Hybrid impact tool with two-speed transmission

Patent metadata

Field	Value
Publication number	US-RE46827-E
Application number	US-201514732133-A
Country	US
Kind code	E1
Filing date	Jun 5, 2015
Priority date	Dec 23, 2009
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A power tool that includes a housing, a motor, a planetary transmission, a first bearing and a second bearing. The motor is disposed in the housing and includes an output shaft. The planetary transmission has a sun gear, a plurality of first planet gears, a first ring gear and a carrier. The sun gear is driven by the output shaft. The first planet gears are driven by the sun gear and have teeth that are meshingly engaged to teeth of the first ring gear. The carrier includes a rear carrier plate and a front carrier plate between which the first and second planet gears are received. The rear carrier plate includes a first bearing aperture. The first bearing is received in the first bearing aperture and is configured to support the output shaft. The second bearing is received onto the rear carrier plate to support the carrier relative to the housing.

First claim

What is claimed is:

1. A power tool comprising:
a housing;
a motor coupled to the housing, the motor having an output shaft;
an output member;
a power transmitting mechanism drivingly coupling the output shaft to the output member, the mechanism comprising a transmission having dual planetary stage with a sun gear, a first planet gear, a second planet gear, a planet carrier, a first ring gear and a second ring gear, the first and second planet gears being rotatably mounted on the planet carrier, the first planet gear being disposed between the motor and the second planet gear and having a pitch diameter that is smaller than a pitch diameter of the second planet gear, the first ring gear being meshingly engaged with the first planet gear, and the second ring gear being meshingly engaged with the second planet gear; and
a shift mechanism having a collar that is non-rotatably but axially slidably coupled to the housing for movement between a first position and a second position, wherein the collar comprises an annular collar body, a first set of external splines and a second set of external splines, the collar body being received about the first ring gear, the first set of external splines extending radially inwardly from the collar body and engaging a third set of external splines formed about the first ring gear when the collar is in the first position to thereby inhibit rotation of the first ring gear relative to the housing, the second set of external splines being coupled to an end of the collar body that faces opposite the motor, the second set of external splines engaging a fourth set of external splines formed on the second ring gear when the collar is in the second position to thereby inhibit rotation of the second ring gear relative to the housing.

2. The power tool of claim 1 , wherein the power transmitting mechanism comprises a rotary impact mechanism having an input spindle and an anvil, the input spindle being coupled for rotation with an output of the transmission, the output member being coupled for rotation with the anvil.

3. The power tool of claim 1 , wherein the shift mechanism further comprises a switch member and a pair of springs, the springs cooperating to bias the collar into a neutral position relative to the switch member.

4. The power tool of claim 3 , wherein the shift mechanism further comprises a rod that is fixedly coupled to the collar, the switch member being movably mounted on the rod.

5. The power tool of claim 4 , wherein the springs are mounted on the rod on opposite sides of the switch member.

6. The power tool of claim 1 , wherein the first and second planet gears are unitarily formed.

7. The power tool of claim 6 , wherein the first planet gear has a first quantity (Q1) of teeth, the second planet gear has second quantity of teeth (Q2) and wherein the quotient of the quantity of teeth on the second planet gear divided by the quantity of teeth on the first planet (Q2/Q1) gear is not an integer.

8. The power tool of claim 7 , wherein a timing aperture is formed in at least one of the first and second planet gears, the timing aperture being indexed at a predetermined angle relative to a timing tooth on one of the first and second planet gears.

9. A power tool comprising:
a housing;
a motor coupled to the housing, the motor having an output shaft;
an output member;
a power transmitting mechanism drivingly coupling the output shaft to the output member, the mechanism comprising a transmission having dual planetary stage with a sun gear, a compound planet gear, a planet carrier, a first ring gear and a second ring gear, the compound planet gear being rotatably mounted on the planet carrier and having first and second planet gears that are fixedly coupled to and integrally formed with one another, the first planet gear being disposed between the motor and the second planet gear and having a pitch diameter that is smaller than a pitch diameter of the second planet gear, the first ring gear being meshingly engaged with the first planet gear, and the second ring gear being meshingly engaged with the second planet gear, wherein the first planet gear has a first quantity (Q1) of teeth, the second planet gear has second quantity of teeth (Q2) and wherein the quotient of the quantity of teeth on the second planet gear divided by the quantity of teeth on the first planet (Q2/Q1) gear is not an integer; and
a shift mechanism with a collar that is non-rotatably but axially slidably coupled to the housing for movement between a first position and a second position, wherein the collar non-rotatably couples the first ring gear to the housing in the first position and non-rotatably couples the second ring gear to the housing in the second position.

10. The power tool of claim 9 , wherein a timing aperture is formed in at least one of the first and second planet gears, the timing aperture being indexed at a predetermined angle relative to a timing tooth on one of the first and second planet gears.

11. A power tool comprising:
a housing;
a motor in the housing, the motor including an output shaft;
a planetary transmission having a sun gear, a plurality of first planet gears, a first ring gear and a carrier, the sun gear being driven by the output shaft, the first planet gears being driven by the sun gear and having teeth that are meshingly engaged to teeth of the first ring gear, the carrier including a rear carrier plate and a front carrier plate between which the first planet gears are received, the rear carrier plate including a first bearing aperture;
a first bearing received in the first bearing aperture and being configured to support the output shaft; and
a second bearing received onto the rear carrier plate to support the carrier relative to the housing.

12. The power tool of claim 11 , wherein the planetary transmission includes a plurality of second planet gears.

13. The power tool of claim 12 , wherein each of the first planet gears is coupled for rotation with a corresponding one of the second planet gears.

14. The power tool of claim 13 , wherein each of the first planet gears has a first pitch diameter and each of the second planet gears has a second pitch diameter that is larger than the first pitch diameter.

15. The power tool of claim 13 , wherein the first ring gear includes a plurality of external teeth that are axially spaced apart from the teeth that are meshingly engaged by the teeth of the first planet gears.

16. The power tool of claim 15 , wherein the external teeth are positioned at least partly vertically in-line with at least one of the first and second bearings.

17. The power tool of claim 15 , further comprising an axially slidable collar that is movable between a first position, in which the collar is engaged to the external teeth of the first ring gear, and a second position in which the collar is engaged to a second ring gear that is meshingly engaged to the second planet gears.

18. The power tool of claim 17 , wherein the collar is non-rotatably coupled to the housing.

19. The power tool of claim 18 , further comprising a switch member, a first spring ( 224 ) and a second spring, the first spring ( 224 ) being compressed when the switch member is moved from a first switch position to a second switch position without a corresponding movement of the collar from the first position to the second position, the second spring being compressed when the switch member is moved from the second switch position to the first switch position without a corresponding movement of the collar from the se

Assignees

• Black & Decker Inc

Inventors

• Rudolph Scott
• Murthy Sankarshan
• Puzio Daniel
• Zhang Qiang
• Cleanthous Aris
• Abolhassani Mehdi
• Wang Ren H
• Tomayko David

Classifications

• B25F5/001 Primary

  Gearings, speed selectors, clutches or the like specially adapted for rotary tools · CPC title

• B25B21/02

  with means for imparting impact to screwdriver blade or nut socket · CPC title