Example embodiments generally relate to battery powered, outdoor power equipment and, more particularly, relate to a battery powered power head that can be interchangeable with a number of different tool attachments.
Outdoor power equipment includes such devices as mowers, trimmers, edgers, chainsaws, blowers and the like. These devices are often used to perform tasks that inherently require the devices to be mobile. Accordingly, these devices are typically made to be relatively robust and capable of handling difficult work in hostile environments, while balancing the requirement for mobility.
Powering such devices could be accomplished in any number of ways. However, for outdoor power equipment that is intended to be handheld, size and weight become important considerations. In some applications, the emissions (i.e., in terms of noise and/or pollutants) generated by the device may also become an important consideration. To reduce emissions, such outdoor power equipment may be selected for employment with electric motors that could employ battery or mains power supplies.
Particularly when battery power supplies are used, mobility and usability can often be dramatically enhanced. Thus, a number of battery powered tools have come onto the market. In an effort to create an ecosystem of products, some manufacturers have adopted a policy of making a single battery usable in a number of different tools. As such, one battery could power each of a trimmer, edger, chainsaw and/or blower. However, even in this paradigm, it is common for each different device to be its own tool that has only an interchangeable battery. While the battery may therefore be useable in each of several different devices, the rest of the device may be entirely uniquely designed, thereby increasing cost and requiring users to acclimate themselves to completely different devices after they plug in the same battery.
Some example embodiments may therefore provide an entire power head that can be interchangeable with a number of different devices. The battery may still plug into the power head, but much less of the remainder of the device (i.e., just the working assembly and perhaps some additional support structure and electronics) may need to be manufactured separately because one power head can be reused with many other devices. Production costs for devices may therefore be lowered, and customer satisfaction may be increased because their familiarity with controls of the power head may enable them to enjoy usage of familiar controls on multiple devices. To achieve this interchangeability, a mating interface is also provided to simultaneously provide safety and long term usability of the power head and its different tool attachments.
In accordance with an example embodiment, a multi-tool is provided. The multi-tool includes a power head including a power head housing having a handle operably coupled thereto, a tool attachment configured to perform a work function where the tool attachment is alternately separable from and operably coupled to the power head, a motor disposed in the power head housing, a battery configured to be operably coupled to the motor to selectively power the motor, a power head mating interface including structures disposed at the power head for defining a physical mating assembly, a drive power transfer assembly and an electronic assembly, and a tool mating interface including structures disposed at a housing of the tool attachment for defining the physical mating assembly, the drive power transfer assembly and the electronic assembly. The structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the physical mating assembly are configured to contact each other before the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the drive power transfer assembly contact each other responsive to operably coupling of the power head mating interface to the tool mating interface. The structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the drive power transfer assembly are configured to contact each other before the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the electronic assembly contact each other responsive to operably coupling of the power head mating interface to the tool mating interface.
In another example embodiment, a power head for providing power for a multi-tool is provided. The power head may include a power head housing having a handle operably coupled thereto, a motor disposed in the power head housing, a battery configured to be operably coupled to the motor to selectively power the motor, and a power head mating interface including structures disposed at the power head for defining a physical mating assembly, a drive power transfer assembly and an electronic assembly. The power head mating interface is configured to mate with a tool mating interface including structures disposed at a housing of the tool attachment for defining the physical mating assembly, the drive power transfer assembly and the electronic assembly. The structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the physical mating assembly are configured to contact each other before the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the drive power transfer assembly contact each other responsive to operably coupling of the power head mating interface to the tool mating interface. The structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the drive power transfer assembly are configured to contact each other before the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the electronic assembly contact each other responsive to operably coupling of the power head mating interface to the tool mating interface.
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
Some example embodiments now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all example embodiments are shown. Indeed, the examples described and pictured herein should not be construed as being limiting as to the scope, applicability or configuration of the present disclosure. Rather, these example embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. Furthermore, as used herein, the term “or” is to be interpreted as a logical operator that results in true whenever one or more of its operands are true. As used herein, operable coupling should be understood to relate to direct or indirect connection that, in either case, enables functional interconnection of components that are operably coupled to each other.
As mentioned above, a typical battery powered device tends to have a predefined function. Even if the battery is interchangeable to multiple devices, the entire device body and electronics of the powered device typically have to be separately produced. Example embodiments provide a common power head that is configured to receive a battery and have basic control electronics, actuation components, rear handle, and the motor all in one container (i.e., the power head housing). The power head can then generate a universal driving rotary output, which can be used directly (to power a coaxial rotary working assembly), or converted into a non-rotary output (e.g., a linear output) or a rotary output that is not coaxial with the universal driving rotary output (e.g., a rotary output for which the working assembly rotates in a plane that is not parallel to the plane of operation of the universal driving rotary output).
When providing such a device, one might expect that the universal driving rotary output could power many different working assemblies including, for example, line trimmers, hedge trimmers, saws, and blowers. However, it must be appreciated that the weight and structure (and therefore the weight distribution) of each different working assembly can be vastly different. Thus, the structure and arrangement of components chosen for the power head is potentially very impactful. A design that is optimal for one device (e.g., a blower) may be suboptimal from the perspective of ergonomics on a different device (e.g., a line trimmer). As such, placement of the motor beneath a front portion of the handle of the power head and the battery under a rear portion of the handle tends to provide a good weight distribution that works well with a number of different working assemblies. In particular, placement of the battery into a rear portion of the power head with a direction of insertion that is substantially parallel to the axis of rotation of the universal driving rotary output is particularly beneficial. Moreover, in some cases, a longitudinal centerline of the battery may actually be coaxial with the axis of rotation of the universal driving rotary output. As a result, a relatively light weight and ergonomically well balanced multi-tool may be provided.
To achieve a multi-tool that is both ergonomically balanced, but also of a size and weight that is not restrictive to users, some example embodiments described herein provide structures for providing a multi-tool that fundamentally alters the ordering and positioning of components of the multi-tool. In this regard, for example, the motor, the battery and a center of gravity of the working assembly may all be substantially equidistant from each other along a common axis. The centers of gravity of each of the main contributors to the weight of the multi-tool may therefore be distributed relative to the handle in such a way as to provide a relatively light, but still powerful and easy to handle multi-tool in any configuration. As such, the relative positioning of the various components described herein can, in some cases, provide significant advantages in terms of providing versatility, maneuverability, and power all in a very ergonomically advantageous and lightweight package.
However, it should also be appreciated that the provision of the device described above further requires physical mating/interface structures to be designed to not only securely attach the power head to each different tool attachment, but to do so in a way that ensures that the electrical and power transfer components in each of the power head and the different tool attachments can also be mated safely and in a manner that prevents damage to components.
As shown in
Given that the power head housing 122 is configured to be separable from each other housing (of the tool attachments), it should be further appreciated that the power head housing 122 may be configured to form a nearly continuous shell when joined with the housing of any one of the tool attachments. Thus, for example, when the power head mating interface 121 is joined with the tool mating interface 123 of any of the tool attachments, a nearly continuous shell (albeit with a visible seam therebetween) may be formed.
In an example embodiment, a handle 124 of the multi-tool 100 may be formed integrally into the power head housing 122 at a top portion of the power head housing 122 (with “top” and all other directions being referenced to the orientation of the multi-tool 100 to the ground and the normal way the multi-tool 100 is held by a user during operation). In an example embodiment, the handle 124 may include an operating member 126 (e.g., a trigger or presence lever) that may be operated by one or more fingers of the operator while the operator holds the handle 124. A power button 128 may also be provided to enable electrical power to be providable from a battery 130 to a motor 140 (see
It should be appreciated that although
The motor 140 or power unit of the multi-tool 100 is configured to provide the driving force that can be transferred to the selected one of the tool attachments to perform a corresponding working function via the working assembly that is associated with the selected one of the tool attachments. For example, in the case of the blower attachment 110 shown in
In some embodiments, the control unit may be housed in its own portion of the power head housing 122 above or otherwise proximate to the location of the motor 140. The portion of the power head housing 122 in which the control unit is housed may be referred to as a control unit housing portion, and the control unit housing portion may be an integral part of a half-shell (as described above) or may be a separate housing portion that is joined to other housing portions. The control unit housing portion may be disposed proximate to a portion of the power head housing 122 near which the handle 124 of the power head 120 is provided (e.g., forward of and below the handle 124).
As discussed above, the power head mating interface 121 is joined with the tool mating interface 123 to form a complete and operational multi-tool 100. However, the multi-tool 100 can be reconfigured by releasing the tool mating interface 123 for a particular one of the tool attachments and replacing it with another tool mating interface 123 of a different tool attachment. Since
As shown in
A shaft 150 may pass from the motor 140 to the fan 142 to translate rotation of the motor 140 to the fan 142. The shaft 150 may be aligned with the common axis 148 and may be coaxial with the common axis 148. As can be appreciated from
For the blower attachment 110, the shaft 150 must therefore pass through an intake chamber 152 that is formed in the blower attachment housing. Thus, air that is to be passed through the blower attachment 110 is drawn into the multi-tool 100 at a location that is between the motor 140 and the fan 142. Moreover, the location at which air is drawn into the multi-tool 100 is a partially enclosed chamber (i.e., the intake chamber 152) that is structured to mute the noise of either the motor 140 or the fan 142 to keep the multi-tool 100 operating relatively quietly from the perspective of the operator. In this regard, the intake chamber 152 may include a rear wall 154 that is disposed at a rear end of the intake chamber 152 and sidewall members 155 that extend forward from the rear wall 154 to define the sides of the intake chamber 152. An intake screen 156 may be disposed opposite the rear wall 154 to define a front boundary of the intake chamber 152. The intake screen 156 of this example curves backward toward the rear wall 154 forming a spherical cap or dome shaped screen through which air is allowed to pass as the air travels from the intake chamber 152 into the chamber in which the fan 142 is located within the blower tube 144. Louvers or other air inlets are formed between the sidewall members 155 to enable air to be drawn therethrough into the intake chamber 152.
At least one of the sidewall members 155 may be substantially wider than others, and may be disposed at a top portion of the intake chamber 152. This particular top one of the sidewall members 155 deflects sound downward toward one of the louvers or air inlets that is also larger than others, and is disposed opposite the top one of the sidewall members 155. This structure deflects sound downward and away from the operator. Meanwhile, the sidewall members 155 also provide additional support for the structure of the blower attachment 110 to prevent bending of the shaft 150 and enable, for a two piece and separable construction, a robust interface to be defined between the blower attachment 110 and the power head 120.
The blower tube 144 may include an inlet portion disposed proximate to the fan 142 and an outlet. The outlet may be at a distal end of the blower tube 144, opposite the inlet portion. Given that the operator typically holds the multi-tool 100 by the handle 124 and the remainder of the multi-tool 100 is suspended below the handle 124 with the outlet aimed in front of the operator, the handle 124 is generally considered to be at a top portion of the multi-tool 100 and the outlet is at the front, while the battery 130 is considered to be at a rear of the multi-tool 100. As mentioned above, the blower tube 144 may taper slightly (i.e., have a decreasing diameter) as the blower tube 144 extends toward the outlet. Thus, a largest diameter of the blower tube 144 may be provided at the point of the blower tube 144 that is closest to the fan 142.
In an example embodiment, the operation of the motor 140 may cause an impeller of the fan 142 to rotate (via the shaft 150) so that a low pressure area is generated to draw air into the intake chamber 152, through the intake screen 156, and to the fan 142 to be expelled from the blower tube 144 at the outlet to blow leaves, debris, or any other material. As mentioned above and as shown in
In an example embodiment, the shaft 150 may pass through the intake chamber 152 through an enclosed shaft housing 158. Thus, the shaft housing 158 may extend from the rear wall 154 to the intake screen 156, and may also be coaxial with the shaft 150 and the common axis 148. The shaft housing 158 may prevent debris from building up on the shaft 150, and from getting into the motor 140 via the opening through the rear wall 154 that permits the shaft 150 to pass therethrough to access the motor 140. The shaft housing 158 may also contribute to the structural rigidity of the blower attachment portion 110 to prevent bending of the shaft 150 and enable, for a two piece and separable construction, a robust interface to be defined between the blower attachment portion 110 and the power head 120.
The power head 120 and the battery 130 will now be described in greater detail in reference to
Referring now to
With the battery 130 removed, the main weight contributor for the power head 120 may be the motor 140. Thus, without the battery 130, the power head 120 may tend to have a forward lean when one hand of the operator is on the handle 124. However, when the battery 130 is inserted, the weight of the motor 140 is offset by the weight of the battery 130, and thus the position of the hand of the operator (i.e., at the front or back of the handle 124) may determine any tendency of the power head 120 to lean forward, backward, or not at all. Meanwhile, the lengths, weights, and positions of the centers of gravity for each of the tool attachments is different, as is the normal position in which the multi-tool 100 will be held for operation of the multi-tool 100 with each respective attachment. Thus, the position and orientation of the battery receiver 160 to receive the battery 130 by insertion in a direction that is substantially parallel to the common axis 148 (and the axis of the motor 140) ensures a relatively compact structure for the power head 120, but also a structure that is adaptable to use with different tool attachments while keeping good ergonomics.
The battery 130 includes a housing 200 that houses one or more individual battery cells. As can be seen in
As shown in
Referring now primarily to
The drive power transfer assembly is defined by a drive provider portion 300 disposed at the power head 120 and a drive receiver portion 320 disposed at the tool attachment. The drive provider portion 300 includes a driving portion 302 of the shaft 150. The driving portion 302 may be operably coupled to and/or extend from the motor 140 and may protrude from an interface plate 304 that may be embedded or otherwise provided in a front wall 306 that is part of the power head housing 122 and that is disposed forward of the motor 140. The interface plate 304 may include one or more holes or orifices provided therein to allow air to pass to or from a space defined between the power head 120 and the tool attachment when the mating interfaces are engaged to a space inside the power head housing 122 where the motor 140 is housed. The power head housing 122 may also include louvers on opposing right and left sides thereof (proximate to the motor 140), and each of the attachment housings may include louvers 308 at a bottom portion thereof, proximate to the mating interfaces, in order to allow cooling air to flow between the attachment housing and the power unit housing 122 for cooling of the motor 140.
The drive provider portion 300 may also include a guide sleeve 310 that extends coaxial with the driving portion 302 (and coaxial with the common axis 148). The guide sleeve 310 may be a hollow cylinder that extends away from the interface plate 304 and has a length and diameter that are each longer than the length and diameter of the driving portion 302.
The drive receiver portion 320 of each of the tool mating interfaces 123 of respective ones of the tool attachments may include similarly structured (and functioned) components. However, slight differences in form (and perhaps also function) may be different between different tool attachments. In an example embodiment, the drive receiver portion 320 may include a driven portion 322 of the shaft 150 that is configured to be operably coupled to the driving portion 302 when the mating interfaces are engaged. The driven portion 322 may extend rearward from an end of the shaft 150 that extends away from the fan 142. The driven portion 322 may be disposed within a guide receiver 324 formed in a rear mating surface base 326 of each of the attachment housings. The guide receiver 324 may be a cylindrically shaped depression formed in the rear mating surface base 326. In an example embodiment, the depth of the guide receiver 324 from the rear mating surface base 326 may be substantially equal to the length of the guide sleeve 310. Additionally, in some cases, the length of the driven portion 322 may be substantially equal to the depth of the guide receiver 324 (and the length of the guide sleeve 310). Moreover, the depth and shape of the guide receiver 324 may substantially match the length and shape of the guide sleeve 310. However, the guide sleeve 310 may have an outside diameter that is slightly less than an inside diameter of the guide receiver 324.
The complementary shapes of the guide receiver 324 and guide sleeve 310 enable the guide sleeve 310 to be inserted into the guide receiver 324 to guide the mating of the driving portion 302 with the driven portion 322 of the shaft 150 when the mating interfaces are engaged. The shaft 150 may then (i.e., when the driving portion 302 and the driven portion 322 are engaged) pass from the motor 140 to the drive receiver portion 320 of the attachment portion. For example, in the context of the blower attachment 110, the shaft 150 may pass from the fan 142 through the intake screen 156 into the intake chamber 152 (albeit within the shaft housing 158) and through the rear wall 154 of the intake chamber 152. From that point, the shaft 150 may pass through the rear mating surface base 326 and into the guide receiver 324 and guide sleeve 310 (which will be coaxial with the guide sleeve 310 inserted into the guide receiver 324), where the driven portion 322 and driving portion 302 actually engage each other. The shaft 150 then continues through the interface plate 304 to the motor 140. In an example embodiment, the driven portion 322 may include longitudinally extending grooves formed in the outer surface of the cylindrical structure that forms the driven portion 322. The driving portion 302 may be a substantially hollow cylinder (or at least terminate as such). In some embodiments, the interior of the driving portion 302 may include longitudinally extending protrusions or teeth that engage corresponding ones of the grooves formed in the driven portion 322. The positions of the grooves and protrusions could, of course, be reversed in some example embodiments.
When the motor 140 operates (e.g., under the control of the control unit), the motor 140 turns the shaft 150. In particular, the motor 140 turns the driving portion 302 of the shaft 150 and the driving portion 302 turns the driven portion 322. The driven portion 322 then provides an output to be used by the working assembly of the tool attachment that is operably coupled to the power unit 120 at that time. For example, if the multi-tool 100 is configured with the blower attachment 110, then the driven portion 322 may directly turn the fan 142 to draw air into the intake chamber 152 and expel the air from the blower tube 144. The drive power transfer assembly is therefore configured to enable the drive provider portion 300 disposed at the power head 120 to be mated with the drive receiver portion 320 disposed at the blower attachment 110 when the mating interface is engaged to provide mechanical (in this case rotary) power from one separable component (i.e., the power head 120) to another separable component (i.e., the blower attachment 110). In this regard, the drive power transfer assembly is configured to operably couple two portions of a split shaft to combine such portions into a working shaft (i.e., shaft 150) that extends through the intake chamber 152 to provide a blower structure that places the air intake between the motor 140 and the fan 142. However, the drive power transfer assembly is configured to ensure the proper alignment of the two portions of the split shaft by ensuring that the guide sleeve 310 inserts into the guide receiver 324 before the driving portion 302 of the shaft 150 engages the driven portion 322 of the shaft 150. Thus, the teeth and/or grooves on the driven portion 322 and the driving portion 302 can be less susceptible to damage, and the driven portion 322 and driving portion 302 can also avoid damage (e.g., due to bending or deformation) that might occur if mating attempts were made without proper alignment.
In the context of the hedge trimmer attachment 106,
The hedge trimmer attachment 106 therefore takes the rotary input provided from the power head 120, which rotates about the common axis 148, and converts such rotary input into a linear work function output by moving the blades of the blade assembly 350 linearly in a direction substantially parallel to the common axis 148. Thus, the hedge trimmer attachment 106 provides a speed change to the rotary input and also changes the direction of the output work function. Meanwhile, the blower attachment 110 described above takes the rotary input provided from the power head 120 and directly converts the rotary input into a rotary output (by moving the fan 142) that is coaxial with the common axis 148 and the rotary input. Thus, the blower attachment 110 preserves the speed (i.e., no speed change) of the rotary input and also preserves the direction of the output work function. The string trimmer attachment 108, as will be seen below, preserves the speed of the rotary input, but changes the direction.
The physical mating assembly may provide further structures for ensuring proper alignment of the power head 120 and the tool attachments for engagement of the mating interfaces. Moreover, the physical mating assembly may also provide the structures that enable the mating interfaces to transition between an engaged state (holding the power head 120 and the selected tool attachment together to operably couple them in a manner that allows the multi-tool 100 to be operable), and a disengaged state (where the power head 120 and selected tool attachment can be separated from each other to permit mating with a different tool attachment).
In an example embodiment, the physical mating assembly may be primarily comprised of an alignment and support assembly, and an engagement assembly. The alignment and support assembly may (similar to the guide sleeve 310 and the guide receiver 324) ensure that certain other structures of the electronic assembly and/or the drive power transfer assembly are properly aligned before engagement thereof. The alignment and support assembly may also ensure that the power head 120 and the selected tool attachment are rigidly and securely mated to each other so that when the engagement assembly engages the power head 120 and selected tool attachment to each other the multi-tool 100 is operable as one structurally stable platform. Meanwhile, the engagement assembly locks the power head 120 and the tool attachment together when in the engaged state. Portions of the alignment and support assembly that are disposed on the power head 120 will be described primarily in reference to
The alignment and support assembly includes a first rail assembly (including rails 400 and 402) and a second rail assembly (including rails 410 and 412), and a corresponding first set of guide grooves (including grooves 420 and 422) and second set of guide grooves (including grooves 430 and 432), where the first rail assembly 400, 402 is configured to slidably engage the first set guide grooves 420, 422 and the second rail assembly 410, 412 is configured to slidably engage the second set of guide grooves 430, 432. The alignment and support assembly is designed so that the power head 120 includes one rail assembly and one set of guide grooves (e.g., the first rail assembly 400, 402 and the first set of guide grooves 420, 422), and each of the tool attachments includes a complementary rail assembly and set of guide grooves (e.g., the second rail assembly 410, 412 and the second set of guide grooves 430, 432).
The first set of guide grooves 420, 422 may be disposed on the power head 120 above the guide sleeve 310, while the first rail assembly 400, 402 is disposed below the guide sleeve 310. Each of the grooves (320 and 322) of the first set of guide grooves 420, 422 may substantially mirror each other relative to a longitudinally extending plane dividing the power head 120 into substantially equal right and left halves. Similarly, each of the rails (400 and 402) of the first rail assembly 400, 402 may substantially mirror each other relative to a longitudinally extending plane dividing the power head 120 into substantially equal right and left halves.
The second set of guide grooves 430, 432 may be disposed on the blower attachment portion 110 below the guide receiver 324, while the second rail assembly 410, 412 is disposed above the guide receiver 324. Each of the grooves (430 and 432) of the second set of guide grooves 430, 432 may substantially mirror each other relative to a longitudinally extending plane dividing the blower attachment portion 110 into substantially equal right and left halves. Similarly, each of the rails (410 and 412) of the second rail assembly 410, 412 may substantially mirror each other relative to a longitudinally extending plane dividing the blower attachment portion 110 into substantially equal right and left halves. Moreover, the first set of guide grooves 420, 422 may be configured to engage respective ones of the second rail assembly 410, 412, while the second set of guide grooves 430, 432 are configured to engage respective ones of the first rail assembly 400, 402. The first rail assembly 400, 402 and the second rail assembly 410, 412 each extend substantially parallel to each other and to the common axis 148. The first set guide grooves 420, 422 and the second set of guide grooves 430, 432 each also extend substantially parallel to each other, to the first rail assembly 400, 402 and the second rail assembly 410, 412, and to the common axis 148.
The first rail assembly 400, 402 includes individual rails (400 and 402) that are not connected to each other in this example. Thus, the rails (400 and 402) of the first rail assembly 400, 402 are separated and spaced apart from each other. The rails (400 and 402) of the first rail assembly 400, 402 extend substantially perpendicularly away from the front wall 306 by a distance that is substantially equal to a distance that the grooves (420 and 422) of the first set of guide grooves 420, 422 extend into the power head 120 to reach the front wall 306.
The second rail assembly 410, 412 includes individual rails (410 and 412) that are disposed on opposite lateral sides of a protruding member 440 that extends substantially perpendicularly away from the rear mating surface base 326 and is substantially parallel to the common axis 148. Thus, the rails (410 and 412) of the second rail assembly 410, 412 are spaced apart from each other by the protruding member 440, but operably coupled to each other via the protruding member 440. The rails (410 and 412) of the second rail assembly 410, 412 also extend substantially perpendicularly away from the rear mating surface base 326 by a distance that is substantially equal to a distance that the grooves (430 and 432) of the second set of guide grooves 430, 432 extend into the tool attachment past the rear mating surface base 326. In an example embodiment, the rails (410 and 412) of the second rail assembly 410, 412 may be substantially equal in length to the grooves (430 and 432) of the second set of guide grooves 430, 432. However, both the rails (410 and 412) of the second rail assembly 410, 412 and the grooves (430 and 432) of the second set of guide grooves 430, 432 may extend beyond the rear mating surface base 326 in both directions perpendicular thereto. In some cases, the rails (410 and 412) of the second rail assembly 410, 412 may be substantially equal in length to the grooves (430 and 432) of the second set of guide grooves 430, 432 may extend past the rear mating surface base 326 in the forward direction by a distance substantially equal to a depth of the guide receiver 324.
The first rail assembly 400, 402 and the second rail assembly 410, 412 may each have a substantially T shape, where a base of the T shape is oriented to extend outward relative to the longitudinally extending planes dividing the tool attachment and power head 120 into substantially equal right and left halves. The first set of guide grooves 420, 422 and the second set of guide grooves 430, 432 may be shaped as grooves that are oriented to receive the base of the T of respective ones of the first rail assembly 400, 402 and the second rail assembly 410, 412. A distance between the rails (400 and 402) of the first rail assembly 400, 402 may be slightly less than (but substantially equal to) a distance between the grooves (420 and 422) of the first set of guide grooves 420, 422. Similarly, a distance between the rails (410 and 412) of the second rail assembly 410, 412 may be slightly less than (but substantially equal to) a distance between the grooves (430 and 432) of the second set of guide grooves 430, 432. However, the distance between the rails (410 and 412) of the second rail assembly 410, 412 may be less than the distance between the rails (400 and 402) of the first rail assembly 400, 402. The different distances (i.e., widths) may ensure that the operator will not attempt to engage the tool attachment to the power head 120 upside down or in any orientation other than the proper orientation.
During engagement, the first rail assembly 400, 402 may engage the second set of guide grooves 430, 432 at approximately the same time that the second rail assembly 410, 412 engages the first set of guide grooves 420, 422. In any case, sliding engagement between these components will be prevented or at least very limited until both sets of rails and grooves are properly aligned. This nearly simultaneous engagement (or at least nearly simultaneous sliding engagement) ensures proper alignment of components of the drive power transfer assembly and the electronic assembly to avoid damaging or breaking such components. In particular, for example, the first rail assembly 400, 402 must slidably engage the second set of guide grooves 430, 432 for at least some distance while the second rail assembly 410, 412 also slidably engages the first set of guide grooves 420, 422 for a similar distance before the guide sleeve 310 begins to be inserted into the guide receiver 324. This sliding engagement must then continue for at least a given distance before the driven portion 322 and the driving portion 302 of the shaft 150 engage each other. Thus, example embodiments provide for the sliding engagement of components the physical mating assembly before any engagement of components of the drive power transfer assembly and the electronic assembly. Moreover, example embodiments define an ordered sequence to the engagement of specific components to limit the potential for damaging components.
The engagement assembly may be configured to lock the selected tool attachment to the power head 120 when in the engaged state. In an example embodiment, the engagement assembly may include an operator (e.g., button 520) that is disposed on the tool attachment and protrudes from a portion of the housing of the tool attachment (e.g., at a top portion thereof). The button 520 may be operably coupled to a locking projection 530 that extends from a portion of the protruding member 440 to move the locking projection 530 whenever the button 520 moves. In some cases, the button 520 may be configured to be depressed against a biasing force provided by a biasing member (e.g., spring 540). Accordingly, when depressed, the button 520 may be retracted into the housing of the tool attachment (and protruding member 440) and the locking projection 530 may correspondingly be retracted into the protruding member 440. However, when the button 520 is released, the spring 540 may urge the button 520 and the locking projection 530 upward and out of the housing of the tool attachment and protruding member 440, respectively.
Meanwhile, the power head housing 122 may include a receiving slot 550 disposed in an interior top portion thereof that corresponds to a position of the locking projection 530 when the selected tool attachment is mated with the power head 120 via engagement of the components of the alignment and support assembly in the manner described above. Thus, for example, while the first rail assembly 400, 402 slidably engaged the second set of guide grooves 430, 432 and the second rail assembly 410, 412 also slidably engages the first set of guide grooves 420, 422 to draw the power head housing 122 closer to the housing of the selected tool attachment, the interior top portion of the power head housing 122 may exert a force on the locking projection 530 to overcome the spring 540 and retract the locking projection 530 into the protruding member 440 to enable continued sliding between the rail assemblies and guide grooves until the locking projection 530 aligns with the receiving slot 450. When the locking projection 530 aligns with the receiving slot 450, the spring 540 may force the locking projection 530 into the receiving slot 450 to lock the power head housing 122 to the housing of the selected tool attachment in the engaged state. When separation of the power head housing 122 and the housing of the selected tool attachment is desired, the operator may depress the button 420, as described above, to withdraw the locking projection 530 from the receiving slot 450 and permit the components of the alignment and support assembly described above to be slidingly moved relative to each other in a direction that separates the power head 120 from the selected tool attachment until the components no longer engage each other and the power head 120 and the selected tool attachment are separated from each other.
The electronic assembly may include one portion at each of the power head 120 and the selected tool attachment. In this regard, the electronic assembly may include a first contact assembly 500 disposed at the selected tool attachment and a second contact assembly 510 disposed at the power head 120. The first and second contact assemblies 500 and 510 may be positioned such that they engage each other when the power head housing 122 and the housing of the selected tool attachment are in the engaged state. One of the first contact assembly 500 or the second contact assembly 510 may include male electrical contacts, and the other may include female electrical contacts configured to receive the male electrical contacts. Which one of the first contact assembly 500 or the second contact assembly 510 includes respective ones of the male/female contact portions does not matter. However, it should be appreciated that the male and female contact portions do not engage each other until the alignment provided by the alignment and support assembly is established in the manner described above.
In the examples shown, male contacts are provided on the second contact assembly 510 on the power head 120. Accordingly, the male contacts are inset within the power head housing 122 and relatively protected from bending or other fouling or damage. Meanwhile the female contacts are provided on the first contact assembly 500, which is disposed on a distal end of the protruding member 440 (e.g., between distal ends of the rails (410 and 412) of the second rail assembly 410, 412. Thus, there are no bendable or breakable components on the protruding member 440.
In an example embodiment, at least some of the contacts of the first and second contact assemblies 500 and 510 may be operably coupled to the control unit of the multi-tool 100 for the implementation of various safety features associated with operation of the multi-tool 100. In the example shown, three contacts are provided on the first and second contact assemblies 500 and 510. Within the protruding member 440 of the blower attachment 110 and the string trimmer attachment 108, one of the contacts of the first contact assembly 500 may be dead ended, and therefore essentially provide no function relative to operation of the multi-tool 100 for the corresponding male contact on the second contact assembly 510. However, the other two contacts of the first contact assembly 500 may be jumpered together within the protruding member 440 to complete an electrical circuit between the corresponding two contacts of the second contact assembly 510. The completion of this electrical circuit could be used as a safety check to prevent operation of the motor 140 unless the attachment of the power head 120 to the selected tool attachment can be confirmed (by completion of the circuit). In some embodiments, the hedge trimmer attachment 106 may be configured such that the contact that is dead ended in the blower attachment 110 and the string trimmer attachment 108 may actually provide a function (e.g., an operational function) in the corresponding other tool. In this regard, the middle contact of the first contact assembly 500 of the hedge trimmer attachment 106 may power at least one operational function of the hedge trimmer attachment 106 when operably coupled to the male contacts of the second contact assembly 510.
As can be appreciated from the descriptions above, the multi-tool 100 may attach the power head 120 to any of a number of different tool attachments via the mating interfaces (i.e., the power head mating interface 121 and the tool mating interface 123). However, these mating interfaces are specifically designed to sequentially engage respective portions thereof to maximize the likelihood of achieving proper alignment of all mating components in each interface and minimize the chances of improper operation of the power head 120, while protecting the least robust or most damage-sensitive components in each interface.
In this regard, as mentioned above, the power head mating interface 121 and the tool mating interface 123 each include respective components of drive power transfer assembly, electronic assembly, and physical mating assembly that engage each other in sequence. The physical mating assembly engages first, and aligns the power head mating interface 121 with the tool mating interface 123 to facilitate next the engagement of the drive power transfer assembly. Finally, the electronic assembly, which has the smallest components and is most likely to be damaged, is engaged last. This both protects the components of the electronic assembly and ensures that electrical power cannot be provided to power the motor 140 until the power head mating interface 121 and the tool mating interface 123 are fully coupled together.
Referring now to
As shown in
The drive power transfer assembly includes a first protruding (or male) part 620 (e.g., the guide sleeve 310) and a second protruding part 622 (the driving portion 302) that is disposed within and coaxial with the first protruding part 620. The second protruding part 622 also has, at a distal end thereof, a first recessed part 624. The first and second protruding parts 620 and 622 and the first recessed part 624 are all parts of the power head mating interface 121. Meanwhile, the tool mating interface 123 includes a second recessed part 630 (e.g., the guide receiver 324), a third protruding part 632 (e.g., driven portion 322) and a fourth protruding part 634. The second recessed part 630 is coaxial with the third protruding part 632, and the fourth protruding part 634 is disposed at a distal end of the third protruding part 632. The length of the first protruding part 620 may be substantially equal to a depth of the second recessed part 630, and the first protruding part 620 may be received in the second recessed part 630 after the bottom male structures 610 and the top female structures 602, have already been slidingly engaged with the top male structures 600 and the bottom female structures 612 as described above. As such, the length of the first protruding part 620 and the depth of the second recessed part 630 may be less than the lengths and depths of the top and bottom male and female structures 600, 602, 610, 612.
The third protruding part 634 may be configured to extend into and engage (e.g., via keying structures or corresponding teeth/ridges/protrusion and grooves) the first recessed part 624. Thus, the length of the third protruding part 634 may be substantially equal to the depth of the first recessed part 624 and the respective external and internal shapes of the parts may be complementary. The second protruding part 622 and the third protruding part 632 may extend toward each other and may have a combined length substantially equal to the length of the first protruding part 620 (and also equal to the depth of the second recessed part 630).
The electronic assembly may include male contacts 640 (e.g., disposed to extend away from the second contact assembly 510) and female contacts 642 (e.g., disposed to extend inwardly from the first contact assembly 500). The depth of the female contacts 642 may be equal to or greater than a length of the male contacts 640. However, the length of the male contacts 640 may be less than the length of any of the first, second, third or fourth protruding parts 620, 622, 632 or 634. Thus, as mentioned above, the physical mating assembly portions on the power head mating interface 121 may engage the physical mating assembly portions of the tool mating interface 123 before any parts of the drive power transfer assembly contact each other, and all the parts of the drive power transfer assembly engage each other before any parts of the electronic assembly engage each other. In other words, the top male structures 600 may engage the top female structures 602 simultaneously with the engagement of the bottom male structures 610 with the bottom female structures 612 before the first protruding part 620 engages the second recessed part 630. However, the third protruding part 634 may also engage the first recessed part 624 before the male contacts 640 engage the female contacts 642. This ensures that the most sensitive (and perhaps easiest components to break) are properly aligned due to many other alignment structures already being engaged before these sensitive parts engage each other. It also ensures that the electronic assembly does not close a circuit that requires engagement of the male contacts 640 and the female contacts 642 until the mating interfaces are closed. Thus, the universal drive power of the drive portion 302 cannot be provided until the mating interfaces are properly mated.
A multi-tool configured to be fitted with multiple different tool attachments is provided. The multi-tool includes a power head including a power head housing having a handle operably coupled thereto, a tool attachment configured to perform a work function where the tool attachment is alternately separable from and operably coupled to the power head, a motor disposed in the power head housing, a battery configured to be operably coupled to the motor to selectively power the motor, a power head mating interface including structures disposed at the power head for defining a physical mating assembly, a drive power transfer assembly and an electronic assembly, and a tool mating interface including structures disposed at a housing of the tool attachment for defining the physical mating assembly, the drive power transfer assembly and the electronic assembly. The structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the physical mating assembly are configured to contact each other before the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the drive power transfer assembly contact each other responsive to operably coupling of the power head mating interface to the tool mating interface. The structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the drive power transfer assembly are configured to contact each other before the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the electronic assembly contact each other responsive to operably coupling of the power head mating interface to the tool mating interface.
In some embodiments, the features or operations of the multi-tool described above may be augmented or modified, or additional features or operations may be added. These augmentations, modifications and additions may be optional and may be provided in any combination. Thus, although some example modifications, augmentations and additions are listed below, it should be appreciated that any of the modifications, augmentations and additions could be implemented individually or in combination with one or more, or even all of the other modifications, augmentations and additions that are listed. As such, for example, (1) all of the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the physical mating assembly are configured to contact each other before any of the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the drive power transfer assembly contact each other responsive to operably coupling of the power head mating interface to the tool mating interface. In some cases, (2) all of the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the drive power transfer assembly are configured to contact each other before any of the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the electronic assembly contact each other responsive to operably coupling of the power head mating interface to the tool mating interface. In an example embodiment, (3) the physical mating assembly may include a pair of top male structures and a pair of bottom male structures configured to be received in a pair of top female structures and a pair of bottom female structures, respectively. In some examples, (4) the structures disposed at the power head for defining the physical mating assembly may include the pair of bottom male structures and the pair of top female structures, and wherein the structures disposed at the housing of the tool attachment for defining the physical mating assembly include the pair of top male structures and the pair of bottom female structures. In some embodiments, (5) wherein the pair of top male structures may each be substantially equal in length to a depth of each of the pair of top female structures, and the pair of bottom male structures may each be substantially equal in length to a depth of each of the pair of bottom female structures. In some cases, (6) the drive power transfer assembly may include a first protruding part and a second protruding part that is disposed within and coaxial with the first protruding part. The second protruding part may include, at a distal end thereof, a first recessed part. The drive power transfer assembly further includes a second recessed part, a third protruding part and a fourth protruding part. The second recessed part may be coaxial with the third protruding part, and the fourth protruding part may be disposed at a distal end of the third protruding part. A length of the first protruding part may be substantially equal to a depth of the second recessed part to enable the first protruding part to be received in the second recessed part after the pair of bottom male structures and the pair of top female structures have already been slidingly engaged with the pair of top male structures and the pair of bottom female structures, respectively. In some examples, (7) the length of the first protruding part and the depth of the second recessed part may each be less than the length of the pair of top male structures, the length of the pair of bottom male structures, the depth of the pair of top female structures and the depth of the bottom female structures. In an example embodiment, (8) the third protruding part may extend into and engages the first recessed part such that a length of the third protruding part is substantially equal to a depth of the first recessed part. In some examples, (9) the second protruding part and the third protruding part may have a combined length substantially equal to the length of the first protruding part. In some cases, (10) the electronic assembly may include male contacts and female contacts, and the male contacts may have a length substantially equal to a depth of the female contacts. In an example embodiment, (11) the length of the male contacts may be less than the length of the fourth protruding part.
A method of assembly of a multi-tool that includes a power head, a tool attachment, a motor, a battery, a power head mating interface, and a tool mating interface may therefore be defined. In the context of such method, the power head may include a power head housing having a handle operably coupled thereto, and the tool attachment may be configured to perform a work function and is removable with respect to the power head. The motor may be disposed in the power head housing, and the battery may be configured to be operably coupled to the motor to selectively power the motor. The power head mating interface may include structures disposed at the power head for defining a physical mating assembly, a drive power transfer assembly and an electronic assembly, and the tool mating interface may include structures disposed at a housing of the tool attachment for defining the physical mating assembly, the drive power transfer assembly and the electronic assembly. The method may include configuring the power head mating interface and the tool mating interface such that, responsive to operably coupling of the power head mating interface to the tool mating interface, the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the physical mating assembly contact each other before the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the drive power transfer assembly contact each other. The method may further include configuring the power head mating interface and the tool mating interface such that, responsive to operably coupling of the power head mating interface to the tool mating interface, the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the drive power transfer assembly contact each other before the structures disposed at the power head and the structures disposed at the housing of the tool attachment for defining the electronic assembly contact each other.
Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe exemplary embodiments in the context of certain exemplary combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. In cases where advantages, benefits or solutions to problems are described herein, it should be appreciated that such advantages, benefits and/or solutions may be applicable to some example embodiments, but not necessarily all example embodiments. Thus, any advantages, benefits or solutions described herein should not be thought of as being critical, required or essential to all embodiments or to that which is claimed herein. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
Filing Document | Filing Date | Country | Kind |
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PCT/CN2017/114871 | 12/6/2017 | WO | 00 |