IE47722B1 - Bus bar with terminal lugs - Google Patents

Abstract

A bus bar is described which may be made of copper strip in a U-shaped cross section. Terminal lugs (3a, 3b) for use with spade connectors are integral with the bus bar and are punched in the web (1) and subsequently bent inwards into the space between the side flanges (4a, 4b) in the U-shaped cross section.

Description

The invention relates to a U-shaped sectional bus bar for use in heavy current applications with terminal lugs for spade connectors, the bus bar comprising a web and side flanges.

Bus bars normally consist of sectional copper or aluminium bars onto which terminal lugs have been fixed for use with connectors. In many instances such bus bars have to resist forces of both a mechanical and an electrical nature, e.g. in the case of unintentional short circuits. In order to simplify the manufacture of such bus bars, the said terminal lugs can be punched or stamped in the bus bar proper. If the bus bar consists of sheet metal which by itself has only little rigidity, then it may be still further weakened by the punching of terminal lugs. If, on the other hand, the bus bar is sectional, by punching the terminal lugs in a suitable manner any appreciable weakening may be avoided.

It is known, for example from Danish printed application 134,378, Danish Publicly Available Application 3983/76, and U.S. Patent No. 3,210,716, to use bus bars which are essentially U-shaped in cross section. It is also known, for example from German AS 1,909,166 and U.S. Patent 3,902,778, to stamp terminal lugs , ..for spade connectors in flat, rectangular bus bars. It has not, -hovireveM7: preyiouslybeen suggested to combine these different methods of manufacture of a: bus bar.

An object of the invention is to provide a construction which combines the advantages of known constructions in such a way that the bus bars acquire sufficient rigidity, at the same time as saving material by reducing the gauge of material required. Furthermore, special clamping provisions for branching may be avoided, thereby reducing the manual work needed when making installations inside cabinets. The bus bars may be manufactured from copper or aluminium strip by simple punching and folding steps.

These advantages are gained in a bus bar according to the invention.

In this manner a bus bar is obtained which is only slightly reduced in strength as compared with a similar bus bar without punched terminal lugs. At the same time a compact construction is obtained, since the connectors are disposed in the space between the side flanges. Furthermore, the bus bar according to the invention may be characterized in that the free ends of the side flanges in the U-shaped section may be bent so as to obtain a still more rigid construction.

The invention is to be described more fully with reference to the drawings, in which;Figure 1 shows a part of a bus bar according to the invention and having a U-shaped cross section viewed into the hollow space.

Figure 2 shows the same in a side view.

Figure 3 shows a cross section at 111-111 in Figure 1, Figure 4 shows a system of bus bars according to the invention mounted in a frame and viewed from below, Figure 5 shows a simpler embodiment of the invention viewed from one end, Figure 6 shows a bus bar according to the invention having H-shaped cross section and viewed from one end, and Figure 7 shows a bus bar with a U-shaped cross section and with the ends of the side flanges bent outwards.

Figure 1 shows the web 1 in which a hole 2 is drilled or punched for mounting the bus bar onto a frame or similar, and two terminal lugs 3a and 3b. These terminal lugs 3a and 3b are bent inwards into the space between the side flanges 4a and 4b at an angle of approximately 45° with respect to the web 1, which may be seen more clearly in Figure 2. As is common in terminal lugs for space connectors, the lugs 3a and 3b are provided with small holes 5a and 5b.

In Figure 3 it can be seen that the ends 6a and 6b of the side flanges 4a and 4b are bent inwards at right angles.

An example of three bus bars according to the invention disposed in parallel is shown in Figure 4. The bus bars are fixed to a frame by means of screws 8. The various parts of the bus bars are numbered in the same manner as above.

The cross section of the bus bar shown in Figure 5 differs from the cross sections shown in Figures 1-4 in that there are no bent-in flange ends.

The best way of attaching the bus bar having an H-shaped cross section shown in Figure 6 to a frame 7 is by means of screws through the side flanges 4a or 4b.

The ends 6a' and 6b' of the side flanges 4a and 4b may be bent outwards as in Figure 7. This is used where a maximum of space is needed around the terminal lugs 3, while retaining the rigidity derived from the bent ends of the side flanges.

A feature which is common to the bus bar cross sections shown in Figures 1 -5 and Figure 7 is that the bus bars according to the invention may conveniently be manufactured by folding and punching copper or aluminium strip in a manner which is well-known in metal-working.

Claims (5)

1. A U-shaped sectional bus bar for use in heavy current applications with terminal lugs for space connectors comprising a web and side flanges, characterized in that the terminal lugs 5 are punched in the web of the sectional bus bar and that the terminal lugs are bent inwards from the web.

2. A sectional bus bar as claimed in claim 1, characterized in that the ends of the side flanges in the U-shaped cross section are bent inwards. 10

3. A sectional bus bar as claimed in claim 1, characterized in that the ends of the side flanges in the U-shaped cross-section are bent outwards.

4. A sectional bus bar as claimed in any of claims 1 to 3 characterized in that it has an H-shaped cross section. 15

5. A sectional bus bar for use in heavy current applications substantially as herein described with reference to the accompanying drawings.