| US 6,213,224 C1 (6750th) | ||
| ELECTRIC POWER TOOL WITH ENHANCED STRENGTH TO AXIALLY-APPLIED EXTERNAL FORCE | ||
| Takefumi Furuta, Anjo, Japan; Shingo Umemura, Okazaki, Japan, and Shinsuke Mori, Takahama, Japan, assignors to Makita Corporation, Anjo-shi, Aichi-ken, Japan | ||
| Reexamination Request No. 90/008,769, Jul. 24, 2007. | ||
| Reexamination Certificate for Patent 6,213,224, issued Apr. 10, 2001, Appl. No. 334,352, Jun. 16, 1999. | ||
| Claims priority, application Japan, Jun. 17, 1998, 10-170304 | ||
| Int. Cl. E21B 03/00 (2006.01) | ||
| U.S. Cl. 173—217 |
| AS A RESULT OF REEXAMINATION, IT HAS BEEN DETERMINED THAT: |
| Claims 1-3, 6, 7, 13, 14 and 15 are determined to be patentable as amended. |
| Claims 4, 5 and 8-12, dependent on an amended claim, are determined to be patentable. |
| New claims 16-23 are added and determined to be patentable. |
| 1. An electric power tool, comprising: a spindle having an axis;
a drive unit including a motor and a reduction mechanism for transmitting the rotation of the motor to the spindle of the tool, the reduction mechanism being an epicycle reduction gear mechanism, the drive unit including a clutch means for interrupting transmission of the rotation of the motor from the epicycle reduction gear mechanism to the spindle responsive to a load applied to the spindle, the clutch means including an adjusting member for adjusting the torque at which the transmission of the motor rotation to the spindle is interrupted; and
a housing for containing the drive unit, the housing having a front end, wherein a portion of the drive unit is made of metal, the metal portion of the drive unit [being exposed to the outside of the tool forward the housing and the metal portion of the drive unit being connected directly to the front end of the housing, the metal portion of the drive unit]including an exterior section exposed to an exterior of the tool that is directly connected to the front end of the housing and an interior section integrally cast with the exterior section, the interior section being a journal bearing portion having at least one bearing that supports the spindle, an entire outer circumferential surface of the interior section between a forwardmost at least one journal bearing and the exterior section being disposed within an interior of the tool, the interior section having an external diameter smaller than an external diameter of the exterior section, the interior section being disposed along the spindle axis, the external section being disposed between the adjusting member and the housing.
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