Terminal Block

Abstract

A terminal block, particularly for use in confined spaces such as telephone units, having a plurality of rectangular recesses arranged in rows and columns, the rows extending in the direction of the longitudinal axes of the recesses. An upwardly projecting rib extends between each pair of adjacent rows, each rib having a cross-section which assists in entering a connector into a terminal in a recess. Terminals are held in position by portions extending through holes in the base of the block and rivetted over. The holes have chamfered edges to assist in initial assembly of terminals. The ribs act as separations between rows to prevent contact between adjacent rows of connections- permitting a high density of connections.

Description

This invention relates to terminal blocks, and in particular to terminal blocks having a large number of contacts to which connection is made by pushing in spade-type terminals.

It is desirable, in many instances, that terminal blocks be as small as possible. In many cases the need for a large number of connections occurs where space is limited. A typical example is a telephone --particularly the type as used domestically and in business. The space inside the telephone set is restricted and yet large numbers of connections often have to be made, preferably in a manner which avoids soldering or use of screws. Typically spade-type terminals are used, pushed into contacts in a terminal block.

A problem with present terminal blocks is that a minimum distance between terminals must be provided to prevent accidental shorting by contact between adjacent terminals. This easily occurs as it is very easy to bend a terminal when inserting a further terminal in an adjacent contact. Present day terminal blocks have reached a minimum in size, below which it is not possible to go without danger of contact between adjacent terminals.

Furthermore, because of confined space and number of connections to a terminal block, the actual insertion of a terminal in the correct position relative to a contact is not easy. Decreasing the size of a terminal block -and thereby increasing the contact density-- increases the difficulty of correctly inserting a terminal.

The present invention is concerned with the provision of a terminal block in which the contact density is increased, while preventing accidental contact between adjacent terminals. A further feature is provision of means for assisting in correctly positioning terminals relative to contacts to ensure correct insertion. Other features relate to the provision of interconnecting circuits for connecting contacts in predetermined patterns simply and economically. A terminal block in accordance with the invention comprises a block having a plurality of recesses of elongate-form, the recesses in rows and in columns. The rows extend in the direction of the long axes of the recesses and separating means extend between adjacent rows. The separating means are shaped to assist entry of terminals. A contact is inserted in each recess, each contact having a projection extending through a hole in the bottom of its recess. The projections can be rivetted over to retain the contacts in the terminal block. Connecting strips can be mounted on the base of the terminal block and can be retained in position by the rivetting of the projections.

The invention will be more readily understood by the following description of certain embodiments, by way of example, in conjunction with the accompanying drawings, in which:-

FIG. 1 is a plan view of the top surface of a block, before installation of terminals;

FIG. 2 is a side view of the back of FIG. 1;

FIG. 3 is a cross-section on the line III--III of FIG. 1, to an enlarged scale;

FIG. 4 is a plan view of the base surface of the block of FIG. 1, before installation of terminals;

FIG. 5 is a plan view of a block of connecting strips for attachment to the base surface of the block of FIGS. 1, 2, 3 and 4;

FIG. 6 is a plan view, as in FIG. 4, but showing attachment of connecting strips and rivetting of terminals;

FIG. 7 is a cross-section similar to that of FIG. 3, on the line VII--VII of FIG. 6; and

FIG. 8 is a plan view of part of the top surface of the block with terminals installed, to an enlarged scale.

As illustrated in the drawings, a block, indicated generally at 10, is of molded form and has a plurality of rectangular recesses 11 extending from a top surface 12. The recesses are arranged in rows 13 and in columns 14. The longitudinal axes of the recesses are in the same direction as the rows.

Between each adjacent pair of rows is a separating portion 15. Portion 15 extends above the top surface 12 to form separating bars 16. Bars 16, as seen more clearly in FIG. 3, have a cross-section viewed on a plane normal to their length which has a tapered section 17 extending from a position level with the top surface 12 followed by a parallel section 18. The surfaces 19 of the tapered section 17 blend smoothly with the side walls 20 of the recesses 11. The outer end of the parallel section 18 is rounded.

Formed in the bottom surface 25 of each recess 11 is a hole 26. The junction of each hole 26 with the related bottom surface 25 is chamfered at 27 on opposite sides, as seen in FIGS. 1 and 3. Each recess 11 is also separated from the recess in an adjacent row by a separating portion 28. At the junctions between separating portions 15 and 27 are formed cylindrical shapes 29. Cylindrical shapes 29 form localized enlargements of the bars 16.

In the example illustrated two locating lugs 30 are formed at one edge for positioning beneath a member forming part of a structure in which the terminal block is to be used. A further lug 31 having a hole 32 therethrough is formed on the edge opposed to that carrying lugs 30. When the terminal block is in position, it can be retained by a screw through the hole 32.

FIG. 5 illustrates one arrangement for providing connecting strips for attachment to the base surface of the terminal block. The connecting strips --indicated at 40 are initially part of a block 41. Block 41 is stamped from sheet metal, for example brass or copper. For convenience in handling, storage, etc., there is a central portion 42. The block is scored or partly sheered through at positions indicated by dotted lines 43. Before positioning a blank on the base surface of a terminal block, the central portion is usually broken out. The connecting strips have holes 44 corresponding to the holes 26 in the terminal block.

The connecting strips are held in place by the rivetting over of rivet portions of the terminals 50. As illustrated in FIGS. 6, 7 and 8, each terminal is of folded sheet metal construction, the fold 51 at the top surface of the terminal block. A terminal has a main portion forming two opposed channel formations 53. These formations are of a size and shape, in the present example, to accept spade-type terminals, a terminal in each of the channels. The terminals 50 have a rivet portion 54 formed at the end remote from the fold 51 and this rivet portion extends through the hole 26 in the related recess 11. The rivet portion also extends through a corresponding hole 44 in a connecting strip. The rivet portion, which is split, being formed on opposed ends of the folded terminal, is then opened and bent over, rivetting (or staking) the terminal into place. This is seen quite clearly in FIGS. 6 and 7, the rivetting of terminals shown at 55.

After rivetting, the unwanted parts of the blank are removed readily by merely gripping one corner or edge and ripping off or by flexing the unwanted parts to break them off. The blank separates along the positions indicated by the dotted lines 43, leaving only the connecting strips 40 behind. The block with only the connecting strips left on is illustrated in FIG. 6.

From consideration of FIGS. 7 and 8 in particular it will be appreciated that when a spade terminal (or similar terminal) is to be inserted into one of the terminals 50, the insertion is facilitated considerably by the formation of the terminal block. With very close packing of connections, as is obtainable with terminal blocks as shown, it would be extremely difficult to ensure correct connections with a normal form of block. Spade terminals could enter the wrong block terminal or adjacent terminals are likely to contact each other. The tapered sections 17 form inclined surfaces which guide the spade terminals into the block terminals. The cylindrical shapes 29 help to define the separate recesses and make initial alignment with the recesses easier.

The chamfering of the edges of the holes 26 considerably eases the positioning of the terminals 50 in the recesses 11. There is a tendency for the opposed parts of a terminal to spring apart and this could cause considerable difficulties in getting the terminals in place. The bars 16 effectively prevent contact occurring between terminals in adjacent rows of recesses. Once a space terminal, or similar terminal is inserted in a block terminal, bending of the whole connection, as could occur in inserting a second spade terminal in a block terminal, will not produce contact with an adjacent terminal as the bars 16 intervene.

In the example illustrated, 50 recesses are provided in an area less than 2 inches by 21/2 inches. Each recess has a terminal which will accept two connections in the form of spade tips or similar terminals. This is a very high density. It would not be possible without the bars 16. Making connections would be extremely difficult without the inclined surfaces on the tapered sections 17 of the bars.

Other forms of connections can be provided on the base surface of the terminal block. Thus instead of the connecting strips 40, a printed circuit can be provided, with the rivet portions of the terminals 50 passing through the circuit board for making contact therewith. It is further possible to rivet the terminals 50 in place without any form of circuit or connecting strips on the base surface. The rivetted ends of the terminals can be pressed into contact with a circuit. In the example illustrated, the base of the terminal block can be flow-soldered to solder the rivetted portions at 55 into firm engagement with the connecting strips 40, to ensure that the terminals 50 do not become loose.

Claims

What is claimed is:

1. A terminal block comprising:

a block member of planar form;

a plurality of elongated recesses in the block member extending from a front face of the member, the recesses arranged in rows and in columns, the longitudinal axes of the recesses in the same direction as the rows;

a separating bar between each adjacent pair of rows, the separating bars extending outwardly from the front face of the block member;

a cross-sectional form to each bar including a tapered section adjacent the front surface of the block member, the section tapering outwardly and downwardly toward the front surface and having inclined surfaces blending with side faces of said recesses;

a hole in the bottom of each recess; and

a terminal in each of said recesses, each terminal including a rivet portion extending through said hole in the recess, said rivet portions rivetted over on the back face of the block member.

2. A terminal block as claimed in claim 1, including a predetermined conductor pattern attached to the back face of the block member, said rivet portions extending through the conductors of said pattern.

3. A terminal block as claimed in claim 2 said conductor pattern comprising a plurality of separate conductor strips.

4. A terminal block as claimed in claim 1 including chamfered edges on said holes at the junctions of the holes with the bottoms of the recess, said chamfered edges on opposed sides of said holes on a plane normal to the longitudinal axes of the recesses.