Patent Application
20070248429
This invention relates to the field of hand held rotary tools and related accessories.
Hand held rotary tools are widely used by many people, including craftspeople, homeowners, and artists. These rotary tools typically include an outer housing designed to be easily held within a human hand. The housing retains an electric motor which is operable to drive a rotatable chuck of the rotary tool. A mandrel may be releasably coupled to the chuck so as to be rotatably driven by the rotary tool. In turn, an accessory may be releasably secured to the mandrel thereby enabling the rotary tool to rotatably drive the accessory. The accessory may be a cut-off wheel, a polishing wheel, a grinding wheel, a sanding disc, or any other similar member.
There exists a variety of mandrels that are configured to releasably secure an accessory thereto. One such mandrel includes a base having a threaded aperture and a clamping screw that cooperate to clamp the accessory to the mandrel between the base and the clamping screw. With the accessory so clamped, rotation of the mandrel by the rotary tool causes rotation of the accessory thereby allowing the user to perform work on a workpiece.
In order to change an accessory that is secured to a mandrel of the type described above, it is typically necessary to loosen and remove the clamping screw from the base. Of course, in order to loosen the clamping screw, the user must first obtain an appropriately sized screwdriver, which may not be immediately available to the user. Furthermore, some users find the task of turning a screw tedious. Also, once the clamping screw is separated from meshing engagement from the base, the clamping screw is susceptible to being inadvertently dropped and lost since it is a relatively small, separate component.
Mandrels that overcome the shortcomings of the threaded aperture mandrel are disclosed in U.S. patent application Ser. No. 11/187,139 and U.S. patent application Ser. No. 11/187,140, both filed on Jul. 21, 2005, which are herein incorporated by reference. The mandrels disclosed in these two applications incorporate a specifically configured coupling portion which is used with a complimentarily formed hub component on an accessory to removably couple the accessory to the mandrel.
While the mandrels with specifically configured coupling portions are a significant improvement over the threaded aperture mandrels, the availability of multiple types of mandrels presents various problems. By way of example, to account for multiple mandrel types, a manufacturing entity must be tooled to produce accessories that are compatible with both types of mandrels. Thus, for each accessory manufactured, such as a cut-off wheel, a polishing wheel, a grinding wheel, a sanding disc, or any other similar accessory, at least two different hub components must be manufactured for each type of accessory. Moreover, each type of accessory must be specially marked to identify the particular type of mandrel the accessory is to be used with.
The use of multiple types of mandrels by consumers presents additional problems in a retail setting. As an initial matter, when exhibiting a single type of accessory, each mandrel type should be separately displayed. Thus, valuable shelf space is lost merely to provide for each type of mandrel. Moreover, each additional type of mandrel increases the administrative burden of properly stocking an adequate number of accessories. Finally, it is inevitable that some customers will purchase an accessory designed for a mandrel other than the type owned by the customers. This leads to additional administrative burdens on the retailer as well as delay and frustration for the customers.
What is needed is a configuration for an accessory that reduces the problems associated with the use by consumers of multiple types of mandrels. It would be beneficial if the configuration was easily incorporated into the manufacturing process and could be used with multiple types of accessories.
In accordance with one embodiment of the present invention, there is provided a rotary tool accessory with a work portion and a hub portion operably connected to the work portion for rotating the work portion. The hub portion includes a first mandrel mounting portion on a first side of the hub portion for mounting with a first mandrel type and a second mandrel mounting portion on a second side of the hub portion for mounting with a second mandrel type, wherein the second mandrel type is different from the first mandrel type.
In accordance with another embodiment of the present invention, there is provided a rotating tool accessory mounting hub with a first mounting element configured to receive a complimentarily keyed mandrel for mounting the hub to the keyed mandrel. The hub includes a second mounting element configured to be compressed against a mandrel having a threaded bore, the second mounting element defining a hole sized to allow the shaft of a screw to pass therethrough.
Pursuant to yet another embodiment there is provided a rotary tool accessory that includes a work portion and a first mounting element operably connected to the work portion for rotating the work portion. The first mounting element includes a slot for receiving a keyed portion of a mandrel. The accessory also includes a second mounting element operably connected to the work portion for rotating the work portion and including a bore for receiving the shaft of a screw.
The mandrel shaft 16 is comprised of a rigid material, such as steel. Referring to
Elongated grooves 30 (only one is shown in
With reference to
Returning to
As best seen in
To assemble the mandrel assembly 14, the elongated grooves 30 are aligned with the tangs 46 and 48 on the collar teeth 42 and 44 and the mandrel shaft 16 is inserted into the opening 40. When fully inserted, the opposing shaft teeth 26 and 28 abut the head portion 34 of the collar 18 at the landing areas 50 and 52. The spring 58 is then inserted within the inner wall 56 of the collar 18 and about the mandrel shaft 16. The retainer 60 is then moved along the mandrel shaft 16 until it snaps into the circular groove 32. At this point, the spring 58 is under compression and is retained about the mandrel shaft 16 between the retainer 52 and the circular head wall 38 of the collar 18. The spring 58 biases the collar 18 away from the second end portion 24 of the shaft 16. The retainer 60 provides a stop for the collar 18, allowing the collar 18 to slide along the mandrel shaft 16 between a first position in which the landing areas 50 and 52 are pressed against the shaft teeth 26 and 28 and a second position in which the spring 58 is compressed with the landing areas 50 and 52 spaced apart from the shaft teeth 26 and 28.
With the tangs 46 and 48 of the collar teeth 42 and 44 properly positioned in the elongated grooves 30 of the shaft 16, the collar teeth 42 and 44 are angularly offset from the shaft teeth 26 and 28. This angular offset allows movement of the shaft teeth 26 and 28 along the collar teeth 42 and 44 and the axis 20, so that the shaft teeth 26 and 28 may be in the same plane as the collar teeth 42 and 48, such as when they abut the landing areas 50 and 52. Alternatively, they may be moved to a position above the plane of the collar teeth 42 and 48, so as to be spaced apart from the landing areas 50 and 52. Advantageously, the tangs 46 and 48 slide along the elongated grooves 30 on the mandrel shaft 16 during movement of the collar 18 in the axial direction, and thereby prevent rotation of the collar 18 with respect to the shaft 16 which would disturb the angular offset relationship between the collar teeth 42 and 44 and the shaft teeth 26 and 28.
Various accessories may be attached to the mandrel assembly 14. One such accessory shown in the embodiment of
Also visible in
The spacer 88 is made from a strong rigid metallic material which in this embodiment is stamped into a pan-like shape to form the spacer portion 92 and the inner wall portion 90. The outer wall 70 is likewise formed from a strong rigid metallic material which is stamped into a pan-like shape complimentary to the spacer 88 to form the inwardly extending portion 94. Both the spacer bore 94 and the slot 68 may be formed prior to or after the stamping of the respective component. Alternatively, the spacer bore 64 and the slot 68 may be formed during the stamping of the component. After stamping of the components, the spacer 88 is joined to the outer wall 70 by a friction fit between the spacer portion 92 and the inwardly extending portion 96. The spacer 88 may be joined to the outer wall 70 by other suitable means such as, but not limited to, welding, threading, and keying.
Once the spacer bore 94 has been formed, the work portion 64 is placed next to the inner wall portion 90 and the rivet 82 is inserted through the work portion 64 and the spacer bore 64. Compression of the rivet 82 results in compression of the work portion 64 and the inner wall 90 of the spacer 88 between the inner portion 80 of the rivet 82 and the outer portion 84 of the rivet 82.
In the embodiment of
In alternative embodiments, the work portion may materials such as a microfiber buffing cloth made of fifty percent polyurethane and fifty percent nylon, commercially available from Hewitex Nederland B.V of The Netherlands, wires or other abrasive material so as to form a grinding wheel, a cut-off wheel a sanding disc, or any other similar accessory.
With reference to
The collar 18 is retracted by applying sufficient force to the collar 18 to further compress the spring 58 thereby moving the collar 18 in the direction of the arrow 98 in
Once the slot 68 is aligned with the shaft 16, the shaft tooth 26 is passed through the fan shape portion 74 while the shaft tooth 28 is passed thorough the fan shape portion 72. In this embodiment, the fan shape portions 72 and 74 are symmetrical as are the shaft teeth 26 and 28. Thus, the shaft teeth 26 and 28 may alternatively be passed through the fan shape portions 72 and 74, respectively. In alternative embodiments, the shapes may be asymmetrical thereby ensuring that the accessory is mounted in a particular configuration. In further embodiments, the keys are in shapes other than fan shapes. Such alternative embodiments may be useful in ensuring that specific accessories are mounted on specific mandrels.
Returning now to the discussion of mounting the accessory 62 onto the mandrel assembly 14, the shaft 16 is further moved until the outer wall 70 is located about the first end portion 22 of the shaft 16 as shown in
Next, the accessory 62 is rotated with respect to the shaft 16. By way of example, the accessory 62, and thus the outer wall 70, may be rotated in the direction of the arrow 100.
As shown in
As described above, an accessory 62 with a central hub 66 is disclosed that allows the accessory 62 to be quickly and conveniently coupled to a keyed mandrel assembly 14 without the need for an additional tool such as a screw driver. Likewise, by reversing the above-described actions, the accessory 62 may be quickly and conveniently decoupled from the mandrel assembly 14.
The central hub 66 may further be used, however, with mandrels that require an additional tool for coupling and decoupling an accessory. By way of example,
Alternatively, the accessory 62 may be mounted in a reversed configuration such that the outer wall 70 of the central hub 66 is located away from the threaded mandrel 102 while the outer portion 84 of the rivet 80 abuts the upper portion 108 of the threaded mandrel 102 as shown in
The buffing wheel 66 may also be mounted to a mandrel that has a diameter greater than the diameter of the slot 68 between the protrusions 76 and 78. As shown in
The buffing wheel 62 may alternatively be mounted in a reversed configuration with the end portion 116 of the mandrel 114 abutting the outer portion 84 of the rivet 82 as shown in
Although the present invention has been described with respect to certain preferred embodiments, those of skill in the art will appreciate that other implementations and adaptations are possible. For example, the central hub may be configured to receive differently shaped keys provided on a mandrel. Additionally, various types of mandrels may be configured with keys. U.S. patent application Ser. No. 11/187,139 and U.S. patent application Ser. No. 11/187,140 describe some of the alternative mandrels, including a mandrel with a retaining groove located on a mandrel shaft which may be used along with a retainer to provide biasing of the mandrel skirt. Moreover, there are advantages to individual advancements described herein that may be obtained without incorporating other aspects described above. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiments contained herein.
