Battery-driven screwdriver with a two-part motor housing and a separate, flanged gear unit

• US 7,197,961 B2
• Filed: 07/21/2004
• Issued: 04/03/2007
• Est. Priority Date: 09/29/2003
• Status: Active Grant

• Current Assignee: Robert Bosch Tool Corporation (Robert Bosch GmbH)
• Original Assignee: Robert Bosch GmbH
• Inventors: Kageler, Sven, Yuh Gan, Ginn, Aziz Zulfikar, Abdul
• Primary Examiner(s): Wilson; Lee D.
• Assistant Examiner(s): OJINI, EZIAMARA ANTHONY
• Application Number:
  US10/554,015
• Publication Number:
  US 20060219059A1
• Time in Patent Office: 986 Days
• Field of Search: 81/52, 81/54, 81/13, 814/58, 814/51, 814/52, 814/56, 811/778, 811/778.5, 811/801, 173/217, 173/170, 173/216
• US Class Current: 81/52
• CPC Class Codes: 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
• CPC Class Codes: B25F 5/00 Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 50/213 adapted for cells having curved cross-section, e.g. round or elliptic H01M50/209, H01M50/216 take precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A cordless screwdriver, having a housing (12, 18) equipped with a handle (14), having an in particular permanently installed rechargeable battery (40), and having a transmission (72), is particularly compact, lightweight, and strong because the transmission (72), embodied in the form of a sun-and-planet gear, is simply inserted into a hollow, cylindrical transmission housing (18) and can be secured in position in it by an axial securing plate (62); the transmission housing (18) is also provided with an internal gearing and serves as the sun gear as well as being integrated into the reinforcing structure of the cordless screwdriver (10).

Claims

1. A cordless screwdriver having a motor housing (12) that is composed of casing halves (16,17), is equipped with a rechargeable battery (40), and is adjoined by a transmission housing (18) containing a transmission (72) equipped with an output spindle (20), wherein the casing halves (16,17) of the motor housing (12), solely with their c-shaped ends adjoining the transmission housing (18), embrace in clamp-like fashion and extend through axial, tab-like extensions (60), of the transmission housing (18), and hold the transmission housing (18) in a centered, non-rotational manner without play.

2. The cordless screwdriver as recited in claim 1, wherein groove/spring connections (60, 53, 54, 55, 56, 60, 97) that engage each other radially are situated between the cylindrical, one-piece transmission housing (18) and the casing halves (16,17) of the motor housing (12), with a flush transition between the outer contours of these housings at a circular butt joint.

3. The cordless screwdriver as recited in claim 1, wherein the groove/spring connections constitute radial plug-type connections between the casing halves (16,17) in such a way that the transmission housing (18), when it is plugged radially into one of the casing halves (16,17) that is oriented with its opening facing upward, is attached to it in a manner that prevents it from falling out.

4. The cordless screwdriver as recited in claim 1, wherein the motor shaft end (47) associated with the transmission (72) has at least one flattened region, preferably two, and an engagement opening (66) of the transmission input shaft has a corresponding negative shape.

5. The cordless screwdriver as recited in claim 1, wherein in the transmission (72) in the form of a sun-and-planet gear is inserted into a hollow, cylindrical transmission housing (18) and a spring washer (62) or an axial securing plate is able to secure it in position therein;

the transmission housing (18) is also provided with an internal gearing and serves as a sun gear.

6. The cordless screwdriver as recited in claim 1, wherein the spring washer (62) is supported against the internal gearing of the transmission housing (18).

7. The cordless screwdriver as recited in claim 1, wherein the spring washer (62) has two wings (64) protruding from its circumference;

it is possible to secure these wings against axial loosening by engaging them in bayonet locking fashion in two corresponding axial recesses of the transmission housing (18) and/or by pressing them and/or rotating them into these recesses.

8. The cordless screwdriver as recited in claim 1, wherein the sun-and-planet gear (72) is provided with an autolock system so that the rotation of the output spindle (20) locks when a torque is exerted on it from the outside.

9. The cordless screwdriver as recited in claim 1, wherein its transmission housing (18), on the motor side, in particular at the top and bottom, has tab-like axial extensions (60) with an annular groove (54) and an annular bead (53).

10. The cordless screwdriver according to the preamble to claim 1, wherein the casing halves of the motor housing (12) engage in this annular groove and annular bead with a corresponding counterpart profile, thus permitting the casing halves to be axially and radially coupled to each other without play in a non-detachable manner.

11. The cordless screwdriver as recited in claim 1, wherein axial counterpart extensions of the casing halves protrude into the tooth gap-like intermediate spaces between the axial extensions and serve to prevent the transmission housing from rotating in relation to the motor housing.

12. The cordless screwdriver as recited in claim 1, wherein the axial extensions (60) of the transmission housing (18) and the protrusions (50, 51) of the motor housing (12) are situated asymmetrically in order to prevent incorrect assembly.

13. The cordless screwdriver as recited in claim 1, wherein the motor and/or the transmission housing and/or the rechargeable battery and/or the circuit board inside the casing halves are integrated into the reinforcing structure of the motor housing (12) and/or the handle (14) so that they increase its inherent stability with a minimum of material consumption.

14. The cordless screwdriver as recited in claim 1, wherein on each casing half (16, 17), the handle (14) has a rubber covering that covers a large area, bulges outward, and is provided with a nubbed structure.

15. A cordless screwdriver having a motor housing (12) that is composed of casing halves (16, 17), is equipped with a rechargeable battery (40), and is adjoined by a transmission housing (18) containing a transmission (72) equipped with an output spindle (20), wherein the casing halves (16, 17) of the motor housing (12), solely with their c-shaped ends adjoining the transmission housing (18) with an annular counterpart bead (53) embossed on the inside and an annular housing groove (54), embrace in clamp-like fashion and extend through axial, tab-like extensions (60) embodied in the form of axial teeth provided with annular counterpart profiles, of the transmission housing (18), and extend with protrusions configured as pedestals (50), between the extensions (60) and hold the transmission housing (18) in a centered, non-rotational fixed manner without play.