# US 5,701,961 A · Electronic push to start nutrunner

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- Number: US 5,701,961 A
- Document ID: US5701961A
- Status: Granted
- Kind: A
- Application number: 08/676,022
- Filed: 1996-07-05
- Granted: 1997-12-30
- Earliest claimed: 1996-07-05
- Assignees: Ingersoll-Rand Company
- Inventors: Donald R. Warner; John A. McCallops; John M. Estep
- Web page: https://patentgrep.com/patent/US5701961A

## CPC

- B25B 21/00: Portable power-driven screw or nut setting or loosening tools; (details or components, e.g. casings, bodies, of portable power-driven tools not particularly related to the operation performed B25F5/00; {for mounting or dismounting wheels B60B29/006}); Attachments for drilling apparatus serving the same purpose (machines B23P19/06)
- B25F 5/00: Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
- H01H 36/0046: {Limit switches, also fail-safe operation or anti-tamper considerations}
- B25B: TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING, OR HOLDING
- B25F: COMBINATION OR MULTI-PURPOSE TOOLS NOT OTHERWISE PROVIDED FOR; DETAILS OR COMPONENTS OF PORTABLE POWER-DRIVEN TOOLS NOT PARTICULARLY RELATED TO THE OPERATIONS PERFORMED AND NOT OTHERWISE PROVIDED FOR {(machines or arrangements of machines for performing specified combinations of different metal-working operations not covered by a single other subclass B23P23/00 and subgroups)}
- H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00)

## Abstract

A latching magnetic switch is utilized to activate a push to start nutrunner or the like wherein the magnetic latching switch is deactivated first by one magnetic pole and thereafter upon engagement with the work piece and compression of the spindle and opposite pole of the magnet is utilized to activate the tool.

## Claims

### Claim 1

A push to start nutrunner comprising:
a power driven nutrunner;
an electronic power controller for controlling power to said nutrunner;
said nutrunner being further provided with a retractable spindle; and
means for magnetically sensing a retracted position of said retractable spindle and for providing a signal of said retracted position to said controller to initiate power to drive said nutrunner.

### Claim 2 (depends on 1)

A push to start nutrunner according to claim 1 wherein:
said power driven nutrunner further comprises a DC electric power driven nutrunner.

### Claim 3 (depends on 1)

A push to start nutrunner according to claim 1 wherein:
said means for magnetically sensing a retracted position of said retractable spindle and for providing a signal of said retracted position to said controller to initiate power to drive said nutrunner further comprises a latching magnetic switch.

### Claim 4 (depends on 3)

A push to start nutrunner according to claim 3 wherein:
said electronic power controller for controlling power to said nutrunner further comprises a computer based controller which further controls a nutrunner tightening function.

### Claim 5 (depends on 3)

A push to start nutrunner according to claim 3 wherein:
said magnetic latching switch requires a first magnetic pole signal to latch and a second opposite magnetic pole signal to unlatch and wherein said retractable spindle is provided with a magnet having opposite poles which activate said magnetic latching switch on moving from an extended position to a retracted position.

### Claim 6 (depends on 5)

A push to start nutrunner according to claim 5 wherein:
powered operation of said nutrunner occurs only upon retraction of said spindle in response to said nutrunner being urged against and engaged with a work piece.

### Claim 7 (depends on 5)

A push to start nutrunner according to claim 5 wherein:
upon retraction of said spindle said second opposite magnetic pole passes said magnetic latching switch first to assure unlatching of said magnetic latching switch followed by said first magnetic pole passing said magnetic latching switch to initiate a power tool operating cycle.

### Claim 8 (depends on 5)

A push to start nutrunner according to claim 5 wherein:
upon extension of said spindle upon removal of said nutrunner from said work piece said first magnetic pole passes said magnetic latching switch first followed by said second opposite magnetic pole passing said magnetic latching switch to shut off said power tool.

### Claim 9 (depends on 5)

A push to start nutrunner according to claim 5 wherein:
said magnet is mounted for reciprocation but not rotation with said retractable spindle.