Tool driving or impacting – Means to drive tool about an axis – Gear drive
Reexamination Certificate
1999-07-07
2001-08-14
Smith, Scott A. (Department: 3721)
Tool driving or impacting
Means to drive tool about an axis
Gear drive
C173S029000, C173S217000, C081S057110, C081S058300, C279S147000
Reexamination Certificate
active
06273200
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to power tools and, more particularly, to power tools such as power screwdrivers with manual spindle locks.
Varying torque or force is applied to a fastener as the fastener, such as a screw or bolt, is advanced into or removed from an anchoring position. Ordinarily, large forces are required to set the screw during installation or to initially break loose the screw during removal. In small power tools, difficulties are encountered in generating these large forces. The underlying limitation of these tools is the motor horsepower. This problem is further aggravated in battery operated tools. In battery operated tools, to have sufficient electrical capacity from the battery to operate a high torque power tool, a large heavy size tool is required. Thus, lightweight self-contained battery operated tools are limited in the amount of torque which can be produced.
To alleviate the shortcomings, the prior art teaches conventional screwdrivers being utilized with power tools to deliver the high torque. Also, elaborate drive trains may be associated with the power tool to deliver the increased torque. However, this lowers the drive speed. Further, different types of shaft locks have been provided. The shaft locks provide the powered screwdriver with the high torque feature of a manual screwdriver when required. Thus, it is desirable to have a power tool with a manual spindle lock to be utilized in high torque situations.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a compact lightweight power tool with conventional shaft speeds that is capable of supplying sufficient torque and includes a manual spindle lock which may be utilized when high torque situations exist. The present invention provides a simple cost-effective design to provide a spindle lock with a power tool such as a compact power screwdriver.
In accordance with a first aspect of the invention, a power tool with a manual spindle lock comprises a housing with a motor positioned in the housing. A power source is coupled with the motor. An activation member is coupled with the motor and the power source to energize and de-energize the motor. An output spindle is coupled with the motor. An output gear is coupled with the output spindle. A locking member, which couples with the output gear, includes a first cam member. A second cam member is coupled with the first cam member and is movable between a first and second position. In the first position, the locking member is disengaged from the output gear and in the second position the locking member engages the output gear prohibiting driving of the output spindle. A drive train is coupled between the motor and output spindle to drive the output spindle. The drive train includes the output gear and a stationary gear housing surrounds the drive train to cooperate with the drive train and the locking member.
In accordance with a second aspect of the invention, a spindle lock for a power tool comprises a first member with a hollow cylindrical portion defining a wall with an inner surface and an outer surface. A mechanism on the wall is adapted to engage a drive train of the power tool. A first cam member is coupled with the hollow cylindrical portion. A second member includes an activation member. A second cam member on the second member is coupled with the first cam member. The activation member is moved between first and second positions which, in turn, moves the hollow cylindrical member between a disengagement position and engagement position with the drive train. The activation member has an annular body adapted to surround a spindle and is rotatable from the first to the second position. The first and second cam members are a pin and a helical slot or, alternatively, first and second partial threads. The inner wall includes teeth to engage the drive train and the outer wall includes teeth or splines to engage the housing. The second member is rotated which, in turn, axially moves the first member. The first cam member includes a cantilever portion extending from the hollow cylinder and a cam element on the cantilevered portion.
In accordance with a third aspect of the invention, a power screwdriver comprises a first member with a hollow cylindrical portion defining a wall with an inner surface and an outer surface. A mechanism on the wall is adapted to engage a drive train of the power tool. A first cam member is coupled with the hollow cylindrical portion. A second member includes an activation member. A second cam member on the second member is coupled with the first cam member. The activation member is moved between the first and second position which, in turn, moves the hollow cylindrical member between a disengagement position and engagement position with the drive train. The activation member has an annular body adapted to surround a spindle and is rotatable from the first to the second position. The first and second cam members are a pin and a helical slot or, alternatively, first and second partial threads. The inner wall includes teeth to engage the drive train and the outer wall includes teeth or splines to engage the housing. The second member is rotated which, in turn, axially moves the first member. The first cam member includes a cantilever portion extending from the hollow cylinder and a cam element on the cantilevered portion.
From the following detailed description, taken in conjunction with the drawings and subjoined claims, other objects and advantages of the present invention will become apparent to those skilled in the art.
REFERENCES:
patent: 2341529 (1944-02-01), Cohen
patent: 2436540 (1948-02-01), Allenby
patent: 2575903 (1951-11-01), Youhouse
patent: 2857997 (1958-10-01), Graybill
patent: 2872197 (1959-02-01), Happe
patent: 2979089 (1961-04-01), Piesker
patent: 3021723 (1962-02-01), Happe
patent: 3329185 (1967-07-01), Hettich et al.
patent: 3802518 (1974-04-01), Albert
patent: 3872951 (1975-03-01), Hastings, Jr.
patent: 3958469 (1976-05-01), Meese
patent: 4159050 (1979-06-01), Hopkins, Sr. et al.
patent: 4249435 (1981-02-01), Villeneuve et al.
patent: 4323324 (1982-04-01), Ebrhardt
patent: 4400995 (1983-08-01), Palm
patent: 4448098 (1984-05-01), Totsu
patent: 4754669 (1988-07-01), Verdier et al.
patent: 4804048 (1989-02-01), Porth, Jr.
patent: 4878405 (1989-11-01), Wolfe
patent: 5016501 (1991-05-01), Holzer, Jr.
patent: 5025903 (1991-06-01), Elligson
patent: 5251706 (1993-10-01), Evans
patent: 5282510 (1994-02-01), Pacher
patent: 5496139 (1996-03-01), Ghode et al.
patent: 5692575 (1997-12-01), Hellström
patent: 1078958 (1960-03-01), None
patent: 1478828 (1969-03-01), None
patent: 3636301 A1 (1988-04-01), None
patent: G 8902 467.2 (1989-09-01), None
patent: 4128651 A1 (1993-03-01), None
patent: 4342464 A1 (1995-06-01), None
patent: 19608499 A1 (1997-09-01), None
patent: 0 088 836 (1986-09-01), None
patent: 0 118 215 (1989-05-01), None
Ho Fung Chi
Kin Tong Chi
Lok Lam Kar
Smith Roger Q.
Black & Decker Inc.
Harness & Dickey & Pierce P.L.C.
Smith Scott A.
LandOfFree
Screwdriver with manuel spindel lock does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Screwdriver with manuel spindel lock, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Screwdriver with manuel spindel lock will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2468975