DE2742967A1 - SPRING CLIP FOR A TUBULAR ELECTRICAL FUSE - Google Patents

Description

Patent attorney DipL-lng. Waiier Jackisch - 4 - ZStuttgartN. Meiuelstrasse 40

7 / estern Electric A 35 831-ko

Company, Incorporated

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195 Broadv / ay * -v * · · - ■ - »··» ο, -

New York, H.Y. 10007

UNITED STATES.

Spring clip for a tubular electrical fuse

The invention relates to a spring clip am mer of the type specified in the preamble of claim 1. Spring clips of this type are used to establish mechanical and electrical contact with a tubular fuse inserted therein, for example a fuse with an alarm trigger.

Spring clips for fuses and spring clip assemblies are well known in the art. With a common Spring clip assembly for fuses is a front clip for making a mechanical and electrical Contact with a connection of the fuse and a second, arranged at a distance from the front bracket Clip for making electrical and mechanical contact with a second connection of the fuse. This arrangement works quite well for two terminal fuses that have electrical current flowing through the fuse only flows if the fuse element is completely or not blown. As soon as the security element is a

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such fuse is overloaded, opens the fuse element, whereby the flow is interrupted.

While toe clamps without wire-wrap connection (i.e. connections, which are wrapped with a lead wire to make electrical contact) in widespread use an alternative, desirable from a manufacturing cost point of view, is to manufacture a spring clip with a wire wrap connector made from a single piece of electrically conductive material. With such a However, the spring clip has the difficulty that the Y / ire-wrap connection to achieve a clean electrical and mechanical contact must have a cross-sectional profile that closes when bent to accommodate the fuse a spring pressure against the inserted fuse of such a size that the removal of the fuse becomes difficult. if the material thickness is reduced to a value that is necessary to achieve a suitable spring pressure, this is Material too thin to ensure clean electrical and mechanical contact with the wire-wrap connection.

There is another type of tubular fuse known as an alarm fuse and a third connector to make electrical contact with an electrical warning circuit that responds when the The fuse element is open or blown. With this type of fuse, a spring clip arrangement must be

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If such an alarm backup would take additional restrictions would be imposed. These limitations stem from the fact that the fuse housing must be held in a fixed position with respect to the alarm terminal of the assembly in order to ensure proper electrical contact after the fuse has blown. Furthermore, the alarm connection of the fuse must contact the alarm connection of the fuse arrangement with a sufficient force so that a layer of dirt or oxide which may be present on the connection is broken through and the electrical contact is maintained for warning purposes .

The object of the invention is accordingly to provide a spring clip of the type mentioned to create, which with excellent electrical and mechanical contact properties an electrical circuit in wire-wrap technology is permitted and also suitable for the use of alarm fuses is.

The object is achieved according to the invention by the features specified in the characterizing part of claim 1.

Advantageous refinements and developments of the spring clip according to claim 1 are characterized in claims 2-8.

In an embodiment of the spring clip arrangement according to the invention that is suitable for alarm fuses, there are three connections

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provided / lie my line along the axis of the inserted Securing are arranged at a mutual distance. The connections are hereinafter referred to as alarm connection, load connection and circuit connection. The fuse is supplied with electrical power via the circuit connection, which is connected to the fuse on the front face of the fuse housing. The load connection, however, is on the rear face of the fuse housing is connected to the fuse and serves to provide a forward-facing Apply pressure to the fuse housing along the longitudinal axis of the fuse.

The circuit connection is designed in such a way that it prevents the fuse from being pushed too far through the forward-facing one Pressure of the load connection prevented. The circuit connection consists of a single piece of electrically conductive material with a strength specification which meets the requirements of a Wire-wrap connection is sufficiently thick and at the same time meets the requirements of the spring clip. This result is achieved by reducing the material thickness only in those places where the material is used for training purposes the U-shape of the bracket is bent. This reduction in thickness takes place in a work step called embossing and is used to reduce the spring pressure by the desired amount without affecting the physical shape of the Wire-V / r ap terminal leg or the structural resistance of the spring clip can be adversely affected. To attach the

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The spring clip on a flat mounting board is attached to the Y / ire wrap connector that is pushed through an opening in the board. A locking nose is attached to the leg. A second, shorter and one-piece leg connected to the spring clip is used for Achieving the situation stability. The locking lugs hold the Spring clip on the flat mounting board without additional help, which significantly reduced manufacturing costs

The alarm connection of the spring clip assembly is shaped so that it only connects the alarm connection of the fuse when it is blown Receives fuse and establishes electrical contact with this. The alarm connection is before the circuit connection placed at such a distance that as long as the fuse is intact, no electrical Contact is made with the alarm terminal of the fuse. The direction from the load connection to the fuse housing The pressure exerted during the alarm response is used to ensure that the a clean electrical contact between the alarm connection of the blown fuse and the alarm connection of the Spring clip. The alarm connection of the spring clip is shaped in such a way that it has the elongated alarm connection the fuse and allows fluctuations in the pressure exerted by this alarm port.

The invention is explained in more detail with reference to the drawings. It shows:

Fig. 1 is a perspective view of a power

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circuit connection of a spring clip device provided spring clip according to the invention;

FIG. 2 is a profile view of the spring clip according to FIG. 1;

FIG. 3 is a plan view of the spring clip according to FIG. 1 in the state before their side parts were bent;

FIG. 4 shows a profile view of the spring clip according to FIG. 1 in the state according to FIG. 3;

5 is a perspective view of a spring clip arrangement provided as an alarm connection spring clip according to the invention;

6 is a perspective view of a load connection a spring clip assembly provided according to the invention spring clip;

Fig. 7 is a perspective view of a spring brackets of FIG _t 1 equipped spring clip arrangement in which only a visual warning display is required, and

8 is a perspective view of a spring clip according to FIGS. 1, 5 and 6 equipped spring clip assembly, with both a visual and an electrical alarm indication.

The illustrated in Fig. 1, used as a circuit terminal 10 spring clip is bent in the shape of a U, the Leg sections 18, 19 of the U-profile for receiving a

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tubular fuse, for example fuse 41 according to FIG Pig. 7 serve. The leg sections 18, 19 start from a yoke section 9 and run in the illustrated embodiment Way first inwards to the point 15 and from there in a curvature with apex 16 outwards, the Curved section is used to accommodate the fuse used. The leg portions of the spring clip practice on the Put 15 and 16 an inward pressure on the electrical connections 43 and 42 of the inserted fuse off, which makes the fuse held in place and a cleaner electrical contact is established. The inward pressure is exerted by the bending of the spring clip on the Positions 14 generated. To control the amount of inward pressure and thus to control the onset forces and removing the fuse, the locations 14 are subjected to an embossing process in which some material of the cross-sectional profile of the spring clip is removed. In this way, a single piece of material can be used for both Spring clip as well as for the wire-wrap connection leg are provided, whereby the wire-wrap connection leg 11 is the physical Dimensions for a clean electrical contact with the wire wound around the leg 11 according to FIG. 7 corresponds .

The spring clip shown is on the wire-wrap connector leg 11 a locking lug 13 is attached, which has the effect that after inserting the wire-wrap connecting leg 11 through

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an opening in a mounting board according to FIG. 8, the spring clip is locked in its seat. Another, short one Leg 12 is used together with locking lug 13 to achieve the mechanical stability required for assembly.

The slots 17 in the leg sections 13 and 19 form an inwardly extending stop and serve to hold an inserted fuse and to prevent the fuse from moving backwards or forwards. This aspect is explained in more detail below. The dimensions denoted by a and h in FIG. 1 are usually 0.76 mm for a and 1.52 mm for b_.

As can be seen from FIG. 2, the curvatures of the leg sections 18 and 19 of the U-profile of the securing clip each form a curve between the points 15 and 16, ura the electrical contact section of the inserted Record backup. These leg sections exert an inward pressure as a result of the bending of the material at the bending points 14 on both sides of the U-profile. the end. As mentioned earlier, the size of the inward will be Pressure and thus the amount of holding force due to the combination of the material used and the material thickness determined at the bending points 14. Since a material of uniform thickness is provided, the inward-facing one becomes Spring tension force controlled by the material thickness at the bending points 14, which is less than the total thickness of the material in the remaining areas of the securing clip.

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During the manufacture of the securing clip, the thickness at "the bending points 14 is reduced with the aid of an embossing process, whereby the material is flattened at a predetermined location.

Pig. 3 shows a securing clip before the bending process. The wire wrap leg 11 extends from one side of the main body of the securing clip, while the short leg 12 extends from the opposite side of the clip body. The distance _c between the top of the locking lug 13 and the yoke section of the spring clip is determined by the thickness of the material on which the spring clip is fastened with the legs 11 and 12 being pushed through. Typically the distance c is 2.54 mm. The length d of the wire-wrap leg 11 is typically 20.32 mm, measured from the underside of the locking nose 13.

In Fig. 4 is a side view of the U-profile of the bracket illustrated before the bending process. From this, the bending points 14 can be clearly seen, which by embossing the clamp be made before the bending process. For a satisfactory spring tension, the thickness should be at the bending points 14 0.51 mm when the tempered beryllium copper alloy 172 is used as the material.

The following describes the production process in general be described, which may include more or fewer manufacturing steps depending on the tool used.

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At the beginning, the slots 17 are punched in a continuous piece of material made of, for example, temper-hardened beryllium-copper alloy 172; then the one in Pig. 3 illustrated basic shape cut or punched; thereupon the basic shape is subjected to an embossing at the points 14; this is followed by a pre-bending to achieve the bending points 15 and 16 and the outwardly curved bend at the slots; then the legs 18 and 19 are bent to form the U-profile; and finally the legs 11 and 12 are bent to form the wire wrap leg and the locking leg. The manufacturing process used to manufacture the securing clip can be a method in which a strip of material is divided up after several processing stations and each of these stations carries out a processing step. The number of work steps required to manufacture the securing clip can be greater or smaller than described above, depending on the size of the machine and the tool design.

The alarm connection 20 illustrated in FIG. 5 also has two legs 21 and 22, each of which has a locking lug 23. The leg 21 represents the wire-wrap leg, whereas the leg 22 is used to hold the clamp. The upper portion of the alarm terminal 20 is provided with an inwardly extending or concave curvature so that when an alarm terminal of the fuse is pressed against this curvature , the alarm terminal of the fuse within the

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Leg sections 25 and 26 defined zone remains. The upper part of the alarm connection 20 is slightly curved inwards, a pushing up of a security alarm connection inserted therein to prevent.

In FIG. 6, a load connection is shown which is designed similarly to the current circuit connection according to FIG. 1, with the exception that a front compression spring 37 is also available to a forward on an inserted fuse exerting directed pressure.

As is apparent from Fig. 7, a fuse 41 has a rear electrical contact 42, a front electrical contact 43 and an electrical alarm contact 44. As long as the Fuse is not blown, the spring 45 remains compressed, so that the leading edge of the Alanrikontaktes 44 about 7.62 mm from the leading edge of contact 43. If the fuse element of the fuse 41 blows, can the alarm contact 44 move in the longitudinal axis, the spring 45 pushing the alarm contact 44 further by at least 5.1 mm .

The mounting board 40 illustrated in FIG. 7 is provided when only a visual display of the fuse status is required. This optical status display is possible because the fuse carries an optical display element 46 which is also moved forward when the fuse blows. Therefore, if the fuse arrangement

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as shown in FIG. 7 with a suitable one Holes of the mounting board 40 inserted pair of securing clips is formed, the optical display element 46 not visible through the slot 47. If, however, the fuse blows, the optical indicator moves 46 forward and passes through slot 47.

Two fuse clips are used to hold each fuse and are placed on board 40 along the longitudinal axis of the fuse Mounted in such a mutual position that the one fuse Klanmer the contact 43 of the fuse and the another fuse clip contacted the contact 42 of the same fuse. The slot 17 in the front securing clip prevents an inserted fuse from moving forward, while the slot 17 in the rear securing bracket the The inserted fuse prevents it from moving backwards. These two securing clips are identical to one another, however, the rear bracket is attached to the board 40 in reverse of the front bracket so that the slots 17 are properly positioned regarding the fuse used.

In Fig. 8 a fuse arrangement is shown in which at the points 51, 52, 53, 54, 55 and 56 fuses are used. The fuse at point 51 is shown in the blown state, while the other fuses are shown in the non-blown state. The port 30 exerts forward pressure on the inserted fuse, while at the same time an electrical

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Contact closure is made with the fuse. The connection As already mentioned, 3 * 0 represents the load connection. The connection 10 forms an electrical contact connection with the Fuse contact 43 »where the slot 1? a shift of the fuse against the alarm connection 20 is prevented. To this In the event of an electrical contact with the leg 11, the clamp or the connection and the action of the leg becomes wise 11 with an electrical current a circuit to the device protected by, the fuse via the leg 31 of the bracket or the connection 30 is closed if the fuse used is not blown. In this state, the alarm contact 44 of the fuse does not make any contact with the alarm connection 20. When a Overload occurs, the securing element separates the leg 31 from the leg 11 electrically. At the same time, the alarm contact 44 is displaced and set under the pressure of the spring 45 a contact connection with the alarm connection 20, whereby the electrical connection with the alarm circuit is closed will. Due to the shape of the alarm connector, the alarm contact 44 of the fuse is pushed down and into the concave Section of the clamp held, whereby a good electrical contact is ensured. Because the fuse is prevented from moving backwards by the spring of the clip 30, is the force exerted by the spring 45 sufficiently large to ensure good electrical contact even in the presence of oxidation or dirt.

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Claims (8)

Patent attorney eStuttgart N. Menzobiraße 40 2742967 Western Electric A 35 831-ko Company, Incorporated Broadway 23, $ 2P, 197? New York, jti.Y. 10007
USA j Claims M.! Spring clip for a tubular electrical fuse, characterized in that the spring clip (10, 20, 30) from a single piece electrically Conductive material is formed with a first thickness dimension that the spring clip is a terminal leg (11, 21, 31) for one by wrapping a lead wire around it ("Wire-Wrap") has to be formed electrical contact that the Fe derlei amme r comprises a U-profile piece (10, 30), which mates with an inserted fuse (41) and a spring pressure on an electrical connection (42, 43) of the fuse (41) exerts, and that the U-profile piece (10, 30) has two leg sections (18, 19) and one Yoke section (9), the leg sections (18, 19) being bent upwards from the yoke section (9). 2. Spring clip according to claim 1, characterized in that the electrically conductive material of The spring clip (10, 20, 30) in the area of the bending points (H) of the U-profile piece (10, 30) has a reduced thickness having. 809813/0980 3. Spring clip according to claim 1 or 2, characterized in that the spring clip (10, 20, 30) comprises a second integrally molded connection leg (12, 22), and that the wire-wrap connection leg (11, 21, 31) and the second connecting leg (12, 22) have molded locking lugs (13, 23). 4. Spring clip according to one of claims 1 to 3 »characterized in that in each the leg sections (18, 19) a slot (17) is present and that the slots (17) of the leg sections with each other are aligned and offset to the longitudinal axis of the leg sections. 5. Spring clip according to claim 1, characterized in that on denv Jochabsclinitt (9) a third, downwardly bent leg section (37) is attached to each U-profile piece (10, 30). 6. Spring clip according to claim 1, characterized in that the second leg portion (19) cut off and the first leg portion (18) is provided with a slot, which the first leg portion (18) divides into two subsections (25, 26). 7. Spring clip according to claim 1 to 6, characterized in that similarly shaped spring clips (10, 20, 30) in rows (51-56) on a mounting board 809813/0980 ~ ³ ~ - ⁵ - 27A2967 (50) are arranged and in electrical contact with the electrical connections (42, 45, 44) of a plurality of Lined up fuses (41) are (Pig. 8). 8. Spring clip according to claim 1 to 5, characterized in that similarly shaped Pederklainmern (10, 30) are arranged in rows on a mounting board (40) which is provided with slots (47) Has side wall, wherein the slots (47) are aligned with the longitudinal axis of the fuses (41). (Pig. 7). 809813/0980