hole provided in a conductor plate. A scraper device according to claim 22, further comprising a cylindrical body (422) having an outer thread (423), partially housing said serration means (421), and an absorber disk (420) for attachment on a conductor surface, having an inner thread to engage said outer thread of said cylindrical body to stably hold said cylindrical body on said absorber disk. A scraper device according to any one of claims 22 to 25, wherein said serration means is provided by a serration member of claim 1 or 2. A scraper device according to any one of claims 22 to 26, wherein said serration means is resiliently and retreatably provided in said scraper device. A scraper device for scraping a conductor surface comprising a turn handle (403), a shaft (401) connected to said turn handle and a serration means (411), attached to the distal end of said shaft, wherein said serration means (411) comprises at least one serration plate (416) that is retreatably received in the distal end of the shaft and is resiliently biased outwards by a coil (417). A scraper device according to any one of claims 22 to 28, wherein said serration means is provided replaceably. An electrical connection device for providing electrical conduction with a conductive plate, said device including a conductive body member (12) and a separate conductive serration means (1) mounted on the body member for rotation therewith, said serration means having a serration portion (14) that scrapes a surface of a conductive plate to provide electrical conduction therewith, when rotated relative to that plate. A connection device according to claim 30, wherein the body member comprises a thread device (13). A connection device according to claim 30 or claim 31, wherein the serration means comprises a metal plate (1) having said serration portion (2) along an edge thereof. A connection device according to claim 32, where said metal plate (1) is bent into a cylindrical ring having a serration portion along an edge thereof. A connection device according to claim 32, wherein said metal plate (28) is mounted in a serration holder (29) and is resiliently biased, said plate being retreatable into said serration holder when pressed back on a conductor surface.

Inventors: UNO TSUYOSHI, UNO, TSUYOSHI
Applicants: NAKASU DENKI KABUSHIKIGAISYA
Application year: 1996
Main classification: H01R4
IPC codes: H01R4