Battery-powered tool

• US 5,298,821 A
• Filed: 02/28/1991
• Issued: 03/29/1994
• Est. Priority Date: 02/28/1991
• Status: Expired due to Fees

• Current Assignee: Credo Technology Corporation
• Original Assignee: S-B Power Tool Company (Robert Bosch GmbH)
• Inventors: Michel, Timothy P.
• Primary Examiner(s): Stephan, Steven L.
• Assistant Examiner(s): NGUYEN, MATTHEW VAN
• Application Number:
  US07/662,615
• Time in Patent Office: 1,125 Days
• Field of Search: 310/47, 310/50, 320/2, 320/3, 320/5, 320/7, 320/16, 429/99, 429/100, 429/96, 429/163, 173/163
• US Class Current: 310/47
• CPC Class Codes: B25F 5/02 Construction of casings, bodies or handles B25F5/006, B25F5/008 take precedence
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction

Abstract

A battery-powered tool (10) generally comprises a motor (24) having a positive terminal (64) and a negative terminal (66) extending therefrom for continuous engagement to a rotatable actuator (26). Actuator (26) has a plurality of conductive arms (28) extending therefrom for contact with a battery assembly (20) such that the actuator (26) can be selectively rotated to engage the motor (24) in both high speed and low speed operations.

Claims

1. A battery power tool comprising:

a motor having a positive terminal and a negative terminal rigidly extending from one end and a rotatable shaft at the other end;

a first battery set having first and second terminals;

a second battery set having first and second terminals;

said first and second battery terminals being substantially axially aligned with said rigid motor electrical terminals; and

an actuator switch abutting the motor and having arcuate connectors on one side continuously rotatably connected to said rigid motor electrical terminals, said arcuate connectors having a plurality of actuator contacts extending from the other side for selectively contacting said battery terminals to cause said motor to rotate at variable speeds.

2. The apparatus as in claim 1 wherein said actuator contacts comprise eight resilient arms extending from the actuator switch and spaced equidistantly about the circumference of said actuator.

3. The apparatus as recited in claim 2 wherein said actuator contacts comprise first and second electrically interconnected sets of three arms and a third electrically interconnected set of two arms positioned to couple all of the batteries in series in a first position of the actuator switch to actuate said motor at high speed.

4. The apparatus as recited in claim 3 wherein said actuator contacts couple the batteries in a parallel arrangement in a second position of the actuator switch to actuate said motor at low speed.

5. The apparatus as recited in claim 4 wherein said battery assembly comprises two sets of two series coupled battery cells for providing power to said motor.

6. The apparatus as recited in claim 5 wherein said battery assembly comprises four battery contacts corresponding to the positive and negative terminals of each of said two battery sets.

7. The apparatus as recited in claim 6 wherein said four battery contacts are selectively positioned to engage said first, second and third sets of actuator arms in said first position of the actuator switch to couple the two battery sets in series and operate said motor at high speed.

8. The apparatus as recited in claim 6 wherein said four battery contacts are selectively positioned to engage said first, second and third sets of actuator arms in said second position of the actuator switch to couple the two battery sets in parallel and operate said motor at low speed.

9. The apparatus as recited in claim 1 further comprising a battery charger for selectively receiving said battery assembly after said battery assembly is removed from said tool, said battery charger being electrically connectible with an AC outlet to permit recharging of said battery cells on engagement.

10. An electrical system for a battery-powered, hand-held motor tool, which comprises:

a motor having first and second rigid electrical terminals projecting from said motor;

a first battery set having first and second terminals;

a second battery set having first and second terminals;

said first and second battery terminals being substantially axially aligned with said rigid motor electrical terminals; and

an actuator rotatably mounted between said motor and said axially aligned first and second battery sets, said actuator having arcuate contacts for continuous electrical connection with said rigid motor terminal projections, said actuator having arms for selective connection with the terminals of said first and second battery sets for operating said motor at variable speeds.

11. The apparatus as recited in claim 10 wherein said first battery set and said second battery set are selectively coupled to said motor by rotating said actuator to a first position to cause said first battery set and said second battery set to be electrically connected in series to drive said motor at high speed.

12. The apparatus as recited in claim 10 wherein said first battery set and said second battery set are selectively coupled to said motor by rotating said actuator to a second position to cause said first battery set and said second battery set to be electrically connected in parallel to drive said motor at low speed.

13. A hand-held motor tool for rotating a bit, which comprises:

a substantially cylindrical-shaped housing;

a direct-current motor mounted in said housing, said motor having a shaft at one end, said motor having first and second electrical terminals at the other end;

a substantially cylindrical-shaped collet connected to said shaft, said collet being selectively engageable with the bit;

a battery assembly detachably and slidably engageable in said housing, said battery assembly having four battery contacts at its first end; and

a substantially disc-shaped actuator switch rotatably held in said housing abutting said motor and coaxially aligned with and between said motor and said first end of said battery assembly, said actuator having a pair of motor contact arms continuously electrically coupled to said motor electrical terminals and having a plurality of battery contact arms, said battery contact arms being selectively connected with said battery contacts to operate the motor at high speed when said actuator switch is rotated to a first position, and being selectively connected with said battery contacts so as to operate said motor at low speed when said actuator switch is rotated to a second position.

14. The tool as recited in claim 13, wherein said battery assembly comprises:

a casing;

four battery cells slidably held in said casing; and

a cap slidably engageable with said casing, said casing having a first resilient locking member for engaging said cap to hold said battery cells in said casing, said cap having a second resilient locking member to engage said housing and hold said battery assembly and casing in said tool.

15. The tool as recited in claim 14, further comprising a battery charger having an AC wall plug integrally connected thereto, said charger having an opening for receiving said battery to recharge said battery cells.