Limit switch housing with reset function

Patent metadata

Field	Value
Publication number	US-9928972-B1
Application number	US-201615347024-A
Country	US
Kind code	B1
Filing date	Nov 9, 2016
Priority date	Nov 9, 2016
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

Embodiments relate generally to a limit switch comprising a switch housing; a contact block assembly comprising a contact plunger and a switch circuit; a head assembly comprising a lever; a reset plunger configured to fit within the housing, configured to interact with the head assembly and the contact plunger; and a reset assembly comprising a reset button and a reset axis, configured to attach to the housing and to interact with the reset plunger, wherein the head assembly moves the reset plunger downward against a bias, wherein, when the reset plunger is moved down a predetermined amount, the reset axis moves into an opening in the reset plunger, due to a bias on the reset axis, wherein when the reset plunger moves downward, the contact plunger also moves downward against a bias, and wherein the contact plunger is configured to control the switch circuit.

First claim

What is claimed is:

1. A limit switch comprising:
a housing comprising a threaded opening;
a contact block assembly configured to fit within the housing, comprising a contact plunger and a switch circuit;
a reset assembly comprising a reset button, a reset axis, and a threaded attachment, wherein the reset assembly is configured to attach to the switch housing via the threaded attachment and the threaded opening;
a head assembly comprising a shaft, configured to attach to the switch housing; and
a reset plunger configured to contact the shaft and the contact plunger,

wherein:
when a measurement is made by the limit switch, the shaft rotates with respect to the switch housing, moving the reset plunger downward against a bias,
when the reset plunger is moved downward a predetermined amount, the reset axis moves into an opening in the reset plunger, due to a bias on the reset axis,
when the reset plunger moves downward, the contact plunger also moves downward against a bias,
the contact plunger is configured to control the switch circuit based on the location of the contact plunger within the contact block, and
when the reset button is pulled by a user, the reset axis is removed from the opening in the reset plunger, thereby releasing the reset plunger and the contact plunger to move upward due to the biases.

2. The limit switch of claim 1 , wherein the contact block is configured to activate an alert based on the controlling of the switch circuit.

3. The limit switch of claim 1 , wherein the reset assembly comprises a sealing ring configured to seal with the threaded opening of the housing.

4. A limit switch comprising:
a switch housing;
a contact block assembly configured to fit within the switch housing, comprising a contact plunger and a switch circuit;
a head assembly comprising a lever, configured to attach to the switch housing;
a reset plunger configured to fit within the housing, configured to interact with the head assembly and the contact plunger; and
a reset assembly comprising a reset button and a reset axis, wherein the reset assembly is configured to attach to the housing, and wherein the reset axis is configured to interact with the reset plunger,

wherein:
when the lever rotates with respect to the switch housing, a shaft within the head assembly moves the reset plunger downward against a bias,
when the reset plunger is moved down a predetermined amount, the reset axis moves into an opening in the reset plunger, due to a bias on the reset axis,
when the reset plunger moves downward, the contact plunger also moves downward against a bias, and
the contact plunger is configured to control the switch circuit based on the location of the contact plunger within the contact block.

5. The limit switch of claim 4 , wherein the reset assembly comprises a threaded attachment configured to secure the reset assembly into the housing.

6. The limit switch of claim 4 , wherein the reset assembly attaches to a threaded opening in the switch housing.

7. The limit switch of claim 4 , wherein the reset assembly comprises a sealing ring configured to seal with the housing.

8. The limit switch of claim 4 , wherein, when assembled, the reset button may be covered by a portion of the head assembly.

9. The limit switch of claim 4 , wherein the switch circuit comprises a normally open/normally closed circuit.

10. The limit switch of claim 4 , further comprising a reset spring configured to provide the bias on the reset axis toward the reset plunger.

11. The limit switch of claim 4 , further comprising a contact spring configured to provide the bias on the contact plunger toward the reset plunger.

12. The limit switch of claim 4 , further comprising a plunger spring configured to provide the bias on the reset plunger toward the head assembly.

13. The limit switch of claim 4 , wherein, when the reset button is pulled by a user, the reset axis is removed from the opening in the reset plunger, thereby allowing the reset plunger and the contact plunger to move upward due to the biases.

14. The limit switch of claim 4 , further comprising a cover assembly configured to attach to the switch housing, and configured to enclose the contact block within the switch housing.

15. The limit switch of claim 14 , wherein the cover assembly comprises a user interface.

16. A method for operating a limit switch comprising:
assembling a reset plunger into a housing of the limit switch, between a head assembly of the limit switch and a contact block of the limit switch, wherein the reset plunger interacts with a contact plunger of the contact block;
attaching a reset assembly to the housing, wherein the reset assembly interacts with the reset plunger;
rotating a shaft of the head assembly to measure physical motion of an object through physical contact between the shaft and the object;
moving the reset plunger downward against a bias due to the rotation of the shaft;
moving the contact plunger downward against a bias due to the downward movement of the reset plunger;
controlling a switch circuit based on the movement of the contact plunger;
when the reset plunger is moved downward a predetermined amount, locking the reset plunger in place via the interaction between the reset assembly reset axis and an opening in the reset plunger;
actuating the reset plunger to move upward by pulling the reset assembly away from the reset plunger;
moving the reset plunger upward based on the bias;
moving the contact plunger upward based on the bias; and
controlling the switch circuit based on the movement of the contact plunger.

17. The method of claim 16 , wherein attaching the reset assembly to the housing comprises threading the reset assembly into an opening in the housing.

18. The method of claim 16 , further comprising activating an alert based on the controlling of the switch circuit.

19. The method of claim 16 , wherein locking the reset plunger in place comprises moving a reset axis of the reset assembly into an opening in the reset plunger.

20. The method of claim 19 , wherein pulling the reset assembly away from the reset plunger comprises pulling a reset button attached to the reset axis, and removing the reset axis from the opening in the reset plunger.

Assignees

• Honeywell Int Inc

Inventors

• Ou Xingjun
• Zhou Keyong
• Shuai Honggui

Classifications

• H01H3/16 Primary

  adapted for actuation at a limit or other predetermined position in the path of a body, the relative movement of switch and body being primarily for a purpose other than the actuation of the switch, e.g. for a door switch, a limit switch, a floor-levelling switch of a lift · CPC title

• H01H2235/01

  Spiral spring · CPC title

• H01H9/0264

  Protective covers for terminals · CPC title

• H01H3/163

  associated with locking or manipulating means of the closing member · CPC title

• H01H21/285

  having an operating arm actuated by the movement of the body and mounted on an axis converting its rotating movement into a rectilinear switch activating movement · CPC title