US 3067403 A
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Description (OCR text may contain errors)
Dec. 4, 1962 E. R. KULKA TERMINAL BLOCK MARKING STRIP AND CLIP Filed June 18, 1959 FIG. 2.
FIG. 4. INVENTOR.
' EUGENE x2. zuuen M 1' v6 ATTORNZYJ TERMINAL BLOCK MAIiKING STRIP AND CLIP Eugene R. Kulka, Mount Vernon, N.Y.,.assignor to Kulka Electric Corp., Mount Vernon, N.Y., a corporation of New York p 1 Filed June 18, 1959, Ser. No. 821,283
2 Claims. (Cl. 339-113) This invention relates to improvements in terminal block assemblies, and has particular relation to novel and improved means for identifying the terminals and insulating them from the block mounting.
Conventional terminal blocks include a block body of insulating material having a plurality of rows of through terminal bores, and metal contact plates associated therewith. The contact plates have indented tapped holes in alignment with the respective bores and have their lower ends peened over beneath a shoulder projecting into the bore for securing the contact plates upon the upper surface of the block body. Because of the necessity of the peening-over operation, the bores must open through the bottom surface of the block body to provide access to the bottom of the contact plates. The tapped contact plate holes mount terminal screws which extend downwardly through the respective terminal bores. Since the bottoms of the bores are open, the assembly presents the problem of sparking between the ends of the terminal screws and a metal support underlying the block body.
Because of this sparking tendency, it has been customary to provide a separate strip of insulating material inserted between the terminal block body and the support therebelow. This strip made of fiber boardor similar material is often of greater width thanv the terminal block so that it has a side portion which protrudes beyond one side of the block, and on this side portion is marked with a series of indicia registering with and identifying particular rows of terminal screws. For this reason, these strips are referred to in the trade as marking strips.
The insulating strips are provided at their ends with screw holes which are intended to register with the screw holes at the ends of the insulating block. so that when clamping screws are inserted through these registering holes into threaded holes provided in the support, the screws clamp both the terminal block and marking strip to the support. This mounting procedure is cumbersome and time consuming, since it requires alignment of both the marking strip and block body holes with the screw holes of the terminal block support.
In addition, the use of a combined marking and insulating strip is costly, since it involves the provision of a marking portion for each terminal block even through in some instances the strip is not intended to be used as a marking strip.
It has also been found that, when the insulating strip is used for marking purposes, its location beneath the block body tends to obscure the view of the marking indicia from certain angles. At the same time, the upper surface of the terminal block assembly is relatively exposed, and there is a danger of contact with the terminals thereof from above;
Accordingly, it is an object of the present invention to provide a terminal block assembly in which insulating means are secured to the block, so that the assembly is self-contained, and no separate insulating members are necessary.
Another object of the invention is the provision of a terminal block assembly of the type described in which the insulating means is secured to the block in proper position during manufacture, so that. the assembly is mountedas a. unit and there is no necessity for aligning 2 t the screw holes of the insulating means during the mount ing operation.
An additional object of the invention is the provision of a terminal blockv assembly in which the screw holes of the various components may be more readily aligned during manufacture.
A further object of the invention is the provision of a terminal block assembly of the character described in which the marking strip is readily visible from all angles.
A still further object of this invention is to provide a terminal block assembly the upper surface of which may be covered to help prevent accidental contact with the terminals thereof from above.
Other objects and advantages of the invention will become apparent during the course of the following specification, when taken in connection with the accompanying drawings, in which:
FIG. 1 is an exploded perspective view of a portion of a terminal block assembly in accordance with the present invention, with parts broken away and removed for clarity of illustration;
FIG. 2 is a top plan view of the terminal block assembly of FIG. 1 showing the marking strip thereof in position to identify and cover the terminals thereof, apart of the marking strip being broken away for the purposes of illustration; I
FIG. 3 is a side elevational view of the terminal block assembly of FIGS. 1 and 2, with parts sectioned; and,
FIG. 4 is an end elevational view of the terminal block assembly of FIGS. 1-3.
Referring in detail to the drawings, there is shown a novel terminal block. assembly including the usual rectangular body 10 molded of Bakelite or similar insulating material.
The block body 10 has a fiat bottom surface 12 and a top surface 13 provided with spaced, upstanding ribs or partition walls 14.. Between each adjacent pair of partition walls 14 in the mid-section 16 of the block are a pair of transversely-spaced bores 18 which extend downwardly entirely through the body block 10, each bore 18 having a lower end which opens through the bottom surface 12 of the terminal block and is of greater diameter than the. upper end to form a discontinuity or shoulder 18a, as is best seen in FIG. 3.
A terminal plate 24, made of conductive metal, is secured against, the top surface 14 of the terminal block 10 between each adjacent pair of partition walls 16. Each plate 24 has a pair of integral depending tubular portions 26 located to register with and extend downwardly through the respective bores 18 of the block body. The tubular portions 26 are made longer than the narrow upper portions of bores 18, so that in their inserted positions the bottom ends thereof may be peenedover to provide terminal flanges 28 which abut theshoulders 22 and secure the plate 24 rigidly and immovably to the block. The use of such integral tubes. 26 is desirable in the manufacture of terminal blocks since it provides a strong attachment which prevents the terminal plates 24 from being pulled off the block by tension of the Wires connected to the plates.
Each terminal plate 24 has a pair of tapped openings which extend through the tubular portions 26 and receive terminal screws 34. The threaded engagement of the terminal screws 34 along the length of the respective tubular portions 26 provides a firm mounting support for the terminal screws, as well as a large area of electrical Contact.
The terminal block 10 is also provided with a pair of bolt -openings 36at each of the end sections 38 thereof, the openings 36 being adapted to receive mounting bolts or other fasteners for mounting the terminal block on a support with the bottom surface 12 thereof overlying the support.
In the use of terminal blocks of this type, it has been found that when the block was mounted on a support made of conductive metal, the terminal screws would short through the metal support, especially if high voltage circuits were involved. Since the bottom ends of the terminal bores 18 are open, a spark would often jump the air gap between the tip of a terminal screw 34 and the support. Consequently, it is now customary to provide a separate marking strip with each terminal block to insulate the terminal screws from the support, the marking strip having at each end a pair of holes positioned to register with the bolt openings 36 of the terminal block 10.
According to this invention there is provided an insulating strip which underlies the bottom surface 12 of the block body 10 to insulate the terminal screws 34 from the support upon which the terminal block assembly is mounted. The length of the insulating strip 40 is such that it extends beneath the end sections 38 of the block body 10. For clamping the block body 10 and insulating strip 40 together in a self-contained, unified assembly, there is provided a pair of clips 42 each of which may be stamped from a piece of resilient sheet metal. The clips 42 are bent to define a pair of opposed jaws 44 and 46 which embrace the end sections 38 of block body 10 and the end of the insulating strip 40 therebetween. The spacing between the opposed jaws 44 and 46 is selected in relation to the combined vertical thickness of end sections 38 and insulating strip 40 for the opposed jaws 44 and 46 to exert a resilient grip for securing the insulating strip 40 to the block body 10 in order to make the block body 10, insulating strip 40, and clips 42 a unified and self-contained assembly which may be mounted as such upon the support. Each end of the insulating strip 40 is provided with a pair of fastener holes 50, and the opposed jaws 44 and 46 are each provided with a pair of fastener holes 52 and 54 respectively, the fastener holes 50, 52 and 54 being located for registry with the fastener holes 36 passing through the end sections 38 of the block body 10. This arrangement enables the mounting of the entire terminal block assembly by simply passing screws or other fasteners through each set of the already aligned fastener holes 52, 36, and 54. As a result, once this selfcontained unit is assembled during manufacture, there is no necessity for aligning the fastener holes of several different component parts when it is desired to mount it upon a support, since the entire terminal block assembly may be mounted as a unit.
In addition, provision is made for greater ease of alignment of the fastener holes of the various components of the terminal block assembly during the manufacture thereof. The fastener holes 54 of the lower jaw 46 have rims 54a which are turned inwardly toward the block body 10 and are sized to seat within the adjacent fastener holes 50 and 3-6 of the insulating strip 40 and block body 10 respectively for facilitating registry therewith. Thus, in the assembly of the terminal block, as the clips 42 are put into place over the end sections 38 and insulating strip 40, the inwardly turned rims 54a will be received within the fastener holes, and in this manner will automatically become aligned therewith.
The clips 42 may, if desired, be bent into a configuration approximating that of an inverted question mark to define upstanding marking strip prongs 55- which cooperate to support a separate marking strip 56 above the upper surface 13 of the block body 10. In this position the marking indicia on the strip 56 will be more readily visible from all angles, and the marking strip 56, which is fabricated of an insulating material, will be in position to prevent accidental contact with terminal screws 34 from above the terminal block assembly. It
is seen that the marking strip 56 has opposed ends formed with tongues 58, and the upstanding marking strip prongs 55 are formed with slots 60 which are sized to receive the tongues 58. By virtue of their construction, the upstanding marking strip prongs 55 may be resiliently spread apart in order to enable the tongues 58 to be inserted into the cooperating slots 60 for mounting the marking strip 56 in its advantageous position above the terminal block assembly. The slots 58 and tongues 60 on one side of the assembly are of different size from the slots and tongues on the other side to prevent the marking strip from being assembled in a wrong position, that is, in a backwards position. Similarly, when it is desired to remove the marking strip 56, the upstanding marking strip prongs 55 may be resiliently spread to release the tongues 58 from the cooperating slot 60. It will be apparent that if no marking strip is desired in a particular installation it is entirely feasible to form the clips 42 in the shape of G-clamp without the upstanding marking strip prongs 55.
It will now be appreciated that with this improved terminal block assembly there is provided a separate marking strip and insulating strip, so that a marking strip need not always be supplied as a part of the insulating strip even though no terminal identification may be required. In addition, this terminal block assembly may be more easily assembled during the manufacturing process by virtue of the fact that the fastener holes of the various components are self-aligning. Once assembled, the terminal block assembly may be mounted on a support as a self-contained unit, only the fastener holes of this unit requiring alignment with the fastener holes of the support, thus facilitating the mounting of the terminal block assembly thereon. In addition, when a marking strip is required to identify the terminals of the assembly, it is seen that the present invention provides a separate marking strip which, by virtue of its location above the terminal block assembly, is readily visible from any angle and has the additional advantage of providing some protection against accidental contact with the screw terminals from above the terminal block assembly.
What I claim is:
1. A terminal block assembly comprising an insulating block body having a bottom surface, opposed end sections and having a mid-section formed with through terminal bores opening through said bottom surface, a plurality of terminals mounted in said terminal bores and extending downwardly, an insulating strip underlying said bottom surface to insulate said terminals, said insulating strip extending beneath said end sections, a pair of opposed resilient clips engaging and extending above said end sections and below said insulating strip holding the same therebetween and exerting a resilient grip thereon for securing said insulating strip to said block body, and a marking strip of insulating material secured to said clips and disposed above said body in spaced relation thereto, said clips having resilient marking strip prongs projecting upwardly from said block body, said prongs having slots of different dimensions therein, said marking strip having tongues of different sizes, said tongues being inserted in said slots.
2. A terminal block assembly according to claim 1, wherein said clips have resilient marking strip prongs projecting upwardly from said block body, said prongs having slots of different dimensions therein, said marking strip having tongues of different sizes, said tongues being inserted in said slots, said end sections and said insulating strip being provided with fastener holes to receive fasteners for securing said assembly to a support, said clips having fastener holes in alignment with said fastener holes in said end sections and having peripheral rim flanges extending upwardly about said apertures in said clips, said References Cited in the file of this patent UNITED STATES PATENTS Johnson et a1 June 16, 1931 Del Camp Mar. 9, 1937 6 Adler ..-5 ":2... Ian. 7, 1941 Ellinwood Oct. 12, 1943 Rollow June 25, 1946 Warnke Nov. 12, 1946 Macy Sept. 28, 1948 Burgess May 20, 1952 Hadden et a1 Mar. 9, 1954 Foote Aug. 19, 1958