Cutlery – Cutting tools – Saw
Patent
1997-09-11
2000-04-11
Peterson, Kenneth E.
Cutlery
Cutting tools
Saw
8369921, 279 91, B23D 4900
Patent
active
060474777
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention is based on a sabre saw.
From Published, Non-Examined German Patent Application DE-OS 41 02 011, a sabre saw is already known whose reciprocating rod, on its lower end, receives the chucking end of a saw blade with two opposed lugs extending crosswise to the longitudinal axis of the saw blade. The chucking end of the saw blade is introduced axially into the reciprocating rod until the lugs on their ends meet the lower end of the reciprocating rod.
A centering slot for receiving the saw blades is disposed inside the end of the reciprocating rod. This slot is optimally inclined only for centering saw blades of a single predetermined thickness. Since many saw blades exist with different thicknesses for the most various intended uses, sabre saws must be capable of receiving if at all possible all types of saw blade, in other words saw blades of any thickness, for the sake of universal utility.
The centering slot for receiving the saw blade lugs is therefore so wide that even the thickest saw blade fits into it. As a result, saw blades of lesser thickness have a certain lateral play within the centering slot. Because of this play of the chucking end, the danger of torsional and fluttering motions of the saw blade exists for the saw blades of lesser thickness, which are vulnerable to bending and twisting.
U.S. Pat. No. 3,750,283 discloses a sabre saw whose chucking device for the saw blades holds the lugs on its face end in V-shaped grooves and keeps the free end of the chucking end centered in a conical bore. As a result, regardless of its thickness, the saw blade finds a firm seat. The device for chucking saw blades functions securely and reliably. It circumferentially engages the reciprocating rod with a chucking tube and spring. However, this has the disadvantage that the lower diameter region of the end of the reciprocating rod opposite the upper end of the reciprocating rod is enlarged in steplike fashion. This is a visual obstacle for the user that hides the blade of the saw blade when the user is working with the sabre saw. Moreover, this saw blade chucking device is exposed to dust and metal chips, so that soiling can cause it to seize and make it harder to release the chucking device or change the saw blade.
SUMMARY OF THE INVENTION
The sabre saw of the invention has the advantage over the prior art that saw blades of all thickness can be chucked, all with the same high chucking quality. Consequently regardless of the thickness of the saw blades, the same good wording results are attainable with the sabre saw in all cases, using this chucking device.
The sabre saw of the invention also has the advantage that a very long bearing spacing between the upper reciprocating rod bearing and the lower reciprocating rod bearing can be chosen for the reciprocating rod; the lower reciprocating rod bearing circumferentially engages the device for chucking the saw blade. As a result, the device for chucking the saw blade indirectly guides the reciprocating rod.
This has the advantage that the interface between the reciprocating rod and the device for chucking the saw blade is shifted into the interior of the gear box and protected against dust and chips, and moreover is lubricated by the gear grease.
As a result, the torsion spring for tightening the chucking tube can be wrapped around the outside of the chucking tube instead of being disposed in the interior of the reciprocating rod. As a result, the function of the torsion spring is not impaired by a possibly too tightly attached chucking tube.
BRIEF DESCRIPTION OF THE DRAWING
Exemplary embodiments of the present invention are described in further detail in the ensuing description in conjunction with the associated drawing.
FIG. 1 shows the longitudinal section through a sabre saw of the invention;
FIG. 2a is a schematic cross section through the reciprocating rod bearing of a sabre saw of the prior art;
FIG. 2b is a schematic cross section through the reciprocating rod bearing a sabre saw of the invention;
FIG. 3 s
REFERENCES:
patent: 2639737 (1953-05-01), Forsberg
patent: 2703716 (1955-03-01), Shore
patent: 3663028 (1972-05-01), King, Jr. et al.
patent: 3665983 (1972-05-01), Wagner et al.
patent: 3750283 (1973-08-01), Hoffman
patent: 4299402 (1981-11-01), Hoffman
patent: 5165173 (1992-11-01), Miller
patent: 5306025 (1994-04-01), Langhoff
patent: 5402580 (1995-04-01), Seto et al.
Peterson Kenneth E.
Scintilla AG
Striker Michael J.
LandOfFree
Compass saw does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Compass saw, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Compass saw will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1167975