US 5,238,336 AGranted

Hand held power dowel tool

OwnerThomas A. Sanders, David A. Gaauweinventors

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Abstract

A hand held power dowel tool includes a high speed universal motor coupled to a relatively simple two-gear transmission. The motor speed gear reduction combination is specifically designed for 1/4 inch and 3/8 inch drilling of wood, making the tool unusually lightweight for the power it delivers. The tool's drive shaft is especially long and well supported to rigidly hold a conventional drill bit without a need for a drill guide bushing. A smooth acting guide assembly aligns the tool to the board and accurately guides the drill bit to a preset depth. The tool also includes an adjustable viewing window that is kept clear by a stream of air discharged by the tool's cooling system. The adjustable viewing window and an adjustable chuck accommodates wood of various width and thicknesses as well as various dowel peg diameters. The tool's range of wood joining capabilities surpasses today's plate joiners.

Claims17

Dependent claims

A dowel tool adapted to drive a drill bit through wood, comprising:

a) a high speed motor having a stator, a rotor, and a rotor shaft, said motor being adapted to run at over 10,000 revolutions per minute;
b) a drive shaft in substantial parallel offset alignment with said motor shaft;
c) at least two bearings supporting said drive shaft, said bearings being axially spaced apart from each other at a distance of at least twice the diameter of said drive shaft;
d) a transmission coupling said motor shaft to said drive shaft, said transmission delivering a torque to said drive shaft that is at least twice as great as the torque exerted by said motor shaft;
e) a housing holding said motor said drive shaft, said two bearings, and said transmission;
f) a face guide slidably mounted with respect to said housing and having a first surface substantially perpendicular to said drive shaft, said face guide having a viewing window therethrough;
g) a top guide having a second surface substantially perpendicular to said first surface, said top guide being repositionable with respect to said drive shaft to vary the distance between said second surface and the longitudinal center line of said drive shaft from at least 0.25 inches to 0.375 inches, thereby providing a variable opening through said window;
h) an alignment mark on said top guide, said alignment mark intersecting a plane substantially perpendicular to said first and second surfaces and passing through said longitudinal center line of said drive shaft;
i) a slide mechanism for varying the axial position of said drive shaft with respect to said face guide while maintaining substantially perpendicular alignment of said drive shaft to said first surface of said face guide;
j) a chuck connected to one end of said drive shaft between said face guide and one of said bearings, said chuck being adapted to couple said drill bit to said drive shaft;
k) a spring urging said face guide away from said chuck;
l) a back stop limiting the distance said spring urges said face guide away from said chuck;
m) an adjustable front stop providing a user selectable limiting distance between said chuck and said first surface of said face guide, whereby said front stop determines the depth to which said drill bit penetrates said wood;
n) a fan coupled to said motor shaft and adapted to draw air into said housing and discharge air out of said housing;
o) a first handle attached to said housing and extending across said plane;
and
p) a second handle associated with a guide assembly comprising said top guide and said face guide.

14 more elements

A dowel tool adapted to drive a drill bit through wood, comprising:

a) a high speed motor having a stator, a rotor, and a rotor shaft, said motor being adapted to run at over 10,000 revolutions per minute;
b) a drive shaft in substantial parallel offset alignment with said motor shaft;
c) at least two bearings supporting said drive shaft, said bearings being axially spaced apart from each other at a distance of at least twice the diameter of said drive shaft.
d) a transmission coupling said motor shaft to said drive shaft, said transmission delivering a torque to said drive shaft that is at least twice as great as the torque exerted by said motor shaft, said motor revolutions per minute of over 10,000 along with said transmission providing said dowel tool with a total weight of less than 20 pounds;
e) a housing holding said motor, said drive shaft, said two bearings, and said transmission;
f) a face guide slidably mounted with respect to said housing and having a first surface substantially perpendicular to said drive shaft, said face guide having a viewing window therethrough;
g) a gripper disposed on said first surface that provides a coefficient of friction against wood that is greater than the coefficient of said first surface against wood if the entire face of said first surface had no gripper and were perfectly flat and smooth;
h) a top guide having a second surface substantially perpendicular to said first surface, said top guide being repositionable with respect to said drive shaft to vary the distance between said second surface and the longitudinal center line of said drive shaft from at least 0.25 inches to 0.375 inches, thereby providing a variable opening through said window;
i) an alignment mark disposed on said top guide, said alignment mark intersecting a plane substantially perpendicular to said first and second surfaces and passing through said longitudinal center line of said drive shaft;
j) a slide mechanism for varying the axial position of said drive shaft with respect to said face guide while maintaining substantially perpendicular alignment of said drive shaft to said first surface of said face guide;
k) an adjustable chuck connected to one end of said drive shaft between said housing and said face guide, said adjustable chuck having a variable opening adapted to hold said drill bit of a diameter of 0.25 to 0.375 inches;
l) a spring urging said face guide away from said adjustable chuck;
m) a back stop limiting the distance of said spring urges said face guide away from said adjustable chuck;
n) an adjustable front stop providing a user selectable limiting distance between said adjustable chuck and said first surface of said face guide, whereby said adjustable front stop determines the depth to which said drill bit penetrates said wood;
o) a fan coupled to said motor shaft and adapted to draw air into said housing and discharge out of said housing, thereby cooling said motor;
p) a first handle attached to said housing and extending across said plane;
and
q) a second handle associated with a guide assembly comprising said top guide and said face guide, said second handle extending across said plane.

15 more elements

A dowel tool adapted to drive a drill bit through wood, comprising:

a) a high speed motor having a stator, a rotor, and a rotor shaft, said motor being adapted to run at over 10,000 revolutions per minute;
b) a drive shaft in substantial parallel offset alignment with said motor shaft;
c) at least two bearings supporting said drive shaft, said beings being axially spaced apart from each other by a distance of at least twice the diameter of said drive shaft;
d) a transmission coupling said motor shaft to said drive shaft to rotate said drive shaft at least 3,000 revolutions per minute when said motor is running at its maximum substantially unloaded speed, said transmission delivering a torque to said drive shaft that is at least twice as great as the torque exerted by said motor shaft, said motor revolutions per minute of over 10,000 along with the gear reduction of said transmission providing said dowel tool with a total weight of less than 20 pounds;
e) a housing holding said motor, said drive shaft, said two bearings, and said transmission;
f) a face guide slidably mounted with respect to said housing and having a first surface substantially perpendicular to said drive shaft, said face guide having a viewing window therethrough that is less than 2 inches wide;
g) a gripper disposed on said first surface that provides a coefficient of friction against wood that is greater than the coefficient of said first surface against wood if the entire face of said first surface had no gripper and were perfectly flat and smooth;
h) a top guide having a second surface substantially perpendicular to said first surface, said top guide being repositionable with respect to said drive shaft to vary the distance between said second surface and the longitudinal center line of said drive shaft from at least 0.25 inches to 0.375 inches, thereby providing a variable opening through said window of at least 0.5 inches;
i) an alignment mark disposed on said top guide, said alignment mark intersecting a plane substantially perpendicular to said first and second surfaces and passing through said longitudinal center line of said drive shaft;
j) a slide mechanism for varying the axial position of said drive shaft with respect to said face guide while maintaining substantially perpendicular alignment of said drive shaft to said first surface of said face guide;
k) an adjustable chuck connected to one end of said drive shaft between said housing and said face guide, said adjustable chuck having a variable opening adapted to hold said drill bit of a diameter of 0.25 inches to 0.375 inches;
l) a spring urging said face guide away from said adjustable chuck;
m) a back stop limiting the distance said spring urges said face guide away from said adjustable chuck;
n) an adjustable front stop providing a user selectable limiting distance between said adjustable chuck and said first surface of said face guide, whereby said adjustable front stop determines the depth to which said drill bit penetrates said wood;
o) a fan coupled to said motor shaft and adapted to draw air into said housing and discharge out of said housing with at least a portion of the discharge air being directed toward said window;
p) a baffle inside said housing, adjacent to said motor, and adapted to promote the flow of a portion of said air through the space between said rotor and said stator by at least partially obstructing free airflow that could otherwise pass across the outer perimeter of said rotor;
q) a first handle attached to said housing and extending across said plane;
and
r) a second handle associated with a guide assembly comprising said top guide and said face guide said second handle extending across said plane.

16 more elements

Dependencies are inferred from the claim text.