DE2350041A1 - Snap-action switch for office machines - has contact arm and snap spring made in one piece from wire in form of yoke etc. - Google Patents

Abstract

The office machine snap-action switch has a contact arm and a snap-action spring, formed in one piece with the arm by suitable bending of a wire in the form of a stirrup, a loop or similar configuration. The stirrup is held between two support points formed one behind the other in the long direction of the contact arm. The support points distance exceeds the spacing of the supported stirrup parts. Two stirrups formed in one piece may be provided in a mirror image in relation to the support points, thus forming a double stirrup. The free wire ends may be bent inwards into the double stirrup to form a hook whose free, parallel ends are located in the movement range of a swivelling switch actuator.

Description

Patent attorney DIPL.-ING.BERTHOLD SCHMID STUTTGART 1 - FALBENHENNENSTRAS SE 17 TELEPHONE (0711) 608893

OUR SIGN

11015 B / S

Company'

J. & J. Marquardt

7201 Rietkeim

Snap switch and switching device with at least two snap switches

The invention relates to a snap switch, in particular for office machines with a contact arm and a snap spring made in one piece with it and also on a switching device with at least two such snap switches. Such snap-action switches and also switching devices are "already in themselves known. They have S-shaped, pre-tensioned flat springs, which when switching a reciprocal S-shaped

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Take shape. The dynamic load on the leaf spring is relatively strong. In addition, a relatively large key travel must be provided, which is when used in miniaturized Equipment is inexpedient. The required shifting force is also considerably high, which increases with longer prolonged manual operation is detrimental.

The present invention now has for its object to provide a switch of the type mentioned, which is particularly ei n times set up and is compact and requires a small operation force. The same applies to the switching device equipped with such switches. To solve the problem, such a switch is proposed, which is characterized according to the invention in that the contact arm with the snap spring is made of a wire and both are shaped together as a bracket, loop or the like, that the bracket or the like between two approximately in the longitudinal direction of the Contact arm support points arranged one behind the other is held, the distance between the support points being greater than the distance between the bracket parts of the loose bracket supported thereon. Due to the latter feature, the two legs of the bracket, which is flat in the loose state, must

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form an angle with each other after assembly, wherein at least the connector is twisted. The two support points are usually on a higher one Level than the surface of the fixed contact and moreover the bracket is mounted in such a way that it assumes an inclined position pointing away from the fixed contact. Both support points must allow pivoting of the supported end of the temple. If you now press against the fixed contact switching movement directed towards one of the different long bow legs is reduced the angle existing between them is continuous. As soon as it is zero degrees, an unstable state is reached. If the switching movement stops, the bracket jumps against the fixed contact Mn in the manner known from snap switches around. The reason is that the distance between the support points is greater than the distance between the bracket parts of the loose bracket supported thereon and the bracket itself must deform elastically when switching in the longitudinal direction. He gives way to this compulsion by jumping into the switch position the end. At the same time, part of the bracket is then twisted again. This torsional force is used to reset of the bracket in the starting position ο

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In the embodiment described, the bracket may show at Switching has a certain tendency to pivot sideways. To prevent this, a particularly preferred one Embodiment of the invention proposed that approximately mirror image two brackets or the like made in one piece with one another are provided for the two support points and form a double bracket. One half of the latter has the tendency to move to the left when switching and the other half leans to the right. Overall, these two tendencies are then compensated for. The double bracket is designed symmetrically to a vertical pivot plane, which does not necessarily have to run exactly through the two support points can be supported two, three or even four places. With three support points, this plane of symmetry runs on the one hand through the middle support point and on the other hand right between the other two. The assembly of the double bracket is at least not more complex than that of the simple bracket. In both cases, the contact arm is also a snap spring or vice versa.

Another feature of the invention is characterized that the free wire ends to form a Hooks are bent into the interior of the double bracket, with the free hook ends, in particular approximately parallel running hook ends in the range of motion of a preferably pivotable

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stored actuator while the hooks Form bearing elements. The middle piece of the double bracket is designed V-shaped or U-shaped. The two hooks on the one hand and the middle part of the V- or U-shaped The middle piece serves to support and at the same time also brace the double bracket. The bracket or double bracket is conveniently located between two bearing slots or notches pointing in opposite directions, in particular a common bearing block blown in. In the case of a double bracket, the distance between the two notches is to hang the hook from the notch for the V- or TJ-shaped center piece according to the invention chosen so that the latter is automatically inclined to the other parts of the double bracket after assembly. One achieves this as I said, by a shorter distance between the adjacent hook parts as seen in the longitudinal direction of the contact arm. the center piece support.

In a further development of the invention, the bearing block has an approximately U-shaped shape, with both its two U-leg ends as well as the outside of the U-center webSmit.je are provided with a cutting edge bearing. As already stated, these point in opposite directions whereby a clamping of the double bracket is possible.

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The bearing block consists in an advantageous manner of electrical conductive material and it is connected to a connection element for an electrical conductor or in one piece manufactured. The connection element can also be used to fasten the bearing block at the same time. For this purpose it can be pushed through a wall and the protruding end can be compressed or bent.

Another variant of the invention is characterized in that the free wire ends are approximately perpendicular to the Extend the level of the loose double bracket and serve as fastening organs are trained. The attachment point does not form a swivel bearing, but rather has to be In this embodiment, the double bracket bend when switching in addition to the aforementioned torsion. Through this additional restoring forces arise in an advantageous manner. The free wire ends enforce according to a Another feature of the invention is a common hole in a switch base plate 'and protrude beyond this to the outside. That protruding end can be connected directly to a continuing wire, in particular soldered.

Another embodiment of the invention is thereby characterized in that the fastening hole for the wire ends, which also acts as a support point for the double bracket serves, which has an inwardly protruding U- or V-shaped Middle piece on one between the fastening

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bore and the bearing block located in the fixed contact is supported and pivoted there at the same time. An advantageous development of the one just described The embodiment is that the pieces of wire located between the bearing block and the fastening bore run approximately parallel to one another, in particular bear against one another and in the range of motion of a Actuator are located. The latter is therefore pressed against the pieces of wire running parallel to one another and causes the double bracket to pivot and finally snap over.

The plague contact is preferably through a flat piece of wire formed, of which at least one end passed through the switch housing or a base plate to the outside and is designed as a fastening element for an electrical line. Both this mating contact and the bracket or double bracket can be surface-finished, in particular gold-plated.

Another feature of the invention is characterized in that there is at least one between the fixed contact and its connecting terminal. electrical component in particular an integrated solution is located. Due to the simple Switch construction as well as the small dimensions of the individual switch parts is itself, in a small and flat

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Switch housing to accommodate a relatively large integrated circuit in terms of space.

The switching device provided with at least two snap switches is according to the invention characterized in that on a common base plate in mutual Distance between several brackets and - or double bumps with the associated fixed contacts, bearings and connection elements are arranged. The smaller the switches themselves are, the smaller the distance between them can be chosen, what at least from this point of view a miniaturization the office machine equipped with such a switching device. A useful further education the invention is characterized in that all switches from a common, in particular watertight Enclosed housing and the electrical connections are made watertight to the outside and that the housing cover surface is elastically deformable and designed as an actuator for all switches. The housing cover surface is comparable to a membrane. If you press the button located above a certain switch Place the housing cover surface against the latter, so the relevant switch can be operated. Unless the housing cover eleven If the laugh is opaque, it must be matched with the appropriate Markings or other auxiliary equipment are provided to enable the

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underneath the switch and its proper Operation permitted.

It is very advantageous in a switching device with switches arranged in rows and columns that support webs for the housing cover surface are arranged between the individual rows or columns, the height of which corresponds to the height of the side wall with which they are in particular made in one piece. In the latter case, the four side walls of a rectangular housing together with the aforementioned support webs form a ladder-like structure. The support webs serve on the one hand for stiffening and on the other hand as a support for the housing cover surface. They are of particular importance when, in a further development of the invention, pivot bearings for switch actuation buttons are arranged on the outer surface of the housing cover, and in the case of plastic production they are especially molded on. When the switch actuation buttons are pressed down, a pressure force is exerted on the housing cover surface, which is absorbed by the webs and transmitted to the base plate.

Unless the housing cover surface is very thin-walled overall is formed, you can use them according to another feature of the invention at least in the area of each switch Form membrane-like and each on their inside

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with a switch actuating plunger, preferably a touched up Mistake. In the assembled state, the latter is exactly that point of the bracket or double bracket assigned to which the switching force is to be initiated.

Another embodiment of the invention is characterized in that the switch actuation buttons as mounted at one end in push-button-like pivot bearings Plate are formed with an attached key head and that on the underside of the plate one of the switch actuating plungers associated wart or the like is attached. The switch actuation buttons are with mounted or even better molded laterally protruding bearing journals, which are in U-shaped, upwardly narrowing bearing blocks are blown in. One and the same bearing block can be used at the same time Pick up two bearing journals pointing towards one another on adjacent switch actuation buttons next to each other · Both For visual reasons as well as to keep things clean, it is of great advantage that all switch actuation buttons are covered by a cover plate provided with cutouts for the key button. The cutouts are formally precisely adapted to the key buttons and dimensioned in such a way that they are minimal Game can be pivoted without contact.

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Incidentally, the pivoting movement is extremely minimal and hardly distinguishable from pressing a button. The key tops can be manufactured in one piece with the operating keys or they can be attached to them interchangeably.

An exemplary embodiment of the invention is shown in the drawing. Show it:

1 shows a first embodiment of a contact arm designed as a double bracket with a snap spring.

J ¹ Ig- 2 A second embodiment of the double bracket also seen from above.

Pig. 3 A side view of! Figure 2.

Pig. 4- A broken vertical section of the invention Switching device with a double bracket according to FIG. 1.

♦ Fig. 5 A perspective view of the bearing block of FIG. 4.

Fig. 6 An exploded view of the invention Switching device, also using double brackets according to Figure i, wherein various parts are drawn broken off.

In the snap switch according to the invention, the contact is poor and the snap spring is made from a wire.

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Both together form a bracket that is flat in the loose state. Instead of a simple bracket, a double bracket 3 which is a mirror image of the plane of symmetry 2 indicated in FIGS. 1 and 2 with dash-dotted lines can be used. When only a simple bracket is used, the one curved bracket end 4 - can be lengthened somewhat beyond the plane of symmetry 2 to form a bearing and fastening end. The double bracket M- has an essentially U-shaped shape in both versions, the middle part of the TJ central web 6 being bent into the interior of the bracket to form a likewise U-shaped loop 5. The two legs 7 and 8 of the U-bracket initially run roughly parallel or slightly inclined to one another, starting from the U-center web 6, and after a kink or bending point 9 merge into U-legs 10 and 11 that are more inclined to one another. In the exemplary embodiment in FIG. 1, the free wire ends are then bent into the interior of the double bracket, each forming a hook 12. The free hook ends 13 run parallel or approximately parallel to one another. If they run parallel, they can also lie directly against one another, as is the case with the free wire ends 14 of the second embodiment. The part 15 of the free wire ends 14 of the second embodiment is, as FIG. 3 expresses, bent downwards at right angles.

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It can be through a base plate in a manner not shown of the switch and · immovable therein be held. The thickness of this floor slab is to choose much lower than the Peil 15 of the free Wire ends 14 so that both wire ends protrude to the outside and can be used for soldering a connecting wire. The above apply to the simple bracket and also the following statements accordingly.

The snap switch shown in Figure 4- is a Double bracket according to Figure 1 is used. The two hooks

12 comprise notches 16 on the free leg ends of the U-shaped bearing block 17 · The free hook ends

13 are therefore between the two U-legs 18 of the bearing block 1? This notch points opposite to the two notches 16. The distance between the notch and the two notches 16 is less than that of the wire parts engaging therein. This leads to the U-shaped loop 5, that is to say the middle part of the ¹ double bracket 3, assuming an inclined position with respect to the bracket legs 7 and 8. The included angle 21 is designated in FIG. As a result of this inclination, the U-central web 6 is twisted.

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At the same time, a bending of the legs 5 and / or 7, IO or 8, 11 can also occur in a manner not shown occur.

If it is now bridged with a switch actuating plunger 22 (Figure 4) in the direction of arrow 23 on the two free U-shaped hook ends 13 »so both the U-shaped Loop 5 as. Also the remaining parts of the double bracket pivoted towards the base plate 4. The U-shaped Loop 5 performs a pivoting movement around the notch, while the remaining double bracket parts the notches have to pivot. The angle 21 decreases continuously. When it reaches the value zero, it takes Double bar in an unstable position. This corresponds to the unstable position of other known snap switches. Holds the Switching movement in the direction of arrow 23, the jumps Double bracket suddenly down until the two sections of the U-center web 6 hit the fixed contact 25. The latter consists of a flat, straight piece of wire (Figure 6), both ends of which form the base plate push through. One of these two ends or both can be connected to a continuing line. Due to the chosen arrangement and storage, the two sections of the U-central web 6 are slightly inclined to the level defined by the fixed contact 25, so that

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a total of two places a contact is made. This brings a high level of contact security with it. In addition, the entire snap system is extremely robust and deformation-proof, which leads to a long service life with a considerable number of switching cycles. The notch 19 on the one hand and the two notches 16 on the other hand are at different levels, but this need not necessarily be so. In any case, it is only important that an angle 21 is created and the contact arm can be moved beyond a dead center position. It is also pointed out that the bearing block 17 has a spike-shaped extension 26 which, as shown in FIG. -M- , also extends through the base plate M-. Its free end can also be connected to a continuing line *.

A frame 27 on the base plate 24 is dustproof and watertight put on, it consists of four perpendicular side walls 28 of a housing of the inventive switching device forming webs and running parallel to a pair of these side walls Support frame 29. The base plate 24, the side walls 28 form with the support webs 29 and a housing cover 30 several adjacent chambers 31 in which each

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because several switches are arranged next to each other In the exemplary embodiment, four rows of switches are provided, each row having three switches. In Figure 6 is only such a switch is drawn. There are also the three through-holes required for each switch 32, 33 and 34- shown. Through the bore 33 is the mandrel 26 of the bearing block 17 inserted, while the bores 32 and 3 ^ · for inserting the wire ends of the fixed contact 25 serve. If a double bracket according to FIG. 2 is used, instead of the mandrel 26, the part 15 becomes the free one Wire ends 14- inserted through the hole 33. The temple end 4-this The double bracket engages in a not shown, merely placed or injection-molded onto the base plate 24 A bearing block, which is attached to the U-middle section 20 of the bearing block 17 and is also provided with a notch 19. After the part 15 of the free wire ends 14 · in the base plate 24- is fixed, an angle 21 is also created with this double bracket. The switch actuating plunger 22 is assigned to the free wire ends 14 running in parallel.

It should also be noted that the double bracket can also be pressed down at another point, however the snap function is best guaranteed

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-v-

when the actuating plunger 22 is at the specified locations attacks.

The side walls 28 and the support webs 29 are in one piece manufactured with the housing cover 30. For attachment to the base plate 24 all have webs or side walls Spigots 35 formed at a mutual distance 'pass through the corresponding bores in the base plate 24-. If plastic is used, their free ends are deformed into "rivet heads" with the aid of heat. In order to achieve good sealing of the side walls and support webs with respect to the base plate 24 · are on the lower ends of which sealing lips 36 and 37 are integrally formed. You can lay flat on the base plate 24- or, as shown in Figure 4-, just with yours sit on the free ends of the sealing lip.

The housing cover 30 is in the area of each switch with the formation of a membrane 38 in each case kept particularly thin-walled. On the inside of this membrane 38 a switch actuating plunger 2 is formed in each case. Due to the mounting pin 35 is a perfect, free assignment of the tappets 22 to the double brackets guaranteed without difficulty «.

Switching takes place with the help of pivoted Switch actuation buttons 39 ».

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They consist of a plate 40 with side-mounted Bearing pin 41. Approximately at the free end of their Each plate 40 carries a key head 42 on the top side which are manufactured in one piece with the housing cover 30. The pivot bearings sit over the support webs 29 and the parallel side walls 28 of the device housing. They have a U-shaped cross-section, where the free U-leg ends as shown in particular in Figure 4, to form the snap locks are slightly directed against each other.

All switch actuation buttons are still covered by a cover plate 44 with one of the number of switches this device corresponding number of cutouts 45 is provided. The key heads protrude through this 42 to the outside.

The base plate 24 can in not shown but more advantageous Way be designed as a printed circuit board provided with a printed circuit. The device mentioned is dust and moisture-proof and is therefore also suitable for rough operation. A single switch could be provided with a correspondingly designed housing.

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Both he and the switching device according to the invention can be assembled by unskilled workers without difficulty due to its simple structure.

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Claims (18)

Expectations 1 / Snap-action switches, especially for office machines, with a contact arm and a snap spring manufactured in one piece therewith, characterized in that the contact arm with the snap spring is made of a wire and both together as a bracket (1), Loop or the like "are shaped that the bracket or the like between two approximately in the longitudinal direction of the contact arm arranged one behind the other support points (16,19) is held, the distance the support points is greater than the distance between the bracket parts supported thereon (4, 12 or 4, 15). of loose bracket. 2. Snap switch according to claim 1, characterized that roughly mirror images of the two support points (6, 19) are two integral parts Brackets or the like are provided and form a double bracket (3). 509815/0729 . - 21 - 3 · Snap switch according to claim 2, characterized in that the free wire ends to form a hook (12) are bent into the interior of the double bracket (3), wherein The free, in particular approximately parallel, hook ends (13) in the range of motion of a preferably pivotably mounted actuator (22) lie while the hooks form storage elements. 4-. Snap switch according to one or more of the preceding Claims characterized in that the bracket (i) or double bracket (3) between two after opposite directions facing bearings or - notches (16 and 19) in particular of a common one Bearing block (7) is blown in. 5- snap switch according to claim. 4- characterized, that the bearing block (17) has an approximately U-shaped Has shape and both its two U-leg ends as well as the outside of the U-middle bar (20) each with a saw cutting file (16 or / 19) are. . - 509815/0729 6. Snap switch after. Claim 5 characterized in that that the bearing block (17) consists of electrically conductive material and with a connection element (26) is connected for an electrical conductor or or made in one piece. 7. Snap switch according to claim 1 or 2, characterized in that that the free wire ends (14-) are approximately perpendicular to the plane of the loose double bracket '(3) extend and are designed as a fastening member (15). 8. Snap switch according to claim 7, characterized in that that the free wire ends (15) penetrate a common bore (33) of a switch base plate (24-) and tower above them to the outside. 9. Snap switch according to claim 8, characterized net that the fastening bonrung 33 for the wire ends (15) also serves as a support point for the double bracket (3), which has an inward-facing, U-shaped or V-shaped center piece (4-) on one located between the fastening bore (53) and the fixed contact 25 Bearing block (20) is additionally, supported and pivoted there at the same time 509815/0729 10. Snap switch according to claim 9, characterized in that between the bearing block 20 and pieces of wire located in the fastening bore (53) run at least partially approximately parallel to one another, in particular bear against each other and are in the range of motion of an actuator (22). 11. Snap switch according to one or more of the preceding claims, characterized in that the fixed contact (25) is formed by a flat piece of wire, of which at least one end (46) out through the switch housing or a base plate (24) and used as a fastening element for an electrical line is formed. 12. Snap switch according to one or more of the preceding claims, characterized in that at least one electrical component between the plague contact (25) and its connecting terminal (46) in particular an integrated circuit is located. 13. Switching device with at least two snap switches according to one or more of the preceding claims characterized in that several at a mutual distance on a common base plate (24) Bracket (1) and / or double bracket (3) with the associated 5 09815/0729 load contacts (25), bearings (16,19) and connection elements (26,46) are arranged. 14. Switching device according to claim 13, characterized in that all switches of a common one in particular waterproof housing (24,28,30) and the electrical connections (26,46) are guided to the outside in a watertight manner and that the housing cover surface (30) is elastically deformable and is designed as an actuator for all switches. 15 · Switching device according to claim 13 or 14 with in Switches arranged in rows and columns, characterized in that between the individual rows or columns support webs (29) are arranged for at least the housing cover surface (30), the Height corresponds to that of the side walls (28) with which they are made in one piece, in particular are. 16. Switching device according to one or more of claims 13 to 15, characterized in that on the Housing cover outer flat pivot bearing (43) for switch actuation buttons (39), with plastic 5098 1 5 / Ü729 - 25 production are in particular molded. 17 · Switching device according to claim. 16, characterized in that the · housing cover surface (30) ' at least in the area of each switch membrane is designed like (38) and on its inside In each case one preferably molded S. switch operation: osse> l (22) carries; » 18. Switching device according to spoke Λ! Ψ characterized, that each Schalipcbetatigungs button C39) as on. one end in push-button-like * pivot bearings (4-3) mounted plate ^ C ^ 0- ^; with the key top (4-2) attached, and that on the underside of the plate a protrusion (44) or; the like: is appropriate. 19 · Switching device according to claim 18, characterized in, that all switch actuation buttons (39) by means of one with cutouts (45) for the key tops (42) provided cover plate (44) are covered. Emptied