Abstract:
An anchor for securing a net cord to a base layer such as carpeting or a thin layer of plastic has a spiral-shaped flange at the end of the anchor which is disposed adjacent the rear surface of the base layer when the anchor is installed. The spiral flange allows the anchor to be mounted to the base layer with a simple twisting motion and without requiring access to the rear surface of the base layer. The anchor is able to swivel freely about its axis yet is highly resistant to being pulled out of the hole. An installation tool has prongs for engaging detent bumps on the anchor and is used by a worker to hold the anchor while it is being mounted the base layer.

Description:
FIELD OF THE INVENTION 
     The present invention is related generally to storage nets such as are used to restrain cargo in automotive vehicles, and more specifically to means for anchoring such a net to a surface within the automotive vehicle. 
     BACKGROUND OF THE INVENTION 
     In is known in the automotive vehicle industry to provide cargo storage or restraint compartments by attaching sections of netting to surfaces within the passenger and/or cargo areas of a vehicle. The netting is known to be formed from elastic cords, non-elastic cords, or a combination thereof to provide a compartment that is somewhat expandable if desired. For example, it is common to attach a non-elastic netting section to the side walls of a vehicle&#39;s trunk or rear cargo area so that the net stretches across the area a short distance forward of the rear bumper. Objects such as grocery bags can then be placed behind the net and are prevented from sliding or rolling forward when the vehicle is in motion. In another example, it is known for a netting section containing some elastic cords to be anchored flat against a vertical surface to form a pocket for holding smaller items, the pocket being somewhat expandable to hold the items snugly against the surface. 
     In the past, the netting has been held in the desired position by anchors having a ring or aperture through which the cord forming the netting passes. Most often, the anchors have included male fastener having a sheet metal or machine thread for engagement with a hole formed in the metal body structure at the desired point of attachment. If the metal body structure is covered by carpeting or a plastic panel at the point where the anchor is to be mounted, a hole must also be formed in the carpet or panel to allow the male fastener to pass through. 
     It may be desired to mount a storage net on a carpeted surface within the vehicle, such as inside the trunk or cargo area, or on a lower inside surface of a door. In such a case, it would greatly simplify the manufacturing and assembly of the vehicle if the netting could be anchored directly to the carpet, rather than to the underlying metal structure. In the past, it has been necessary to attach anchors to the carpet prior to the carpet being permanently installed in the vehicle, since the known types of anchors have required that a worker have access to the back surface of the carpet in order to fix the anchor in place. Typically, such an anchor has been inserted through a hole in the carpet and the end of the anchor on the back side of the carpet has been heat staked, or a nut or similar female fastener has been affixed to the end of the anchor projecting through the hole. 
     It would be simpler, faster, and less expensive to install a net cargo restraint if the anchors holding the net cords in place could be secured to the carpet without requiring access to the back surface. This would allow the anchor to be secured in position after the carpet has been permanently installed in the vehicle. This would be advantageous both when the anchors are installed as original equipment at the time the vehicle is manufactured, and also would greatly simplify the installation of a net cargo restraint as an after-market feature. 
     Another disadvantage to prior art anchors of the type used for net cargo restraints is that they typically are not able to freely swivel once they are secured to a base layer. As the cord passing through the aperture of an anchor is tugged and moved during normal use, the net cord may tend to become wrapped around or bind in a non-swivelling anchor, and so may be subjected to additional stress which, over time, could damage the cord. 
     It would be advantageous to provide an anchor that can be simply and quickly attached to a thin base layer, such as carpet or a plastic panel, and which may freely swivel during use. 
     SUMMARY OF THE INVENTION 
     It is an objective of this invention to provide an anchor for attachment to a base layer such as carpeting or a thin layer of plastic, which may be installed quickly and simply and without requiring access to a rear surface of the base layer. In general, this objective is achieved by an anchor having a spiral-shaped flange at the end of the anchor which is disposed adjacent the rear surface of the base layer when the anchor is installed. To install the anchor, the end of the anchor having the spiral flange is urged against a hole in the base layer, and the anchor is twisted approximately 90° so that the flange works its way through the hole. The anchor is then able to swivel freely about its axis yet is highly resistant to being pulled out of the hole. 
     It is another objective of the invention to provide an anchoring system comprising an anchor securable to a base layer and an installation tool used by a worker to hold the anchor imparts the twisting motion to secure it to the base layer. Such an anchoring system allows the anchor to be installed more easily than if the worker were to hold the anchor in his/her bare hand during installation. In the preferred embodiment of the invention, the anchor has a pair of detent bumps formed on either side of an attachment tab, and the installation tool comprises a handle graspable by the worker and first and second arms which fit over the opposite sides of the tab and have holes formed therein for receiving the respective detent bumps. 
     It is a further objective of this invention to provide a method of quickly and easily anchoring a cord or portion of a netting member to a base layer without requiring access to a rear side of the base layer. The preferred embodiment of the invention method comprises forming a circular hole in the base layer, inserting the cord into engagement with an anchor having a spiral-shaped lower flange, and urging the anchor into the hole and simultaneously rotating it with respect to the base layer so that the spiral-shaped flange draws the anchor into the hole in a screw-like fashion until the base layer is retained between the spiral-shaped flange and a parallel flange of the anchor. 
     Other objects, advantages and applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein: 
     FIG. 1 is a perspective view of an anchor according to the present invention; 
     FIG. 2 is a perspective view of a netting storage compartment in a vehicle utilizing four anchors according to the present invention to hold a netting section in connection with a carpeted panel; 
     FIG. 3 is a side view of the anchor of FIG. 1; 
     FIG. 4 is a bottom view of the invention anchor; 
     FIG. 5 is a side view of an installation tool according to the present invention; 
     FIG. 6 is a perspective detail view of the head of the installation tool of FIG. 5; 
     FIG. 7 is a perspective view of the installation tool with an anchor operatively engaged therewith just prior to insertion into a hole in a panel; and 
     FIG. 8 is a front view of a second embodiment of the invention anchor with a clip attached thereto. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1-4, an anchor  10  according to the present invention is adapted to attach a cord  12  which forms part of a netting section  14  to a base layer  16  such as carpet or a thin plastic panel. One possible application for the invention anchor  10  is shown in FIG. 2, where four anchors  10  are used to restrain the corners of rectangular netting section  14  to an interior rear quarter panel covered in carpeting, thereby forming a storage compartment for preventing articles from rolling or sliding around the vehicle interior. Once attached to the carpet  16 , the invention anchor  10  is able to swivel freely relative to the carpet so as to adjust itself to stretching and other movement of the netting section during use. Additional non-swiveling anchors  20  may be located at other points on the netting section  14  to restrain one or more edges of the netting section against the surface so that objects retained in the storage compartment are unlikely to slip out through the closed edge. 
     The invention anchor  10  may be formed of any appropriate material and by any method, however in the preferred embodiment it is formed as a single, integrally molded piece of high-strength plastic material such as ABS. The anchor  10  generally comprises a cylindrical central plug  22 , a circular upper flange  24  disposed at the top end of the plug, an attachment tab  26  extending upwardly from the upper flange and having an aperture  28  formed therethrough, and a spiral-shaped lower flange  30  disposed at the lower end of the plug. The confronting surfaces of the upper and lower flanges  24 , 30  which are oriented toward the plug  22  are preferably substantially flat and parallel with one another. 
     In the preferred embodiment, the attachment tab  26  is generally semi-circular when viewed along the axis of the aperture  28 , and extends perpendicular to the plane of the upper flange  24  (see FIG.  3 ). The aperture  28  in the attachment tab  26  is of the proper diameter to allow the cord  12  to pass therethrough, as illustrated in FIGS. 2 and 6. 
     A pair of detent bumps  32  are formed on each side of the attachment tab  26 . The detent bumps  32  have smooth, rounded outer surfaces and project outwardly from the surface of the tab  26  by only a small amount, on the order of one millimeter. 
     The lower flange  30  is spiral-shaped, having a minimum radius approximately equal to the radius of the plug  22  and gradually increasing to a maximum radius somewhat greater than the plug radius and the radius of the hole which the anchor  10  is designed to fit. A radially extending step  34  in the outer edge of the lower flange  30  connects the point of minimum radius and the point of maximum radius. 
     Referring to FIGS. 4 and 5, an installation tool  36  for use with the invention anchor  10  comprises a handle portion  38  shaped to be grasped by a worker (not shown) and an arm  40  projecting generally perpendicularly from the handle. Two upper prongs  42   a , 42   b  and two lower prongs  44   a , 44   b  extend from the distal end of the arm  40 . Each of the prongs  42   a , 42   b , 44   a , 44   b  has a hole  46  passing therethrough in a direction generally perpendicular to the longitudinal axis of the arm  40 . 
     The prongs  42   a , 42   b , 44   a , 44   b  are properly configured to receive the attachment tab  26  therebetween, with the upper prongs  42   a , 42   b  on one side of the attachment tab  26  and the lower prongs  44   a , 44   b  on the opposite side, as seen in FIG.  7 . As the anchor  10  is inserted between the prongs  42   a , 42   b , 44   a , 44   b , the tips of the prongs contact the respective detent bumps  32  and are forced to flex slightly outward to allow the detent bumps  32  to pass therebetween The prongs  42   a , 42   b , 44   a , 44   b  then snap back inwardly as the detent bumps  32  come into alignment with the respective holes  46  in the prongs. The engagement of the detent bumps  32  with the holes  46  retains the anchor  10  in connection with the installation tool  36 . 
     Although the invention is shown with the engagement between the anchor  10  and the installation tool  36  provided by detent bumps  32  disposed on the anchor and mating holes  46  disposed on the installation tool  36 , any equivalent engagement means may be substituted without departing from the scope of the invention. For example, any type, shape, or number of male or female features may be disposed on the sides of the attachment tab  26  for engagement with mating features disposed in corresponding positions on the installation tool  36 . 
     A first gap  48  divides the two upper prongs  42   a , 42   b , and a second gap  50  divides the two lower prongs  44   a , 44   b . The gaps  48 , 50  prevent the installation tool  36  from obstructing the aperture  28  through the tab  26  when the anchor  10  is engaged with the installation tool. This allows the installation tool  36  to be snapped into engagement with an anchor  10  having a cord  12  passing through its aperture  28 , as shown in FIG.  7 . 
     In a preferred embodiment of the invention anchor  10 , the plug  22  has a diameter of 15 millimeters (mm), the upper flange  24  has a diameter of 25 mm, the lower flange  30  has a minimum radius of 7.5 mm and a maximum radius of 10 mm, the upper and lower flanges are spaced 5 mm apart, and the aperture  28  has a diameter of 6 mm. 
     According to the invention method of anchoring a cord  12  to a flexible base layer  16 , a circular hole  52  is first formed in the base layer  16 . An anchor  10  for installation in the hole  52  should have a plug  22  of a diameter approximately equal to the diameter of the hole, and the distance between the upper and lower flanges  24 , 30  should be approximately equal to the thickness of the base layer  16  for which the anchor is intended. 
     The anchor  10  is inserted into engagement with the prongs  42   a , 42   b , 44   a , 44   b  of the installation tool  36 . The cord  12  to be anchored may already be threaded through the aperture  28  in the attachment tab  26 , or this may be accomplished later. The worker then urges the anchor  10  against the base layer  16  directly over the hole  52 , tilting the tool  36  slightly with respect to the plane of the base layer  16  so that the point of minimum radius of the lower flange  30  is urged into the hole  52 . The worker then twists the anchor  10  approximately 90° in the clockwise direction, as viewed in FIG. 7, so that the spiral lower flange  30  works its way through the hole  52  until the base layer  16  is between the upper and lower flanges  24 , 30 . As can be seen in FIG. 7, the anchor  10  is inserted into the base layer  16 . The lower flange  30  passes from the first side  18  of the base layer  16  to the second side  19  thereof. The worker then disengages the installation tool  36  from the anchor  10  by simply pulling the tool away from the anchor, the prongs  42   a , 42   b , 44   a , 44   b  flexing outwardly a small distance to allow the detent bumps  32  to escape from the holes  46  in the prongs. 
     An alternative embodiment of the invention anchor  110  shown in FIG. 8 is adapted for use with a clip  112 . A narrow slit  114  passes through the attachment tab  126  and communicates with the aperture  128  in the tab. The clip  112  has a similar arrangement of an aperture  112   a and slit  112   b . The anchor  110  and clip  112  may be joined and separated by aligning their respective slits  114 ,  112   b . The anchor  110  is shown without any means for engaging an installation tool, but this feature may be added if desired. 
     As is apparent from the above description, the invention provides an anchor that is easily and quickly mounted to a flexible base layer such as carpet without requiring access to the rear surface of the base layer. When installed, the invention anchor is able to freely swivel within its hole so that it is not necessary to install the anchor in any particular angular position that might be required for a given netting installation. As the cord  12  passing through the aperture  28  moves during loading and unloading of the netting storage compartment, the anchor is able to swivel in response to that movement. Accordingly, the anchor maintains a secure grip on the cord, without the cord being subjected to undesired stress and/or becoming wrapped around the attachment tab  26  in a manner which would cause it to bind within the aperture  28 . 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.