Ergonomic router assembly

An ergonomically designed router assembly includes a base assembly coupled with a motor casing including a grip assembly which provides an overall narrower profile to the router assembly. The grip assembly may relieves stress on the muscles and allows the operator to more securely grasp the router with one hand thus decreasing fatigue levels as compared to those routers which require both hands of the operator to be engaged for control over the router.

FIELD OF THE INVENTION

The present invention generally relates to the field of power tools, and particularly to an ergonomically designed power tool, such as a router.

BACKGROUND OF THE INVENTION

Routers are employed to accomplish a variety of tasks. Used for shaping objects typically composed of wood, plastic, metal, and the like, routers have become a mainstay of the construction work site and home work shops. From handles located on either side of the housing, to attachments which extend away from the housing, to base designs which allow an operator to guide the operation of the router, controlling the router while in operation has been the purview of many design configurations. And in typical workman-like fashion the design of these handles have often been focused on functionality and not taken into account ergonomic considerations.

Typically, ergonomic designs have focused on the structure of the handles and/or external attachments to the routers. For instance, differently shaped handles or various attachment angles thought to provide easier functionality. Additionally, typical router configurations may require the user to grasp the motor housing of the router. These motor housings, surround the motor, and typically leave unused space between the interior of the walls of the housing and the windings of the motor. This may result in a large housing of the router, which may be difficult for the user to firmly grasp, thus, limiting the effective control over the router. Further, the demands placed on the hands of the user, in grasping the large motor housing, may increase fatigue levels which may decrease productivity. Unfortunately, attempts to construct more ergonomically configured routers have fallen short of the goal of providing a significantly easier to operate router.

Therefore, it would be desirable to provide an ergonomically designed router to reduce fatigue and improve control over the router.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a router with an ergonomically designed base and motor casing. Ergonomic design features function to relieve stress on the parts of an operator being used to operate a machine. For instance, providing a thinner handle enables the hand to more comfortably grip an object. This in turn relieves stress on the muscles used for gripping which in turn decreases fatigue levels in those muscles and increases overall performance of the muscles. In the present invention, an ergonomically designed motor casing provides an overall narrower profile, reducing the amount of unused space between the interior of the walls of the motor casing and the windings of the motor. Additionally, a base with a hand cradle assembly is provided for engaging the side of the hand of an operator. These features provide support to the hand of the operator which relieves stress on the muscles and allows the operator to firmly grasp the router with one hand thus decreasing fatigue levels as compared to those routers which require both hands of the operator to be engaged for control over the router.

The present invention, further enables the hand of the operator to engage with a grip assembly which provides additionally ergonomic functionality. The grip assembly is designed to incorporate materials which engage the hand of the operator with material as opposed to the metal of the motor casing. The material is designed to flexibly engage the hand of the operator and provide absorption of operational stresses. Such flexible engagement may comprise a grip zone which provides a flexible or cushioned gripping region for the hand of the operator. Operational stress absorption may be provided by the choice of materials employed on the grip assembly, for instance a firmer material may provide a firmer grip region but translate stresses, such as vibrations, at a higher rate than a more flexible material.

It is an object of the present invention to provide a router which is ergonomically designed to increase operator comfort and control when operating the router. It is a further object of the present invention to reduce muscle fatigue and the concomitant productivity decrease experienced by users of typical routers.

DETAILED DESCRIPTION OF THE INVENTION

Referring generally now toFIGS. 1A through 6, exemplary embodiments of the present invention are shown.

A router assembly100including a motor casing102coupled with a base assembly104, is shown inFIGS. 1A through 1D. The motor casing102is generally configured to surround a motor. The motor casing102is disposed with a first grip zone106of a grip assembly105. The grip assembly, in the current embodiment, includes the first grip zone106disposed on the motor casing102in a location proximal to a first knob handle108coupled with the base assembly104. The base assembly104is coupled with the first knob handle108and a second knob handle110.

In the preferred embodiment, the grip assembly is integrally defined within the configuration of the motor casing102. In alternative embodiments, the grip assembly may be established in a variety of ways as contemplated by those of ordinary skill in the art. The dimensions established by the configuration of the motor casing102, including the first grip zone106of the grip assembly105, may substantially correspond to a grasp size of an average human hand. The grasp size being defined generally as the area circumscribed by a grasp of a thumb and forefingers of the average human hand. It is understood that the motor casing102, which at least partially encompasses a motor (i.e., motor windings), including the grip assembly105may provide a configuration which may result in the increased ease of operation of the router and reduction of muscle fatigue in an operator of the router. In alternative embodiments, the motor casing102may assume a variety of configurations, which enable the motor casing102to surround the windings of the motor and provide similar advantages. It is understood that alternate configuration parameters may be employed without departing from the scope and spirit of the present invention.

The motor casing102encompasses the motor which includes a router bit engagement assembly112that couples with a router bit114. An actuator116is disposed upon the motor casing102for selecting the operation of the router assembly100. It is contemplated that the motor casing102may be removed from the base assembly104. This may allow a secondary motor casing to be coupled with the base assembly104or a secondary base assembly, such as a plunge base assembly, to be coupled with the motor casing102, thereby increasing the functionality of the motor casing102and the base assembly104.

In the preferred embodiment, the first grip zone106of the grip assembly105provides an operator a flat surface with which to engage the hand of the operator. Thus, the first grip zone106establishes a flat side which may make grasping engagement of the router assembly100by the hand of the operator more secure and may decrease fatigue in the hand of the operator. It is understood that the first grip zone106may establish various ergonomically correct configurations for the grasping of the router100by the hand of the operator without departing from the scope and spirit of the present invention. For example, the first grip zone106may be configured with contoured grooves for engaging with individual fingers of the hand of the operator. Alternatively, the first grip zone106may be configured with alternating flat regions and rounded regions.

In the present embodiment, the first grip zone106is disposed on the motor casing102proximal to the first knob handle108. This location is exemplary for an operator who is right-hand dominant, allowing the operator to engage the dominant hand with the flat surface securing the router assembly100in the grasp of the operator. It is understood that the location of the first grip zone106may be adjusted to accommodate an operator with a left-hand dominance. In such an instance, the first grip zone106may be located proximally to the second knob handle110.

The position of the first grip zone106is changed through use of an adjustment assembly which enables the position of the motor casing102, and thusly the first grip zone106, to be adjusted in various positions relative to the base assembly104. As shown inFIG. 1Ba main horizontal axis ‘A’ and a main vertical axis ‘B’ may be established for identifying the position of the motor casing102relative to the base assembly104. For instance, the motor casing102and the first grip zone106may be located approximately between the first and second knob handles. The various presentation positions of the motor casing102and the first grip zone106is enabled through the operational coupling of the adjustment assembly with the motor casing102and the base assembly104. Thus, the motor casing102is able to present at various angles relative to a horizontal main axis ‘A’ and the vertical main axis ‘B’. This adjustment capability may promote use of the router assembly100when the motor casing102is positioned below the operator's elbow.

The adjustment assembly, in preferred embodiments, may comprise a variety of systems allowing for releasing, adjusting, and securing the position of the motor casing102relative to the base assembly104. For example, a pin alignment system may employ one or more pins which may be removably coupled with one or more grooves disposed within the base assembly104. The pins may removably engage with the motor casing102, through a boss assembly, and the like, and into the one or more grooves. This type of assembly allows for pre-set angular adjustments to be made.

Other assemblies may allow for a user of the present invention to establish a plurality of discrete positions through angular adjustment of the motor casing102relative to the base assembly104. For example, a compression lock assembly comprising a sleeve defining an open and closed position, disposed within the base assembly104and at least partially surrounding the motor casing102, may be engaged by a fastener which allows the operator to secure the sleeve in either the open or closed position. When in the open position the operator may rotate the motor casing102relative to the base assembly104without being limited by pre-set angular adjustment sites. Once the operator has established the desired position of the motor casing102relative to the base assembly104, the operator may engage the fastener, thereby establishing the sleeve in the closed position. In the closed position the sleeve secures the position of the motor casing102.

In a still further alternative, the fastening assembly may include a latch assembly which may be released to allow the position of the motor casing102to be adjusted relative to the base assembly104. Once the new position of the motor casing102is established the latch assembly may be engaged to secure the new position and prevent further movement of the motor casing102during operation of the router assembly100. It is understood that a variety of fastening assemblies may be employed, such as a strap lock assembly, and the like. Alternatively, the fastening assembly may employ fasteners, such as bolts, screws, clips, and the like, which may secure the position of the motor casing102relative to the base assembly104. It is understood that alternate configurations of the adjustment assembly as contemplated by those of ordinary skill in the art may be employed without departing from the scope and spirit of the present invention.

As shown inFIG. 1B, the motor casing102is at a zero degree position, relative to the horizontal main axis ‘A’ of the base assembly104, when the first grip zone106is located proximal to the first knob handle108. The motor casing102may be rotated, relative to the base assembly104, thereby presenting the first grip zone106at various angles relative to the horizontal main axis ‘A’ of the base assembly104. In preferred embodiments, the motor casing102may be enabled to rotate on the horizontal axis ‘A’ from zero to three hundred sixty degrees or to a discrete position within this range, relative to the base assembly104. As shown inFIG. 1C, the motor casing102may rotate so as to position the first grip zone106approximately ninety degrees from the initial horizontal zero degree position ofFIG. 1B. In the exemplary embodiment ofFIG. 1D, the motor casing102is rotated approximately one hundred eighty degrees on the horizontal axis ‘A’ from the zero degree position ofFIG. 1B. In this embodiment the first grip zone106is proximal to the second knob handle110, which may enable the use of the router assembly by an operator who is left hand dominant.

It is further contemplated that the adjustment assembly may promote the presentation of the motor casing102at various angles relative to the vertical main axis ‘B’ of the base assembly104, as shown inFIG. 1B. Preferably, the range of angular adjustment of the motor casing102relative to the vertical main axis ‘B’ of the base assembly104is between zero to thirty degrees or zero to forty five degrees. Thus, the motor casing102may enhance the operator's ability to utilize the router assembly when the router assembly is positioned below the operator's elbow. In operation, when the motor casing102is presented at an angle relative to the vertical axis ‘B’ of the base assembly104, the grip assembly may be located in various positions. For example, the grip assembly may be located on the underside of the motor casing102providing the first grip zone106in the area engaged by the fingers of the operator when gripping the angled motor casing102.

Referring now toFIG. 2A, a router assembly200including a motor casing202, disposed with a motor casing grip assembly comprising a first motor casing grip zone204, is coupled with a base assembly206disposed with a base grip assembly comprising a base first grip zone208, is shown. In the current embodiment, the first motor casing grip zone204and the base first grip zone208establish a generally flat gripping area for the hand of the operator. Similar to the grip zone for the router assembly100, these two grip zones may be variously configured to provide increased grip-ability and comfort. In the exemplary embodiment, the base first grip zone208is located directly in line with the first motor casing grip zone204disposed on the motor casing202. This alignment of the motor casing first grip zone204with the base first grip zone208provides an increased flat surface area with which the operator may grasp the router. This may enhance the operator's grasp of the router, control over the router, and may reduce muscle fatigue due to gripping the router assembly200. It is understood that the router assembly200may include similar angular adjustment capabilities as described above with respect toFIGS. 1A through 1D. Therefore, the positioning of the motor casing first grip zone204may vary relative to the position of the base first grip zone208.

It is contemplated that the base grip assembly include a base second grip zone. The base second grip zone may be aligned with a second motor casing grip zone of the motor casing grip assembly, providing an overall narrower profile to the router assembly200. It is further contemplated that the motor casing grip assembly and the base grip assembly may include first and second grips coupled with the first and second grip zones disposed upon the motor casing and the base assembly. The grips may provide vibration dampening and may reduce the heat transfer from the router assembly to the hand of an operator.

The router assembly200further includes a first knob handle210and a second knob handle212coupled with the base assembly206. A router bit engagement assembly214is coupled with a router bit216, the router bit engagement assembly214is also coupled with a motor which is disposed within the motor casing202. An actuator218is disposed on the motor casing202for controlling the operation of the router assembly200. It is contemplated that the base assembly206disposed with the base first grip zone208and the motor casing202disposed with the first motor casing grip zone204may present at an angle relative to a main axis of the router bit engagement assembly214and the router bit216. Providing an angled motor casing202and base assembly206may allow the operator to utilize the router with the router positioned below the operator's elbow.

In the embodiment shown inFIG. 2B, a router assembly250includes a hand cradle assembly comprising a cradle256. In the preferred embodiment, the cradle256is enabled as a ledge. It is understood that the raised portion, established by the cradle256, may be enabled in variety of configurations without departing from the scope and spirit of the present invention. Further, the ledge256may be ergonomically configured to engage fully and in the most comfortable manner with the hand of the operator. It is contemplated that the ledge assembly may include an actuator for selecting the operation of the router assembly250. In the exemplary embodiment, the ledge256is disposed on a base assembly254and is located directly in line with a first motor casing flat side258disposed on a motor casing252. The ledge256may be engaged by the hand of the operator, allowing the hand to rest against the ledge256which may reduce muscle fatigue. In the preferred embodiment, the ledge256is aligned with the first grip zone258. Alternatively, the ledge256may be in various locations relative to the first grip zone258, as enabled by the angular adjustment capabilities of the router assembly250which are similar to those shown and described inFIGS. 1A through 1Cfor router assembly100.

As shown inFIG. 2C, a motor casing272, coupled with a base assembly274, comprises a first grip zone276including a first actuator278for controlling operation of a router assembly270. The actuator278may be a variety of configurations, such as a two position “on/off” switch, a toggle switch, a button assembly, and the like. It is understood that the positioning of the actuator278may increase the ease of controlling the operation of the router assembly270. Further, the actuator278may be positioned at a bottom or top end of the first grip zone276in order to promote efficient control of the motor during operation of the router assembly270. Each actuator assembly may be operationally coupled with the motor to control the operation of the motor.

Referring now toFIGS. 3 and 4, a router assembly300is shown. The router assembly300includes a motor casing302disposed with a grip assembly comprising a first grip zone304and a second grip zone306. The motor casing302is coupled with a base assembly308which includes a first knob handle310and a second knob handle312. An actuator314is disposed on the motor casing302for controlling the operation of the router assembly300. The first and second grip zone304and306narrow the profile of the router assembly300. This narrower profile may enable an operator to grasp the router assembly300more securely, maintaining increased control during operation. Additionally, a narrower profile may further increase the gripping comfort experienced by the operator of the router assembly300, thereby reducing muscle fatigue in the hand of the operator. For example,FIG. 4shows the router assembly300being engaged by a hand of an operator. The engagement points of the hand with the router assembly300are the first and second grip zone304and306which allow the operator to establish a secure grasp. In the current embodiment, the thumb engages with the first grip zone304and the forefingers engage against the second grip zone306. As shown, the palm of the hand may be extended away from contact with the motor casing or in the alternative the palm may be engaged against the motor casing.

A router bit engagement assembly316couples to a motor disposed within the motor casing302. A router bit318couples with the router bit engagement assembly316. Similar to the angular adjustment capabilities shown and described for the router assembly100, inFIGS. 1A through 1D, it is contemplated that the motor casing302may present at an angle relative to a horizontal and vertical main axis of the base assembly308. Further, the motor casing302may be removed from the base assembly308enabling the base assembly308to be engaged by a secondary motor casing or the motor casing302to be engaged by a secondary base assembly.

FIG. 5shows a router assembly500including a first grip502disposed on a motor casing504. In the exemplary embodiment, the first grip502is disposed upon a first grip zone506of a grip assembly of the router assembly500. The first grip502may allow for a more comfortable and secure grasp of the router assembly500by an operator. The first grip502may be composed of polymeric material, elastomeric material, and the like. In a preferred embodiment, for example, the first grip502may be composed of SANOPRENE™, a registered trademark of Roush Industries. The addition of the first grip502, upon the first grip zone506, may provide vibration dampening and/or vibration attenuation during operation of the router assembly500and may reduce heat transfer from the router assembly500. It is further contemplated that the first grip502may comprise a contoured and/or textured design to enable a firmer grasp by the operator. For example, the first grip502may include raised patches, raised lines, relief points, and the like. It is understood that the contouring of the first grip502may be varied as contemplated by one of ordinary skill in the art without departing from the scope and spirit of the present invention.

It is understood that the location of the first grip zone506and thus the first grip502may be varied. In the exemplary embodiment, the first grip zone506including the first grip502is disposed proximal to a first knob handle510. This is preferable for a right hand dominant operator of the router assembly500. Alternatively, the first grip zone506and the first grip502may be disposed proximal to a second knob handle512which provides increased grasping ability and control over the router assembly500to a left hand dominant operator. The position of the first grip502may be adjusted through use of an adjustment assembly similar to the adjustment assembly described above in reference toFIGS. 1 through 4.

The router assembly500further includes a base assembly508coupled with the motor casing504. The base assembly508includes the first knob handle510and the second knob handle512. A router bit engagement assembly514is coupled with a router bit516, the router bit engagement assembly514being coupled with a motor disposed within the motor casing504. An actuator518, for selection of the operation of the router assembly500, is disposed upon the motor casing504. As described above, inFIG. 2C, the actuator may be disposed in various locations and comprise a variety of configurations as contemplated by those of ordinary skill in the art.

In the preferred embodiment, the first grip502is disposed integrally with the configuration of the motor casing504. For example, the first grip zone506establishes a recess from the plane of the motor casing504and the first grip502, coupled with the first grip zone506, may fill the recess and re-establish the planar surface. It is contemplated that the first grip502may be coupled to the first grip zone506of the motor casing504using various fastening assemblies. For example, the first grip502may be adhered to the first grip zone506through a standard manufacture process. The adhering may be accomplished through the use of glue, epoxy, or other substances which provide a similar effect. Alternatively, the first grip502may be affixed to the first grip zone506of the motor casing504through the use of fasteners. Fasteners may include screws, bolts, and the like. Additionally, the first grip502may couple with the first grip zone506of the motor casing504through the use of a magnetic system. The magnetic system may comprise a magnetic strip being placed upon the first grip502which is attracted to the metal of the motor casing. Other fastening assemblies may be employed as contemplated by those of ordinary skill in the art.

It is contemplated that the first grip502may be removed from the first grip zone506. Upon removal the first grip502may be stored to protect the material composing the first grip502and increase its usable life. The enablement of removal may be accomplished through the use of a variety of design implementations. For example, the first grip502may be disposed with a loop and hook system. In such an instance, a receiving loop patch may be affixed in position on the first grip zone506of the motor casing504and be enabled to couple with the first grip502which may include a hook patch. Alternatively, when the first grip502is secured to the first grip zone506through the use of fasteners, as described above, the fasteners may be removed.

Referring now toFIG. 6, a router assembly600including a depth adjustment assembly602and a motor casing604disposed with a grip assembly comprising a first grip zone606and a second grip zone608, is shown. It is contemplated that the depth adjustment assembly602may be of various configurations and that the assembly shown is merely exemplary and not intended to limit or restrict the use of the present invention. In alternative embodiments the router assembly600may include one or three or more grip zones. The first grip zone606is further disposed with a first grip610and the second grip zone608is further disposed with a second grip612. The first and second grip610and612may be similar to those described above in reference toFIG. 5. The first grip zone606is proximal to the depth adjustment assembly602. The motor casing604is coupled with a base assembly614which is disposed with a first knob handle616and a second knob handle618. A router bit engagement assembly620is coupled with a router bit622, the router bit engagement assembly620being coupled with a motor disposed within the motor casing604. It is understood that the motor casing604and/or the base assembly614may present at various angles relative to the main vertical and horizontal axis of the base assembly614, as described previously inFIGS. 1 through 5.

The first grip610and the second grip612may be disposed in various locations upon the motor casing604. Further, it is contemplated that the material composing the first and second grips may be disposed within the first and second grip zones locations or may be disposed continuously upon the motor casing604, at least partially encompassing the motor casing604. In an alternative embodiment, the base assembly614may be disposed with a grip assembly comprising a first grip zone and a second grip zone. The base assembly first and second grip zones may be located in alignment with the first grip zone606and the second grip zone608disposed on the motor casing604. However, the first and second grip zones of the base assembly614may be disposed in various locations upon the base assembly614not necessarily in alignment with the first grip zone606and the second grip zone608of the motor casing604. Further, the base assembly first and second grip zones may be include a base first grip and base second grip, composed of material similar to or varying from the first grip610and the second grip612, disposed on the first and second grip zone606and608, respectively. The manner in which the material of the base first grip and base second grip may be disposed on the base assembly is similar to that described previously inFIG. 5.

It is contemplated that the motor casings and base assemblies shown and described inFIGS. 1 through 6are enabled to be retrofitted with existing router assemblies. This is advantageous in providing an operator of the router assembly with interchangeable options. It is believed that the present invention and many of its attendant advantages will be understood by the forgoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely an explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.