DE2301471A1 - ELECTRIC SWITCH FOR PORTABLE ELECTRICAL DEVICES - Google Patents

Description

ARRGiMIAR? (EUROPE) LJJilTüD-, Plynbridge Road, Estover, Plymouth PL6 7PN (England)

Electrical switch for portable electrical devices

The invention relates to an electrical switch, which is particularly suitable for switching portable electrical devices. Although the switch is preferred for portable device use suitable, such as vacuum cleaners, blenders and portable hand tools, for example hand drills and hand grinders, Mainly used in the home, it is also used for portable electrical devices suitable that are mainly used outside of the house, for example lawn mowers, lawn edging cutters, Hedge cutters and sowing machines.

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Many portable electrical devices pose significant threats to the safety of those using them with itself, because these devices can be operated while the user is still in a position where he can be injured by the device. This is the case with electric lawnmowers, for example possible to set the knives in discussion while someone Makes settings on the mower.

In an attempt to prevent such accidents with portable electrical devices, the suggestion has already been made that Provide on / off switches that control the power supply to the device with the help of a mechanical locking device, which can be moved into a safety position which prevents the switch from being operated in the on position. The person handling the device can move this locking device into the safety position and thus put the device out of operation hold while he makes minor adjustments or repairs to the device. This arrangement has the disadvantage, however, that the person operating the device moves the locking device into the safety position must move before the device remains inoperative. But he can forget this activity or carry it out incorrectly.

The present invention strives to create a electrical switch that is suitable for portable electrical devices and does not have the disadvantages indicated above having.

The electrical switch according to the invention contains a carrier / a first contact which is fixed relative to the carrier, a second in and out of engagement with the first contact bringable contact, a movable relative to the carrier

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Contact actuator for making contact between the first and the second contact, a relative to the carrier movable locking member between a first position in which it prevents engagement of the first and second contacts, and a second Position; in which it makes the engagement of the first and second contact possible, is movable and means, which push the locking member in the direction of the first position.

The carrier is preferably made of electrically insulating material, the first contact being directly on the Carrier is mounted.

The salaries may have facilities that support the Push the second contact out of engagement with the first contact. In this case, the contact actuator is used for this purpose, the second contact in engagement with the first contact opposite to the biasing means to move. The second contact can be mounted on one end of a leaf spring, the other Tind is attached to the end of the beam as a pretensioning device which pushes the second contact out of engagement with the first font act.

"Has Kontalrtbetati ^ un ^ s member can be a lever or trigger, c ^J it is pivotable or slidable on the carrier 5?. Ent i it t. The pretensioning device assigned to the second contact can serve to control the Kontal't.b ^ t ^ ti.-nngsrlied to move into a limit position, in w ^ lrlie "de""first and second contact not with each other: ir intervening st ^ r .. Desired.;? alls can

i-tim · "* den" ontaktbet.ti ^ uin-s-

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member to be assigned to this in the limit position to press.

In a modified embodiment , the switch may include means for biasing the second contact into engagement with the first contact. In this case, the contact operating member normally assumes a first position in which it holds the second contact out of engagement with the first contact and movement of the contact operating member into the second position allows the second contact to engage the first contact under the influence of the clamping device. In this embodiment, the second contact can in turn be mounted on one end of a leaf spring, the other end of which is attached to the carrier, the leaf spring serving as a biasing device which presses the second contact into engagement with the first contact. In the case of the first embodiment, the contact operating member can be a lever or trigger which is pivotably or slidably mounted on the carrier. In this case, however, the contact actuating member is provided with a second biasing device which normally overcomes the biasing device which presses the first and second contacts together and holds the contact actuating member in a limit position in which the first and second contacts are disengaged from one another .

In any of the embodiments described above, the locking member may be a push button which is slidably mounted on the carrier. This push button is preferred arranged relative to the contact actuator so that both the push button and the contact

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actuator can be operated by the fingers of one hand of the person operating the device.

The switch is preferably a double-pole switch, two / one fixed contacts interacting with two movable contacts.

In the case of a switch for a device with a handle, For example, a lawnmower or lawn edge trimmer, the carrier can at least part of the handle make up this device. In this case it is advisable to design the carrier in the form of a tubular housing, which receives the first and second contacts inside, with the contact operating member and the locking member outward protrude from the tubular housing.

Embodiments of switches according to the present invention The invention will be explained in more detail below with reference to the drawings, for example. The drawings show in

Fig. 1 is a cross section through part of a handle of a lawnmower, which is with the invention Switch is equipped;

FIG. 2 shows a section along the line II-II in FIG. 1; FIG.

Fig. 3 is a section along the line HI-III of Fig. 1; and in

4 and 5, similar to FIGS. 1 and 2, representations of a modified embodiment of the lawnmower handle according to FIGS. 1 to 5, FIG. 5 showing a

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Represents section along the line V-V of fig.

In Figures 1 to 3, the reference numeral 1 generally designates part of a handle, for example a lawn mower. This handle consists of a metal tube 2 with a handle part 3 attached to one end is. This handle part consists of electrically insulating material and consists of three parts 3a, 3b and 3c composed of generally U-shaped cross-section, the are held together by screws 4 to form a tubular housing. A screw 5 extends through the housing parts 3a and 3b and through the tube 2 for the purpose of jamming the handle part 3 with the tube

A plate 6 made of electrically insulating material is mounted in the housing part 3d on columns 7, 8, the one-piece Represent parts of the housing part 3b. In the assembled state of the three housing parts, the end 9 of the plate is seated 6 in the part of the handle part which is formed by parts 3a and 3c, while the end 10 of the plate 6 is housed in the part of the handle part that is formed by parts 3a and 3b.

Two contact strips 11 are attached to the underside of the plate 6 at its end 9. Take these contact strips Screws 12, with the help of which the conductors 13 of a feed cable 14 are connected to the strips can. This connection can be made by removing of the housing part 3c from the housing part 3a, with a conventional cable gripping device 15 in the housing part 3a for grasping the Cable 14 is provided. A rubber sleeve 16 surrounds the cable 14 at the exit point from the housing parts? A,

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At the end applied by the screw 12, each carries Contact strip 11 has a fixed contact button 17 which is attached to it there, one of these contact buttons can be seen in FIG. These fixed contact buttons cooperate with movable contact buttons 18, which are each attached to one end of their own spring contact strip 1Q. The ends of the contact strips 19 »which are turned away from the contact buttons 18 are on the underside of the plate 6 in the vicinity of the end 10 of the same fastened by rivets 20. The spring contact strips 19 serve as biasing means for separating the contact buttons 18 from the fixed contact buttons 17.

A contact actuating member, generally designated by the reference numeral 21, is mounted in an opening 22 in the housing part 3b. The member 21 consists essentially of a block 23 of electrically insulating material mounted on a pin 24 fixed at both ends in the columns 8, the axis of the pin 24 being parallel to the plane of the plate 6. At the end facing away from the pivot bearing in the housing part 3b, the block 23 is provided on each side with a projecting finp _r -er 25, the fingers being arranged essentially parallel to the axis of the pivot pin 24. In the edge 20 of the block 23, which is opposite the plate 6, two blind holes 26, 27 are provided. The axes of these two blind holes are essentially parallel and are essentially perpendicular to the axis of the pivot pin 24 .. A short rod 29 made of electrically insulating material is slidably mounted in the hole 26 and is pressed in the direction of the plate 6 by a helical spring 30

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This spring 30 pushes the block 23 counterclockwise around the pivot pin 24 into a limit position (see. Fig. 1) in which the fingers 23 are out of engagement with the contact strips 19 and against the wall of the housing part 3b on each side of the opening 2.2 issue. If the contact actuating member 21 is rotated clockwise around the pivot pin 24, for example by the fingers of the hand of the person holding the handle part 3 and actuating the device, then the fingers 25 grasp the contact strips 19 and the latter are bent in the opposite direction to their inherent elasticity, so that the contact buttons 18 come into engagement with the fixed contact buttons .17.

A plate 31 made of electrically insulating material is slidably mounted within the housing part 3a. This plate can be spaced in a direction perpendicular to the pivot pin 24 in a plane and parallel to the Plate 6 can be moved by a push button 32 which is provided on the outside of the housing part 3a and has a shaft 33 through an elongated Hole 34 protrudes in the wall of the housing part 3a and is connected to the plate 31. A feather in the shape of a Helical spring 35 presses plate 31 in the direction of arrow A into a limit position in which shaft 33 against one end of the hole 34 is applied.

A finger 36 protrudes from the plate 31 through an elongated slot 6a in the plate 6 into the housing part 3b. In the position of the various parts, as shown in Fig., The finger 36 acts as a stop for Prevention of a substantially clockwise pivoting movement of the contact operating member

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However, if the push button 32 is moved in a direction opposite to the arrow A against the action of the spring 35, then the plate 31 can be moved into a position in which the finger 36 comes to lie opposite the hole 27 in the block 26. The contact operating member 21 can then pivoted clockwise so that the contact buttons 17 and 18 come into engagement. The push button 32 is arranged so that it can be adjusted so that it can be pulled over by the thumb of the hand of the device the handle part 5 actuators can be operated.

The conductors 37 of a cable 38 are connected to those of the contact strips 19 which are attached to the plate 6 are riveted. This cable leads the electric current to the motor of the mower (not shown).

From the preceding description it can be seen that the contact buttons 17, 18 are only connected to one another by actuation of the contact operating member 21 can be brought into engagement when the push button 32 is opposed is moved to the direction of part A. Once the contact actuator 21 is released, it is opposed by the spring 30 and the elasticity of the strips 19 moved clockwise. This releases the block 23 from the finger 36 and the spring 35 brings the Push button 32 immediately back into the position shown in Fig. 1, so that a re-engagement of the contact buttons 17 and 18 can only take place when the push button 32 moves again in the direction opposite to arrow A. will.

The housing part 3b is preferably designed in such a way that a finger stop 39 is created which supports the fingers of the hand

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of the person operating the device from sliding over the contact operating member 21 from the handle.

4 and 5 show a modified embodiment of the lawnmower handle according to FIGS. 1 to 3, the same reference numerals in FIGS. 4 and 5 as in 1 to 3 are used to denote the same or substantially the same parts.

The difference between the switch of the handle 4 and 5 in comparison to the switch of the handle according to FIGS. 1 to 3 is that the two resilient contact strips 19 of the üzteren replaced by two spring contact strips 39 are both formed and shaped to partially wrap around one of the protruding fingers 25 of the Actuator 21 lie. The spring contact strips 39 serve as a biasing device around the contact buttons 18 into engagement with the fixed contact buttons 17. However, prevent in the one shown in Fig. 4 Position of the switch parts the protruding fingers 25 of the contact operating member the engagement the contact buttons 18 with the contact buttons 17 as a result of the biasing action of the spring 30.

In all other respects the switch for the handle of Figures 4 and 5 is the same as that for the handle according to FIGS. 1 to 3. It can thus be seen that the contact buttons 18 only then with the contact: button 17 under the influence of the spring tension of the strips 38 can be brought into engagement when the Block 23 of the contact actuator in clockwise

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direction (seen from Fig. 4) is rotated about the pivot pin. As in the case of the embodiment according to FIGS. 1 to 3, a movement of the block 23 can only take place when the push-button 32 is moved in the direction opposite to the arrow A. In addition, when the contact actuating member 21 is released, it is moved counterclockwise by the spring 30 in the opposite direction to the elasticity of the strips 39. This releases the block 23 from the finger 36 and the spring 35
brings the push button 32 immediately back to the position of FIG. 4, so that the low engagement of the
Contact buttons 17 and 1-1 can only be made if the
Push button 3 ° is pressed again in the direction opposite to arrow A.

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Claims (11)

Pat e η ta η s ρ r ü ehe Λ J electrical switch with a carrier, a first contact attached to the carrier, a second contact which can be brought into and out of engagement with the first contact, a contact actuating element movable relative to the carrier for establishing the electrical contact between the first and the second contact, and with a relative to the carrier movable locking member, which prevents the engagement of the first contact and the second contact in a first position and enables the engagement of the first and the second contact in a second position, characterized by means which press the locking member in the direction of the first position. 2. Switch according to claim 1, characterized by means for biasing the second contact disengaged from the first contact and further characterized in that the contact actuator is movable relative to the carrier and opposes the second contact in engagement with the first contact the direction of action of the pretensioner moves. 3. Switch according to claim 2, characterized in that g e k e η, η draws that the second contact is mounted on one end of a leaf spring, the other end on the Is attached to the carrier and serves as a biasing device that disengages the second contact with the first contact presses. 4. Switch according to claim 2 or 3, characterized in that the second contact assigned pretensioning device serves to keep the contact 9831/0430 - 13 - to push actuator into a limit position in which the first and second contacts are not engaged with each other. 5. Switch according to claim 4, characterized in that the contact operating member is a further biasing device is assigned, which presses the contact actuator into the limit position. 6. Switch according to claim 1, characterized in that a device for biasing of the second contact is provided in engagement with the first contact and the contact operating member is normally assumes a first position in which it disengages the second contact from the first contact holds, but is movable to a second position in which it engages the second contact with the allows first contact under the influence of the biasing device. 7. Switch according to claim 6, characterized in that the second contact is on one end a leaf spring is mounted, the other end of which is attached to the carrier and that the leaf spring is used as a pretensioning device which presses the second contact into engagement with the first contact. 8. Switch according to claim 6 or 7, characterized in that the contact operating member is provided with a further pretensioning device, which normally the first and second 309831/0430 - 14 - ■ Il -tr- Contact compressing biasing device overcomes and the contact actuator in a limit position holds in which first and second contacts are disengaged from each other. 9. Switch according to one or more of claims 1 to 8, characterized in that the locking device comprises a push button which is displaceable is mounted on the carrier, is adjusted relative to the contact actuator so that as well push button as well as contact actuator can be operated by the fingers of a person's hand, the the device on which the switch is mounted. 10. Switch according to one or more of claims 1 to 9, characterized in that the switch is a double pole switch in which two fixed contacts interact with two movable contacts. 11. Switch according to one or more of the claims 1 to 10, characterized .that the contact actuator is a lever pivotably mounted on the carrier. ■ * ■ * ■ * ■ ** · 309831/0430