Patent Application
20090183887
The present invention relates to a power hand tool system and more particularly to a motorized power hand tool system.
Power tools including battery operated tools are well-known. These tools typically include an electric motor having an output shaft that is coupled to a spindle for holding an implement. The implement may be a drill bit, sanding disc, a de-burring implement, or the like. Electrical power is supplied to the electric motor from a power source. The power source may be provided to the power tool through a cord. Alternatively, the power source may be a battery source such as a Ni-Cad or other rechargeable battery that may be de-coupled from the tool to charge the battery and coupled to the tool to provide power.
Such power tools may be designed for a variety of special uses. Relatively small rotary hand tools have been marketed for many years for use in carrying out woodworking and metal working tasks by hobbyists as well as commercial artisans. These small rotary hand tools, like the larger power tools, generally have a motor unit with a rotary output shaft that is adapted to be connected to a number of implements such as sanding implements, rotary cutting implements, planing attachments, filing implements, buffing implements and polishing implements.
The foregoing implements are typically sold separately or as a part of a combined set. In addition to the implements that are used with the rotary tools, various attachments are also available. A common example of an attachment is a cutting guide attachment that is installed onto the rotary tool for use with a cutting implement to guide the cutting path of the rotary tool in a controlled manner relative to a work-piece. Other attachments available include work lights, tool and blade sharpeners, grout removal guides, holders, routing attachments, drilling attachments and shaper tables.
Many of the implements identified above may be provided with a long flexible shaft that transfers the rotary movement of the output shaft of the rotary tool to the implement. The use of a flexible shaft provides a number of advantages. For example, the implement may be much more maneuverable since the additional bulk of the rotary tool motor need not be manipulated. Additionally, the implement may be fashioned within a housing that is better adapted to the manner in which the implement will be gripped when in use.
The provision of an implement with a flexible shaft does, however, incur some disadvantages. For example, the implement cannot be directly connected to the rotary tool. Thus, even when the maneuverability of the flexible shaft is not required, the flexible shaft must still be connected. Alternatively, a user can purchase one implement with a flexible shaft and a second instrument without a flexible shaft. This alternative obviously increases both the cost of a tool set as well as the storage area required for the tools set.
Moreover, the flexible shafts must be accounted for within the storage container. For example, when tool kits are sold, a storage container is frequently provided which is specially formed to both organize the implements and to protect the implements. While providing for one implement with a flexible shaft may not be overly cumbersome within a storage container, the arrangement of a number of different flexible shafts within a single container may become a significant problem when each such shaft is connected to an implement with its own unique storage requirements.
There is a need to reduce the number of redundant implements that must be maintained without losing the flexibility of using an implement either directly connected to a rotary tool or connected to the rotary tool through a flexible shaft. There is a further need to reduce the number of shafts that are needed to provide for the use of various implements with a flexible shaft.
Some of the limitations of previously known hand power tools may be overcome by a rotary tool system and method of operating. In one embodiment, a rotary tool system includes a rotary tool with a rotary motor, an output shaft operatively connected to the motor for transferring rotational force from the motor and a first coupler assembly, a flexible power transmission shaft including a first end portion with a second coupler assembly configured to removably couple with the first coupler assembly, a transfer shaft operatively coupled with the output shaft for receiving rotational force from the output shaft, and a third coupler assembly located at a second end portion of the flexible power transmission shaft and at least one implement, the at least one implement including a fourth coupler assembly configured to removably couple with the second coupler assembly and an input shaft operably connected to the transfer shaft for receiving rotational force from the transfer shaft.
In another embodiment, a universal flexible shaft includes a transfer shaft having a first end portion and a second end portion, a first coupler assembly located at the first end portion for removably coupling with a rotary tool and a second coupler assembly located at the second end portion for removably coupling with a rotary tool implement.
One method of operating a rotary tool system includes coupling a first end portion of a transfer shaft assembly to a rotary tool, coupling a second end portion of the transfer shaft assembly to a first implement, transferring rotational movement of the rotating tool to the first implement through the transfer shaft assembly, decoupling the first end portion of the transfer shaft assembly from the rotary tool and decoupling the second end portion of the transfer shaft assembly from the first implement.
The present invention may take form in various system and method components and arrangement of system and method components. The drawings are only for purposes of illustrating exemplary embodiments and are not to be construed as limiting the invention.
A power tool system generally designated 100 is shown in
The flexible shaft 104 includes a female coupler assembly 116 which is configured to be coupled with the male coupler assembly 108. The female coupler assembly 116 includes a threaded coupler 118 and the end portion 122 of a transfer shaft 120 which extends outwardly from the threaded coupler 118. The transfer shaft 120 extends from the female coupler assembly 116 to a male coupler assembly 126 located at the opposite end of the flexible shaft 104. The transfer shaft 120 is located within a sheath or casing 128 with a coil support 130 disposed between the transfer shaft 120 and the casing 128 as shown in
The transfer shaft 120 is preferably made from a flexible metal while the casing 128 is preferably made of durable, inexpensive, thermoformable plastic material such as polyvinylchloride (PVC). Other suitable materials for these components are contemplated. The coil support 130 allows the transfer shaft 120 to rotate within the casing 128. Coiled, spring-like bend protectors 132 and 134 are located at the end portions of the casing 128 to restrict the ability of the flexible shaft 104 to bend at the end portions of the casing 128.
The male coupler assembly 126, in this embodiment, is configured in the same manner as the male coupler portion 108. Thus, the male coupler assembly 126 includes an output shaft 136 with a recess 138 and a threaded coupler 140. A collet 142 is configured to fit over the output shaft 136.
Returning to
The power tool system 100 further includes an implement 144 shown in
The housing 146 is made from a lightweight material and is shaped to be easily held by a user as shown in
As discussed above, the male coupler assembly 126 is identical to the male coupler assembly 108. Accordingly, the drive shaft (not shown) of the implement 144 also couples with the output shaft 106 through the recess 112 and the threaded portion (not shown) of the implement 144 mates with the threaded coupler 110 to provide the configuration shown in
An alternative implement 154 is shown in
Referring to
An eccentric member 180 is connected to the end of the main drive shaft 172. The eccentric member 180 includes a coupling portion 182, a mid portion 184 and an end portion 186. The eccentric member 180 is made of steel. The coupling portion 182 is configured to couple with the main drive shaft 172 via a friction fit. As best seen in
Returning to
In operation, the implement 154 is mounted to either the rotary tool 102 or the flexible shaft 104. In this example, the implement 154 will be mounted to the flexible shaft 104. Accordingly, the input drive shaft 170 is inserted through the collet 142 and into the recess 138. The overthrow nut mechanism 158, which is a female coupler assembly, is then used to firmly couple the implement 154 with the male coupler assembly 126 of the flexible shaft 104. As a user rotates the outer sleeve 162 in a first direction, the threads of the nut 164 engage the threads of the threaded coupler 140. Continued rotation of the sleeve 162 forces the threads of the nut 164 to firmly engage the threads of the threaded coupler 140, thereby rotationally coupling the input drive shaft 170 with the output shaft 136 as the nut 164 compresses the collet 142 to bind the input drive shaft 170 within the recess 138.
The flexible shaft 104 is similarly mounted to the rotary tool 102. The end portion 122 of the transfer shaft 120 is inserted through the collet 114 and into the recess 112. The female coupler assembly 116 is then used to firmly couple the flexible shaft 104 with the male coupler assembly 108 of the rotary tool 102. As a user rotates the threaded coupler 118 in a first direction, the threads of the threaded coupler 118 engage the threads of the threaded coupler 110. Continued rotation of the threaded coupler 118 forces the threads of the threaded coupler 118 to firmly engage the threads of the threaded coupler 110, thereby rotationally coupling the transfer shaft 120 with the output shaft 106 as the threaded coupler 118 compresses the collet 114 to bind the end portion 122 of the transfer shaft 120 within the recess 112.
Next, the rotary tool 102 is energized. In this embodiment, energization is accomplished using a switch on the rotary tool 102. In alternative embodiments, energization of the rotary tool may be accomplished using a switch on the implement. Energization of the rotary tool 102 causes the motor (not shown) to rotate which in turn causes the output shaft 106 to rotate. The output shaft 106 is coupled with the transfer shaft 120, preferably through the use of a keyed configuration, while the transfer shaft 120 is rotatably supported by the coil support 130. Accordingly, rotation of the output shaft 106 causes the transfer shaft 120 to rotate.
The transfer shaft 120 is coupled, through the output shaft 136, with the input drive shaft 170, preferably through the use of a keyed configuration. Accordingly, rotation of the transfer shaft 120 causes the input drive shaft 170 to rotate. The input drive shaft 170 is coupled with the main drive shaft 172 which is rotatably supported by the bearings 174 and 176. Thus, rotation of the input drive shaft 170 is transferred to the main drive shaft 172 which in turn causes rotation of the eccentric member 180.
The eccentric member 180 is operatively coupled to the pad holder 194 through the bearing 190. Thus, rotation of the eccentric member 180 provides the orbital motion for the pad holder 194. The centerline of the bearing 190, however, is offset from the axis 188 of the main drive shaft 172 and the pad holder 194 is free to rotate about the bearing 190. Accordingly, movement of the pad holder 194 is not purely orbital. This eccentric movement creates the random orbital movement also known in the trade as dual action.
The rotational speed of a rotary tool such as the rotary tool 102 can be several thousand rounds per minute. For some applications, the cycling of the particular instrument is preferably much lower. Additionally, some instruments require reciprocating motion. The implement 200 shown in
The implement 200 includes a drive train assembly 210 and a cam follower assembly 212 shown in
The planetary gear set 220 reduces the rotational speed between the input and the output of the planetary gear set 220 as more fully detailed in U.S. Patent Publication No. 2005/0252670, published Nov. 17, 2005, the teaching of which is herein incorporated in its entirety by reference. Additionally, the threaded cylinder 222 cooperates with the knob 224 to convert rotational movement to reciprocating movement. More specifically, as the threaded cylinder 222 rotates, the knob 224 is forced to move in an axial direction, thereby creating a reciprocating movement.
The features identified above may be provided in a number of different combinations for a variety of implements. Referring to
Referring to
A working attachment or bit 258, may be coupled with an attachment such as, but not restricted to a drill bit, a polishing disk, a grinding wheel, a sanding wheel, a cutting wheel or bit, a wire brush, a saw or other known rotary tool attachment. Preferably, one or more attachments are provided in the power tool system 250. The implement 252 is designed for enhancing user control of the rotary action of an attachment coupled with the bit 258 for delicate and/or difficult to reach operations. As such, the implement 252 is easier and lighter to hold than the main rotary tool (not shown).
The implement 252 further includes a lock-out activator 260 which can temporarily lock the bit 258 from rotation. The lock-out activator is configured such that a single hand may be used to hold the implement 250 and to operate the lock-out activator 260. This operation is helpful when exchanging working attachments. In one embodiment, the lock-out activator 260 is preferably a single pin or button for releasable engagement with a drive shaft coupled with the bit 258.
In operation, a user merely depresses the lock-out activator 260 into the implement 250. The lock-out activator 260 may be outwardly biased by a spring (not shown) so as to hold an actuator out of engagement with the drive shaft or the bit 258. In one embodiment, the spring is a flat spring formed into a “C”-shape, and defines a gap facing away from the lock-out activator 260. Thus, depression of the lock-out activator 260 interferes with rotation of the bit 258.
While the present invention has been illustrated by the description of exemplary processes and system components, and while the various processes and components have been described in considerable detail, the applicant does not intend to restrict or in any limit the scope of the appended claims to such detail. Additional advantages and modifications will also readily appear to those skilled in the art. The invention in its broadest aspects is therefore not limited to the specific details, implementations, or illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept disclosed herein.
