PATENT ABSTRACT
A removable surface positioning guide for a rotary hand-held tool provides one or more adjustable features for selective positioning of a surface engaging bit driven by the rotary hand-held tool. The surface positioning guide may include a pivot joint between a guide base and a mounting adapter. The guide base pivots relative to the mounting adapter about the pivot joint between operable positions. The surface positioning guide may include at least one spring supported by the mounting adapter either directly or indirectly that biases a guide base axially away from the mounting adapter. The guide base is movable toward the mounting adapter against the biasing of the at least one spring to effect a plunging movement. The surface positioning guide may include a reversible or interchangeable base flange with differently configured faces that are adapted to be placed against a working surface.

PATENT DESCRIPTION
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
   This patent application claims the benefit of U.S. Provisional Patent Application No. 60/463,615, filed Apr. 17, 2003. 

   FIELD OF THE INVENTION 
   This invention pertains to surface positioning guides for rotary hand-held tools and more specifically to removable surface positioning guides that can be removably mounted to rotary hand-held tools. 
   BACKGROUND OF THE INVENTION 
   Rotary hand-held tools are common tools that are frequently used for a variety of work tasks around the house and workplace. There are literally hundreds of different attachable and detachable surface engaging bits for these rotary hand-held tools, including, for example bits configured for such tasks as carving, engraving, routing, grinding, sanding, sawing, sharpening, cutting, polishing, cleaning, drilling and other work tasks. The versatility of such rotary hand-held tools and interchangeability of bits has made these tools very popular in the marketplace. The small size of these tools are also advantageous and provide for easy manipulation. One of the more popular rotary hand held tools include the Dremel® brand rotary tools. 
   These rotary hand-held tools include a housing having a size and contour that provides a gripping surface and a rotary output that is driven by a motor contained within the housing (e.g. an output shaft, chuck and/or collet). Different types of bits can be readily attached and detached to the rotary output to be driven thereby about an axis of rotation. In addition, the housings of these devices conventionally provide a screw thread for attachment of a surface positioning guide. Such positioning guides are sometimes referred to as “cutting guides”. The guides may be used in such applications as dry wall cutting to cut holes for electrical switches, outlets and the like. A surface positioning guide is disclosed in U.S. Pat. No. 6,244,796 to Schuebel et al. The &#39;796 patent generally discloses a surface positioning guide that is angled and includes groove tabs to facilitate use of the rotary tool for such applications as grout removal. 
   While rotary hand-held tools are very versatile, it will be readily appreciated that the large number of bits and different guides and other housing attachments can quickly run up the costs and expense for someone who wishes to have all of the available options and features for their tool. Further, the more different bits and attachments a person has, the more difficult it is to organize the attachments in an orderly and compact manner. Further, there is always a desire to increase the functions and versatility of such rotary tools. Heretofore, there have been significant drawbacks in some existing products, which will readily be appreciated once the present invention is appreciated. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention provides a more adjustable surface positioning guide that increases the versatility of rotary hand-held tools and that decreases the number of different surface positioning guides and/or other attachments needed for rotary hand-held tools. Several different inventive aspects are disclosed and claimed herein. 
   According to one aspect, the surface positioning guide includes a pivot joint between a guide base and a mounting adapter adapted to be removably coupled to the screw thread of rotary hand-held tools. The guide base pivots relative to the mounting adapter about the pivot joint between operable positions. The respective openings of the mounting adapter and the guide base align with each other in the operable positions so as to communicate the driven bit of the rotary hand-held tool through the guide base. 
   According to another aspect of the present invention, a surface positioning guide includes at least one spring supported by the mounting adapter either directly or indirectly that biases a guide base axially away from the mounting adapter. The guide base is movable toward the mounting adapter against the biasing of the at least one spring to effect a plunging movement such that the bits of rotary hand-held tools can be selectively plunged into a working surface. The surface positioning guide includes a first stop arranged to limit how far the guide base is biased away from the mounting adapter and a second stop arranged to limit how far the guide base can be moved toward the mounting adapter. 
   According to another aspect of the present invention, the guide base of a surface positioning guide includes a reversible and/or interchangeable base flange. The base flange defines an opening which is adapted to receive the surface engaging bit therethrough. The base flange also defines first and second faces. The base flange is movable relative to a support member which is carried by the mounting adapter to selectively locate either the first face or the second face at a foremost end of the removable surface positioning guide for engaging the working surface. 
   According to another aspect of the present invention, a removable surface positioning guide for a rotary hand-held tool comprises a mounting adapter integrally including an internally threaded sleeve portion concentric about a tool axis that is adapted to be threadably mounted to the housing of the rotary hand-held tool. The mounting adapter also includes a pair of axially extending linear guides and a first stop. The removable surface positioning guide also comprises a pivot body integrally including a pair of linear tracks sliding against the linear guides such that the pivot body is axially movable relative to the mounting adapter. The pivot body defines a pivot axis perpendicular to the tool axis and a pair of pivot support structures on the pivot axis. At least one spring that is supported by the mounting adapter biases the pivot body away from the mounting adapter. The first stop engages the pivot body to limit how far the pivot body is biased away from the mounting adapter. A pair of pillow blocks integrally provide hinge structures pivotably supported by the pivot support structures. The pillow blocks support a base flange is a position for engaging the working surface. The base flange is supported by the pillow blocks and defines an enclosed opening adapted to receive the surface engaging bit therethrough. 
   Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an isometric view of a removable surface positioning guide for a rotary hand-held tool in accordance with an embodiment of the present invention. 
       FIG. 2  is an isometric view of the removable surface positioning guide in combination with a rotary hand-held tool shown in dashed lines to illustrate how the surface positioning guide mounts to the front end of a rotary hand-held tool. 
       FIG. 3  is an exploded isometric assembly drawing of the surface positioning guide shown in previous Figures. 
       FIGS. 4–6  are plan, side elevation and bottom side views of the surface positioning guide shown in previous Figures. 
       FIG. 7  is a cross section of the surface positioning guide taken about line  7 — 7  of  FIG. 4 . 
       FIG. 8  is a cross section of the surface positioning guide taken about line  8 — 8  of  FIG. 5 . 
       FIGS. 9–10  are isometric illustrations of an alternative embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1–2 , an embodiment of the present invention is illustrated as a removable surface positioning guide  10  for a rotary hand-held tool  12  (which is illustrated as a commercially available Dremel® rotary tool). 
   Before turning to the details of the removable surface positioning guide  10 , a brief description of the rotary hand-held tool  12  will be given to provide a better understanding of the disclosed embodiments. Referring to  FIG. 2 , the rotary hand-held tool  12  includes a generally ring shaped housing  14  which can be manually grasped for manipulation. The housing  14  contains a motor (not shown) and a rotary output at its front end shown as a chuck or collet  16  that is extended by a surface engaging bit  20  when attached. The collet  16  is driven about a tool axis  18  by the motor and provides for ready attachment and detachment from the surface engaging bit  20  which is used to engage a working surface. Also at the front end, the housing  14  defines a threaded attachment tip  24  which can be used to removably attach various surface positioning guides, such as the guide  10  disclosed herein. A protective cover or cap  26  that screws on the is threaded attachment tip  24  is typically provided to protect the threaded attachment tip  24  of the rotary hand-held tool  12  when a surface positioning guide attachment is not being used. 
   Referring now to  FIGS. 1–3 , the illustrated embodiment of the surface positioning guide  10  includes a mounting adapter  30 , a pivot body  32 , and a guide base  33 , which may comprise a pair of pillow blocks  34  and a base flange  36 . In a preferred embodiment, all of these primary structural components may be molded or formed from plastic material. With this arrangement axial sliding occurs with plastic to plastic sliding contact and pivoting occurs with plastic to plastic pivoting contact. The mounting adapter  30  integrally includes an internally threaded sleeve portion  38  that is concentric about the tool&#39;s rotational axis  18 . As indicated in  FIG. 2 , the threaded sleeve portion  38  screws onto to thread threaded attachment tip  24  of the housing  14  of the rotary hand-held tool  10 . The mounting adapter  30  carries and supports, either directly or indirectly, the other components of the surface positioning guide  10  when mounted to the rotary hand-held tool  10 . The mounting adapter  30  also defines a central opening  39  extending therethough is sized and arranged to communicate the rotary output communicated by the collet  16  and the surface engaging bit  20  through the middle region of the surface positioning guide  10  when mounted to the rotary hand-held tool  12 . 
   The pivot body  32  is slidably carried by the mounting adapter  30 . The pivot body  32  defines a central opening  41  therethrough about the tool axis  18  that slidably receives the mounting adapter  30  and that also provides central clearance for communicating the surface engaging bit  20  through the surface positioning guide  10 . To facilitate and guide linear sliding motion, and referring to  FIGS. 1 ,  3 , and  8 , the mounting adapter  30  integrally includes and unitarily defines a pair of linear guide rails  40  that are received in linear guide tracks  42  of the pivot body  32 . The ends of at least one of the rails  40  integrally defines a stop tab  44  that engages a corresponding abutment surface  46  on the pivot body  32  to limit how far the pivot body  32  can axially slide away from the mounting adapter  30 . The stop tab  44  may also be used to axially retain the pivot body  32  on the mounting adapter  30  as indicated in the preferred embodiment. 
   Referring to  FIGS. 3 and 7 , one or more springs  48  are arranged between the pivot body  32  and the mounting adapter  30 . The springs  48  may be contained within a spring chamber  50 , with different portions of the spring chamber  50   a ,  50   b  being integrally formed into the pivot body  32  and the mounting adapter  30 . As shown, when multiple springs are used, the springs are preferably equally spaced angularly about the tool axis  18  to ensure balance of forces along the linear guide mechanism. The springs  48  are supported by the mounting adapter  30  and serve to bias the pivot body  32  and the guide base  33  away from the mounting adapter  30 . 
   The mounting adapter  30  also includes another stop which may be adjustable for limiting the linear sliding movement of the pivot body  32  and guide base  33  toward the mounting adapter  30 . In the disclosed embodiment, the adjustable stop is provided by a threaded bolt  52  that is screwed into a threaded hole  54  formed into the mounting adapter  30 . The threaded bolt  54  may be rotated to adjust its axial position with an axially aligned abutment surface  56  defined by an outward extending tab  58  on the pivot body  32 . When the end of the bolt  54  strikes the abutment surface  56 , the linear sliding movement of the pivot body  32  and guide base  33  is stopped. 
   An advantage of this arrangement is that the guide base  33  is movable toward the mounting adapter  30  against the biasing of the springs  48  to effect a plunging movement such that the bit  20  driven by the rotary hand-held tool  12  can be plunged into a working surface. The adjustable stop provided by the threaded bolt  52  can be used to control the depth of the plunging movement and therefore the depth of the bit  20  into the working surface. Since the guide base  33  can be positioned against the working surface, the guide base  33  can be utilized to hold and position the rotary tool  12  at a fixed angular orientation, such the plunging movement can be effected directly along the axis  18 . This can prevent lateral movement or shifts in orientation, thereby increasing accuracy and precision when drilling holes with drilling bits or driving into a working surface with other surface engaging bits. 
   In addition, a lock is preferably provided to hold relative axial positions when plunging movement is not desired. The lock is provided by a thumb screw  59  (shown as a shoulder bolt) that can be used to selectively clamp the pivot body  32  to the mounting adapter  30 . Although a thumb screw  59  is illustrated, it will be appreciated that the lock may be alternatively provided by other forms of clamping mechanisms or lock mechanisms (e.g. a pin and hole device). The thumb screw  59  is screwed into a nut  61  that is supported by the pivot body  32 . The end of the thumb screw  59  fits into a axial slot  63  formed into the mounting adapter  30 . The screw  59  can be selectively tightened to axially fix the relative positions of the pivot body  32  (and thereby the guide base) at one of a number of relative axial positions or selectively loosened to allow for plunging movement. 
   The pivot body  32  defines a pivot axis  60  perpendicular to the tool axis  18  and a pair of cylindrical pivot support structures  62  that project laterally outward along the pivot axis  60 . The pivot support structures  62  may include lateral slits  64  such that the pivot support structures  62  have some flexibility and are able to flex radially outward slightly when wedges  70 ,  71  are inserted into conical openings  66  formed centrally in the pivot support structures  62 . The slits  64  may also provide for a detent mechanism that provides for clicking between discrete angular positions when the guide base  33  is pivoted about the pivot axis  60 . 
   Referring to  FIG. 3 , the pillow blocks  34  of the support base  33  comprise pivot/hinge structures shown cylindrical openings  68  that slidably received the pivot support structures  62  of the pivot body  32 . The pillow blocks  34  are fitted on the pivot support structures  62  on opposed lateral ends of the pivot body  32  for pivoting movement relative thereto about the pivot axis  60 . The wedges  70 ,  71  when pressed into the conical openings  66  of the support structure are operable to flex the pivot structures  62  outwardly in a manner that laterally retains the pillow blocks  34  on the pivot body  32 , while also allowing for pivoting movement of the guide base  33  relative to the pivot body  32 . One or more screws  74  may be used to better secure the wedges  70 ,  71  in place if desired. 
   In addition, one or both of the screws  74  can serve as a locking device for selectively fixing the angular position of the pivot body  32  relative to the guide base  33 . Although a thumb screw  74  is illustrated, it will be appreciated that the locking device may be alternatively provided by other forms of clamping mechanisms or lock mechanisms (e.g. a pin and hole device). 
   The pillow blocks  34  carry and support the base flange  36 . The base flange  36  defines a central opening  76  that is large enough such that the central opening  76  axially aligns with central opening  39  of the mounting adapter  30  in different operable axial and angular positions between the guide base  33  and the mounting adapter  30 . In this manner, a suitable surface engaging bit  20  can be communicated through the openings  39 ,  76  for engaging a working surface. The base flange  36  may comprise flat outer rail surfaces  48  that can be used to laterally position or offset the surface engaging bit  20  laterally from an edge or wall perpendicular to the working surface. However, it will be appreciated that the base flange  36  can alternative take multiple shapes or forms such as circular if desired. The base flange  36  may fully enclose the opening  76  or partially enclose the central opening  76 . 
   The base flange  36  includes tabs  80  that project laterally outward. The tabs  80  slide and/or snaps into a corresponding receiving slots  82  formed into the pillow blocks  34 . In this manner, the base flange  36  is readily removable and can be interchanged with outer flange members of different configuration if desired. Additionally, the base flange  36  can be reversed to locate either a first face  84  or a second face  86  at the foremost end of the guide  10  and tool  12 , where the face is positioned for engaging and if desired sliding against a surface. This provides the advantage of further increasing versatility of the positioning guide  10 . As shown the first face  84  (currently located at the foremost end) is planar such that it can slide easily against a planar surface (e.g. drywall). The second face  86  is generally planar but also includes projecting guide tabs  88  that can be received into grooves in a working surface (e.g. such as grout grooves) which can be useful if it is desired that the surface positioning guide  10  follow a groove in the working surface during use. The guide tabs  88  are linearly aligned perpendicular relative to the pivot axis  60  such that the surface engaging bit  20  aligns linearly with the guide tabs  88  when in use. The base flange  36  can readily be reversed by unscrewing the thumb screw  74  and removing one of the pillow blocks  34  to release the base flange  36 . The base flange  36  can be flipped and reconnected to the pillow blocks  34  to selectively locate either of the first and second faces  84 ,  86  at the foremost end for engaging a working surface. 
   In either position, the base flange  36  is generally open above to provide viewing windows  98 . The viewing windows  98  may be defined by multiple components when assembled as shown in  FIGS. 1 ,  4  and  5 , where it is shown to be generally between the base flange  36 , pillow blocks  34  and pivot body  32 . Users can look through the viewing windows  98  to view the surface engaging bit  20  as it acts upon the working surface. 
   The surface positioning guide  10  may also optionally include indicating mechanisms that indicate the angle and axial depth of the surface engaging bit  20  relative to the working surface when in use. Accordingly, an axial scale  90  and point  92  may be provided between the pivot body  32  and the mounting adapter  30  for indicating axial position and depth. An angular scale  94  and pointer  96  may be provided between the pivot body  32  and one or both of the pillow blocks  34  for indicating angular position. 
   An alternative embodiment of a removable surface positioning guide  10   a  is shown in  FIGS. 9–10 . This embodiment is very similar to the first embodiment and it will be understood by one of ordinary skill in the art that this embodiment has similar structures that operate in a very similar manner to the first embodiment. Therefore, only significant changes will be addressed. First it will be noted that there are some cosmetic changes in the design of the surface positioning guide  10   a.    
   Turning to other differences, the guide base and more particularly the base flange  36   a  of this embodiment includes an intermediate cavity portion  100  along the outer rail surface  48   a . This provides laterally spaced coplanar linear guide edges  102  that are connected to the intermediate cavity portion  100  by rounded corners  104 . The advantage of this arrangement is that the outer rail surface  48   a  of the base flange  36   a  can slide flat or square against flat surfaces for accurate position and also can be maintained at a constant or predetermined location against circular, annular or curved surfaces in which the projecting portion or the working surface enters the cavity portion  100  and the rounded corners  104  engage two spaced points along the circular, annular or curved working surface. 
   In addition, the arrangement of the axial locking mechanism has been rotated ninety degrees. As shown in  FIGS. 9 and 10 , a thumb screw  59   a  extends through the pivot body  32   a  to engage a rail surface of the mounting adapter  30   a . Thus, the thumb screw  59   a  need not extend through the pillow blocks  34   a.    
   Although preferred embodiments have been shown, there are several alternatives that are also encompassed by the invention. For example, the pivot body  32  could be eliminated and pivoting could take place directly between the mounting adapter and the base member. Another alternative is that linearly sliding and/or plunging movement could take place between the pillow blocks or other support members and the base flange. The base could be a unitary member with integrally formed pillow blocks and base flange members. It should be appreciated that any single aspect, whether it be axially plunging, pivoting adjustment, or interchangeability of the base member could be provided independently in alternative embodiments, not just in combination as shown. These alternatives are not exhaustive of possibilities but are included herein to provide a more comprehensive understanding of the protection that is intended to be afforded herein. 
   All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
   The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
   Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.