Electric switch

Patent metadata

Field	Value
Publication number	US-9761385-B2
Application number	US-201514849014-A
Country	US
Kind code	B2
Filing date	Sep 9, 2015
Priority date	Sep 9, 2014
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

An electric switch, in particular for manually operated electric tools or appliances with an electric motor, is switchable from outside by means of a plunger. A changeover device is provided for setting the direction of rotation of the electric motor, which changeover device can be activated for example by a tappet arranged on the outside. The switch is constructed very compactly, which simplifies the sealing of a switch of this type.

First claim

The invention claimed is:

1. An electric switch for a manually operated electric device with an electric motor, comprising:
a switch housing;
a contact system having at least one contact arranged in the switch housing;
a plunger which protrudes out of the switch housing, is connected to an activation element, and by means of its movement can switch at least one of the contacts of the contact system from an off position into an on position; and
a circuit board fixed in the switch housing and has contact surfaces in the form of potentiometer circuits on one of its sides;
wherein the plunger within the switch housing comprises a slider which has sliding contacts on the side of the slider facing the circuit board,
wherein the rotational speed or the torque of the electric motor is adjustable through interaction of the sliding contacts with the contact surfaces of the circuit board,
wherein the contact surfaces and the at least one contact of the contact system are arranged on the upper face of circuit board, wherein the slider is moveable along the orientation of the contact surfaces in a plane parallel to the circuit board and the working direction of the contacts of the contact system likewise lies in a plane parallel to the circuit board, and
wherein a projection provided on the plunger prevents a switching of the contact system in the off position.

2. The switch of claim 1 , wherein the slider can be moved linearly along the contact surfaces oriented in straight lines or can be moved by means of a rotational movement along contact surfaces oriented as circular shapes, the plunger is movable linearly with the slider.

3. The switch of claim 1 , further comprising a changeover device for changing the direction of rotation of the electric motor,
wherein conducting paths are provided on a lower face of the circuit board and interact with the changeover device for running the electric motor in a selectable direction of rotation.

4. The switch of claim 3 , wherein the changeover device includes a position encoder which can be adjusted to switch over between a clockwise and a counter-clockwise rotation by means of a displacement movement or by means of a rotational movement.

5. The switch of claim 3 , wherein the changeover device comprises a position encoder, which can be operated from outside, and a switch lever arranged moveably inside the switch housing parallel to the circuit board, wherein the switch lever is connected on the one side to the position encoder and is mounted on the other side by means of a support arm on the circuit board, wherein the support arm forms the pivot axis of the switch lever.

6. The switch of claim 5 , wherein two contact tongues are provided on a side of the switch lever facing the circuit board, the two contact tongues, according to the pivot position of the switch lever, selectively contact the conducting paths provided on the lower face of the circuit board for clockwise rotation of the electric motor or contact the conducting paths for the counter-clockwise rotation of the electric motor.

7. The switch of claim 5 , wherein the switch lever is a two-armed lever having a short arm and a long arm, and the switch lever is connected on the free end of the short lever arm to the support arm and on the free end of the long lever arm to the position encoder.

8. The switch of claim 5 , wherein the switch housing comprises a top shell and a bottom shell which in the assembled state delimit a common opening on a side wall of the switch housing for the plunger.

9. The switch of claim 8 , wherein the two shells are connected to one another via a clamping connection.

10. The switch of claim 8 , wherein a one-piece circumferential seal is provided between the two shells of the switch housing, which seal is formed into a ring in the area of the opening of the switch housing.

11. The switch of claim 8 , wherein the bottom shell has a recess for the position encoder of the changeover device and a cable connection, which are both provided with seals.

12. The switch of claim 11 , wherein a sealing ring is inserted into an annular groove of the recess and a multilayer sealing packet is inserted into the cable connection.

13. The switch of claim 8 , wherein the position encoder is configured as a disk and the disk is rotatably mounted in a recess of the switch housing, a tappet for rotational activation is provided on an outside of the disk, and the disk is connected on an inner side to the switch lever in a torque transmitting way.

14. The switch of claim 13 , wherein a haptic element is provided between the inner side of the disk and the switch lever, which haptic element interacts with a peripheral contour of the recess of the switch housing.

15. The switch of claim 1 , wherein a return spring mounted in the switch housing engages with the plunger and the spring force of said return spring works in the direction of the off position.

16. The switch of claim 1 , wherein the at least one contact of the contact system comprises a fixed contact and a switch contact, wherein the fixed contact is a pin fixed on the circuit board and the switch contact comprises a pin fixed on the circuit board however with an associated torsion spring, wherein in the on position, due to the spring force of the torsion spring, said spring laterally contacts the fixed contact with a spring arm, and wherein in the off position, the projection on the plunger holds the arm of the torsion spring at a distance from the fixed contact and prevents contacting.

Assignees

• Johnson Electric Sa

Inventors

• Balgheim Udo
• Fangmann Gerhard

Classifications

• H01H2009/048

  using a sealing boot, e.g. the casing having separate elastic body surrounding the operating member and hermetically closing the opening for it · CPC title

• H01H19/38

  Change-over switches · CPC title

• H01H19/11

  with indexing means · CPC title

• H01H9/063 Primary

  enclosing a reversing switch · CPC title

• H01H9/061 Primary

  enclosing a continuously variable impedance · CPC title