Motor pack for circular saw

• US 4,694,721 A
• Filed: 04/08/1986
• Issued: 09/22/1987
• Est. Priority Date: 04/08/1986
• Status: Expired due to Fees

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Delta International Machinery Corp. (Stanley Black & Decker, Inc.)
• Inventors: Brickner, Louis C. Jr.
• Primary Examiner(s): YOST, FRANK
• Application Number:
  US06/848,592
• Time in Patent Office: 532 Days
• Field of Search: 83/574, 83/490, 83/581, 83/471.3, 30/388, 30/390, 30/391
• US Class Current: 83/471.3
• CPC Class Codes: B23D 47/12 of drives for circular saw blades
• CPC Class Codes: Y10T 83/7697 Tool angularly adjustable relative to work-support
• CPC Class Codes: Y10T 83/7788 Tool carrier oscillated or rotated
• CPC Class Codes: Y10T 83/8773 Bevel or miter cut

Abstract

Method and apparatus for providing motive power to a tool are disclosed. A preferred power mitre box (10) including a base (12), a table (14) and electrically-powered motor unit (18) suitable for driving a saw blade (20) is described. The motor unit (18) includes an armature (40) and an arbor shaft (22) which are respectively supported by armature bearings 42 and arbor bearings 44 and are preferably substantially parallel and of substantially the same length. Also, the distances between the armature bearings (42) and the arbor bearings (44) are preferably substantially equal. The relatively large distance between the arbor bearings (44) causes the blade (20) to have very little play or deflection due to looseness in the bearings (44). In preferred embodiments, a speed reducer assembly (34) is located on the opposite end of the arbor shaft (22) in relation to the blade (20). Also, the speed reducer assembly is preferably of the cog belt type.

Claims

1. A power saw arrangement comprising:

(a) a base;

(b) a table pivotably connected to said base for pivoting about a substantially vertical axis;

(c) a circular saw blade having a first radius, and a central axis;

(d) a motor unit pivotably connected to said table, said motor unit including;

a casing;

a motor armature having a longitudinal axis;

an arbor shaft;

a speed reducer arrangement; and

, a casing extension;

(i) said casing having a first sidewall and a second sidewall;

(ii) said motor unit including a pair of armature bearings operatively mounted in said casing and arranged to rotatably support said armature in extension substantially between said first and second casing sidewalls;

(iii) said motor unit including a pair of arbor bearings operatively mounted in said casing and arranged to rotatably support said arbor shaft in extension substantially between said first and second casing sidewalls;

(iv) said arbor shaft being mounted in said arbor bearings and said armature being mounted in said armature bearings, said arbor shaft and said armature being spaced apart and extending substantially parallel to one another;

(v) said speed reducer arrangement being mounted substantially adjacent said casing first sidewall and including means operatively coupling said armature to said arbor shaft;

said casing extension being arranged to enclose said speed reducer arrangement;

(vi) said circular saw blade being mounted on said arbor shaft substantially adjacent said casing second sidewall, and exterior to said casing;

(vii) said saw blade being mounted relative to said armature such that a line coaxial with said armature longitudinal axis intersects said saw blade within a distance of said first radius from said saw blade central axis;

(e) a distance between said arbor bearings being at least about one-third a distance between said armature bearings.

2. The power saw arrangement of claim 1 wherein:

(a) said distance between said arbor bearings is at least about one-half of the distance between said armature bearings.

3. The power saw arrangement of claim 1 wherein:

(a) said distance between said arbor bearings is about equal to a distance between said armature bearings.

4. The power saw arrangement of claim 1 wherein:

(a) said distance between said arbor bearings is at least about 7 inches.

5. A power saw arrangement comprising:

(a) a base;

(b) a table pivotably connected to said base for pivoting about a substantially vertical axis;

(c) a circular saw blade having a first radius and a central axis;

(d) a motor unit pivotably connected to said table, said motor unit including;

a casing;

a motor armature having a longitudinal axis;

an arbor shaft;

a speed reducer arrangement; and

, a casing extension;

(i) said casing having a first sidewall and a second sidewall;

(ii) said motor unit including a pair of armature bearings operatively mounted in said casing and arranged to rotatably support said armature in extension substantially between said first and second casing sidewalls;

(iii) said motor unit including a pair of arbor bearings operatively mounted in said casing and arranged to rotatably support said arbor shaft in extension substantially between said first and second casing sidewalls;

(iv) said arbor shaft being mounted in said arbor bearings and said armature being mounted in said armature bearings, said arbor shaft and said armature being spaced apart and extending substantially parallel to one another;

(v) said speed reducer arrangement being mounted substantially adjacent said casing first sidewall and including means operatively coupling said armature to said arbor shaft;

said casing extension being arranged to enclose said speed reducer arrangement;

(vi) said circular saw blade being mounted on said arbor shaft substantially adjacent said casing second sidewall, and exterior to said casing;

(vii) said saw blade being mounted relative to said armature such that a line co-axial with said armature longitudinal axis intersects said saw blade within a distance of said first radius from said saw blade central axis;

(e) a distance between said arbor bearings being at least about one-half a diameter of said saw blade.

6. The power saw arrangement of claim 5 wherein:

(a) a distance between said arbor bearings is at least about one-third of a distance between said armature bearings.

7. The power saw arrangement of claim 6 wherein:

(a) said distance between said arbor bearings is at least about 7 inches.

8. The power saw arrangement of claim 5 wherein:

(a) a distance between said arbor bearings is about equal to a distance between said armature bearings.

9. A power arrangement for the mounting and operation of a circular saw blade having a first radius and a first central axis;

said power arrangement comprising;

(a) a base;

(b) a table pivotably connected to said base for pivoting about a substantially vertical axis;

(c) a motor unit pivotably connected to the table for pivoting about a substantially horizontal axis, said motor unit including;

a casing;

a motor armature having a longitudinal axis;

an arbor shaft having a longitudinal axis;

a speed reducer arrangement;

a casing extension; and

, a saw blade mount;

(i) said casing having a first sidewall and a second sidewall;

(ii) said motor unit including a pair of armature bearings operatively mounted in said casing and arranged to rotatably support said armature in extension substantially between said first and second casing sidewalls;

(iii) said motor unit including a pair of arbor bearings operatively mounted in said casing and arranged to rotatably support said arbor shaft in extension substantially between said first and second casing sidewalls;

(iv) said arbor shaft being mounted in said arbor bearings and said armature being mounted in said armature bearings, said armature longitudinal axis and said arbor shaft longitudinal axis being spaced apart a first distance and extending substantially parallel to one another;

(v) said speed reducer arrangement being mounted substantially adjacent said casing first sidewall and including means operatively coupling said armature to said arbor shaft, said casing extension being arranged over said casing first sidewall to enclose said speed reducer arrangement;

(vi) said saw blade mount being positioned on a portion of said arbor shaft substantially adjacent said casing second sidewall, and exterior to said casing;

(d) a distance between said arbor bearings being at least about one-third a distance between said armature bearings;

(e) said first distance between said arbor shaft and armature axes being less than a first radius of a saw blade to be mounted on said blade mount;

(f) whereby a line co-axial with said armature longitudinal axis will intersect a mounted saw blade within a distance of less than the saw blade radius from the saw blade center.

10. The power arrangement of claim 9 wherein:

(a) said distance between said arbor bearings is at least about one-half of the distance between said armature bearings.

11. The power arrangement of claim 9 wherein:

(a) said distance between said arbor bearings is about equal to a distance between said armature bearings.

12. The power arrangement of claim 9 wherein:

(a) said distance between said arbor bearings is at least about 7 inches.

13. A power saw arrangement comprising:

(a) a base;

(b) a table mounted on said base;

(c) a circular saw blade;

(d) a motor unit mounted on said table, said motor unit including;

a casing;

a motor armature;

an arbor shaft;

a power transmission coupling; and

, a casing extension;

(i) said casing having first and second opposite sidewalls;

(ii) said motor unit including a pair of armature bearings operatively mounted in said casing and arranged to rotatably support said armature in extension between said first and second casing sidewalls;

(iii) said motor unit including a pair of arbor bearings operatively mounted in said casing and arranged to rotatably support said arbor shaft in extension between said first and second casing sidewalls;

(iv) said arbor shaft being mounted in said arbor bearings and said armature being mounted in said armature bearings;

(v) said power transmission coupling being constructed and arranged to transmit power from said motor armature to said arbor shaft, said power transmission coupling being positioned substantially adjacent said casing first sidewall, said casing extension being arranged to enclose said power transmission coupling;

(vi) said circular saw blade being mounted on said arbor shaft substantially adjacent said casing second sidewall, and exterior to said casing; and

(e) a distance between said arbor bearings being at least about one-third a distance between said armature bearings.

14. The power saw arrangement of claim 13 wherein:

(a) said distance between said arbor bearings is at least about one-half of the distance between said armature

15. The power saw arrangement of claim 13 wherein:

(a) said distance between said arbor bearings is about equal to a distance between said armature bearings.

16. The power saw arrangement of claim 13 wherein:

(a) said distance between said arbor bearings is at least about 7 inches.

17. A power saw arrangement comprising:

(a) a base;

(b) a table mounted on said base;

(c) a circular saw blade;

(d) a motor unit mounted on said table, said motor unit including;

a casing;

a motor armature;

an arbor shaft;

a power transmission coupling; and

, a casing extension;

(i) said casing having first and second opposite sidewalls;

(ii) said motor unit including a pair of armature bearings operatively mounted in said casing and arranged to rotatably support said armature in extension between said first and second casing sidewalls;

(iii) said motor unit including a pair of arbor bearings operatively mounted in said casing and arranged to rotatably support said arbor shaft in extension between said first and second casing sidewalls;

(iv) said arbor shaft being mounted in said arbor bearings and said armature being mounted in said armature bearings;

(v) said power transmission coupling being constructed and arranged to transmit power from said motor armature to said arbor shaft, said power transmission coupling being positioned substantially adjacent said casing first sidewall;

said casing extension being arranged to enclose said power transmission coupling;

(vi) said circular saw blade being mounted on said arbor shaft substantially adjacent said casing second sidewall and exterior to said casing; and

(e) a distance between said arbor bearings being at least about one-half of diameter of said circular saw blade.

18. The power saw arrangement of claim 17 wherein:

(a) a distance between said arbor bearings is at least about one-third of a distance between said armature bearings.

19. The power saw arrangement of claim 18 wherein:

(a) a distance between said arbor bearings is at least about 7 inches.

20. The power saw arrangement of claim 17 wherein:

(a) a distance between said arbor bearings is about equal to a distance between said armature bearings.

21. A power arrangement for mounting a circular saw blade, said power arrangement comprising:

(a) a base;

(b) a table mounted on said base;

(c) a motor unit mounted on said table, said motor unit including;

a casing, a motor armature, an arbor shaft;

a power coupling;

a casing extension; and

, a saw blade mount;

(i) said casing having first and second opposite sidewalls;

(ii) said motor unit including a pair of armature bearings operatively mounted in said casing and arranged to rotatably support said armature in extension between said first and second casing sidewalls;

(iii) said motor unit including a pair of arbor bearings operatively mounted in said casing and arranged to rotatably support said arbor shaft in extension between said first and second casing sidewalls;

(iv) said arbor shaft being mounted in said arbor bearings and said armature being mounted in said armature bearings;

(v) said power transmission coupling being constructed and arranged to transmit power from said motor armature to said arbor shaft, said power transmission coupling being positioned substantially adjacent said casing first sidewall;

said casing extension being arranged to enclose said power transmission coupling;

(vi) said saw blade mount being positioned on said arbor shaft substantially adjacent said casing second sidewall and exterior to said casing; and

(d) a distance between said arbor bearings being at least about one-third of a distance between said armature bearings.

22. The power arrangement of claim 21 wherein:

(a) said distance between said arbor bearings is at least about one-half of the distance between said armature bearings.

23. The power arrangement of claim 21 wherein:

(a) said distance between said arbor bearings is about equal to a distance between said armature bearings.

24. The power arrangement of claim 21 wherein:

(a) said distance between said arbor bearings is at least about 7 inches.