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US-20260124730-A1 - POWER TOOL WITH MULTISPEED TRANSMISSION

US20260124730A1US 20260124730 A1US20260124730 A1US 20260124730A1US-20260124730-A1

Abstract

A multi-speed, power-driven tool may include a transmission mechanism that transmits power from a motor to an output device. A speed selection mechanism may be coupled to the transmission mechanism, to control a speed reduction through the transmission mechanism, and an output speed of the tool. The transmission mechanism may employ a compound, stepped, planetary gear assembly. The speed selection mechanism may employ a compliant speed selection mechanism.

Inventors

  • Robert S. Gehret
  • David C. Tomayko
  • Heather Schafer
  • Joseph Patrick Kelleher
  • Joseph Carl Biser
  • Trevor J. Koenig

Assignees

  • BLACK & DECKER INC.

Dates

Publication Date
20260507
Application Date
20251230

Claims (20)

  1. 1 . A multi-speed power tool comprising: a housing; a motor received in the housing; a multi-speed planetary transmission rotationally driven by the motor and defining a transmission axis, wherein the multi-speed transmission includes a plurality of sub-sections each of which is configured to provide an intermediate speed reduction when that subsection is active, an output shaft rotationally driven by the transmission at an output rotational speed defined by intermediate speed reductions of any of the active subsections; and a speed selector including a shift member inside the housing that is moveable among a first plurality of positions where the shift member engages a one or more of the subsections of the transmission to activate one or more of the subjections so as to cause the transmission to rotate the output shaft at a plurality of different output rotational speeds, a switch accessible from outside the housing, coupled to the shift member, and moveable among a second plurality of positions corresponding to selected output speeds of the transmission to cause movement of the shift member among the first plurality of positions; and a plurality of springs disposed in parallel between the shift member and the switch without any of the plurality of springs arranged serially, the plurality of springs exerting a bi-directional biasing force on the shift member in both an axial forward and an axial rearward direction relative to the switch, wherein if the switch is moved from a first switch position to a second switch position of the second plurality of positions and the shift member is blocked from moving from the a first speed position to a second speed position of the first plurality of positions, the shift member remains stationary and when the shift member is later unblocked from moving from the first speed position to the second speed position, a force provided by the plurality of springs urge the shift member to move to the second speed position while the switch remains stationary.
  2. 2 . The multi-speed power tool of claim 1 , wherein each subsection includes a plurality of planet gears and a ring gear engaged with the planet gears.
  3. 3 . The multi-speed power tool of claim 2 , wherein the shift member comprises an at least partially ring shaped shift ring configured to engage a ring gear in at least one of the subsections of the transmission, wherein the subsection is active when the shift ring engages the ring gear.
  4. 4 . The multi-speed power tool of claim 1 , wherein the shifter is fixedly coupled to a first end of an axial pin that and is moveable with the axial pin parallel to the transmission axis.
  5. 5 . The multi-speed power tool of claim 4 , wherein the speed selector further comprises a carriage fixedly coupled to a second end of the axial pin and moveable with the axial pin parallel to the transmission axis.
  6. 6 . The multi-speed power tool of claim 5 , wherein the switch includes a base portion moveably coupled to the carriage with the plurality of springs disposed between the base portion and the carriage.
  7. 7 . The multi-speed power tool of claim 6 , wherein the switch further includes a shutter slidably coupled on a second side portion of the base portion, opposite the first side portion thereof; and a grasping portion extending from the base portion through an opening formed in the shutter, wherein the grasping is movable to a plurality of different positions between a first end of the opening in the housing and a second end of the opening in the housing, the plurality of different positions corresponding to a plurality of different axial positions of the shift member with respect to the transmission.
  8. 8 . The multi-speed power tool of claim 7 , wherein a distance from a first end of the base portion to a second end of the base portion is less than a distance from the first end of the opening in the housing to the second end of the opening in the housing, and the shutter is configured to slide with respect to the base portion as the selection device moves in the opening, such that the shutter and the base portion close the opening in the housing at the plurality of positions of the shift member between the first end and the second end of the opening.
  9. 9 . The multi-speed power tool of claim 1 , wherein the plurality of springs comprises two parallel compression springs.
  10. 10 . The multi-speed power tool of claim 9 , wherein the compression springs are disposed on a pair of axial pins fixedly coupled to the shifting member.
  11. 11 . The multi-speed power tool of claim 1 , wherein the plurality of sub-sections includes a first subsection having a first set of planet gears and a first ring gear meshed with the first set of planet gears, and a second subsection having a second set of planet gears and a second ring gear meshed with the second set of planet gears, and the shifting member is configured to selectively ground the first ring gear relative to the housing in a first shift position of the shifting member for a first output speed of the output shaft and the second ring gear relative to the housing in a second shift position of the shifting member for a second output speed of the output shaft.
  12. 12 . The multi-speed power tool of claim 11 , wherein the plurality of sub-sections further includes a third subsection having a third set of planet gears and a third ring gear meshed with the third set of planet gears.
  13. 13 . The multi-speed power tool of claim 12 , wherein the shifting member is configured to selectively ground the third ring gear relative to the housing in a third shift position of the shifting member for a third output speed of the output shaft.
  14. 14 . A multi-speed power tool, comprising: a housing; a motor received in the housing; a multi-speed planetary transmission rotationally driven by the motor and defining a transmission axis, wherein the multi-speed transmission includes a plurality of subsections, each of the plurality of subsections being configured to produce a corresponding speed reduction; an output shaft rotationally driven by the transmission; and a speed selector moveable among a plurality of positions in which the speed selector engages one or more of the plurality of subsections of the transmission so as to cause the transmission to rotate the output shaft at a plurality of different output speeds, wherein the speed selector comprises: a switch that is accessible from an outside of the housing, and that is movable within an opening formed in the housing; and at least one shift rail having a first end portion fixed to the switch and a second end portion fixed to a shift member that selectively engages one of the plurality of subsections of the transmission, wherein the switch includes: a base portion having a first side portion coupled to the at least one shift rail; a shutter slidably coupled on a second side portion of the base portion, opposite the first side portion thereof; and a grasping portion extending from the base portion through an opening formed in the shutter, wherein the grasping portion is movable to a plurality of different positions between a first end of the opening in the housing and a second end of the opening in the housing, the plurality of different positions corresponding to a plurality of different axial positions of the shifter with respect to the transmission.
  15. 15 . The multi-speed power tool of claim 14 , further comprising a hammer mechanism coupled to the output shaft, wherein the hammer mechanism includes: a first ratchet fixed to the output shaft so as to rotate with the output shaft; a second ratchet axially aligned with the first ratchet; and a cam mechanism surrounding the second ratchet, wherein the second ratchet is non-rotatable, and is axially movable with respect to the first ratchet.
  16. 16 . The multi-speed power tool of claim 15 , wherein the cam mechanism includes: a cam ring; a plurality of lugs extending radially inward from the cam ring; and a plurality of ramp surfaces defined on the plurality of lugs; and the second ratchet includes: a hub; a plurality of lugs extending outward from the hub; and a plurality of teeth formed on a surface of the hub facing the first ratchet.
  17. 17 . The multi-speed power tool of claim 16 , wherein, in a first mode of operation, the cam ring is in a first axial position and a first radial position; each lug of the plurality of lugs of the second ratchet is positioned between a pair of lugs of the cam mechanism; and the first ratchet and the second ratchet are axially separated and in a disengaged state.
  18. 18 . The multi-speed power tool of claim 17 , wherein, in a second mode of operation, the cam ring is in a second axial position and a second radial position; the ramp surface of each lug of the plurality of lugs of the cam mechanism is positioned against a corresponding lug of the plurality of lugs of the second ratchet; and the hub of the second ratchet is positioned against a mating surface of the first ratchet, such that the teeth defined on the hub of the second ratchet are engaged with teeth on the mating surface of the first ratchet, and an axial percussive force is imparted on the output shaft.
  19. 19 . The multi-speed power tool of claim 15 , wherein the shift member comprises an at least partially ring shaped shift ring configured to engage a gear in at least one of the subsections of the transmission.
  20. 20 . The multi-speed power tool of claim 15 , wherein the grasping portion comprises at least one of a button or a lever.

Description

RELATED APPLICATIONS This application claims priority, under 35 U.S.C. § 120, as a continuation of U.S. patent application Ser. No. 18/608,326, filed Mar. 18, 2024, titled “Power Tool with Multispeed Transmission,” which claims priority, under 35 U.S.C. § 120, as a continuation of U.S. patent application Ser. No. 16/952,758, filed Nov. 19, 2020, titled “Power Tool with Multispeed Transmission,” which claims priority under 35 U.S.C. § 119(e), to U.S. Provisional Application No. 63/198,123, filed Sep. 30, 2020 and U.S. Provisional Application No. 62/941,043, filed Nov. 27, 2019. Each of the foregoing patent applications is incorporated by reference. FIELD This application relates, generally, to a multi-speed power tool. BACKGROUND A power driven tool may output a force generated by a motor of the tool to perform an operation on a workpiece. Multi-speed power tools may operate at multiple different speeds to, for example, accommodate different types of tasks, and/or allow different tasks to be performed at an appropriate operational speed for the particular task. Such multi-speed power tools may employ a transmission mechanism and a clutching mechanism, allowing for power from the motor to be output by an output device of the tool at different speeds to accommodate a variety of different tasks with the same tool. The arrangement of these components within a housing of the tool may render the tool relatively large, and relatively difficult to operate in confined spaces. More compact internal components may enhance utility and functionality of this type of multi-speed tool, thus enhancing utility to the operator. SUMMARY In one general aspect, a multi-speed power tool may include a housing, a motor received in the housing, and a multi-speed planetary transmission rotationally driven by the motor and defining a transmission axis, wherein the multi-speed transmission includes a plurality of subsections, each of the plurality of subsections being configured to produce a corresponding speed reduction, the plurality of subsections including a first subsection having a first set of planet gears and a first ring gear meshed with the first set of planet gears, and a second subsection having a second set of planet gears and a second ring gear meshed with the second set of planet gears. The transmission may include a carrier assembly, including a first carrier segment, a second carrier segment, a third carrier segment, a first set of supports or pins connecting the first carrier segment to one of the second carrier segment and the third carrier segment and carrying the first set of planet gears, and a second set of supports or pins connecting the third carrier segment to one of the first carrier segment and the third carrier segment and carrying the second set of planet gears, such that the first, second, and third carrier segments rotate in unison about the transmission axis, wherein the first and second sets of supports or pins are arranged such that each of the first set of planet gears is radially offset from each of the second set of planet gears. The tool may also include an output shaft rotationally driven by the transmission, and a speed selector moveable among a plurality of positions where the speed selector engages one or more of the plurality of subsections so as to cause the transmission to rotate the output shaft at a plurality of different output speeds. In some implementations, each of the first set of planet gears may include a front face facing the second set of planet gears and aligned in a first plane, and each of the second set of planet gears may include a rear face facing the first set of planet gears and aligned in a second plane, wherein the first plane and the second plane are substantially coplanar. In some implementations, the transmission may also include a first sun gear meshed with the first set of planet gears and a second sun gear meshed with the second set of planet gears. The first and second sun gears may be axially aligned, with at least the first sun gear being rotatably driven by the motor. In some implementations, the speed selector may be configured to ground the first ring gear to the housing in a first position to cause the transmission to rotate the output shaft a first speed, and to ground the second ring gear to the housing in a second position to cause the transmission to rotate the output shaft at a second speed that is different than the first speed. In some implementations, the transmission may include a third subsection having a third set of planet gears and a third ring gear meshed with the third set of planet gears. The third set of planet gears may be carried by a third set of supports or pins connected to one of the first carrier segment, the second carrier segment or the third carrier segment. The speed selector may be configured to ground the first ring gear to the housing in a first position to cause the transmission to rotate the output shaft a first speed, to gro