MXPA98002368A - Pre-ensambl electrical panel connection screw - Google Patents

Abstract

The present invention relates to a preassembled connection screw in a distribution panel in a non-union position that does not connect a neutral bar within the panel enclosure to the enclosure wall. This allows a panel installer to select between the option to keep the connecting screw in the position without pre-assembled joint and the option of placing the connecting screw from the un-joined position to a joint position. A base container is positioned within the enclosure between the neutral bar and the rear wall of the enclosure. The unattached position is defined by the threading of the screw shank having a threaded coupling with a through hole in a base container, the head of the connecting screw being separated from the neutral bar and the shank of the connecting screw being separated from the Rear seat wall. The joint position is defined by the head of the electrically conductive part that is positioned against the neutral bar and the rod that is screwed into an extruded hole in the back wall of the recliner.

Description

He PRE-ASSEMBLED ELECTRICAL PANEL CONNECTION SCREW Reference to a Related Request and 5 Incorporation for Reference This invention is an improvement in a certain subject matter of common property, pending, of the ß application of United States Patent No. of 0 Series 08 / 622,971, filed on March 27, 1996, the complete description of which is incorporated for reference as it is described in its entirety in the present.

Field of the Invention This invention relates generally to electrical panels, such as load centers and downstream feeder panels, for example, which are used to distribute electrical power from one installation to various charging circuits through circuit protection devices such as electrical switches. .

* Background and Brief Description of the Invention The patent application of the States United common property pending referred to above describes an electrical panel comprising a confined enclosure containing an electrically non-conductive base container mounted thereon. The enclosure and the reservoir container are generally? F of rectangular shape. A respective one of a pair of 0 neutral bars, is positioned along one respective side of the opposite reservoir container, and parallel to the other. These neutral bars provide the connection of individual neutral return wires from individual load circuits to a neutral that is provided by the electrical power. The neutral from the Electric power can be carried to the panel by one or more neutral input wires attached to a neutral junction bar within the 0 panel. The neutral tie bar is placed against one side of the transverse base container on the sides against which the pair of neutral bars are placed, and each of its opposite ends is mechanically clamped in electrical relation. * - conductive to a respective end of a respective neutral bar. The installation of electric power generally maintains the neutral at, almost close to, 5 a ground potential, that is zero volts of electrical potential referred to ground. In at least some panel insulations, the enclosure is grounded by an earth path that may include a ground wire that extends from the panel to a suitable ground location. In any installation where it may be necessary to ensure that there is no potential difference between the neutral of the installation and the ground, a conductive path is provided 5 within the panel between the ground connected enclosure ^^ and certain panel components, such as the neutral bars and the neutral junction bar that are connected to the neutral of the electrical power installation. The creation of such a conductive path 0 is. sometimes referred to as a joint, and a known means for attaining the joint comprises a connecting screw, as described in the pending commonly-owned pending United States patent application.

It is considered that such a union has been executed so far by a panel installer whenever the union is required. While a panel construction may have been adapted to the possible joint to provide a hole in a neutral bar or a neutral tie bar, an underlying hole in the enclosure, the screw been a separate part installed by a Installer whenever it is required to join a given panel 0. The pending common property patent application of the United States provides the possible connection by having the installer pass a connecting screw through preexisting aligned clearance holes in the neutral tie bar 5 and the underlying container container. , and screwing the body or rod of the screw into a pre-existing hole in the back wall of the enclosure. Because such a connecting screw is a separate part, there is a possibility that it may come loose or be misplaced before installation. In addition, an installer must execute the operations of inserting the connecting screw through the aligned clearance holes 5 in the neutral union bar and the base container * Underlying, place the tip of the screw shank in the preexisting enclosure orifice and then screw the shank of the screw into the enclosure to finally splice the screw head against the neutral tie bar. The present invention is directed to an improvement where a connecting screw is preassembled in a panel and pre-positioned in the same ßp for optional joining whenever the union. All that an installer needs to do to achieve the union is only to attach the head of the connecting screw by means of a suitable tool, such as a screwdriver, and then turn the screw to advance as completely as possible. ! 5 towards the rear wall of the enclosure until the ^ Feed is stopped by the splicing of the screw head with the neutral tie rod. As the screw is advanced, the tip of the rod is screwed into a hole aligned in the wall or back of the enclosure. The connection is completed when the connection screw head splices the neutral junction bar, creating an adequate electrical path between the neutral junction bar and the enclosure so that the possibility of a potential difference between them is excluded.

• The present invention is considered to provide significant savings since a connecting screw can be easily and easily pre-installed in a desired prior position in the factory by an automated process and at the time of panel installation, an installer does not need to locate and assembling the connecting screw in the previously described manner. Although a The connection screw is pre-assembled, an additional advantage of its particular prior placement is that it is sufficiently separated from the enclosure to meet any installation requirement that can prevent the joint, for example when a panel is a downstream feeder panel. . It is an object of the invention to provide an electrical distribution panel comprising: a w - f confined enclosure comprising an electrically conductive wall that forms a portion of the enclosure; an electrically conductive neutral bar 0 positioned within the enclosure; an electrically non-conductive part placed between the neutral bar and the wall to place the neutral bar in a non-wall-bound relationship; a through hole in the neutral bar; a through hole in 5 l electrically nonconductive part in * non-underlying coincidence with the through hole in the neutral bar; an electrically conductive part adapted for optionally joining the neutral bar to the wall, the electrically conducting part comprising a head and a rod extending distally from the head, the rod comprising a screw; wherein the electrically conductive part is pre-assembled to the M "non-conductive party in a position without joining the neutral bar to the wall so that it allows a panel installer to select between the option to keep the electrically conductive part in the position without pre-ens amblada junction and the option of placing the electrically conductive part from the I5 position without union to a joint position in ^ where the electrically conductive part joins the neutral to the wall; wherein the position without pre-assembled joint is defined by the threaded rod having a threaded coupling with the through hole in the electrically non-conductive part, the head of the electrically conductive part being separated from the neutral bar and the rod being separated from the wall; and where the joint position is defined by the head of the electrically conductive part that is placed * against the neutral bar and the rod that is placed against the wall. It is another object of the invention to provide an electrical distribution panel as set forth above wherein the wall comprises an underlyingly coincident hole with the through holes in the neutral bar and in the dielectrically non-conductive part and the threaded rod is screwed into the hole in the wall when the electrically conductive part is placed in the joint position. It is a further object of the invention to provide an electrical distribution panel as set forth above wherein the hole in the wall 5 is an extruded orifice, and the threaded rod It comprises a self-threading thread which is screwed into the extruded hole in the wall when the electrically conductive part is placed in a joint position. It is another object of the invention to provide an electrical distribution panel as set forth above wherein the threaded rod has at least two complete turns of coupling with the extruded hole in the wall when the part The electrically conductive is placed in the joint position. It is a further object of the invention to provide an electrical distribution panel as was established earlier where the neutral bar is a neutral junction bar that is at a right angle to, and joins together, several neutral bars together. It is another object of the invention to provide An electrical distribution panel as set forth above wherein the electrically non-conductive part comprises a base container placed between the neutral bars and the wall. It is a further object of the invention to provide an electrical distribution panel as established before wherein the threaded coupling of the threaded rod with the through hole in the electrically non-conductive part has a frictional coupling which is located within a scale of about five point seventy-six kilograms on centimeters (five inches-pounds) of torque to approximately nine point twenty-two kilograms over centimeters (eight inches-pounds) of torque when the electrically non-conductive part is in the pre-assembled position.

It is still another object of the invention to provide an electrical distribution panel as set forth above wherein the rod is separated by at least one point twenty-seven 5 centimeters (one-half inch) from the wall when the electrically non-conductive part is in the pre-positioned position. assembled It is still another object of the invention The provision of an electrical distribution panel such as 0 was established earlier where the threaded rod maintains a threaded coupling with the through hole in the electrically non-conductive part when the electrically non-conductive part is in the joint position. The foregoing, together with the features, advantages and additional benefits of the invention will be observed in the following description and claims, which is accompanied by the drawings. 0 The description and drawings describe a currently preferred embodiment of the invention in accordance with the best mode contemplated at this time to carry out the invention.

* Brief Description of the Drawings Figure 1 is a fragmentary perspective view of a portion of an electrical panel 5 illustrative behind the principles that modalize the drive front of the present invention, certain portions that have been removed for illustrative presentation. Figure 2 is a fragmentary view ° elongated partially in cross section, in the general direction of arrow 2 in Figure 1, showing a pre-assembled connecting screw in the non-union position. Figure 3 is a view similar to Figure 2, but with the connecting screw that has been operated to the joint position.

Description of the Preferred Modality 0 _ Figure 1 shows a portion of an electrical panel 10 comprising an enclosure 12 and a base container 14. The particular panel shown is of a type that is sometimes referred to as a load center. The entire enclosure 12 is formed 5 of electrically conductive metal and is generally rectangular shape that has a front wall, - a back wall 16 and four side walls, a back wall portion 16 being the only portion of the enclosure 12 shown in Figure 1.

. • The base container 14 is formed of electrically non-conductive material and is generally rectangular in shape to fit within the interior of the enclosure 12. The front wall The enclosure 12 comprises a door which is latched by closure although it may be disengaged to open by rotation to expose the drive front and circuit breaker handles protruding through the openings in the front of the drive. The electrical apparatus is contained within the enclosure 12 behind the drive front. The device Electric F includes a pair of neutral bars 18, 20 each of which is positioned along a respective side of the base container 14 0 opposite and parallel to each other. These neutral bars comprise a series of openings 19 and fasteners 21 which provide the connection of the individual neutral return cables (not shown) or of individual charging circuits to the neutral which is provided by the power installation.

Electric. The neutral of the electrical power installation can be carried inside the panel by one or more neutral input cables (not shown) fastened to a neutral junction bar 22 inside the enclosure 12. The neutral junction bar 22 is placed against one side of a base container 14 perpendicular to the sides against which the neutral bars 18, 20 are placed and each one * from its opposite ends is mechanically fastened 1 ° in electrically conductive relationship towards a respective end of a respective neutral bar, such as by the screw 24. The neutral tie bar 22 comprises at least one vertical tongue 26 within which one end of a cable I5 neutral can be inserted and held in place ^ in place by a set screw 28. The neutral tie bars are disposed in the respective slots 30 of base container 14, and the neutral tie bar comprises through holes 32 by means of which it is mounted on the base container 14 to be electrically isolated from the enclosure 12. The base container 14 is self-secured on the enclosure 12 by suitable joining means.

The base container 14 comprises staggered mounting posts 34 whose ends 36 pass through and beyond the through holes 32 in the neutral tie bar 22, while to the margin that surround each through hole 32 is slightly separated from a circular stepped shoulder 38 of the respective post 34. When the ends 36 protrude through the through holes of the neutral tie bar, they are subsequently deformed, such as by heat accumulation, to assist in the maintenance of the neutral tie bar. The base container 14 comprises additional features for the assembly of I5 circuit breakers (not shown) in two adjacent f rows, one row being adjacent and -, functionally associated, with one of the neutral bars 18, 20 and the other row being adjacent and functionally associated with the other neutral bar.

The particular circuit breakers used in the illustrated embodiment are circuit breakers of the feedback type and are powered by voltage line by features that are not visible in the view of Figure 1.

The above description of Figure 1 has been -for the purpose of providing the sufficient construction detail of the preparatory panel 10 to present the detailed description of the improvement which is the object of the present invention. If the reader desires additional information about more specific aspects of panel 10 that are not considered to refer to the present invention, the pending pending patent application of the United States of America may be consulted. Although the near right corner of the base container 14 is separated from Figure 1, it is essentially a mirror image of the near left corner 5 and Figure 2 describes a view, ^ on an enlarged scale, which reveals the general appearance of that near right corner, looking in the general direction of arrow 2 in Figure 1.

Although the rear part of the base container 14 ° is placed against the rear wall 16 of the enclosure 12, the actual contact is located in several locations. In the location shown by Figure 2, the base container 14 is formed with a protuberance or vertical conductor 37 that is # extends frontally from the rear of the base container to provide a wall 40 that closely confronts a portion of the neutral tie bar 22. Wall 40 comprises a circular through hole 42 which coincides in substantial coaxial alignment with a through hole additional circular 44 in the neutral tie bar 22. F A connecting screw 46 comprising 0 a head 48 and a threaded rod 50 extends distally from the head and is preassembled in a particular manner. The through hole 44 is slightly larger than the maximum height diameter of the threaded rod 50 to allow the distal end of the rod to pass through Il through the through hole 44 with clearance. The diameter of the through hole 42 is slightly smaller than The diameter of the maximum height of the threaded rod 50, so that the rod will coil inside 0 the. circular cylindrical surface of the through hole 42 when a suitable tool (not shown) is coupled with a tool engaging surface on the head of the screw 48 and rotated to advance the screw in a direction toward the rear wall 16. Through the With suitable selection of the respective materials of the base receiver 14 and the screw 46 and the diameter of the through hole 42 in relation to the threaded rod screw, the rod can easily self-tap into the through hole. The connecting screw 46 is advanced to a certain amount so that it will be preassembled in a desired position when the tip of its distal end is spaced at least a certain minimum distance from the rear wall 16 of the enclosure 12. Figure 2 illustrates this presetting, which represents a posture without connection of the connecting screw 46. In this previous position, the frictional engagement of the screw thread with the through hole 42 maintains the connecting screw 46 in this previous position during typical shipping and handling that are between the moment of union of the pre-assembly of the screw in the factory and the installation of. final panel, just like in a building. As an example, the frictional coupling provided by the holding torque is located within a scale of about five point seventy-six kilograms per centimeter (five inches-pounds) to approximately nine point twenty-two * kilograms per centimeter (eight inches s - 1 lb s) and found to be satisfactory for a screw thread of 32 turns for every two point fifty-four centimeters (one inch). By separating the rod from the tip end of the screw rod at least a certain minimum distance from the rear wall 16, in compliance with the relevant specifications and / or standards for the 0 lack of union of the bars Neutral and the neutral union bar can be obtained. Even, the invention provides fast bonding when the joint is required. The wall panel 16 comprises an extruded through hole 5 in substantial coaxial alignment with the screw 46. When joining is required, an installer uses only a suitable tool to advance the screw 46 from its pre-ambleted unattached position until the rod of 0 self-tapping screw threaded in the through hole 52 and the head 48 forcedly spliced to the neutral tie bar surrounding the through hole 44, as shown by Figure 3. The dimensions of the screw 46 are such that when the head 48 splices the neutral link bar 22, the Sufficient coupling of the screw thread when the jpasante orifice 52 has taken place to ensure adequate electrical contact between them. For a connecting screw having a thread of 5 32 turns per two-point fifty-four centimeters (one inch) it is considered that such a coupling is desirable to comprise at least two full turns of the thread. - • a i ^ From the above, I could see that The convenient and economical manufacture and installation has been provided by the present invention. The manufactured panels can be standardized for boarding without connection. If the connection of the panel is not required the connecting screw I5 simply remains in its position without preassembled joint. If the connection of a panel is required the connection screw is simply advanced completely by the installer to a joint position. While the present invention has been described with reference to a preferred embodiment as contemplated herein, it should be understood that the invention is not intended to be limited to that embodiment. Therefore, it is intended that the The invention covers several modifications and * Dispositions that are within the scope of the claims. W F

Claims (9)

1. A compliant electrical distribution panel: a confined enclosure comprising an electrically conductive wall that forms a portion of the enclosure; an electrically conductive neutral bar ? placed inside the enclosure; Or an electrically non-conductive part placed between the neutral bar in the wall to place the neutral bar in a relationship not attached to the wall; a through hole in the neutral bar; 5 a through hole in the electrically nonconductive part in coincidence * underlying with the through hole in the neutral bar; an electrically conductive part 0 adapted for optionally joining the neutral bar to the wall, the electrically conductive part comprising a head and a rod extending distally from the head, the rod comprising a screw; wherein the electrically conductive part is pre-enslaved to the non-conductive part in an unbonded position that does not link the neutral bar in the wall in a manner that allows a panel installer to select between the option to keep the electrically conductive part in the position without pre-ens amblada union and the option of the electrically conductive part from the ^ position without connection to a joint position where the electrically conductive part is joined to the neutral bar towards the wall; wherein the position without pre-assembled joint is defined by the threaded rod having a threaded coupling with the through hole in the electrically non-conductive part, the head of the electrically conductive part being spaced from the neutral bar and the rod being separated from the Wall; and wherein the joint position is defined by the head of the electrically conductive part that is placed against the neutral bar and the rod that is placed against the wall.

2. An electrical distribution panel as set forth in claim 1, wherein the The wall comprises an under-coinciding hole with the through holes in the neutral bar and in the electrically non-conductive part, and the threaded rod is screwed into the hole in the wall when the electrically conductive part is placed in the joint position.

3. An electrical distribution panel as i 'is set forth in claim 2, wherein the orifice in the wall is an extruded orifice, and the threaded rod comprises a self-screwing threaded that is screwed into the orifice. Extruded on the wall when the electrically conductive part is placed in the bonding position. 5 ~ MF

4. An electrical distribution panel as set forth in claim 3, wherein the threaded rod has at least two complete turns of coupling with the extruded hole 0 in the wall when the electrically conductive part is placed in position of Union.

5. An electrical distribution panel as set forth in claim 1, wherein the neutral bar is a neutral link bar that is n a right angle to, and joins together, several neutral bars together.

6. An electrical distribution panel as set forth in claim 5, wherein the electrically non-conductive part comprises a base container placed between the neutral bars and the wall.

7. An electrical distribution panel as set forth in rei indication 1, in which the threaded coupling of the threaded rod with the through hole in the electrically non-conductive part has a frictional coupling which is located within a scale of about five point seventy and six kilograms per centimeter (five inches-pounds) of torque to approximately nine point twenty-two kilograms (eight inches-pounds) of torque, when the electrically non-conductive part is in a pre-assembled position.

8. An electrical distribution panel as set forth in claim 1 wherein the rod is separated by at least one point twenty-seven centimeters (one-half inch) from the wall when the electrically non-conductive part is in the pre-ens amblada position.

9. An electrical distribution panel as set forth in claim 1, wherein the threaded rod maintains a threaded coupling (With the through hole in the electrical part - non-conductive when the electrically non-conductive part is in the joint position