US2397283A - Terminal - Google Patents

Description

. March 26, 1946. N. H. MARTIN TERMINAL ASSEMBLY FOR ELECTRIC CIRCUITS Filed Nov. 6, 1945 Inventor J/. 14. Mum.

A tt orne Patented Mar. 26, 1946 TERMINAL ASSEMBLY FOR ELECTRIC CIRCUITS Norman Hadlow Martin, London, England, as-

signor, by mesne assignments, to International Standard Electric Corporation, N. Y.', a corporation of'Delaware V 7 Application November 6,1943, Serial no. 509,178

In Great Britain December 1, 1942 2 Claims. (Cl. 173 324) The present invention relates to terminalassemblies for electric circuits and in particular to improvements in the construction of such assemblies.

' In electric circuits and apparatus employed in the communication'art, assemblies of large numbers of closely arranged terminals are commonly used for convenience in wiring and arranging circuits. The necessity for combining compactness,

flexibility, and cheapness of construction, raises a number of problems in design and arrangements hitherto used have failed to meet all the requirements in a'completely satisfactory way.

For example, it is well known to mount rows of metal terminal punchings in holes in strips of insulating material (frequently ebonite or other similar rubber product). It is necessary that'theterminals should be fixed so that they cannot be easily removed during subsequent assembly and soldering operations, and to avoid complicated interlocking arrangements involving a lot of different piece-parts, it has been customary to fix the terminal punchings by forcing them into (usually) circular holes drilled in the ebonite strips. This requires an elaborate assembly fixture, and close control of the dimensions of the terminals and holes and is not satisfactory, since the terminals are liable to come out later on, owing to the softening of the ebonite by heating from the soldering iron.

It is the object of the present invention to provide a terminal assembly which can employ terminal punchings of the same type as those previously used, and in which the difficulties experienced in meeting the requirements are avoided by means of a cheap and flexible arrangement.

According to the invention, there is provided an insulating strip for loosely holding a plurality of electrical terminal punchings, the strip being formed so that when a plurality of such strips are piled in contact, each strip locks in position the terminals carried by one of the adjacent strips in such manner that they are not removable.

More specifically the invention may comprise an insulating strip for loosely holding electrical terminal punchings, provided with two substantially parallel longitudinally extending faces, one of which faces has formed thereon along one longitudinal edge a projecting ledge having a surface inclined to the said face, the corresponding edge of the other face being formed to provide clearance for the said inclined surface.

According to another aspect the invention comprises an electrical terminal punching assembly comprising a plurality of similar insulating strips piled in contact, each being adapted to hold loosely aplurality of terminal punchings and being so formed that each strip locks in position the terminals carried by one of the adjacent strips in such manner that the are not removable.

The. invention will be explained with reference to the accompanying drawing, in which:

Fig. 1 shows; part of the rear elevation of a ter-. minal strip. assembly according to the invention; Fig, 2 shows a side view, partlyin section, of the assembly of Fig. 1; r r

Fig; 3 shows a-plan view of a terminal strip according to the invention. r c Fig. 4 shows a front elevation of the terminal strip; 'and' Fig. 5 shows asection at 3and4.-;;;" 7

Referring to Figs. 1 and'2',-the terminalassembly according to the invention comprises a base I of any suitable material having on the upper surface a rectangular packing strip 2. Piled on this strip are any number of insulating strips. 3 (two only are shown) each carrying any number of terminal punchings 4 arranged side by side. The pile is surmounted by a capping strip 5 which may be the same as the strips 3, but will preferably be unprovided with any terminal drillings. The whole assembly is fixed by a suitable number of screwed rods 6 and nuts (one only being shown), which may be secured at the lower ends to a plate 1 assembled in a recess or channel in the base i, or they may have separate hexagonal or screw-driver heads, or the like.

One of the insulating strips 3 is shown in detail in Figs. 3, 4 and 5. The section seen in Fig. 5 is mainly rectangular. The strip has two parallel longitudinally extending faces I! and I8, and faces 8 and 9 at right angles thereto. The lower face 8 terminates in a projecting ledge to which runs longitudinally along the strip, and which has a fiat surface l9 inclined to theface H,

the lines AA of Figs,

The opposite edge of the strip is chamfered or otherwise reduced at l I forming a surface roughly parallel to the surface 19, so that when the strips are piled up as shown in Fig. 2, the chamfer on each strip provides clearance for the ledge H! of the strip next above. Similarly, if necessary, the packing strip 2 may be chamfered as shown at l2. It will be evident that the capping strip 5 need not hav this chamfer.

The strip 3 is provided with a number of circular holes l3, the face 8 being recessed with a rectangular slot or key-Way It at the mouth of each hole. The diameter of the holes It should preferably be such that the thermal punchings 4 can be easily inserted therein without any force,

the shoulders l5 of each terminal entering the keyway I 4, thus holding the terminal upright and preventing it ,from twisting. it

- It will be seen that when the terminals 4 are inserted in the holes l3 in the manner described,

and when the strips are piled up as shown in.

that while the terminals can actually bequite loosely held so that no special fixture'is required for putting them in place, they cannot be removed during any subsequent operatiom,

The holes l6 shown in Figs. 3, 4 and 5 are provided to clear the fixing screws 6. v Th designpof the strips 3 is adapted for moulding so that they maybe manufactured from phenol condensation products and the like in the well known way; These materials are not liableto be appreciably softened by the heat of solder- As many strips 3- fitted with terminals-as desired maybe piled'up in the manner indicated, and it can be easily arranged so: that a given assembly may be added to at any later time without disturbing seriously the strips already wired. It will be noted that the necessary locking of the terminals is accomplished by the use of only two diiierent piece-parts (3 and 5), and these can be reduced to one only if another strip 3 is used instead of 5. r r

It will be understood that the terminals have been shown in Fig. 2 as having difiere-nt lengths. This is purely a matter of convenience; and as regards the present invention, the terminals can have any desired lengths. Terminals formed with shoulders It: as shown are well known in the art. 7

Furthermore, the holes I3 are shown cylindrical because this is a convenient shape tor manufacture. They could however be any; other shape, for example, they could be rectangular slots having cross-sections sufiiciently large to allow the terminals to be easily inserted. In such a.case,..the key-ways i4 would not be necessary. What is claimed is: 1. In a mountingfor electric terminals, a plurali'ty of strips of insulating material, each having two substantially'parallel longitudinally extending faces and a ledge projecting from a longitudinal edge of one face. the corresponding edge of 1 the other iace being cut away to provide clear- 'anc for the ledge of an adjacent strip, a hole threughi each of said strips intermediate said faces, said hole havingan enlarged portion form ing a shoulder; terminal-s within said holes {and projecting from each stripfandremovable there from, a shoulder-on each terminal adapted'to-fit against the shoulder formed by the enlarged er tion of said hole and" toextend' into the cut-away portion, and -means' for holding to-getherfsaid strips with the ledg of each'overlyingthe'-eut---* away edge of the; adjacen-tstri-pand the shoulf ders'of terminals that stripand obstructing the removal of the terminals therefrom.=- 2". The mounting accordingtoclaim 1-,and in which'the shoulder o f each terminaliis atone" side'thereof and theenlarged portion of the hole through. each strip is shaped to fit said, terminal shoulder,. whereby said terminal is held in a} hole 7 or its stripagainst rotation but is free to move longitudinally. r. 5; it v NORMANHADLOW MAI-EH19?

Images