US2221710A - Wire terminal - Google Patents

Description

UNITED STATES PATENT OFFICE WIRE TERMINAL David W. Johnson, New Britain, Conn., assignor to The Arrow-Hart & Hegeman Electric Company, Hartford, Conn., a corporation of Connecticut Application February 15, 1939, Serial No. 256,570

2 3 Claims.

This invention-relates to wire terminals and is usable generally on all types of electrical equipment. More particularly it relates to wire terminals of the type employing a screw to secure a wire to a metal plate, which plate is maintained in body of an electrical device.

ventional plates to place on an insulating base or onthe 1 Among the conmeans used to ure the terminal the insulating body have been screws,

rivets and the like, which were provided expressly for the purpose and which in most cases performed no other function than that of attaching the plate to the body.

It is an object of my invention to make a wire terminal device in which the terminal plate thereof is maintained in place on an insulating block without the use of conventional securing means, or of any especially provided devices for holding the metal terminal to the insulating block.

Another object of my invention is to provide a Wiring terminal which-in the absence of, and in elimination of the need for, conventional securing devices-is maintained on an insulating body by the interengagement of the terminal plate and screw with parts of the body.

Other objects and advantages of the invention will become apparent as it is described in connection with the accompanying drawing.

In the drawing:

Fig. 1 is a plan view of a wiring terminal device embodying the principles of my invention;

Fig. 2 is a side elevation view of the device illustrated in Fig- 1;

Fig. 3 is a section view taken along line 3-3 of Fig. 1;

invention Fig. 8 is a plan view of a modified form of terminal plate.

Referring to the drawing, it will be noted that a wire terminal member ID, which may be stamped from sheet metal in the form of a bar or plate, is mounted upon an insulating body or block l2.

The plate I0 is provided with tapped holes into which are threaded binding screws l4 and I6.

These terminal screws have relatively seated.

formed a narrow sub-channel 20 extending from 10 long shanks for the purpose of securing wires of varying thickness to the wire terminal plate l0 and also for the purpose of preventing removal of the terminal plate ID from the insulating body l2, as will hereinafter be more particularly described. As illustrated, the insulating block or body I2 is provided with a central transverse channel l8 in which the terminal plate In is In the bottom of the channel I8 is one side of the block partially across the block, in the central portion of the channel Hi. In the bottom of the sub-channel 20 there are bored two spaced bores 22 and 24, the bore 24 being at the inner end of the sub-channel 20. The 18 spacing of the bores 22 and 24 is equal to the spacing of the terminal screws I4 and I6 so that the bores may accommodate the ends of the terminal screws when the screws are turned through the terminal plate N). In diameter, the bores 22 and 24 slightly exceed the diameters of the terminal screws, so that the terminal screws may fit loosely within the bores 22 and 24 without binding. For a similar reason, the width of the sub-channel 20 is equal to or slightly greater than the diameter of the bores 22 and 24.

For the purpose of holding the terminal plate l0 against movement out of the channel in a direction perpendicular to the floor of the channel, there are provided on the side walls of the channel semi-cylindrical extensions 26 terminating above the floor of the channel a distance slightly greater than the thickness of the terminal plate l0. Obviously the semi-cylindrical extensions might take other forms. essary that there be some extension or protuberance from the side walls of the channel over the top surface of the terminal bar I0 so as to prevent upward movement of the terminal plate out of the channel.

It is only nec- 35 From the foregoing, it will be apparent that when the terminal screws l4 and I6 are screwed into the terminal plate so that their shanks extend beneath the terminal plate a less distance than the depth of the sub-channel 20, the terminal bar In may be slid longitudinally along the bottom of the channel l8 until the shank of one of the'terminal screws strikes against the end of the sub-channel 20 directly over the bore 24. When in this position electric wires may be connected to the terminal device by winding around one or both of the terminal screws l4 and I6. Alternatively, electric wires may be wound around one or both terminal screws before the plate is slid into position. It is much easier to connect wires to the device while the plate is removed. The ability to do this is an important advantage of my invention.

The wires may be secured in position by screwing the terminal screws H or IE into the terminal plate until they bind the wires and plates together. The act of scewing these terminal screws l4 and I6 further into the terminal plate than their original position will cause the shank of the screws to take into the bores 24 and 22 so that planar movement of the terminal plate l0 out of the channel will thus be prevented by the shanks engaging the walls of the bores 22 and 24. In this manner, planar movement of the terminal plate In longitudinally out of the channel i8 is prevented while at the same time movement of the terminal plate I 0 out of the channel l8 in a perpendicular direction is prevented by the engagement of the upper surface of the terminal plate with the protuberances 26. Thus it will be seen that I have provided a novel arrangement of terminal plates and binding screws in association with a mounting block whereby the terminal holds itself in place upon the mounting block without the necessity for the use of any independent or separate securing device, such as a screw or rivet or the like.

Fig. 8 shows a modified form of terminal plate requiring less metal than the plate shown in Fig. 6. In this form of the invention, the extensions "la and [0b from the sides of the terminal plate will underlie the projections or protuberances such as 26 in the side of the channel l8 and will prevent movement of the terminal plate out of the channel in a perpendicular direction in the same manner as in the case of the modification shown in Figs. 1-6.

In Fig. 7 another form. of the invention is shown. In this form the sub-channel 20l is enlarged at its inner end portion for manufacturing reasons. The main channel lB-l (the equivalent to channel I 8 in Figs. 1-6) is shallow and does not run entirely across the block I 2, but its end is in abutment with the end of the terminal plate l0 when the terminal screws are in register with the recesses 22 and 24. As in the' previously described form protuberances 26 overlie the terminal plate and hold it in position. In Fig. 7 the terminal plate can be slid into place in one direction only, but it automatically positions itself without the necessity of the screw it being turned into the plate any particular distance. In Fig. 7 the block 12 is recessed transversely entirely across the block from its top surface forming a subsurface 13 preferably in the same plane as of the upper surface of the terminal plate l0.

It will be obvious to those skilled in the art that many other modifications within the scope of this invention may be made without departing from the spirit of the invention. By way of example and not by way of limitation, it may be mentioned that the sub-channel 20 may be omitted and sliding movement of the terminal plate l0 out of the channel i 8 may be prevented by the shank of the terminal screws taking directly into bores such as 22 and 24, which are bored directly in the bottom of the channel l8. An advantage of the sub-channel 20 is that the terminal plate Ill may be slid into position and it will automatically stop when the terminal screw comes in register with the bore 24. In that manner the delicate operation of moving the terminal plate [0 backward and forward until the terminal screws are in direct register with the bores 22 and 24 is obviated. This same advantage is accomplished in another way in the form shown in Fig. 7.

Another example of a change in form of the structure without departing from the scope of the invention would be narrowing of the channel l8 and widening of the terminal plate I 0 or increasing the size of the extensions "Ia and lb so as to fit in lateral groves which might be cut into the walls of the channel [8 adjacent the floor of the channel. Other modifications will occur to those skilled in the art. Therefore I do not limit myself to the specific forms of the invention shownand-described, but as my invention, I claim:

1. An electric wire terminal device comprising an insulating block having an open and uncovered channel extending across a face thereof, a metallic terminal plate non-permanently seated in said channel, a terminal screw comprising a head and a threaded end, said end threaded into said plate and adapted to extend therethrough, said channel having a recess adapted to receive said end to prevent planar movement of said plate into or out of said channel, protuberances from the opposite walls of said channel overlying portions of said plate to prevent movement of said plate from the channel in a direction perpendicular to the floor of the channel, the distance between said protuberances being greater than the diameters of the head and threaded end of said terminal screw, whereby said plate with the terminal screw attached may be moved into said channel and into a position where said terminal screw is in register with said recess, said terminal screw passing between said protuberances during such movement.

2. An electric terminal device comprising an insulating block having a main channel therein, a sub-channel in the floor of the main channel and extending a portion of the length of the main.

channel, a metallic terminal plate located in said main channel, a terminal screw threaded into said plate and adapted to have its end extend through said plate, said sub-channel accommodating said screw end upon movement of said plate into said main channel, said sub-channel having a recess adapted to receive said screw end to hold said plate against planar movement outwardly of the channel, said screw end abutting the end of said sub-channel when in register with said recess, and means engaging the surface of said plate to prevent movement of said plate from said channel in a direction perpendicular to the main channel floor.

3. An electric terminal device comprising an insulating block having a main channel therein, a sub-channel in the floor of the main channel and extending a portion of the length of the main channel, a metallic terminal plate located in said main channel, a terminal screw threaded into said plate and adapted to have its end extend through said plate, said sub-channel accommodating said screw end upon movement of said plate into said main channel, said sub-channel having a recess adapted to receive said screw end to hold said plate against planar movement outwardly of the channel, said screw end abutting the end of said sub-channel when in register with said recess, and protuberances on the walls of said main channel to prevent movement of said plate from said channel in a direction perpendicular to the main channel floor.

DAVID W. JOHNSON.

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