US2911508A - Contact spring set - Google Patents

Description

Nov. 3, 1959 S. D. VIGREN ETAL CONTACT SPRING SET Filed May 28, 1956 mwww Patented Nov. 3, 1959 2,911.50: CONTACT spams sar- Sten Daniel Vlgren, Stockholm, Erlk Arne Angerby and Walter Otto Wilhelm Broberg, Nynashamn, and Rolf Albln Zander, Stockholm, Sweden Application May 28, 1956, Serial No. 591,053

Claims priority, application Sweden June 3, 1955 Claims. Cl. 200-466) The present invention relates to a contact spring set of the kind used in electric switching devices as for instance relays. The spring set comprises movable as well as stationary contact springs which are arranged to form various contact combinations such as make contacts, break contacts and change-over contacts. The contact springs are positioned between two plates of insulating material which extend in planes substantially at right angles to the planes of the contact springs, and those ends of the contact springs which are intended for connection to external conductors are attached to these plates.

It is an object of the invention to provide a contact spring set of the type defined above in which the contactcarrying ends of the stationary contact springs are eifeotively supported so that contact vibrations which are liable to occur when contacts on a movable contact spring strike the contacts on a stationary contact spring are reduced.

It is another object of the invention to provide a contact spring set which is easy to manufacture and in which the said plates are so designed that they can be used for any desired combination of movable and stationary contact springs. It is also an object of the invention to pro vide a contact spring set which can be made in a separate unit which can easily be mounted on, or removed from the switching device to which it belongs.

According to the invention the said plates have such an extension that a part of each plate is positioned at or adjacent to the contact-carrying-ends of the stationary contact springs, and the stationary contact springs are provided with projections adjacent to their contact-carrying ends which projections are fitted or riveted into closed slots or apertures in said parts of the plates.

In a preferred embodiment of the invention parts of the said plates together with transversal members bridging the space between the plates define a hollow in which a supporting member for carrying the contact spring set can be inserted.

Other features and objects of the invention will appear from the following description in conjunction with the accompanying drawing on which:

Figure 1 shows a contact spring set according to the invention in side view with one of the side plates removed.

Figure 2 shows the same contact spring set in front view.

Figure 3 shows the same contact spring set as seen from above.

Figure 4 shows one of the said plates of insulating material.

Figures 5 and 6 show in plane view and front view respectively a core of a relay on which one or more contact spring sets in accordance with the invention can be mounted.

Figure 7 shows a movable contactspring.

Figure .8 shows a stationary contact spring.

The contact spring set shown in Figures 1 to 3 comprises a number of movable contact springs 3 and a number of stationary contact springs 4. As will be seen from Figure 1, the contact springs are so arranged that they form one make contact, one break contact and one change-over contact. The movable contact springs are arranged for so called indirect operation, which means that these springs are so tensioned that they strive to move their contacts towards the contacts on the cooperating stationary contact springs. A toothed operating stud 10 is provided for operating the movable contact springs 3. When this stud is in non-operated position as shown in Figure 1, some of the movable contact springs are kept out of engagement with the corresponding stationary springs by teeth on the stud 10, and when the stud is operated, e.g. by means of the armature of a relay, the stud is moved upwards whereby the last mentioned movable contact springs are released and press their contacts against the contacts on the corresponding stationary contact springs, while at the same time other movable contact springs which are in engagement with stationary contact springs when the stud 10 is in nonoperated position, are moved out of engagement with the stationary contact springs by the teeth on the stud 10.

- The lower end of stud 10 rests on a supporting strip 8 and a narrow extension of the stud protrudes through a hole in the strip 8, as will be seen from Figure l. The stud is actuated by e.g. the armature of a relay (not shown) acting upon the said extension. The top end of the stud 10 engages the free end of a spring 7 which -.is so tensioned that it exerts a pressure in downward direction on the stud.

The contact springs 3 and 4 as well as the pressure spring 7 and the strip 8 are positioned between two plates of insulating material. These plates are both designated 1 in the figures. (In Figure 1 only one of these plates is shown for the sake of clarity.) The movable as well as the stationary contact springs are provided with 'projections 5 extending from both edges of each spring adjacent to that end of the spring which is intended for connection to external conductors as shown in Figures 7 and 8. The projections 5 are fitted into slots or apertures 20 in the plates 1. Preferably there are two projections 5 on each edge of the contact springs as shown in Figures 7 and 8, and consequently there are two rows of slots or apertures 20 in each of the plates 1 as shown in Figure 4, so that the said ends of the contact springs are securely attached to the plates 1.

Each of the plates 1 has a part 11 (see Figure 4) which is positioned adjacent to the contact-carrying ends of the stationary contact springs. In the part 11 there is a row of closed slots or apertures 2 which have an oblong shape. Each of the stationary contact springs 4 is provided with projections 6 (see Figure 8) adjacent to the contact-carrying end, and these projections are fitted or riveted into the slots or apertures 2 in part 11 of plates -1. Preferably the projections 6 should have such dimensions that they are tightly fitted into the apertures 2. However, they may also be more or less loosely fitted into the apertures 2, in which case they may be deformed like rivets so that they are prevented from sliding in the apertures.

It is essential that the slots or apertures 2 are closed, that'is the contour of each slot or aperture should be a wholly closed line. If the slots or apertures. were not closed, that is if they were in the 1m of recesses extending from the edge of the plate, the tooth-shaped parts between the slots would be very easily broken when the contact-carrying ends of the stationary contact springs are bent for adjustment of the position of the contacts.

Although only the stationary contact springs 4 have projections fitted into slots or apertures 2, the number of such slots or apertures in each plate 1 should preferably be equal to or larger than the total number of contact springs in the contact spring set. Hereby the same plate can be used for contact spring sets having different combinations of movable and stationary contact springs. The slots or apertures 2 should then be positioned on level with the corresponding slots 20 and should have the same spacing as the last mentioned slots.

As will be seenfrom Figure 4, the plate 1 is provided with a recess limited by the parts 11, 12 and 13 of the plate. This recess leaves parts of the contact springs uncovered by the plate, so that the springs are easily accessible for inspection and adjustment.

After the contact springs have been mounted in their places in the set, an adjustment of the springs is usually necessary in order that the required contact pressure shall be achieved, and also in the case that it is desired that the make and break functions of the different contacts in the set shall take place in a predetermined order. This adjustment is effected by bending the contact springs. The movable contact springs are adjusted by being bent through a small angle adjacent to those of the projections 5 which are located nearest to the contact-carrying ends of the springs. The stationary contact springs are adjusted by being bent adjacent to the projections 6. Since the projections 6 are securely fitted into the apertures 2, those parts of the stationary contact springs which are located between the projections 5 and 6, will not be at fected by the adjustment, and nor will any tension that may be present in these parts, have any effect on the contact pressure and the positions of the contacts on the stationary contact springs.

The pressure spring 7 is attached to parts 12 of plates 1 in the same manner as the contact springs, that is by means of projections fitted into apertures 20 in the parts 12 of the side plates 1.

The strip 8 one end of which serves as a support for the operating stud 10, is also attached to plates 1 by means of projections fitted into apertures in the plates. This strip is preferably made of insulating material.

As will be seen from Figures 1 and 2 there is another strip 9 inserted between the plates 1 at some distance from strip 8. The two strips 8 and 9 together with those parts of plates 1 which are positioned between the strips 8 and 9, define a hollow or channel designated 14 in Figures 1 and 2.v In this hollow a supporting member for carrying the contact spring set can be inserted. The supporting member may for instance consist of a leg of the core of a relay. Figures 5 and 6 show a relay core having three legs 16, 17 and 19. This cone is intended for a relay having two contact spring sets, one set being mounted on each of the side legs 16 and 17. When mounting the contact spring sets on the core, the side legs 16 and 17 are fitted into the channel 14 of the respective spring set. The strip 9 which is preferably made of metal, is somewhat resilient and is provided with a wart or knob 15. When the contact spring set has been mounted in its proper place on the core leg, the wart 15 engages a depression 18 in the core leg and thus serves to lock the contact spring set to the core leg. The width and height of channel 14 should of course be substantially equal to the width and thickness of the core leg 16 and 17.

The channel 14 need not necessarily be located below the contact springs as in the embodiment shown on the number of short strips or rods arranged in two parallel rows.

The embodiment of the invention described above in conjunction with the drawing is given by way of example only, and numerous other embodiments are possible within the scope of the invention.

Having now particularly described and ascertained the nature of our invention and in what manner the same is to be performed, we declare that what we claim is:

1. A contact spring set comprising: stationary and movable contact springs arranged between two plates of insulating material, the contact springs having lateral projections fitting in apertures in said plates having portions; said plates extending, in a direction transverse to the elongate disposition of said contact springs, beyond the space occupied by the contact springs; and members extending transversely between said extended portions of said plates and forming, together with said extended portions of the plates, a box construction offset from the space occupied by the contact springs.

2. A contact spring set as defined in claim 1 in which said transverse members consist of two parallel strips attached to said plates.

3. A contact spring set as defined in claim 1 in which at least one of the members forming the walls of said box construction is resilient.

4. A contact spring set as defined in claim 3 wherein said box construction further comprises means for mounting and retaining the spring set in position on an electromagnet member.

5. A contact spring set as defined in claim 3, wherein the retaining means in said box construction is on, and utilizes the resiliency of, said resilient member.

References Cited in the file of this patent UNITED STATES PATENTS

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