A polisher may include a polishing pad, a motor, a transmission device, and a mode selection device. The transmission device can transmit a rotational drive force of the motor to the polishing pad in a plurality of different modes with respect to a motion of the polishing pad. The mode selection device may be used for selecting a desired motion mode of the output member. Additionally, a motor and handle housing with an accompanying power cord may be constructed to aid in ease of manipulation of the polisher by the user with minimal interference.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims priorities to Japanese Patent Application Serial No. 2015-203916 filed on Oct. 15, 2015, Japanese Patent Application Serial No. 2016-075187 filed on Apr. 4, 2016, and Japanese Patent Application Serial No. 2016-197370 filed on Oct. 5, 2016, the contents of which are incorporated in their entirety herein by reference.

BACKGROUND

Technical Field

The invention generally relates to polishers that may be used for polishing target surfaces to be polished, such as painted or coated surfaces of articles, machines or equipments.

Related Art

Japanese Laid-Open Patent Publication No. 2004-122337 (JP-A-2004-122337) discloses a polisher including a built-in motor as a drive source. The rotational force generated by the motor may be transmitted to an output shaft, to which a polishing pad may be attached. The attached polishing pad may rotate with the output shaft for polishing a target surface to be polished. The polishing pad may be detachable to the output shaft. Therefore, the user can selectively use a suitable pad from different types of polishing pads in accordance with a desired polishing mode.

There is a need in the art for a technique of enabling a plurality of polishing modes without needing to change a polishing pad.

SUMMARY

In one aspect according to the present teachings, a polisher may include a polishing pad, a motor, a transmission device, and a mode selecting device. The transmission device can transmit a rotational drive force of the motor to the polishing pad in any one of a plurality of different modes, to accordingly effect motion of the polishing pad. The mode selecting device may allow selection of a desired motion mode of the polishing pad.

In one embodiment, a polisher may include a polishing pad, a motor, an output member, and a transmission device. The polishing pad may have a polishing surface and may be used for polishing a target surface. The output member may be coupled to the polishing pad. The motor may generate a rotational drive force. The transmission device may transmit the rotational drive force to the output member in any one of a plurality of different modes with respect to effecting motion of the output member. A mode selection device may be coupled to the transmission device and may allow selection of a motion mode from a plurality of different modes, such that a desired motion mode for the output member may be selected. The polisher may further include a transmission housing that supports or accommodates the transmission device. The mode selection device may also be disposed in the transmission housing. The polishing pad may be detachably attached to the output member or alternatively may be integrated with the output member.

This manner of construction and arrangement of the polisher enables the user to select a desired mode from the plurality of different modes to effect motion of the output member coupled to the polishing pad. Therefore, a variety of polishing modes are available for the user without needing to change of the polishing pad.

The plurality of different modes may include a first mode and a second mode. The first mode may cause the output member to revolve about a first axis and to freely rotate about a second axis displaced from the first axis. The second mode may cause the output member to revolve about the first axis and to forcibly rotate the output member about the second axis. In this way, the user can select a free rotation mode or a forced rotation mode with respect to the rotation of the output shaft (i.e., the rotation of the polishing pad) about the second axis, while the output shaft revolves about the first axis.

The transmission device may include a support shaft portion rotatably driven about the first axis by the rotational drive force of the motor. An eccentric shaft portion may be rotatable with the support shaft portion about the first axis and may further rotate about the second axis. The output member may be coupled to the eccentric shaft portion so as to be rotatable along with the eccentric shaft portion about the second axis. The output member may include an external gear portion. An internal gear member may be rotatable about the first axis relative to the transmission housing and may include an internal gear portion that is in engagement with the external gear portion of the output member. The mode change device may include an engaging member movable between an engaging position and a disengaging position. The internal gear member may include an engagement portion for engagement with the engaging member of the mode change device. The first mode of the mode change device may cause its engaging member to be disengaged from the engaging portion of the internal gear member, so that the output member is allowed to freely rotate about the second axis while the output member revolves about the first axis. The second mode of the mode change device may cause its engaging member to engage the engaging portion of the internal gear member, so that the output member is forced to rotate about the second axis while the output member revolves abut the first axis.

The internal gear member may further include an engagement prohibiting portion configured to prohibit engagement of the engaging member of the mode change device with the engaging portion of the internal gear member when the engaging member moves from the disengaging position to the engaging portion while the internal gear member rotates at a speed higher than a predetermined speed.

For example, if the internal gear rotates at a relatively high speed when the mode selection device is operated to change the motion mode from the first mode (i.e., the free rotation mode) to the second mode (i.e., the forced rotation mode), the engaging member of the mode change device may abruptly engage the engaging portion of the internal gear member. If this occurs, the engaging member and/or the engaging portion may be damaged. The engagement prohibiting portion may prohibit engagement of the engaging member with the engaging portion when the internal gear member rotates at a speed higher than the predetermined speed. In light of the above, doing so may prevent potential damage to the mode changing device and/or internal gear member, and further may extend the lifetime of the polisher.

The engagement prohibiting portion of the internal gear member may be disposed proximally, relative to the engaging portion, in a rotational direction, and may include a surface inclined outward in a direction opposite to the rotational direction.

With this arrangement of the engagement prohibiting portion, as the engaging member of the mode changing device moves from the disengaging position to the engaging position when the internal gear member rotates at a speed higher than the predetermined speed, the engaging member is prevented from contacting the engaging portion. Instead, the engaging member contacts the inclined surface of the engagement prohibiting portion and may move away from the internal gear along the inclined surface as the internal gear member rotates further. Therefore, it is possible to prevent the engaging member from engagement with the engaging portion. When the rotational speed of the internal gear is reduced to be lower than the predetermined speed, the engaging member may move along the inclined surface toward the internal gear and may automatically engage the engaging portion. In this manner, it is possible to prevent potential damage to the engaging member of the mode changing device and/or the engaging portion of the internal gear member, by providing the inclined surface on the internal gear member.

The engaging portion of the internal gear member may be a plurality of engaging grooves formed in an outer circumferential surface of the internal gear member. The engaging member of the mode changing device may be an engaging pin movable between the engaging position and the disengaging position in a radial direction with respect to a rotational axis of the internal gear member.

With this arrangement, the engaging pin of the mode selection device moves in the radial direction toward and away from the internal gear member and may be disposed on a radially outer side of the internal gear member. Due to the movable pin arrangement, it may be possible to minimize the size of the combination of the internal gear member and the mode change device in the axial direction of the internal gear member. Because the mode selection device is disposed in the transmission housing that may support the internal gear member, where the combination of both may be minimized as described, it is possible to minimize the size of the transmission housing in the axial direction, and by extension, it is therefore possible to minimize the size of the polisher in the axial direction, where said axial direction may be a vertical direction.

Alternatively, the plurality of engaging grooves of the engaging portion may be formed in one of the opposite surfaces in the axial direction of the internal gear member, and the engaging pin of the mode selection device may move between the engaging position and the disengaging position in an axial direction parallel to a rotational axis of the internal gear member.

The circumferential speed of the engaging portion formed in one of the opposite surfaces in the axial direction of the internal gear member may be naturally lower than the circumferential speed of the outer circumferential surface of the internal gear member. In addition, the circumferential speed of the engaging portion formed in this way may become lower as the position of the engaging portion approaches the rotation center of the internal gear member. Therefore, a freedom in design with respect to the circumferential speed of the engaging portion may be achieved.

In another embodiment, a polisher may include a polishing pad, a motor housing, a handle housing and a power cord. The polishing pad may have a polishing surface that can polish a target surface. The motor housing may accommodate a motor that may serve as a drive source of the polishing pad. The handle housing may be disposed on a rear side of the motor housing and configured to be grasped by user's hands. The motor housing may have a longitudinal axis that extends substantially parallel to the polishing surface of the polishing pad. The power cord may be electrically connected to the motor and may extend in an extending direction from within a rear portion of the handle housing to an outside of the handle housing. The extending direction of the power cord may be inclined relative to the longitudinal axis by a predetermined angle such that the power cord extends upward away from the polishing surface in a rearward direction.

With this arrangement of the polisher's various components and the extending direction of the power cord, it is possible to inhibit or minimize occasions where the power cord accidentally contacts a surface of a target to be polished during the polishing operation. As a result, the polishing operation can be quickly performed to achieve a fine finish of the target surface without undesired interference by the power cord contacting the target surface.

Further, in some cases, for the purpose of avoiding the power cord from contacting the target surface, the user may hang a part of the power cord of the polisher on his or her shoulder while performing the polishing operation. In this case, due to the extending direction, resulting in the upward inclination of the power cord from the rear portion of the handle housing, it may be possible to prevent a portion of the power cord extending between the rear portion of the handle housing and the shoulder of the user from being abruptly bent or curved. Therefore, with this mode of construction, it is possible to prevent potential breakage of wires of the power cord.

The aforementioned predetermined angle may lie within a range of about 5 to 90 degrees, preferably within a range of about 10 to 60 degrees, and more preferably 15 degrees.

In a further embodiment, a polisher may include a polishing pad, a motor housing, a handle housing, a power cord and a holding sleeve. The polishing pad may have a polishing surface that can polish a target surface to be polished. The motor housing may accommodate a motor serving as a drive source of the polishing pad. The handle housing may be disposed on a rear side of the motor housing and configured to be grasped by a hand of a user. The motor housing may have a longitudinal axis that extends substantially parallel to a polishing surface of the polishing pad. A power cord may be electrically connected to the motor and may extend in an extending direction from within a rear portion of the handle housing to an outside of the handle housing. A holding sleeve may be pivotally attached to the rear portion of the handle housing, such that a tilt angle of the holding sleeve in a vertical direction relative to the polishing surface is adjustable. The power cord may extend from the rear portion of the handle housing to the outside of the handle housing through the holding sleeve.

With this arrangement, it may also be possible to inhibit or minimize occasions where the power cord contacts a surface of a target to be polished during the polishing operation, by positioning the holding sleeve to be tilted upward. As a result, the polishing operation can be quickly performed to achieve a fine finish of the target surface without undesired interference by the power cord contacting the target surface. Further, because the tilt angle of the holding sleeve in a vertical direction relative to the polishing surface can be changed, it may be possible to adjust the upward inclination angle, for example, depending on a posture of the user taken during the polishing operation. As a result, it may be possible to further reliably inhibit or minimize such an occasion that the power cord contacts the target surface to be polished, during the polishing operation. Further, it may be possible to further reliably prevent the power cord from being abruptly bent or curved, whereby it may be possible to further reliably prevent potential breakage of wires of the power cord.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

First Embodiment

A polisher10according to a first embodiment will now be described with reference toFIGS. 1 to 12. The polisher10may be used for polishing surfaces to be polished, such as painted or coated surfaces of articles, machines and equipments (hereinafter called “target surfaces”). The polisher10may include a built-in motor32that generates a rotational drive force. The rotational drive force of the motor32may be transmitted to an eccentric shaft61. The eccentric shaft61may rotatably support an output member65. A polishing pad100may be detachably attached to the output member65by using a screw105. A polishing sponge110may be detachably attached to the lower surface of the polishing pad100via an attaching device. The attaching device may be a suitable fastener, such as a hook and loop fastener known as a “Velcro” (registered trademark) fastener. The fastener may include a first fastener member107and a second fastener member108. The first fastener member107may be fixedly attached to the lower surface of the polishing pad100. The second fastener member111may be fixedly attached to the upper surface of the polishing sponge110for engagement with the first fastener member107. Engagement between the first fastener member107and the second fastener member111may attach the polishing sponge110to the polishing pad100, so that the polishing sponge110may rotate with the polishing pad100for polishing the target surfaces. Any other polishing element than the polishing sponge110may be used as a polishing material. For example, a woolen fabric may be used in place of the polishing sponge110.

As will be explained later, the polishing pad100may make an eccentric motion (i.e. revolution) together with the eccentric shaft61about an axis X1while also rotating relative to the eccentric shaft61about an axis X2that may be offset or displaced from the axis X1in the direction of the front-rear axis (seeFIGS. 2 and 7). Further, a mode selection device80may be manually operable for selection between a forced rotation mode and a free rotation mode with respect to the rotation of the polishing pad100about the axis X2.

Referring toFIG. 1, the polisher10may generally include a handle20, a motor portion30and an output gear portion40that are arranged along a substantially straight line in the order from rear to front inFIG. 1. The handle20may include a handle housing21with a right housing half21R and a left housing half21L that are joined together at a vertical joint plane (seeFIGS. 4 and 5). The handle housing21may have an outer shape suitably designed for allowing the handle housing21to be grasped by the user.

As shown inFIG. 1, a switch device22may be disposed at the handle housing21and may be manually operated for starting and stopping the motor32. The switch device22may include a switch main body23and a trigger24. The switch main body23may be disposed within the handle housing21and may be a contact switch device. The trigger24may be mounted to (connected to) the switch main body23and may be partly exposed to the outside from the handle housing21. More specifically, the trigger24may be positioned such that it can be operated or pulled by a finger(s) of the user when the user grasps the handle20. When the user pulls the trigger24to move the trigger24from an off-operation position to an on-operation position, the switch main body23may be turned on, starting the motor32. A lock-on button27may be disposed at the left side portion of the handle housing21. The lock-on button27may be coupled to the switch device22such that the trigger24may be locked into the on-operation position when the user pushes the lock-on button27with the trigger24in the on-operation position. Therefore, even in the case when the user releases the pulling force applied to the trigger24to initially move it to an on-operation position, the trigger24may be held in said position, so that the switch main body23will continue to remain on. Hence, the user can continue the polishing operation in a comfortable position with his or her finger(s) removed from the trigger24. Pushing the lock-on button27again may release the lock state of the trigger24, so that the rotation of the motor32can be stopped.

As shown inFIGS. 1 and 2, a power cord1may be drawn into the rear portion of the handle housing21and may have a connector (not shown) for connection with a commercial AC power source, such as AC 100 V power source, so that the motor32can receive a supply of an electric power via the power cord1. A controller25may be disposed within the front portion of the handle housing21. The controller25may electrically connect the power cord1to the motor32and may control the supply of the electric power to the motor32. The switch main body23and an adjusting dial26that will be explained later may be electrically connected to the controller25, so that the controller25may control the motor32based on input signals from the switch main body23and the adjusting dial26. The adjusting dial26may serve as an input device for inputting a set value for the rotational speed of the motor32, and more specifically, the revolutions per minute (RPM) of the polishing pad100.

The motor portion30may be connected to the front portion of the handle20so as to be disposed on the front side thereof. The motor portion30may include a substantially cylindrical motor housing31. The motor32may be disposed within the motor housing31. The motor32may be a brush-less motor and may have a stator33and a rotor34. The stator33may be fixedly attached to the motor housing31. The rotor34may be attached to a motor shaft35that is rotatably supported by the motor housing31via a rear bearing351and a front bearing352.

The rotor34may include a rotor coil36and a commutator37through which the electric power may be supplied from the controller25to the rotor coil36. A cooling fan38may be attached to the front portion of the motor shaft35and may rotate together with the motor shaft35. The rotating cooling fan38may produce a stream of air that flows toward the cooling fan38from its rear side in an axial direction and thereafter flows in a centrifugal direction of the cooling fan38. The air flowing in the centrifugal direction may be discharged to the outside via discharge holes28formed in the rear portion of the output gear portion40(seeFIG. 1). As shown inFIGS. 2 and 7, a first bevel gear39may be attached to the front end portion of the motor shaft35. The first bevel gear39may serve as a rotational force input device for inputting the rotational force to a gear unit50that will be explained later.

The output gear portion40may include a gear housing41that may be made of metal. The gear unit50may be disposed within the gear housing41. The gear housing41may include an upper housing portion42and a lower housing portion43that are joined together by a suitable joint device such as screws (not shown). The outer circumference of the gear housing41may be covered with a cover member45that may be a resin-molded member. The cover member45may include an upper cover portion46and a front cover portion47. The upper cover portion46may cover the upper portion of the gear housing41. The front cover portion47may cover the front portion of the gear housing41. The front cover portion47may protrude forward from the gear housing41and may serve as a sub-handle that can be grasped by the hand of the user. More specifically, during the polishing operation, the user may apply a pressing force to the polisher10via the sub-handle for pressing the polishing pad100against the target surfaces.

The rotation of the first bevel gear39attached to the front end of the motor shaft35may be transmitted to the output member65via the gear unit50. The mode selection device80used for selection between the forced rotation mode and the free rotation mode may be directly or indirectly mounted to the gear housing41.

The gear unit50may generally include a second bevel gear51, a driven shaft member52and an internal gear member70that are disposed within the gear housing41. The second bevel gear51may engage the first bevel gear39. The driven shaft member52may include a support shaft portion53and an eccentric shaft portion61that is connected to or integrated with the support shaft portion53. As shown inFIG. 7, the support shaft portion53may have the axis X1, while the eccentric shaft portion61may have the axis X2that is offset or displaced from the axis X1in the front-rear direction. The second bevel gear51may be attached to and supported by the support shaft portion53, so that the second bevel gear51may rotate with the support shaft portion53about the axis X1.

The upper housing portion42of the gear housing41may rotatably support the upper end of the support shaft portion53via an upper bearing521. The lower housing portion43of the gear housing41may rotatably support the lower end of the support shaft portion53via a lower bearing522. Each of the upper and lower bearings521and522may be a ball bearing. An upper counterweight55may be fitted on the support shaft portion53for rotation therewith. More specifically, the counterweight55may be joined to the second bevel gear51via a plurality of pins56each having an upper portion inserted into the counterweight55and a lower portion inserted into the second bevel gear51. Therefore, the counterweight55may rotate together with the second bevel gear51and eventually, together with the support shaft portion53.

The support shaft portion53may include a diameter-enlarged portion54positioned on the lower side of the lower bearing522. The diameter-enlarge portion54may have an outer diameter larger than that of the support shaft portion53. The eccentric shaft portion61may extend downward from the diameter-enlarged portion54. As described previously, the eccentric shaft portion61has the axis X2that is offset or displaced from the axis X1of the support shaft portion53, so that the eccentric shaft portion61makes a revolution (an eccentric motion) about the axis X1. The output member65may be mounted to the eccentric shaft portion61and may make a revolution (an eccentric motion) together with the eccentric shaft portion61.

A lower counterweight57may be mounted to the diameter-enlarged portion54and the eccentric shaft portion61in a manner astride between both portions in the axial direction, so that the lower counterweight57rotates together with the diameter-enlarged portion54and the eccentric shaft portion61about the axis X1. The lower counterweight57may cooperate with the upper counterweight55for balancing the eccentric motion of the output member65. Two bearings631and632may be interposed between the outer periphery of the eccentric shaft portion61and the inner periphery of the output member65so as to be arranged side-by-side in the axial direction. More specifically, each of the bearings631and632may have an inner race641, an outer race642and a plurality of bearing balls643interposed between the inner race64and the outer race642. The inner races641of the bearings631and632may be fixedly attached to the outer periphery of the eccentric shaft portion61via a first fixing member62. The outer races642of the bearings631and632may be fixedly attached to the inner periphery of the output member65via a second fixing member651. Therefore, the output member65can rotate about the axis X2relative to the eccentric shaft portion61via the bearings631and632.

The output member65may have an upper tubular portion and a lower tubular portion that are integrally formed in series with each other. The upper tubular portion may have a diameter larger than that of the lower tubular portion and may constitute the first fixing member651. The lower tubular portion may constitute a mount portion652to which the polishing pad100can be detachably attached. More specifically, a female thread may be formed on the inner circumferential surface of the mount portion652for engagement with the male screw105. The polishing pad100may have a mount flange101for attachment to the mount portion652. For attaching the polishing pad100to the output member65, the male screw105may be tightened into the female screw of the mount portion652while the mount flange101being positioned between the head portion of the male screw105and the lower end surface of the mount portion652. Thus, the mount flange101may be clamped between the head portion of the male screw105and the lower end surface of the mount portion652. With the polishing pad100attached to the output member65in this way, the polishing pad100may be fixed in position relative to the output member65.

An annular plate672may be fixedly attached to the lower portion of the output member65, more specifically, to a downwardly facing surface of a stepped portion formed between the upper tubular portion and the lower tubular portion of the output member65. Therefore, the annular plate672may move (revolve and rotate) together with the output member65. A support plate671serving as a dust cover may be fixedly attached to the lower end of the lower housing portion43via screws68. The support plate671may have a central support portion positioned on the lower side of the annular plate672and spaced vertically therefrom by a given distance. The central support portion of the support plate671may have a central opening through which the lower tubular portion of the output member65extends downward. An annular dust seal66may be interposed between the lower surface of the annular plate672and the upper surface of the central support portion of the support plate671. The dust seal66may be fixedly attached to the upper surface of the central support portion of the support plate671, so that the annular plate672may slidably contacts the upper surface of the dust seal66. More specifically, throughout the movement of the annular plate672, the entire circumference of the lower surface of the annular plate672may be in slide-contact with the upper surface of the dust seal66. Therefore, it may be possible to prevent dust and/or water from entering into the internal space of the gear housing41during the polishing operation. The dust seal66may have a two-layer structure including an upper layer and a lower layer. The lower layer may be adhered to the upper surface of the support plate671and may be formed of a sponge material. The upper layer may be attached to the upper surface of the lower layer and may be formed of a sheet material of high slidability.

A substantially cylindrical gear member69may be fixedly fitted on the upper tubular portion of the output member65so as to be rotatable together with the output member65about the axis X2. An external gear691that may be a spur gear may be formed on the outer circumferential surface of the gear member69. The external gear691may engage an internal gear71of the internal gear member70that will be described later.

The internal gear member70may be disposed on the radially outer side of the external gear member69. Similar to the external gear691, the internal gear71may be a spur gear and may be formed on the inner circumferential surface of the internal gear member70along a path of revolution of the output member65for engagement with the external gear691of the gear member69. The lower housing portion43of the gear housing41may support the internal gear member70via a bearing79, so that the internal gear member70can rotate relative to the gear housing41about an axis that may coincide with the axis X1of the support shaft portion53.

As shown inFIG. 9, the internal gear member70may have a substantially ring shape. The outer circumferential surface of the internal gear member70may include an upper half portion and a lower half portion that are configured differently from each other. More specifically, the lower half portion may be configured as a support circumferential surface72that may be a smooth surface fitted with the inner circumferential surface of the bearing79.

On the other hand, the upper half portion of the outer circumferential surface of the internal gear member70may be configured as a pin engaging portion73. The pin engaging portion73may include a plurality of engaging grooves74spaced equally from each other in the circumferential direction. In this embodiment, twelve engaging grooves74are provided. As will be explained later, an engaging pin81of the mode selection device80may be movable in a radial direction of the internal gear member70for engaging with any one of the engaging grooves74and for disengagement therefrom. When the engaging pin81engages any one of the engaging grooves74, the internal gear member70may be fixed in position relative to the gear housing41in the circumferential direction. When the engaging pin81disengages from the engaging grooves74, the internal gear member70may be free to rotate relative to the gear housing41.

Separating portions75may be each formed between two engaging grooves74arranged adjacent to each other in the circumferential direction. Each of the separating portions75may have a shape of a projection that projects radially outward with respect to the two engaging grooves74disposed on its opposite sides. The radially outer surface of each separating portion75may be configured as an engagement prohibiting surface76. The engagement inhibiting surface76may be inclined radially outward in a reverse rotational direction that is opposite to a normal rotational direction R1of the internal gear member70.

As will be explained later, the engagement prohibiting surfaces76may serve to prohibit engagement of the engaging pin81with the engaging grooves74when the rotational speed of the internal gear member70exceeds a predetermined speed.

As described above, the mode selection device80may include the engaging pin81. In addition, as shown inFIGS. 7, 9 and 10, the mode selection device80may further include a switch knob83and a biasing spring87. The engaging pin81may be inserted into an insertion hole formed in the lower housing portion of the gear housing41in the radial direction such that its head portion (the right end portion as shown according to the legend inFIG. 8) protrudes into the internal space of the gear housing41. The head portion of the engaging pin81may be configured to correspond to the grooved shape of the engaging grooves74. The engaging pin81may have an axial hole with a right closed end and a left open end for receiving the biasing spring87. A flange82may be formed on the end portion (the left end portion as shown in according to the legend inFIG. 8) opposite to the head portion. The flange82may serve to limit the stroke end of the engaging pin81in an engaging direction (i.e., the radial direction) toward the engaging grooves74. A guide shaft88may be inserted into the axial hole of the engaging pin81. The biasing spring87may be fitted over the guide shaft88so as to be arranged between the outer circumferential surface of the guide shat88and the inner circumferential surface of the axial hole of the engaging pin81. The biasing spring87may have opposite ends contacting the closed end of the axial hole of the engaging pin81and a flanged left end of the guide shaft88, respectively. The guide shaft88may serve to support the biasing spring87such that the biasing spring87is held to extend in the axial direction of the guide shaft88(i.e., the radial direction of the internal gear member70) during the movement of the engaging pin81. In this way, the biasing force of the biasing spring87can be adequately applied to the engaging pin81in the axial direction of the guide shaft88, so that the engaging pin81may be biased in the radial direction toward the internal gear member70. The flanged left end of the guide shaft88may slidably contact a radially outwardly flanged portion of the switching knob83by the biasing force of the biasing spring87.

The switching knob83may be mounted to the left side outer surface of the lower hosing portion43of the gear housing41via a screw85such that the knob can rotate about an axis of the screw85which lies parallel to the movement axis of the engaging pin81and the right-left axis, per the legend as shown inFIG. 8. In this way, the switching knob83may be configured as a rotary dial. The switching knob83may have a guide portion84formed on its inner side (right side). The guide portion84may define a cam surface841which may be contacted by the upper flange portion82of the engaging pin81due to the biasing force of the biasing spring87. The cam surface841may be configured such that its position in the left-to-right direction changes in the rotational direction of the switching knob83, so that the position in the left-to-right direction of the engaging pin81contacting the cam surface841may vary with a change of the rotational position of the cam surface841. As the switching knob83rotates in a clockwise direction, for example, from its counterclockwise limit position, to reach its clockwise limit position, the engaging pin81may move against the biasing force of the biasing spring87to reach a left limit position as shown inFIG. 8. In other words, the anti-biasing force amount applied to the engaging pin81in the left direction given by the cam surface841of the guide portion84may reach a maximum in this manner. The engaging pin81thus positioned at the left limit position may be away from the internal gear member70and may not interact with the engaging grooves74or the engagement prohibiting surfaces76of the internal gear member70.

On the other hand, as the switching knob83rotates in a counterclockwise direction, for example, from its clockwise limit, to reach its counterclockwise limit position, the anti-biasing force amount applied to the engaging pin81in the left direction given by the cam surface841of the guide portion84reaches a minimum, such that the biasing force of the biasing spring87is inhibited to a lesser degree, enabling the head portion of the engaging pin81to protrude into the internal space of the gear housing41at a right limit position as shown inFIG. 10. The engaging pin81thus positioned at the right limit position may engage any one of the engaging grooves74or may contact any one of the engagement prohibiting surfaces76. The engaging pin81having contacted with any one of the engagement prohibiting surfaces76may be brought to engage the adjacent engaging groove74as the internal gear member70rotates as will be explained later.

When the engaging pin81engages any one of the engaging grooves74of the internal gear70as shown inFIG. 10, the internal gear member71may be fixed in position relative to the gear housing41with respect to rotation. In this state, the gear member69is forced to rotate relative to the internal gear member70through engagement between the external gear691and the internal gear71, so that the output member65may rotate together with the gear member69and also together with the polishing pad100about the axis X2while the output member65revolves about the axis X1together with the gear member69and the polishing pad100. In this way, the polishing pad100may be forced to rotate about the axis X2while it revolves about the axis X1. This mode will be hereinafter called a “forced rotation mode.”

On the other hand, when the engaging pin81does not engage any of the engaging grooves74of the internal gear70and is at the left limit position as shown inFIG. 8, the internal gear member71may be free to rotate relative to the gear housing41. In this state, the polishing pad100may be free to rotate about the axis X2while it revolves about the axis X1. More specifically, depending on the load applied to the polishing pad100during the polishing operation, the polishing pad100may rotate about the axis X2at a speed equal to or lower than the revolution speed (around axis X1) of the polishing pad100or may not rotate about the axis X2. This mode will be hereinafter called a “free rotation mode.”

If the user wishes to change the operation mode from the free rotation mode to the forced rotation mode, the user may rotate the switching knob83in the clockwise direction to move the engaging pin81to the right limit position for engagement with any one of the engaging grooves74of the internal gear member70. However, it may be possible that the internal gear member70is already rotating at the time of change of the operation mode. This scenario poses the risk of the engaging pin81abruptly engaging any one of the engaging grooves74of the rotating internal gear member70, which would cause damage to the engaging pin81and/or the engaging grooves74. For this reason, in the present embodiment, the internal gear member70may be provided with the engagement prohibiting surfaces76that can prohibit abrupt engagement of the engaging pin81with the engaging grooves74when the internal gear member70rotates at a speed higher than a predetermined speed.

As described previously, the engagement prohibiting surfaces76may be inclined radially outward in a reverse rotational direction that is opposite to the normal rotational direction R1of the internal gear member70. Therefore, as the engaging pin81moves radially toward the rotating internal gear member70, the engaging pin81may first contact one of the engagement prohibiting surfaces76as shown inFIG. 11. As the internal gear member70further rotates, due to the radially outward force provided by the movement of surface76, against pin81and the radially inward biasing force of the biasing spring87, the engaging pin81may be forced to move radially outward as shown inFIG. 12such that it may traverse the engagement prohibiting surface76first contacted. Thereafter, the engaging pin81may contact the engagement prohibiting surface76positioned next to the previous one, in the rotational direction, and may consequently traverse that surface76as well. This action of the engaging pin81traversing the engagement prohibiting surfaces76may continue to occur until the rotational speed of the internal gear member70is lower than the predetermined speed, where the rotational speed of the internal gear member70is reduced to the extent that the radially outward centrifugal force applied to the engaging pin81by any of the engagement prohibiting surfaces76(hereinafter called “the last engagement prohibiting surface76”) becomes smaller than the biasing force of the biasing spring87). After the engaging pin81has contacted the last engagement prohibiting surface76, the internal gear member70may rotate in the opposite rotational direction by a small distance due to the biasing force applied by the engaging pin81, such that the engaging pin81may move along the last engagement prohibiting surface76so as to be brought to engage the engaging groove74positioned adjacent to the last engagement prohibiting surface76in the opposite rotational direction relative to the initial rotation of the internal gear member. In this way, the engagement prohibiting surfaces76may act in a multi-purpose manner, serving not only as a brake device for stopping the rotation of the internal gear member70but also as a guide device for guiding the engaging pin18for engagement with the engaging grooves74.

As described previously, the handle housing21of the handle20may include the right and left housing halves21R and21L that are joined together, and the power cord1may be drawn into the rear portion of the handle housing21. More specifically, a holding sleeve2may be attached to the rear portion of the housing21. The power cord1may be inserted into the holding sleeve2, so that the power cord1may extend from the inside to the outside of the handle housing21under the guide of the holding sleeve2. In this way, the holding sleeve2may serve as a support device or a guide device for the power cord1as well as serving as a holding device. In this embodiment, the holding sleeve2may be made of a resilient material, such as rubber, to allow resilient deformation or bending of the holding device2, while the original shape (substantially straight shape in this embodiment) of the holding device2may be normally kept when no load is applied to the holding sleeve2except for a load normally applied by the weight of the power cord1. Therefore, due to the guiding and support functions of holding sleeve2, it may be possible to prevent wires of the power cord1from being broken as a result of abruptly bending at a portion that is drawn from within the handle housing21, The extending direction of the power cord1through the holding sleeve2may coincide with the extending direction of the holding sleeve2. Therefore, the extending direction of the power cord1may change with a change of the extending direction of the holding sleeve2, which may be caused within a resiliently deformable range of the holding sleeve2, for example, by applying an external force to the holding sleeve2.

As shown inFIGS. 2 and 3, the extending direction of the power cord1from within the handle housing21may be inclined upward with respect to a polishing surface of the polishing pad100, which may contact a target surface G (i.e., a surface of an article, a machine or an equipment to be polished). In this embodiment, the polishing surface is the lower surface of the polishing sponge110. As long as the holding sleeve2maintains its original shape, for example, when no external force is applied to the holding sleeve2, the holding sleeve2may be inclined upward in the rear direction in the state of being attached to the handle housing21. More specifically, the holding sleeve2may be attached to the handle housing21in such a state that its longitudinal axis J is inclined upward by an angle α relative to the polishing surface (or the target surface G). Therefore, the extending direction of the power cord1may be also inclined upward by the angle α relative to the polishing surface. The angle α may be set, for example, to about 15 degrees.

A flange2amay be formed at the front end of the holding sleeve2and may have a substantially rectangular shape as viewed in the front-rear direction along the longitudinal axis J as shown inFIG. 4. An engaging groove21ahaving a substantially rectangular shape complementary to the shape of the flange2amay be formed in the rear end of the handle housing21. More specifically, the engaging groove21amay include a left part formed in the left housing half21L and a right part formed in the right housing half21R. The left part and the right part may jointly form the engaging groove21awhen the left housing half21L and the right housing half21R are joined together. Therefore, the flange2amay be engaged with the engaging groove21awhen the left housing half21L and the right housing half21R are joined together with the flange2apositioned between the left part and the right part of the engaging groove21a. With the flange2aengaged with the engaging groove21aof the rear end of the handle housing21, the holding sleeve2may be prevented from moving relative to the handle housing21in the direction of the longitudinal axis J and may be also prevented from rotating about the longitudinal axis J.

Referring toFIGS. 3 and 5, a cord fixing device3may be disposed within the rear portion of the handle housing21at a position on the front side of the engaging groove21a. The cord fixing device3may serve to fix a part of the power cord1that extends forward from the front end having the flange2aof the holding sleeve2. The cord fixing device3may include a receiving member3aand a fixing member3b. The receiving member3amay be fixedly attached to or integrated with the inner surface of the left housing half21L. A recess3aahaving a semicircular shape may be formed in the right side surface of the receiving member3a. The fixing member3bmay have a shape of a substantially flat plate and may be fixedly attached to the receiving member3awith a part of the power cord1positioned between the receiving member3aand the fixing member3b. In particular, power cord1may be engaged by the recess3aaof the receiving member3aand the right side surface of the fixing member3bfrom opposite sides (i.e., the left and right sides), fixedly clamping the power cord. Preferably, in constructing the housing, the operation for fixing the power cord1by the cord fixing device3may be performed before the left housing portion21L and the right housing portion21R are joined together. Thus, after the power cord1has been fixed by the cord fixing device3, the left housing portion21L and the right housing portion21R may be joined together, and at the same time, the flange2aof the holding sleeve2may be engaged with the engaging groove21a.

In the polisher10according to the first embodiment described above, the gear unit50is designed such that the rotational drive force is transmitted to the output member65to enable two different modes with respect to the rotational output of the polishing pad100(i.e., the forced rotation mode and the free rotation mode). In addition, for changing or selecting the output mode, the mode selection device80including the engaging pin81may be disposed in the gear housing41, which also supports the gear unit50. Therefore, the user can select the output mode from two different modes by operating the mode selection device80. In this way, two different polishing modes can be achieved without needing to change the polishing pad100.

In addition, in the above embodiment, the internal gear member70may be provided with the engagement prohibiting surfaces76that can prohibit engagement of the engaging pin81with the engaging grooves74when the internal gear member70rotates at a speed higher than the predetermined speed, as described above. Therefore, it may be possible to prevent potential damage to the engaging pin81and/or the engaging grooves74, which may be caused by abrupt engagement of the engaging pin81with the engaging grooves74. As a result, it may be possible to extend a lifetime of the polisher10.

Further, the engagement prohibiting surface76may be formed between each pair of adjacent engaging grooves74and may be configured as an inclined surface inclined radially outward in the direction opposite to the normal rotational direction R1. Therefore, the engagement prohibiting function can occur without need of a separate device apart from the internal gear member70. Furthermore, the engaging pin81may move in the radial inward direction towards the internal gear member70for engagement and disengagement with the engaging grooves74. Therefore, the engaging pin81may be disposed on a radially outer side of the internal gear member70. Hence, the polisher10may be designed to be compact in size in the axial direction of the internal gear member70, i.e., the vertical direction.

Furthermore, in the polisher10of the above embodiment, the power cord1may extend from the rear portion of the handle housing21(i.e., the rear portion of the handle20) in a direction inclined upward by the angle α that may be 15 degrees. With this arrangement, it may be possible to inhibit or minimize such an occasion that the power cord1accidentally contacts the target surface G to be polished, during the polishing operation. As a result, the polishing operation can be quickly performed to achieve a fine finish of the target surface G without undesired interference by the power cord contacting the target surface. Further, as shown inFIG. 6, it is possible for a user M to perform the polishing operation of the target surface G by the polisher10while the power cord1of the polisher10is hung over his/her shoulder, to prevent the power cord1from contacting the target surface G or any other surfaces. In this case, because of the upward inclination of the power cord1from the rear portion of the handle20, it is also possible to prevent a portion of the power cord1extending between the rear portion of the handle20and the shoulder S of the user M from being abruptly bent or curved, aiding in preventing potential breakage of wires of the power cord1.

The upward inclination angle α with respect to the polishing surface (or the target surface G) of the extending direction of the power cord1from the rear portion of the handle20, i.e., the extending direction of the holding sleeve2, may not be limited to 15 degrees. For example, the upward inclination angle α may be set within a range of about 5 to 90 degrees. Preferably, the upward inclination angle α may be set such that the upper end of the holding sleeve2is lower than a height H (seeFIG. 3) of the polisher10with respect to the polishing surface (or the target surface G) and may be, for example, within a range of about 10 to 60 degrees. With this setting of the upward inclination angle α, it may be possible to prevent a potential deformation (bending or curving) of the holding sleeve2when the polisher10is stored within a limited storage space.

Further, although the upward inclination angle α of the extending direction of the power cord1is a fixed value in the above embodiment, it may be possible to configure such that the upward inclination angle α can be adjusted to a desired value. For example, the holding sleeve2may be pivotally connected to the rear portion of the handle20such that the holding sleeve2can be tilted vertically relative to the handle20. In this case, a fixing device may preferably be provided for fixing the tilt position of the holding sleeve2. With this arrangement, it may be possible to adjust the upward inclination angle α, for example, depending on a posture to be taken by the user during the polishing operation. As a result, it may be possible to further reliably inhibit or minimize such an occasion that the power cord1accidentally contacts the target surface G to be polished, during the polishing operation. Further, it may be possible to further reliably prevent the power cord1from being abruptly bent or curved, whereby it may be possible to further reliably prevent potential breakage of wires of the power cord1.

Second Embodiment

A second embodiment will now be described with reference toFIGS. 13 to 15. The second embodiment is a modification of the first embodiment. Therefore, inFIGS. 13 to 15, like members are given the same reference numerals as the first embodiment, and a description of these members will be omitted. Further, as reference numerals of members that are similar to those of the first embodiment but are somewhat different in construction or shape from them, the reference numerals of the corresponding members of the first embodiment may be used with an alphabet “A” affixed to the last digit of each reference numeral.

A polisher10A of the second embodiment may be different from the polisher10of the first embodiment mainly in the construction of an internal gear member70A, a mode selection device80A and their associated structure.

The internal gear member70A may be different from the internal gear member70of the first embodiment in that a pin engaging portion73A is disposed at a different position from the pin engaging portion73. More specifically, the pin engaging portion73A may be disposed at an upper surface77A, i.e., one of two surfaces of the internal gear member70A facing opposite to each other. The pin engaging portion73A may include a plurality of engaging grooves74A spaced equally from each other in the circumferential direction. Also in this embodiment, twelve engaging grooves74A are provided. Each of the engaging grooves74A may have a substantially circular shape for engagement with an engaging pin81A of the mode selection device80A.

Separating portions75A may be each formed between two engaging grooves74A arranged adjacent to each other in the circumferential direction. Each of the separating portions75A may have a shape of a projection protruding upward with respect to the two engaging grooves74A disposed on its opposite sides. The upper surface of each separating portion75A may be configured as an engagement prohibiting surface76A. The engagement prohibiting surface76A may be inclined upward in a reverse rotational direction that is opposite to a normal rotational direction R1of the internal gear member70A.

Similar to the engagement prohibiting surfaces76of the first embodiment, the engagement prohibiting surfaces76A may serve to prohibit engagement of the engaging pin81A with the engaging grooves74A when the rotational speed of the internal gear member70A exceeds a predetermined speed. Also in this embodiment, the mode selection device80A may be directly or indirectly mounted to the gear housing41A for enabling selection between the forced rotation mode and the free rotation mode.

Similar to the mode selection device80of the first embodiment, the mode selection device80A may include a switch knob83A and a biasing spring87A in addition to the engaging pin81A as shown inFIGS. 13 and 14. The engaging pin81A may be inserted into an insertion hole formed in the gear housing41A in the axial direction (i.e., a direction parallel to the axes X1and X2) such that its head portion (the lower end portion as viewed inFIGS. 13 and 14) protrudes into the internal space of the gear housing41A. The head portion of the engaging pin81A may be configured to correspond to the grooved shape of the engaging grooves74A. The engaging pin81A may have an axial hole with a lower closed end and an upper open end for receiving the biasing spring87A. A flange82A may be formed on the upper end portion opposite to the head portion. A guide shaft88A may be inserted into the axial hole of the engaging pin81A. The guide shaft88A may have a flanged upper end that is fixedly attached to the inner wall of the upper part of the lower housing portion43of the gear housing41A, so that the guide shaft88A protrudes downward toward the internal gear71A of the internal gear member70A. The biasing spring87A may be fitted over the guide shaft88A and may have opposite ends contacting the closed end of the axial hole and the flanged upper end of the guide shaft88A, respectively, so that the engaging pin81may be biased downward toward the internal gear71A.

The switching knob83A may be mounted to the upper surface of the left side portion of the lower hosing portion43of the gear housing41A via a screw85A such that it can rotate about an axis of the screw85A which lies parallel to the movement axis of the engaging pin81A, and the up-down axis. In this way, the switching knob83A may be configured as a rotary dial. The switching knob83A may have a guide portion84A formed on its inner side (lower side). The guide portion84may define a cam surface which the flange portion82A of the engaging pin81A contacts due to the downwards biasing force of the biasing spring87A. The cam surface of the guide portion84A may be configured such that its position in the vertical direction is effected by the rotational direction of the switching knob83A, such that, consequently, due to the biasing force of spring87A the position in the vertical direction of the engaging pin81contacting the cam surface may change according to the rotational position of the guide portion84A. As the switching knob83A rotates in a counterclockwise direction, for example, from its clockwise limit position to its counterclockwise limit position, due to the cam surface providing an anti-biasing force in the upwards direction, the engaging pin81A may move upward against the downwards biasing force of the biasing spring87A, such that the engaging pin81A may reach an upper limit position as shown inFIG. 13. In this position, the anti-biasing force amount acting upwards on the engaging pin81A provided by the cam surface of the guide portion84A may reach a maximum. The engaging pin81A thus positioned at the upper limit position may be distal to the internal gear member70A and is prevented from interacting with the engaging grooves74A and the engagement prohibiting surfaces76A.

On the other hand, as the switching knob83A rotates in a clockwise direction, for example, from the counterclockwise limit position to its clockwise limit position, the anti-biasing upwards force acting on the engaging pin81A provided by the cam surface of the guide portion84A may reach a minimum. Therefore, the engaging pin81A may move in a manner where the downwards biasing force of the biasing spring87A is inhibited to a minimal degree by the cam surface of the guide portion84A, where the pin may reach a lower limit position as shown inFIG. 14. The engaging pin81A thus positioned at the lower limit position is able to engage any one of the engaging grooves74A or contact any one of the engagement prohibiting surfaces76A. Similar to the first embodiment as described above, the engaging pin81A contacting any one of the engagement prohibiting surfaces76A may be brought to engage the adjacent engaging groove74A as the internal gear70A rotates, depending on the speed.

Also in this second embodiment, it may be possible to achieve a forced rotation mode and a free rotation mode of the polishing pad100by the operation of the switching device80A. In addition, when the engaging pin81A moves downward as a result of the operation of the switching device80afor changing from the free rotation mode to the forced rotation mode, the engagement prohibiting surfaces76A may prevent engagement of the engaging pin81A with the engaging grooves74A until the rotational speed of the internal gear member70A is reduced to be lower than a predetermined speed (in other words, until the force applied to the engaging pin81A in the upward direction by any of the engagement prohibiting surfaces76A becomes smaller than the downwards biasing force of the biasing spring87A, analogous to the engagement prohibiting surfaces76acting with the biasing spring87, as described above).

In the second embodiment, the pin engaging portion73A may be disposed at the upper surface77A of the internal gear member70A. Therefore, the pin engaging portion73A may be positioned on a radially inner side compared to the pin engaging portion73of the first embodiment, where the pin engaging portion73is disposed on the outer circumferential surface of the internal gear member70A. As a result, the circumferential speed of the pin engaging portion73A may be lesser than the circumferential speed of the pin engaging portion73of the first embodiment during the rotation of the internal gear70(70A). In addition, the circumferential speed of the pin engaging portion73A may vary with a change of the position of the pin engaging portion73A in the radial direction. Hence, the arrangement of the second embodiment provides a degree of freedom in design of the internal gear member with respect to the circumferential speed of the pin engaging portion73A.

Third Embodiment

A third embodiment will now be described with reference toFIGS. 16 and 17. Also, the third embodiment is a modification of the first embodiment. Therefore, inFIGS. 16 and 17, like members are given the same reference numerals as the first embodiment, and a description of these members will be omitted. Further, as reference numerals of members that are similar to those of the first embodiment but are somewhat different in construction or shape from them, the reference numerals of the corresponding members of the first embodiment may be used with an alphabet “B” affixed to the last digit of each reference numeral.

A polisher10B of the third embodiment may be different from the polisher10of the first embodiment mainly in the construction relating to a driven shaft member52B and an eccentric shaft portion61B. Further in the second embodiment, the polishing pad100may be replaced with a polishing pad90. The construction of an internal gear member70B may be the same as the construction of the internal gear member70of the first embodiment. In addition, the construction of a mode selection device80B may be the same as the construction of the mode selection device80.

In the third embodiment, a gear unit50B may generally include a second bevel gear51B, the driven shaft member52B and the internal gear member70B. The second bevel gear51B, the driven shaft member52B and the internal gear member70B may be disposed within a gear housing41B. The second bevel gear51B may engage the first bevel gear39(not shown inFIGS. 16 and 17, seeFIG. 7). The driven shaft member52B may include a support shaft portion53B and the eccentric shaft portion61B. The second bevel gear51B may be attached to and supported by the support shaft portion53B, so that the second bevel gear51B may rotate together with the support shaft portion53B about an axis X1. The support shaft portion53B may have a lower portion with an enlarged diameter portion54B. The enlarged diameter portion54B may have a shaft receiving hole56B having an axis X2that is offset or displaced from the axis X1. The eccentric shaft portion61B may be inserted into and rotatably supported within the shaft receiving hole56B via bearings631B and632B, so that the eccentric shaft portion61B can rotate about the axis X2. In this embodiment, the bearing631B may be a needle bearing, while the bearing632B may be a ball bearing. The enlarged diameter portion54B of the driven shaft member52B may be rotatably supported by the gear housing41B via a lower bearing522B that may be a ball bearing. An upper counterweight55B may be fixedly attached to the support shaft portion53B so as to rotate therewith. A lower counterweight57B may be fixedly attached to the diameter enlarged portion54B.

In this way, the support shaft portion53B may rotate about the axis X1, while the eccentric shaft portion61B may rotate about the axis X2. A mount portion652B may be formed on the lower end portion of the eccentric shaft portion61B. The polishing pad90may be detachably attached to the mount portion652B via a screw93B.

In this embodiment, the polishing pad90may have a function similar to that of the polishing pad100of the above embodiments. In addition, the polishing pad90of this embodiment may have additional functions that may be similar to the functions of the output member65and the gear member69of the first embodiment. More specifically, the polishing pad90may include a pad body91configured to be similar in function to the polishing pad100, an attaching portion92configured to be similar in function to the output member65, and a gear portion95configured to be similar in function to the gear member69. The pad body91, the attaching portion92and the gear portion95may be formed integrally with each other. The attaching portion92may be attached to the mount portion652B of the eccentric shaft portion61B via the screw93B. The gear portion95may be disposed on the upper side of the pad body91and may serve to engage the internal gear71B of the internal gear member70B. Although not shown in the drawings, a polishing material similar to the polishing sponge110of the first embodiment and defining a polishing surface may be detachably attached to the lower surface of the pad body91via an appropriate attaching device.

In this embodiment, the support shaft portion53B may rotate about the axis X1, and the eccentric shaft portion61B may be supported by the support shaft portion53B via the bearings631B and632B so as to be rotatable about the axis X2that is displaced or offset from the axis X1. As the eccentric shaft portion61B rotates about the axis X2, the polishing pad90may rotate together with the eccentric shaft portion61B about the axis X2. In this way, the polishing pad90can revolve about the axis X1, while it can rotate about the axis X2. The lower counterweight57B may cooperate with the upper counterweight55B for balancing the eccentric motion of the polishing pad90.

The internal gear member70B and the mode selection device80B may be configured to be substantially the same as the internal gear member70and the switch device80of the first embodiment, respectively. More specifically, the internal gear member70B may have a substantially ring shape and may be rotatably supported by the gear housing41B via a bearing79B. The outer circumferential surface of the internal gear member70B has an upper half portion and a lower half portion. The lower half portion may fitted with the inner circumferential surface of the bearing79B. The upper half portion of the outer circumferential surface of the internal gear member70B may be configured as a pin engaging portion73B that may include a plurality of engaging grooves74B spaced equally from each other in the circumferential direction. In this embodiment, twelve engaging grooves74B are provided. An engaging pin81B of the mode selection device80may be movable in a radial direction towards and away from the internal gear member70B for engaging with and disengaging from any one of the engaging grooves74B.

Although not shown inFIGS. 16 and 17, separating portions similar to the separating portions75of the first embodiment may be each formed between two engaging grooves74B arranged adjacent to each other in the circumferential direction. Each of the separating portions may have a shape of a projection that protrudes radially outward with respect to the two engaging grooves74B disposed on its opposite sides. The radially outer surface of each separating portion may be configured as an engagement prohibiting surface similar to the engagement prohibiting surface76of the first embodiment.

Fourth Embodiment

A fourth embodiment will now be described with reference toFIGS. 18 and 19. The fourth embodiment is a modification of the third embodiment. Therefore, inFIGS. 16 and 17, like members are given the same reference numerals as the third embodiment, and a description of these members will be omitted. Further, as reference numerals of members that are similar to those of the third embodiment but are somewhat different in construction or shape from them, the reference numerals of the corresponding members of the first embodiment may be used with an alphabet “C” affixed to the last digit of each reference numeral, instead of the alphabet “B”.

A polisher50C according to the fourth embodiment may be similar to the polisher50B of the third embodiment but may be different from the polisher50B in that the pin engaging portion73A and the mode selection device80A of the second embodiment are incorporated. Thus, a gear unit50C of the polisher50C may be similar to the gear unit50B of the third embodiment but may be different from the gear unit50B in that an internal gear member70C has the pin engaging portion73A. In addition, the mode selection device80B is replaced with the mode selection device80A of the second embodiment. Also in this embodiment, it may be possible to achieve the same advantages as the second embodiment in addition to the advantages that may be achieved by the construction of the gear unit50B and the polishing pad90of the third embodiment.

The above embodiments may be modified in various ways. For example, the gear unit50(50A,50B,50C) may incorporate any other constructions than those in the above embodiments as long as they can transmit the rotational movement of the motor32to the polishing pad100(90) as a revolution motion about the axis X1while allowing rotation of the polishing pad about the axis X2. Further, the engaging mechanism constituted by the engaging pin81(81A,81B) and the pin engaging portion73(73A,73B) may be replaced with any other engaging mechanisms as long as they can engage and disengage the internal gear (71,71A,71B).

Representative, non-limiting examples were described above in detail with reference to the attached drawings. The detailed description is intended to teach a person of skill in the art details for practicing aspects of the present teachings and thus is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be applied and/or utilized separately or in conjunction with other features and teachings to provide improved polishers, and methods of making and using the same.

All features disclosed in the description and/or the claims are intended to be disclosed as informational, instructive and/or representative and may thus be construed separately and independently from each other. In addition, all value ranges and/or indications of groups of entities are also intended to include possible intermediate values and/or intermediate entities for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.