|Publication number||USRE35258 E|
|Application number||US 08/174,047|
|Publication date||Jun 4, 1996|
|Filing date||Dec 28, 1993|
|Priority date||Nov 13, 1990|
|Also published as||DE4108984A1, DE4108984C2, US5079844|
|Publication number||08174047, 174047, US RE35258 E, US RE35258E, US-E-RE35258, USRE35258 E, USRE35258E|
|Original Assignee||Milwaukee Electric Tool Corporation|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (22), Referenced by (35), Classifications (19), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This invention relates to reciprocating saws of the type using an eccentric drive. Saws of this type develop considerable vibration. This invention is directed to reducing such vibration.
My application Ser. No. 541,093 filed Jun. 20, 1990, .Iadd.now U.S. Pat. No. 5,025,562, .Iaddend.as a continuation-in-part of Ser. No. 487,219 filed Mar. 1, 1990, .Iadd.now abandoned, .Iaddend.shows an in-line saw using a counterbalanced wobble plate drive.
This invention provides a pinion gear driving a crown gear which has an eccentric drive to the shaft on which a saw blade is mounted. The crown gear also has an eccentric drive to a counterbalance, the saw blade and the counterbalance reciprocate 180 degrees out of phase, thus essentially eliminating all vibration.
More specifically, this invention provides an eccentric drive to a saw blade to reciprocate the saw blade while at the same time reciprocating a counterbalance. The eccentric drive of the saw blade is somewhat conventional. The spindle which supports the saw blade reciprocates inside a tube fixed in the housing. A counterbalance mass reciprocates on the tube and is prevented from rotating about the tube. The crown gear is provided with a cylindrical drive which is eccentric to the center of the crown gear. This cylindrical circular drive engages the counterbalance which, as noted, is constrained to reciprocating motion. The momentum of the counterbalance and the combined momentum of the spindle and a typical saw blade are essentially equal so the vibration is cancelled. Material is removed from the crown gear and cylindrical drive member to ensure that the crown gear, the eccentric drive and the cylindrical drive are balanced and do not set up lateral vibration.
FIG. 1 is a side elevation view of a reciprocating saw provided with this invention.
FIG. 2 is a vertical section through a portion of the saw shown in FIG. 1.
FIG. 3 is a horizontal view taken on line 3--3 in FIG. 2.
FIG. 4 is an exploded perspective view of the main parts of the drive for the spindle and the counterbalance.
The reciprocating saw shown in the drawings has a gear case 10 on the front of handle portion 12. Drive motor 14 has a drive shaft 16 with gear 18 driving crown gear 20 which is fixed on shaft 22 by key 24. Shaft 22 is rotatably mounted in bearings 26, 28 fixed in the gear case 10. Bearing 26 is retained in the case by annular plate 30 held in place by screws 32.
Spindle 34 on which saw blade 36 is mounted in the usual manner reciprocates in tube 38 which has its ends fixed in the gear case. The bottom portion of the tube is cut away as indicated by the dashed line 40 in FIG. 2 to allow the inverted channel 42, which is connected to the spindle 34 by fastener 44, to move between the ends of the cutout. A first or primary eccentric drive means, reciprocates the spindle. This drive means includes eccentric drive pin 46 which projects upwardly from the top of the crown gear and has a square drive block 48 mounted thereon on roller bearings 50. The opposed sides of the block slideably fit inside the depending legs of the inverted channel. The flat sides of the block minimize the loading between the drive pin and the channel to thereby reduce wear. As the crown gear rotates, the eccentric drive pin and block force the channel and spindle to reciprocate in the tube 38.
A secondary or second drive means reciprocates the counterweight and includes a cylindrical drive member 52 which projects upwardly from the top of the crown gear and is eccentric to the center of the crown gear in the direction opposite the eccentricity of the pin. This cylindrical member engages cylindrical hole 54 in the generally square transfer block 56. Block 56 engages the depending legs 58, 58 of counterweight 60 which slides on the outside of tube 38. Since there is a substantial surface contact between the block and the legs of the counterweight wear is minimized. If desired, a ring bearing can be provided between the circular drive member and hole 54 in the block.
It will be noted that the crown gear and cylindrical drive member have a crescent shaped cutout 62 to reduce material and counterbalance both the block 56 and the cylindrical eccentric drive member/gear about the gear axis. It is well to keep in mind that the crown gear and the associated eccentric drives (pin 46 and cylindrical member 52) and the transfer block 48 are effectively a unitary rotating mass and the removal of the material in the cutout can balance the mass. Thus, the counterbalance 60 counterbalances the spindle and saw blade while the eccentric drives for both the spindle and the counterbalance are counterbalanced to avoid inducing vibration either parallel to or transverse to the spindle motion.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2639737 *||Jul 3, 1948||May 26, 1953||Forsberg Harold S||Motor driven reciprocating saw|
|US2793661 *||Oct 4, 1954||May 28, 1957||Olson Holly M||Power driven reciprocating saw unit|
|US3170496 *||Oct 2, 1962||Feb 23, 1965||Black & Decker Mfg Co||Power-operated reciprocating tool with integral bearing block|
|US3547166 *||Jul 3, 1968||Dec 15, 1970||Singer Co||Chuck attachment for sabre saws|
|US3729822 *||Mar 9, 1972||May 1, 1973||Singer Co||Sabre saws with lockable swivel saw bars|
|US3863342 *||Sep 17, 1971||Feb 4, 1975||Rockwell International Corp||Saber saw|
|US3897630 *||Apr 24, 1974||Aug 5, 1975||Black & Decker Mfg Co||Double cam drive for a hedge trimmer having two reciprocating cutting blades|
|US3945120 *||Apr 25, 1974||Mar 23, 1976||Milwaukee Electric Tool Corporation||Vibration dampening and heat sink mechanism for a reciprocating power saw|
|US3971132 *||Oct 7, 1974||Jul 27, 1976||Rockwell International Corporation||Saber saw|
|US4699036 *||Dec 10, 1985||Oct 13, 1987||G.O. Stumpf Gmbh & Co. Kg||Cutting apparatus|
|US4976164 *||Nov 14, 1988||Dec 11, 1990||Black & Decker Inc.||Thrust bearing arrangement for a power tool transmission|
|US5099705 *||Dec 5, 1989||Mar 31, 1992||Konstantins Dravnieks||Hand-held reciprocating working tool|
|CA1014826A *||Oct 27, 1975||Aug 2, 1977||Milwaukee Electric Tool Corp||Control for the orbital action of a reciprocating power saw|
|DE8808036U1 *||Jun 22, 1988||Sep 8, 1988||Moskovskoe Naucno-Proizvodstvennoe Ob"Edinenie Po Mechanizirovannomu Stroitel'nomu Instrumentu I Otdelocnym Masinam (Npo "Vniismi"), Chimki, Moskovskaja Oblast', Su||Title not available|
|FR2373370A1 *||Title not available|
|GB635227A *||Title not available|
|GB1312025A *||Title not available|
|GB1596408A *||Title not available|
|GB2042973A *||Title not available|
|GB2180791A *||Title not available|
|GB2181693A *||Title not available|
|GB2234034A *||Title not available|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US6212781||Oct 9, 1998||Apr 10, 2001||Milwaukee Electric Tool Corporation||Reciprocating saw|
|US6286217||Apr 9, 1998||Sep 11, 2001||Black & Decker Inc.||Reciprocating saw with pivoted arm drive|
|US6370781 *||Nov 12, 1999||Apr 16, 2002||Hitachi Koki Co., Ltd.||Reciprocating tool|
|US6523267 *||Apr 14, 2000||Feb 25, 2003||Hitachi Koki Co., Ltd.||Insulating cover for a saber saw|
|US6698177 *||Jan 28, 2000||Mar 2, 2004||Delta Kogyo Co, Ltd||Cam mechanism for translation of circular motion into reciprocal motion|
|US6742267||Apr 10, 2001||Jun 1, 2004||Milwaukee Electric Tool Corporation||Reciprocating saw|
|US6772662||Apr 9, 2002||Aug 10, 2004||Milwaukee Electric Tool Corporation||Reciprocating saw|
|US6857348 *||Dec 15, 1999||Feb 22, 2005||Black & Decker Inc.||Arrangement for clamping a saw blade|
|US7096590||Aug 10, 2004||Aug 29, 2006||Milwaukee Electric Tool Corporation||Reciprocating saw|
|US7188425||Feb 7, 2005||Mar 13, 2007||Milwaukee Electric Tool Corporation||Reciprocating saw|
|US7246533||Jun 21, 2004||Jul 24, 2007||Black & Decker Inc.||Reciprocating counterweight structure for a reciprocating saw|
|US7557534||May 17, 2006||Jul 7, 2009||Milwaukee Electric Tool Corporation||Power tool, battery, charger and method of operating the same|
|US7649337||May 17, 2006||Jan 19, 2010||Milwaukee Electric Tool Corporation||Power tool including a fuel gauge and method of operating the same|
|US7658012||Dec 22, 2003||Feb 9, 2010||Milwaukee Electric Tool Corporation||Drive mechanism and power tool|
|US7814816||Nov 15, 2007||Oct 19, 2010||Milwaukee Electric Tool Corporation||Power tool, battery, charger and method of operating the same|
|US7932695||Dec 22, 2008||Apr 26, 2011||Milwaukee Electric Tool Corporation||Power tool, battery, charger and method of operating the same|
|US8141444||Oct 26, 2007||Mar 27, 2012||Black & Decker Inc.||Bearing structure for a reciprocating shaft in a reciprocating saw|
|US8230607||May 8, 2009||Jul 31, 2012||Milwaukee Electric Tool Corporation||Keyless blade clamp for a power tool|
|US8407902||Mar 10, 2010||Apr 2, 2013||Milwaukee Electric Tool Corporation||Reciprocating power tool having a counterbalance device|
|US8640347 *||Oct 29, 2009||Feb 4, 2014||Hilti Aktiengesellschaft||Hand-operated jigsaw|
|US8646185 *||Sep 16, 2011||Feb 11, 2014||Jian-Shiou Liaw||Hand tool having a reciprocally driving mechanism|
|US9061411||Feb 28, 2013||Jun 23, 2015||Milwaukee Electric Tool Corporation||Reciprocating power tool having a counterbalance device|
|US9073563||May 17, 2012||Jul 7, 2015||Crystal Glass Canada Ltd.||Reciprocating power tool|
|US20040187324 *||Dec 22, 2003||Sep 30, 2004||James Thomas P.||Drive mechanism and power tool|
|US20050005458 *||Aug 10, 2004||Jan 13, 2005||Milwaukee Electric Tool Corporation||Reciprocating saw|
|US20050132583 *||Feb 7, 2005||Jun 23, 2005||Milwaukee Electric Tool Corporation||Reciprocating saw|
|US20060117580 *||Oct 14, 2005||Jun 8, 2006||Serdynski David P||Power tool and method of operating the same|
|US20060267548 *||May 17, 2006||Nov 30, 2006||Milwaukee Electric Tool Corporation||Power tool, battery, charger and method of operating the same|
|US20060267556 *||May 17, 2006||Nov 30, 2006||Milwaukee Electric Tool Corporation||Power tool, battery, charger and method of operating the same|
|US20080041174 *||Oct 26, 2007||Feb 21, 2008||Michael Lagaly||Bearing Structure for a Reciprocating Shaft in a Reciprocating Saw|
|US20090031865 *||Nov 15, 2007||Feb 5, 2009||Alberti Daniel J||Power tool, battery, charger and method of operating the same|
|US20090102420 *||Dec 22, 2008||Apr 23, 2009||Nancy Uehlein-Proctor||Power tool, battery, charger and method of operating the same|
|US20100107427 *||Oct 29, 2009||May 6, 2010||Hilti Aktiengesellschaft||Hand-operated jigsaw|
|US20100162579 *||Mar 10, 2010||Jul 1, 2010||Michael Naughton||Reciprocating power tool having a counterbalance device|
|US20120151782 *||Sep 16, 2011||Jun 21, 2012||Jian-Shiou Liaw||Hand tool having a reciprocally driving mechanism|
|U.S. Classification||30/392, 30/277.4, 74/50|
|International Classification||B23D49/16, B23D51/02, F16H21/18, F16F15/28, B23D51/16|
|Cooperative Classification||B23D51/16, F16F15/28, Y10T74/18256, F16H21/18, B23D51/02, B23D49/162|
|European Classification||F16H21/18, B23D49/16B, B23D51/02, B23D51/16, F16F15/28|
|Jun 28, 1999||FPAY||Fee payment|
Year of fee payment: 8
|Jul 14, 2003||FPAY||Fee payment|
Year of fee payment: 12