Abstract:
A handheld power tool and a removable accessory, which is changeable without requiring extra tools, include various elements. For example, the handheld power tool includes a platen having an aperture therein and a locking mechanism coupled with the platen. The locking mechanism includes a cam member. The removable accessory includes a tab that fits into the aperture and that is engagable by the cam member to bias the removable accessory into abutting contact with the platen to securely couple the removable accessory with the tool.

Description:
BACKGROUND 
       [0001]    Handheld power tools are generally know in which an accessory, such as a tool or a tip, can be changed to include a different configuration or is replaceable with a different accessory. For example, a handheld sanding device, commonly known as a palm sander, might include a removable tip portion designed to access corners and perform detailed work. The tip might be removed for various reasons, such as to replace the tip with a less worn or different tool or to change a configuration of the tip. 
         [0002]    An accessory might be changed on a handheld power tool using various mechanisms. For example, some handheld power tools utilize a screw to secure the removable accessory in position. The screw can then be loosened, or removed altogether, to enable the change and then re-fastened to secure the tool back into position. However, such attachment mechanisms rely on a separate fastener (e.g., screw) and require additional tools, such as a screwdriver, to secure the fastener in place. 
       SUMMARY 
       [0003]    This Summary is provided to introduce a selection of concepts in a simplified form that are further described in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
         [0004]    Embodiments of present invention are directed to a power tool having a removable accessory, which is changeable without requiring extra tools. In one aspect, an embodiment of the present invention is directed to a handheld power tool having a platen that transmits a motion provided by a drive mechanism and that includes an aperture, a locking mechanism that is attached to the platen and that includes a cam member, and a removable accessory comprising a tab that fits into the aperture and that is engaged by the cam member. 
         [0005]    In another aspect of the present invention, a locking mechanism is described for quickly and releasably attaching a removable accessory to a tool, the locking mechanism including a body, a cam member that extends from the body and that includes a cam surface for biasing the removable accessory, and a pivot mechanism providing a rotatable connection to the handheld power tool. 
         [0006]    A further aspect of the present invention includes a removable accessory for a tool, the removable accessory including a body and tabs extending from the body that are insertable into respective apertures of the tool to provide a secure fit which prohibits lateral, longitudinal, and/or vertical movement of the removable accessory. 
         [0007]    In yet another aspect of the invention, a combination of the locking mechanism and removable accessory is described. For example, the locking mechanism might include a cam member and a pivot mechanism providing a rotatable connection to the tool, and the removable accessory might include a tab configured to insert into an aperture of the tool and to be engaged by the cam member to provide a secure coupling. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Illustrative embodiments of the present invention are described in detail below with reference to the attached figures, which are incorporated herein by reference to form part of the specification and are to be considered in conjunction with the specification, wherein: 
           [0009]      FIG. 1  is a perspective view of an sample handheld power tool having a removable accessory in accordance with an embodiment of the present invention; 
           [0010]      FIG. 2  is a bottom perspective view of a platen of the handheld power tool of  FIG. 1  and depicts the removable accessory of  FIG. 1  in accordance with an embodiment of the present invention prior to coupling with the platen; 
           [0011]      FIG. 3  is a top perspective view of the platen depicted in  FIG. 2  and depicts in an exploded view various elements of a locking mechanism in accordance with an embodiment of the present invention; 
           [0012]      FIGS. 4   a  and  4   b  illustrate an operation of the locking mechanism in accordance with an embodiment of the present invention; 
           [0013]      FIG. 5  is a fragmentary, side elevation view in cross-section of the platen, the locking mechanism, and the removable accessory when coupled together in accordance with an embodiment of the present invention; and 
           [0014]      FIGS. 6   a  and  6   b  illustrate top perspective views of possible alternate embodiments of removable accessories. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    The subject matter of embodiments of the present invention is described with specificity herein to meet statutory requirements. The description itself, however, is not intended to necessarily limit the scope of claims. Rather, the claimed subject matter might be embodied in other ways to include different elements or combinations of elements similar to the ones described in this document, in conjunction with other present or future technologies. 
         [0016]    When referencing the drawings, like reference characters designate like parts throughout the different views. Referring now to  FIG. 1 , a sample handheld power tool  100  (also referred to as “power tool”) is depicted. The handheld power tool  100  comprises a motor housing  102 , which encloses a motor (not depicted). In addition, the power tool  100  includes control buttons  104  and  106  that are used to control operations of the motor. When using the power tool  100 , a user might grasp near an upper surface  108  of the motor housing  102  to handle and maneuver the power tool  100 . The upper surface  108  might include mold-in features or a grip surface to facilitate easier grasping of the power tool  100 . The handheld power tool  100  might include other elements not depicted such as a battery or other power source, one or more tools, and a dust-collection compartment. It should be noted that while the depicted sample or exemplary power tool  100  is a sander, commonly referred to as a palm sander, the present invention is not limited to use with such a tool. The present invention could be used to couple accessories to other items and/or tools, including manually operated or non-powered tools. Nonetheless, for the purpose of depicting a specific implementation or embodiment of the present invention, a handheld power sander is used. 
         [0017]    In this embodiment of the present invention, the power tool  100  includes a platen  110  to which tools and accessories are directly or indirectly attached. For example, if the power tool  100  were being used as a handheld sanding device, an abrasive sheet could be attached to a bottom of the platen  110  to sand a work piece. That is, the platen  110  includes other features (not shown, but known in the art) that allow the abrasive sheet to attach to platen  110 . Based on the orientation of the power tool  110  in  FIG. 1 , the abrasive sheet would attach to a bottom surface (see e.g.,  FIG. 2 ) of the platen  110 . In addition, the platen  110  is coupled with a drive mechanism of the motor, such that the motor transmits a motion provided by the drive mechanism of the motor to the platen  110 . For example, the motor and drive mechanism might transmit a regular or irregular oscillation or vibration to the platen  110  and, in turn, the abrasive sheet which would then work on the surface to be abraded or sanded. 
         [0018]    The power tool  100  also includes a removable accessory  112  that releasably attaches to or couples with the platen  110 , and a locking mechanism  114  that connects and locks the removable accessory  112  to the platen  110 . The removable accessory  112  might include various tools and shapes. For example, a first type of removable accessory  112  might have a triangular profile of a first width (see, e.g., removable accessory  112  in  FIG. 2 ), whereas a second type of removable accessory might have an elongate profile with a second width, which is narrower than the first width (see, e.g., removable accessory  112 ′ in  FIG. 6   a ). As such, the first type of removable accessory might be usable to perform work across a larger surface area, whereas the second type of removable accessory might be usable to perform more detailed work. In another example, one type of removable accessory includes a substantially flat configuration for working on pieces (e.g., wood surface) having a substantially flat surface (see, e.g., removable accessory  112  in  FIG. 2 ), whereas another type of removable accessory includes a concave configuration for working on pieces having a rounded surface (see, e.g., removable accessory  112 ″ in  FIG. 6   b ). If the power tool  100  is a sanding device, then an abrasive sheet might be coupled adjacent to a bottom surface (hidden from view) of the removable accessory  112 . 
         [0019]    In accordance with an embodiment of the present invention, the different types of removable accessories are interchangeable using the connection features of the removable accessory  112  and the locking mechanism  114 . The removable accessory  112  and the locking mechanism  114  are described in more detail in other portions of this Detailed Description. 
         [0020]    Referring now to  FIG. 2 , the platen  110  is depicted from a bottom perspective, which shows the platen bottom surface that was hidden from view in  FIG. 1 , and the removable accessory  112  is depicted from a top perspective. The terms “bottom” and “top” are relative based on the orientation of the tool  100 , and as such, the “bottom surface” might be the top surface of the platen  110  if the power tool  110  is rotated in a platen-upward orientation. The platen  110  includes a first bottom surface  116  and a second bottom surface  118 . In an aspect of the present invention, one or more tools are attached adjacent to the first bottom surface  116  and the second bottom surface  118 . 
         [0021]    In addition, the platen  110  includes a wall  120  connecting the first bottom surface  116  and the second bottom surface  118 . In the embodiment depicted in  FIG. 2 , the first bottom surface  116  is more recessed into a body portion of the platen  110  relative to the second bottom surface  118 . As such, the first bottom surface  116  and the wall  120  form a partially enclosed space into which a portion of the removable accessory  112  is insertable. 
         [0022]    The platen  110  further includes an aperture  122  extending through a thickness of the platen  110 , and in the illustrated embodiment, the aperture  122  is positioned in the wall  120 . In addition, the aperture  122  might also extend though the second bottom surface  118 . In another aspect, the platen  110  includes a channel  124  that connects with the aperture  122 . The channel  124  is constructed (e.g., molded) into the first bottom surface  116 , and the channel  124  includes a first channel end  126  terminating in an interior portion of the first surface  116 . A portion of the channel  124  that opposes the first channel end  126  connects with, and is continuous with, the aperture  122 . 
         [0023]    In a further aspect of the present invention, the platen  110  includes a slot  125 , which also extends through a thickness of the platen  110 . In one embodiment, the slot  125  is constructed into the first bottom surface  116  and extends inward from a periphery of the platen  110  towards an interior portion of the first bottom surface  116 . The slot  125  includes a slot base  129 , which represents a terminating end of the slot  125  and, in some regards, is similar to the wall  120 . In the illustrated embodiment, the slot  125 , the channel  126 , and the aperture  122  are substantially aligned. 
         [0024]    In  FIG. 2 , the removable accessory  112  is depicted disengaged from the platen  110 . The removable accessory  112  includes a tab  113  having a cam-engaging surface  111 . The removable accessory  112  also includes a flanged tab  115 . In addition, the removable accessory  112  includes a finger  117  that extends from a base portion  119  and the tab  113  extends from the finger  117 . 
         [0025]    In accordance with an aspect of the present invention, the tab  113  is insertable into the channel  124  of the platen  110 . In addition, the tab  113  is traversable through the channel  124  and toward the aperture  122 . The finger  117  and the tab  113  include respective widths that are sized to allow the finger  117  and the tab  113  to pass through the aperture  122 . In an embodiment of the present invention, a portion  121  of a cam member, which is a component of the locking mechanism  114 , is rotated to not obstruct the aperture  122 , thereby providing an unobstructed path through the aperture  122  through which the tab  113  and finger  117  may pass. 
         [0026]    In a further embodiment of the present invention, the flanged tab  115  is insertable into the slot  125 . The flanged tab  115  includes a trunk  123  extending from the base  119 . In addition, one or more flanges  127  extends outward from the trunk  123 . As such, the one or more flanges  127  are spaced apart from the base  119  of the removable accessory. In an embodiment of the present invention, the trunk  123  of the flanged tab  115  may be slid from a periphery of the platen  110  into the slot  125 . When the flanged tab  115  is positioned in the slot  125 , the body  119  is positioned adjacent the first bottom surface  116  of the platen  110  and the one or more flanges  127  engage a top surface of the platen  110  that generally opposes the first bottom surface  116 . The top surface of the platen  110  is hidden from view in  FIG. 2  and is identified by reference numeral  144  in  FIG. 3 . In an embodiment of the present invention, the tab  113  and the flanged tab  115  are inserted through the aperture  122  and the slot  125  (respectively) near simultaneously when connecting the removable accessory  112  to the platen  110 . 
         [0027]    In an embodiment of the present invention, a T-shaped configuration of the flanged tab  115  also contributes to a rigidity of the connection between the removable accessory  112  and the platen  110 . That is, the flanges  127  engage the top surface  144  of the platen, thereby limiting movement in a vertical or first axis. In addition, the trunk  123  of the flanged tab  115  engages the slot base  129 , thereby limiting movement in a longitudinal or second axis, which is substantially perpendicular to the first axis. The trunk  123  of the flanged tab  115  also engages the sides of the slot  125  to limit movement in a lateral or third axis, which is perpendicular to the first axis and the second axis. 
         [0028]    Referring to  FIG. 3 , the platen  110  is depicted from a top perspective. In  FIG. 3 , another view of the aperture  122  and the channel  124  is provided.  FIG. 3  depicts that the aperture  122  and a portion of the channel  124  are continuous with one another and extend through the platen  110 . 
         [0029]    The platen  110  further includes a screw boss  130 . The screw boss  130  includes a periphery wall  132  that circumscribes a hollow middle region  134 . The screw boss  130  mates with a pivot boss hole  136  passing through a body  138  of the locking mechanism  114 . A screw  140  or other appropriate fastener is fastened inside the hollow middle region  134  when the screw boss  130  is positioned in the pivot boss hole  136 . In addition, a washer  142  may be positioned between the screw head and the body  138  to reduce the risk of the locking mechanism  114  sliding off of, or otherwise breaking away from, the screw  140 . 
         [0030]    In an aspect of the present invention, a slider or cam member  146  extends from the body  138  of the locking mechanism  114 . When the body  138  is secured onto the screw boss  130 , the cam member  146  is movable to different positions relative to the aperture  122  and the channel  124 . For example,  FIG. 2  depicts an arrangement in which a portion  121  of the cam member  146  at least partially covers the aperture  122  and the channel  124 . In an embodiment of the present invention, the locking mechanism  114  rotates at least partially about the screw boss  130  in order to move the cam member  146  between selectable positions. As such, the locking mechanism  114  is rotatable to move the cam member  146  to a side of the aperture  122  and the channel  124 , such that the cam member  146  does not obstruct the aperture  122  and the channel  124 . 
         [0031]    An enlarged view of one embodiment of the cam member  146  is provided by  FIG. 3 , in which the cam member  146  includes various elements. For example, the cam member  146  includes a camming surface  156 . As will be described in other portions of the Detailed Description, the camming surface  156  is usable to engage the tab  113  of the removable accessory  112  when the tab  113  is inserted through the aperture  122 . In another embodiment, the cam member  146  includes a compressible member  158 , such as a rubber plug or other similar device. The compressible member  158  might also engage the tab  113  in a manner similar to the camming surface  156 . However, the compressible nature of member  158  allows for a greater tolerance between the cam member  146  and the tab  113 . 
         [0032]    In a further aspect of the present invention, a lever  152  extends from the body  138  of the locking mechanism  114  and is usable to rotate the body  138  about the screw boss  130 . In addition, the platen  110  includes various detent pockets  150 . The detent pockets  150  radially align with a detent (identified in  FIG. 5  by reference numeral  164 ) of the locking mechanism  114 . The detent  164  engages one of the detent pockets  150  in order to bias the locking mechanism  114  in a selected position. 
         [0033]    When the aperture  122  and the channel  124  are not obstructed by the cam member  146 , an unobstructed path is provided through the aperture  122  and the channel  124 , and the tab  112  and the finger  117  of the removable accessory  112  may pass through the path. In addition, as described with respect to  FIG. 2 , the flanged tab  115  is insertable into slot  125  when the tab  113  is inserted through the aperture  122 . The top surface  144  of the platen  110  is shown in  FIG. 3 . When the flanged tab  115  is slid into the slot  125 , the flanges  127  of the flanged tab  115  engage the top surface  144  of the platen  110 , as discussed above. 
         [0034]    Referring now to  FIGS. 4   a  and  4   b , an operation of the cam member  146  is depicted in accordance with an embodiment of the present invention. In  FIG. 4   a , the locking mechanism  114  has been moved to an unlocked position in which the cam member  146  does not obstruct a path through the aperture  122 . In addition, the tab  113  of the removable accessory  112  has been inserted through the aperture  122 , and the flanged tab  115  has been inserted into the slot  125 . In  FIG. 4   a , a gap exists between the cam-engaging surface  111  ( FIG. 2 ) of the tab  113  and the platen  110 . The gap intersects with a path that is traveled by the cam member  146  when the locking mechanism  114  is rotated about the screw boss  130 . 
         [0035]    In  FIG. 4   b , the locking mechanism  114  has been rotated counter-clockwise (relative to  FIG. 4   a ) to a lock position, such that the cam member  146  fills the gap adjacent to the cam-engaging surface  111  of the tab  113 . In accordance with an embodiment of the present invention, the camming surface  156  of the cam member  146  biases the tab  113  away from the aperture  122 . In addition, such biasing action of the camming surface  156  against the tab  113  also pulls the flanged tab  115  toward the platen  110 . 
         [0036]    In an embodiment of the present invention, the removable accessory  112  depicted in  FIG. 4   b  is disconnectable from the platen  110 . For example, the locking mechanism  114  in  FIG. 4   b  is rotatable in either a clockwise or counter-clockwise direction. Rotating the locking mechanism  114  in either direction will disengage the cam member  146  from the tab  113  and will create an unobstructed path through the aperture  122  and into the channel  124 . When the tab  113  is moved through the aperture  122  and into the channel  124 , the flanged tab  115  is slid out of the slot  125 . When the tab  113  and the flanged tab  115  have substantially cleared the aperture  122  and the slot  125 , respectively, the removable accessory  112  may be disconnected from the platen  110 . 
         [0037]    Referring now to  FIG. 5 , a fragmentary cross-section view is provided showing the removable accessory  112  coupled to the platen  110  via the locking mechanism  114  (i.e., the locking mechanism  114  is in the same position as in  FIG. 4   b ). The tab  113  of the removable accessory  112  has been inserted in the channel  124  and traversed through the channel  124  and the aperture  122 . In addition, the trunk  123  of the flanged tab has been inserted into the slot  125  (not shown in  FIG. 5 ), such that the flanged tab is abuts the slot base  129 . 
         [0038]    In an embodiment of the present invention, the cam-facing surface  111  of the tab  113  and the trunk  123  of the flanged tab  115  are spaced a distance apart, which is identified by reference numeral  160 . In addition, the slot base  129  of the slot  125  is spaced a distance apart from the camming surface  156 , the distance represented by reference numeral  162 . In an embodiment of the present invention, the distance  160  and the distance  162  are substantially similar. As such, when camming surface  156  biases the tab  113  away from the aperture  122 , the trunk  123  of the flanged tab  115  is pulled into the slot base  129  of the platen  110  and into abutting contact with the slot base  129 , thereby creating a secure connection between the removable accessory  112  and the platen  110 . As described in other parts of this Detailed Description, an embodiment of the present invention includes a compressible member  158  that is coupled to the cam member  146  and that compressibly engages the cam-engaging surface  111  of the tab  113 . The compressible member  158  helps to account for different sized gaps between the cam-engaging surface  111  and the cam member  146  created by tolerances in the manufacturing process. 
         [0039]      FIG. 5  also depicts one of the detent pockets  150 . In an aspect of the present invention, the detent  164  is received in and underneath of the lever  152  and a ball of the detent  164  that is biased downwardly engages the detent pockets  150  as the locking mechanism  114  is rotated. As such, the detent  164  provides a friction fit with the detent pockets  150  to bias the locking mechanism in a selected position. 
         [0040]    Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the scope of the claims below. Embodiments of the technology have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to readers of this disclosure after and because of reading it. For example, while the illustrated embodiments are described herein as having a cam member, the use of the word cam should not be narrowly defined, but should be broadly interpreted to cover objects of any shape, which can rotate or move in an alternate path (e.g., such as a straight line), and perform the function of closing the gap between the cam-engaging surface  111  ( FIG. 2 ) of the tab  113  and the cam member  146 , as the cam member is moved and which bias the tab  113  in a direction to draw the accessory  112  into abutting contact with the platen  110  (e.g., a wedge or other item with an inclined face or surface). Alternative means of implementing the aforementioned can be completed without departing from the scope of the claims below. Certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims.