Abstract:
A method of applying a tensile or compressive force to a selected location of a work piece or surface without damaging the work piece or the surface and without leaving adhesive residue thereon includes providing a device including a body member and a force applying member movably connected with the body member, attaching the body member and/or the force applying member to the work piece and/or surface using a double-sided stretch releasing adhesive such that one end of the force applying member is adjacent the selected location, and moving the force applying member toward the work piece or surface to generate a compressive force, or moving the force applying member away from the work piece or surface to generate a tensile force.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to a method of applying a force, which can be either a compressive force or tensile force, to an object or surface, and more particularly, to such a method that allows a device to be attached to a surface to apply the force, and allows the device to be easily removed from the surface and/or object without damaging the surface and/or object or leaving adhesive residue thereon.  
       BACKGROUND OF THE INVENTION  
       [0002]     Clamping devices for applying a force to an object or surface are known in the prior art. U.S. Pat. No. 5,820,116 (Haese), for example, discloses a suction attachable retaining clamp for holding an object such as a molding or mounting bracket against a surface such as a windshield. U.S. Pat. No. 4,457,503 (Conner) discloses a suction clamp for holding moldings in place on front or rear windshields of automobiles, while an adhesive material sets or dries, and it simultaneously prevents damage to the adjacent surface. Such clamps, however, are limited to producing compressive forces, and work best on clean, slightly moistened, non-porous surfaces such as metal and glass.  
         [0003]     There is a need, therefore, for a method that allows either a compressive (i.e. clamping) force or a tensile (i.e. pulling) force to be directed to a surface or object. It would therefore be desirable to provide a method of applying a tensile or compressive force to a surface or object that allows a device to be attached to the surface and/or object to apply the force, and allows the device to be easily removed from the surface and/or object without damaging the surface and/or object and without leaving unwanted residue on the surface and/or object. It would also be desirable to provide a method that allows a force to be applied to surfaces made from a wide variety of surfaces including metal, glass, paper, masonry and unfinished wood, and is not limited to use on non-porous surfaces such as metal and glass.  
       SUMMARY OF THE INVENTION  
       [0004]     The present invention overcomes the above-identified limitations by providing a method of applying a tensile or compressive force to a selected location of a work piece. In one aspect, the method comprises the steps of providing a device including a body member and a force applying member movably connected with the body member, attaching the body member to a surface using double-sided stretch releasable adhesive, whereby one end of the force applying member is adjacent the selected location, and moving the force applying member toward the surface to generate a compressive force.  
         [0005]     In another aspect, the present invention provides a method comprising the steps of providing a device including a body member and a force applying member movably connected with the body member, arranging the body member on a surface, whereby one end of the force applying member is adjacent the selected location, attaching the force applying member to the surface using double-sided stretch releasable adhesive, and moving the force applying member away from the surface to generate a tensile force.  
         [0006]     In an advantageous aspect of the invention, the surface may be formed of a cellulosic material such as paper, paperboard, or cardboard, or from masonry or cement-like materials such as stone, cinder blocks, and concrete.  
         [0007]     In one embodiment of the invention, the body member includes a connecting portion containing a through bore, a pair of legs extending in the same direction from opposite sides of the connecting portion, and a pair of feet portions extending in opposite directions from the ends of the leg portions opposite from the connecting portion. In a more specific aspect, each foot portion is provided with a double-sided strip of stretch releasing adhesive for attaching the body to a surface.  
         [0008]     In another embodiment, the body includes a main body portion and a cantilever portion extending laterally outwardly from the main body portion, wherein the force applying member is movably connected with the cantilever portion.  
         [0009]     The force applying member may be a plunger threadably connected with the body, whereby the plunger can be rotated clockwise and counter clockwise to produce the compressive and tensile forces. In an alternate embodiment, the plunger is slidably connected with the body, and the plunger is biased by a spring or the like to produce the forces. In yet another embodiment, the force applying member is pivotally connected with the body member in the form of a lever and the lever is pivoted to produce the compressive and tensile forces.  
         [0010]     The compressive and tensile forces generated by the method of the present invention can be used for a wide variety of uses and applications such as holding an object in place while an adhesive, such as a hot melt adhesive, glue, or epoxy sets, dries, or otherwise cures. This may be useful, for example, to mount a soap dish to a ceramic tile wall using an epoxy. The force may also find use in woodworking, crafts, or other uses in the home, office, or in industrial applications. For example, the present invention may be used to stamp or emboss a piece of paper or piece of wood.  
         [0011]     In a more specific aspect, the invention provides a method of removing a dent from a surface, comprising the steps of providing a device including a body member and a force applying member movably connected with the body member, arranging the device on the surface such that one end of the force applying member is adjacent the dent, attaching the force applying member to the dented surface using stretch releasable adhesive, and moving the force applying member away from the surface to generate a pulling force, whereby the pulling force is sufficient to remove the dent. In this aspect, the invention may be used to generate a tensile force for removing a dent from a variety of surfaces such as, for example, automotive vehicles including automobiles, boats, and RV&#39;s, or from aluminum siding, without damaging the surface and without leaving any adhesive residue on the surface.  
         [0012]     Thus, the invention may be used interchangeably to produce either a compressive (i.e. clamping) force or a tensile (i.e. pulling) force where in the past, separate devices were needed to create compressive and tensile forces. In a preferred embodiment, the method uses a simple and inexpensive single-sided clamp-like device that can be arranged on a surface and used not only as a clamp, but can also be used to produce a pulling or tensile force at a selected location on a surface or an object. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     The present invention will be further described with reference to the accompanying drawings, in which:  
         [0014]      FIG. 1  is a perspective view of a device that can be used in accordance with the method of the invention;  
         [0015]      FIG. 2  is a sectional view taken along line  2 - 2  of  FIG. 1 ;  
         [0016]      FIG. 3  is a side sectional view of a second embodiment of a device that can be used in accordance with the invention;  
         [0017]      FIG. 4  is a side sectional view of a third embodiment of a device that can be used in accordance with the invention;  
         [0018]      FIG. 5  is a side view of a fourth embodiment of a device that can be used in accordance with the invention; and  
         [0019]      FIG. 6  is a side view of a fifth embodiment of a device that can be used in accordance with the invention. 
     
    
     DETAILED DESCRIPTION  
       [0020]     Referring now to the drawings,  FIGS. 1 and 2  show a device  2  that can be used in accordance with the method of the present invention. The device  2  includes a body member  4 , a force applying member in the form of a plunger  6  rotatably attached to the body member  4 , a pair of double-sided stretch releasing adhesive strips  8   a  attached to the body member  4  to removably adhesively bond the body member  4  to a surface  10 , and a double-sided stretch releasing adhesive strip  8   b  attached to the plunger  6  for adhesively bonding the plunger  6  to either the surface  10 , or an object (not shown) arranged between the plunger  6  and the surface  10 . Throughout the description and the accompanying figures, functionally similar features are referred to with like reference numerals incremented by 100.  
         [0021]     Stretch releasing adhesive tapes represent a class of high performance pressure-sensitive adhesives combining strong holding power with clean removal and no surface damage. Such stretch releasing adhesive tapes are useful in a wide variety of assembling, joining, attaching, and mounting applications. The double-sided adhesive strips  8   a,b  may be any conventionally known stretch releasing adhesive tape including a stretch releasing adhesive tape with an elastic backing, a stretch releasing adhesive tape with a highly extensible and substantially inelastic backing, or a stretch releasing adhesive tape comprising a solid elastic pressure sensitive adhesive.  
         [0022]     Specific tapes suitable for use in the various embodiments of the present invention include the pressure sensitive adhesives with elastic backings described in U.S. Pat. No. 4,024,312 (Korpman), the pressure sensitive adhesives with highly extensible and substantially inelastic backings described in U.S. Pat. No. 5,516,581 (Kreckel et al.) and Bries et al. (U.S. Pat. No. 6,231,962), and the solid elastic pressure sensitive adhesive described in German Patent No. 33 31 016.  
         [0023]     A suitable double-sided commercially available stretch releasing adhesive is the product sold under the trade designation COMMAND adhesive by 3M Company, St. Paul, Minn. This product is currently manufactured in discrete strips with one end of the strip including a non-adhesive pull tab to facilitate stretching of the strip during removal.  
         [0024]     In the embodiment depicted in  FIGS. 1 and 2 , the body member  4  includes a bridge portion  4   a  containing an internally threaded opening  12  for rotatably receiving the plunger  6 , a pair of parallel leg portions  4   b  extending perpendicularly in the same direction from opposite sides of the bridge portion  4   a,  and a pair of feet portions  4   c  extending outwardly in opposite directions from the ends of the leg portions  4   b.  The adhesive strips  8   a  are affixed to the bottom surfaces of the feet portions  4   c  to adhesively bond the body member  4  to surface  10 , and thereby securely bond the device  2  to the surface  10 .  
         [0025]     Plunger  6  is arranged generally perpendicular to the bridge portion  4   a  and includes a cylindrical threaded body portion  6   a  which mates with and rotatably engages the threaded opening  12  in the body member  4 , a handle  14  arranged at one end of the body portion  6   a  to facilitate manual rotation of the plunger  6 , and a head  16  arranged at the end of the body portion  6   a  opposite the handle  14 . The handle  14  is arranged above the bridge portion  4   a  of the body member  4  to allow a user to readily access the handle  14  and thereby manually rotate the plunger  6 . The head  16  is arranged below the bridge portion  4   a  and is axially movable by rotational actuation of the plunger  6  via handle  14  either in the direction of the surface  10 , thereby to apply a force to the surface, or away from the surface  10 , thereby to generate a tensile force relative to the surface. Head  16  is preferably connected with the plunger  6  with a slip fit type of connection to allow the body portion  6   a  and the head  16  to move independently. That is, the body portion  6   a  of the plunger  6  is permitted to rotate while the head  16  does not rotate.  
         [0026]     In accordance with one aspect of the method of the present invention, the device  2  is used to apply a force to surface  10  or an object (not shown) arranged between the plunger  6  and the surface  10 , by rotating the plunger  6  such that the head  16  moves in the direction of the surface  10 . As the plunger  6  moves toward and engages the surface  10 , a compressive force will be exerted on the surface  10  or on the object. It will be recognized that when the device is used in this manner (i.e. as a clamp to generate a compressive force), adhesive strips  8   a  are needed to maintain the device  2  in engagement with surface  10 , but that adhesive strip  8   b  is not needed because the plunger  6  is maintained in contact with surface  10  via compression. Stated another way, when the device  2  is used as a clamp, the plunger  6  is forced against the surface  10  which, in turn, forces the body member  4  away from the surface  10 , and the adhesive strips  8   a  serve to hold the body member  4  in contact with the surface  10  to allow the plunger  6  to exert a compressive force on the surface. To remove the device  2  from the surface  10 , each adhesive strip  8   a  is stretched in the known manner to debond the adhesive strip from the device and surface simultaneously.  
         [0027]     Conversely, to use the device  2  to generate a pulling or stretching force on surface  10  or on an object (not shown) arranged between the surface  10  and the head  16 , stretch releasing adhesive strip  8   b  is provided to attach the head  16  to the surface  10  or object, thereby to adhesively bond the plunger  6  to the surface  10  or object. When the plunger  6  is rotated such that the head  16  moves away from the surface  10 , a tensile force will be exerted on the surface  10  or object. When used in this manner (i.e. as a pulling device to generate a tensile force relative to the surface), adhesive strip  8   b  is needed to attach the plunger  6  to the surface  10  or object, but it will be recognized that adhesive strips  8   a  are not needed to secure the device  2  to the surface because the device is maintained in contact with the surface  10  via compression.  
         [0028]      FIG. 3  shows another device  102  that can be used to apply a tensile or compressive force to an object or surface. The device  102  is similar to the device  2  shown in  FIGS. 1 and 2  except the device  102  includes a spring  120  which urges the plunger  106  toward the surface  110 , thereby to produce a compression force on the surface  110 .  
         [0029]     The device  102  includes a body member  104 , a force applying member in the form of a plunger  106  movably connected with the body member  104 , a pair of double-sided stretch releasing adhesive strips  108   a  attached to the body member  104  to removably adhesively bond the body member  104  to the surface  110 , and a double-sided stretch releasing adhesive strip  108   b  attached to the plunger  106  for adhesively bonding the plunger  106  to surface  110  or an object (not shown) arranged between the plunger  106  and the surface  110 .  
         [0030]     The body member  104  includes a bridge portion  104   a  containing an opening  112  for slidably receiving the plunger  106 , a pair of parallel leg portions  104   b  extending perpendicularly in the same direction from opposite sides of the bridge portion  104   a,  and a pair of feet portions  104   c  extending outwardly in opposite directions from the ends of the leg portions  104   b.  The adhesive strips  108   a  are affixed to the bottom surfaces of the feet portions  104   c  to adhesively bond the body member  104  to surface  110 , and thereby securely bond the device  102  to the surface  110 .  
         [0031]     Plunger  106  is arranged generally perpendicular to the bridge portion  104   a  and includes a cylindrical body portion  106   a  slidably engaging the opening  112  in the body member  104 , a handle  114  arranged at one end of the body portion  106   a  to facilitate manual actuation of the plunger  106 , and a head  116  arranged at the end of the body portion  106   a  opposite the handle  114 . The handle  114  is arranged above the bridge portion  104   a  of the body member  104  to allow a user to readily access the handle  114 , and thereby manually actuate the plunger  106  away from the surface  110 .  
         [0032]     Spring  120  is arranged between the bridge portion  104   a  of the device  102  and the head  116 . To use the device  102  to produce a compressive force, spring  120  is provided as a compression spring that is under compression when the head  116  engages the surface  110 , thereby forcing the head  116  against the surface  110 . In this manner, spring  120  serves to urge the head  116  toward the surface  110  whenever the head  116  is arranged either against or above the surface  110 . It will be recognized that when the device is used in this manner (i.e. as a clamp to generate a compressive force), adhesive strips  108   a  are needed to maintain the device  102  in engagement with surface  110 , but that adhesive strip  108   b  is not needed because the plunger  106  is maintained in contact with surface  110  via compression. Stated another way, when the device  102  is used as a clamp, the plunger  106  is forced against the surface  110  via spring  120  which, in turn, forces the body member  104  away from the surface  110 , and the adhesive strips  108   a  serve to hold the body member  104  in contact with the surface  110  to allow the plunger  106  to exert a compressive force on the surface. To remove the device  102  from the surface  110 , each adhesive strip  108   a  is stretched in the known manner to debond the adhesive strip from the device and surface simultaneously.  
         [0033]     Alternatively, the spring  120  can be a tension spring that is attached to the bridge portion  104   a  and the head  116 , such that when the spring is urged downwardly in the direction of the surface  110 , the spring is put in tension. In this manner, when the head  116  is attached to the surface  110  via adhesive strip  108   b,  a tensile force is produced on the surface  110 . When used in this manner (i.e. as a pulling device to generate a tensile force relative to the surface), adhesive strip  108   b  is needed to attach the plunger  106  to the surface  110  or the object, but it will be recognized that adhesive strips  108   a  are not needed to secure the device  102  to the surface because the device is maintained in contact with the surface  110  via compression.  
         [0034]     As with the device  2  of  FIGS. 1 and 2 , head  116  is preferably connected with the plunger  106  with a slip fit type of connection to allow the body portion  106   a  and the head  116  to move independently.  
         [0035]      FIG. 4  shows another device  202  that can be used to apply a tensile or compressive force to an object or surface. The device  202  includes a body member  204 , a force applying member in the form of a plunger  206  rotatably attached to the body member  204 , a pair of double-sided stretch releasing adhesive strips  208   a  attached to the body member  204  to removably adhesively bond the body member  204  to a surface  210 , and a double-sided stretch releasing adhesive strip  208   b  attached to the plunger  206  for adhesively bonding the plunger  206  to surface  210  or an object  218  arranged between the plunger  206  and the surface  210 . The device of  FIG. 4  is particularly suited for applying a tensile or compressive force in a tight location such as a corner, where the device shown in  FIGS. 1 and 2  would not fit.  
         [0036]     The body member  204  includes a main body portion  204   a  and a cantilever portion  204   b  containing a threaded opening  212  for receiving the plunger  206 . The cantilever portion  204   b  extends laterally outwardly from the upper edge of the main body portion  204   a.  Adhesive strips  208   a  are affixed to the bottom of the main body portion  204   a  to adhesively bond the body member  204  to the surface  210 , and thereby secure the device  202  to the surface  210 .  
         [0037]     Plunger  206  is arranged generally perpendicular to the cantilever portion  204   b  and includes a cylindrical threaded body portion  206   a  rotatably engaging the opening  212  in the body member  204 , a handle  214  arranged at one end of the body portion  206   a  to facilitate manual rotation of the plunger  206 , and a head  216  arranged at the opposite end of the body portion  206   a.  The handle  214  is arranged above the cantilever portion  204   b  of the body member  204  to allow a user to readily access the handle  214 , and thereby manually adjust the plunger  206 . The head  216  is arranged below the cantilever portion  204   b  and may be rotatably urged via handle  214  either in the direction of the surface  210  to apply a compressive force to the surface, or urged away from the surface  210  to generate a tensile force relative to the surface.  
         [0038]     Device  202  is used to apply a compressive force to object  218  in the same manner as the device of  FIGS. 1 and 2 , that is, the plunger  206  is rotated such that the head  216  moves in the direction of the surface  210 . As the plunger  206  moves toward and engages the object  218 , a compressive force will be exerted on object  218 . And to use the device  202  to impart a pulling or stretching force on object  218  which is secured to the surface  210 , stretch releasing adhesive strip  208   b  is used to attach the head  216  to the object  218 , thereby adhesively bonding the plunger  206  to the object  218 . Secured in this manner, when the plunger  206  is rotated such that the head  216  moves away from the surface  210 , a tensile force will be exerted on the object  218 .  
         [0039]     Because of its cantilevered design, the device  202  of  FIG. 4  is less stable than the device  2  of  FIGS. 1 and 2 . Consequently, when the device  202  of  FIG. 4  is used as either a clamping device to generate a compressive force or as a pulling device to generate a tensile force, it is desirable to include stretch releasing adhesive strips  208   a  to firmly bond and thereby secure the body member  204  to the support surface  210 . As with the device  2  of  FIGS. 1 and 2 , when the device  202  is used to generate a tensile force, adhesive strip  208   b  is required, but when the device is used as a clamp, adhesive strip  208   b  may be omitted.  
         [0040]      FIG. 5  shows a clamp-like device  302  similar to the device shown in  FIGS. 1 and 2  except it includes two force applying members  306 ′,  306 ″ arranged at 90 degree angles to allow tensile or compressive forces to be applied at two separate locations of a work piece  324 . It will be recognized that the particular angle of the device and the number of force applying members can be varied depending on the intended end-use application for the device.  
         [0041]     The device  302  includes an angled body member  304  and a pair of force applying members  306 ′,  306 ″ in the form of plungers that are rotatably attached to the body member  304 . Double-sided stretch releasing adhesive strips  308   a  are provided to removably adhesively bond the body member  304  to the surface  310  of a work piece  324 , and adhesive strips  308   b  are provided to removably adhesively bond each plunger  306 ′,  306 ″ to the surface  310  of the work piece  324 . The work piece  324  may be, for example, a frame including two pieces  324   a,b  being joined along a joint  326 .  
         [0042]     The body member  304  includes a 90 degree angle portion  304   a  containing a pair of internally threaded openings  312 ′,  312 ″ for rotatably receiving plungers  306 ′,  306 ″ respectively. A pair of leg portions  304   b  extend perpendicularly inwardly toward the work piece  324  from opposite ends of the angle portion  304   a,  and a pair of feet portions  304   c  are provided on the ends of each leg portion  304   b.  Adhesive strips  308   a  are affixed to the bottom surfaces of the feet portions  304   c  to adhesively bond the body member  304  to surface  310 , and thereby securely bond the device  302  to the surface  310 .  
         [0043]     The plungers  306 ′,  306 ″ are arranged generally perpendicular to the angle portion  304   a  and each include a cylindrical threaded body portion  306   a ′,  306   a ″ which mates with and rotatably engages the respective threaded openings  312 ′,  312 ″ contained in the body member  304 . Each plunger  306 ′,  306 ″ includes a handle  314 ′,  314 ″, respectively, arranged at one end of the body portion  306   a ′,  306   a ″ to facilitate manual rotation of the plunger  306 , and a head  316 ′,  316 ″ arranged at the end of the body portion  306   a ′,  306   a ″ opposite the handle  314 ′,  314 ″, respectively. To generate a force using the device  302 , it is operated in the same manner as the device  2  described above except each plunger  306 ′,  306 ″ must be separately actuated to generate a force.  
         [0044]      FIG. 6  shows another device  402  in the form of a simple first class lever that can be used to apply a tensile or compressive force to an object or surface in accordance with the method of the present invention. Although only a first class lever is shown and described, it will be recognized that the method of the present invention may also be carried out using other types of levers.  
         [0045]     The device  402  includes a body or base member  404 , a force applying member  406  in the form of an elongated bar pivotally connected with the body member  404  via pin connection  422 , a double-sided stretch releasing adhesive strip  408   a  attached to the base member  404  to removably adhesively bond the body member  404  to a surface  410 , and a double-sided stretch releasing adhesive strip  408   b  attached to the force applying member  406  for adhesively bonding the force applying member  406  to surface  410  or an object  418  arranged between the force applying member  406  and the surface  410 . A head  416  is provided on the end of the force applying member  406  that engages the object  418  or surface  410 .  
         [0046]     To generate a compressive force using the device, the device  402  is first attached to the surface  410  with double-sided stretch releasing adhesive strip  408   a.  A force is then applied to the force applying member  406  as indicated by F 1 , thereby urging the head  416  in the direction of the object  418  and surface  410 . When using the device to generate such a compressive force, adhesive strip  408   b  may be omitted. Conversely, to generate a tensile force using the device, the head  416  is attached to the object  418  with double-sided stretch releasing adhesive strip  408   b.  A force indicated by F 2  is then applied to the force applying member  406  to urge the head away from the object  418  and surface  410  and thereby impart a tensile force to the object  418  or surface  410 . In this case, adhesive strip  408   a  may be omitted. The forces F 1  and F 2  may be produced manually, with a spring, hydraulically, pneumatically, or using other conventional means.  
         [0047]     The various embodiments of the device, including both the body member and the force applying member, may be formed of a variety of materials depending on the particular intended end use application of the device. Suitable materials include metals such as aluminum and steel, synthetic plastic materials such as polycarbonate and polyvinyl chloride, and wood. The particular material selected is not significant to the invention hereof, so long as it provides the desired combination of properties such as adequate strength, low cost, and ease of manufacture.  
         [0048]     It will be apparent to those of ordinary skill in the art that various changes and modifications may be made without deviating from the inventive concept set forth above. For example, it will be recognized that the size and shape of the device may be modified to adapt the device for certain specific end use applications. For example, the force may be generated by means other than a threaded connection or a spring. In addition, the number and size of the adhesive strips may be varied, the plunger may be provided with a pointed tip, drill bit, or other implement depending on the specific end use application intended for the device, and the location of the cantilever portion  204   b  may be moved. Thus, the scope of the present invention should not be limited to the structures described in this application, but only by the structures described by the language of the claims and the equivalents of those structures.