Abstract:
A strap winder includes a base having a first strap end connecting structure; a ratchet wheel rotatably mounted in the base and having a second strap end connecting structure; and a handle pivotably mounted to the base and preferably engaging the ratchet member so that pivot of the handle in an opening movement, wherein the handle is moved away from the base, does not rotate the ratchet wheel, and wherein pivot of the handle in a closing movement, wherein the handle is moved toward the base, rotates the ratchet wheel. The strap winder is preferably made at least partially from plastic, and has characteristics which facilitate injection molding.

Description:
CROSS-REFERENCE TO PROVISIONAL APPLICATION 
     This application claims the benefit of provisional application Ser. No. 60/778,498 filed Mar. 1, 2006. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to a ratcheting strap winder and, more particularly, to a light weight, preferably injection-molded, strap winder which is especially useful in portable applications, for example in backpacks and other items intended to be carried. 
     Conventional strap winders are typically made of metallic materials and are heavy and somewhat expense to manufacture. These assemblies work very well for their intended purpose, but can be significantly over-designed for some uses. For example, some uses do not involve stresses to the extent which require metal components, and further are in an environment where the assembly is part of a structure which is to be carried, for example by a person. Under such circumstances, the typical metallic strap winder is too expense, too heavy and far “over-designed” for the task at hand. 
     It is clear that the need exists for a light-duty strap winder structure. 
     It is therefore the primary object of the present invention to provide such a device. 
     It is a further object of the present invention to provide a strap winder which is simple and ergonomic in use. 
     It is a still further object of the present invention to provide a strap winder which is efficient and relatively low cost in manufacture. 
     Other objects and advantages of the present invention will appear below. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, the foregoing objects and advantages have been readily obtained. 
     According the invention, a light weight strap winder assembly is provided which is made of plastic material preferably through injection molding, and which advantageously includes three components. The assembly includes a base member, a handle member and a ratchet wheel which advantageously snaps into place to hold the assembly together. In further accordance with the invention, the ratchet wheel and handle are designed so that the strap pulling motion is performed by pulling the handle back toward the base. This is in contrast to many conventional strap winders wherein the winding motion is performed on the up-stroke while moving the handle away from the base. 
     Still further according to the invention, the ratchet wheel is advantageously designed having ratchet teeth and other features which are advantageously aligned so as to assist in efficient injection molding. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A detailed description of preferred embodiments of the present invention follows, with reference to the attached drawings, wherein: 
         FIG. 1  is an exploded view of a strap winder according to the invention; 
         FIG. 2  illustrates the strap winder of  FIG. 1  in a closed position; 
         FIG. 3  further illustrates the strap winder of  FIG. 1  in an environment of use with the handle pivoted away from the base; 
         FIG. 4  is a sectional view taken through a strap winder according to the invention; and 
         FIG. 5  is an enlarged sectional view of the front portion of the apparatus shown in  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION 
     The invention relates to a strap winder assembly and, more particularly, to a light weight strap winder assembly preferably made from plastic, further preferably made through injection molding, which is suitable for light-duty applications, and which has reduced weight and cost as compared to metallic conventional strap winders. 
       FIG. 1  shows a strap winder assembly  10  in accordance with the present invention which comprises a base  12 , a handle  14  and a ratchet wheel  16 .  FIG. 1  shows these components in an exploded state to better illustrate their details, while  FIG. 2  shows the assembled device. 
     With continuing reference to both  FIGS. 1 and 2 , each of the above-described components will be further discussed. 
     Base  12 , as shown in the drawings is preferably provided in the form of a relatively flat rectangular structure having a strap end connecting structure  18  at one end  20 , and having mounting structure  22  for receiving handle  14  and ratchet wheel  16  at the other end  24 . 
     Strap end connecting structure  18  can suitably be a transverse beam or shaft of material with an opening  26  position behind same to allow connection of a strap as desired and in well known fashion. 
     The structure for accepting handle  14  and ratchet wheel  16  can suitably be two spaced walls  28 ,  30 , each of which has a hole  32 ,  34  defined therein. Holes  32 ,  34  define ratchet wheel mounting openings, and serve to rotatably receive ratchet wheel  16  in a manner which will be further discussed below. 
     Base  12  also preferably includes a ratchet stop  36 , which can advantageously be a substantially elongate member which extends into contact with at least one tooth of ratchet wheel  16  in order to prevent reverse-rotation of ratchet wheel  16  as will be further discussed below. 
     Base  12  still further preferably has a centrally defined rib  38  which serves as a stop for handle  14 , as is best illustrated in  FIG. 4  to be discussed below. Still further, base  12  preferably includes an upstanding stabilizing member  40 , which is positioned to engage with handle  14  when handle  14  is in the closed position of  FIG. 2 , and thereby stabilize ratchet assembly  10  as desired. 
     Base  12 , further preferably includes a substantially flat portion  42  which can advantageously be positioned rearwardly of central rib  38  and which provides an area for gripping with one hand while operating the ratchet assembly  10  according to the invention. 
     The structure of base  12  as illustrated in  FIG. 1  is readily manufacturable through conventional injection molding techniques and such preparation is preferred so as to provide a plastic and therefore light-weight assembly for use in accordance with the present invention. 
     Still referring to  FIGS. 1 and 2 , handle  14  advantageously has structure at one end  44  for rotatably engaging with ratchet wheel  16  and a substantially flat and preferably ergonomically designed handle  46  at the other end  48 . Handle  46  is preferably a flat member which is positioned and oriented such that when ratchet assembly  10  is assembled, handle  46  in a closed position such as is shown in  FIG. 2  is substantially parallel to the flat plane of base  12 . 
     Structure  44  for rotably connecting ratchet wheel  16  is advantageously provided in the form of two walls  50 ,  52  which depend downwardly from handle  46  and have holes  54 ,  56  formed therein. Holes  54 ,  56  advantageously define ratchet wheel passing openings, and align with holes  32 ,  34  of base  12 , such that ratchet wheel  16  can advantageously be snapped through both pairs of holes to lock assembly  10  in an operative condition. This will be further discussed below. 
     Handle member  14  further preferably includes at least one advancing ratchet  58  which is positioned to engage with ratchet wheel  16  when assembly  10  is assembled in an operative condition, and to advance ratchet wheel  16  when handle member  14  is rotated or pivoted relative to base  12 . As illustrated in  FIGS. 4 and 5  to be discussed below, advancing ratchet  58  is preferably structured and positioned to advance ratchet wheel  16  along with a strap held thereby during a downward or closing stroke of handle  14  relative to base  12 . A downward stroke as used herein is defined as movement of handle  14  from an open position as illustrated in  FIG. 3  toward the closed position as illustrated in  FIG. 2 . 
     Advancing ratchet  58  is preferably provided in the form of a downwardly-depending tooth or hook which can slide over teeth of ratchet wheel  16  during an opening-stroke of handle  14  relative to base  12 , and which engages with a tooth of ratchet wheel  16  during the closing stroke. 
     Handle  14  further preferably includes an opening  60  which is aligned to receive stabilizing member  40  when handle  14  is in the closed position with respect to base  12  as illustrated in  FIG. 2 . This serves to further stabilize assembly  10  in a rest condition. 
     Ratchet wheel  16  is advantageously a substantially elongated shaft  62  having a collar  64  arranged at one end and a locking structure  66  positioned at the other end. Along shaft  62  and between collar  64  and locking structure  66 , ratchet wheel  16  further preferably includes at least one ratchet gear  68  position to engage with advancing ratchet  58  during a downward stroke of handle  14  as discussed above. 
     Shaft  62  of ratchet wheel  16  is advantageously a split shaft having two halves as better illustrated in  FIGS. 4 and 5 . This helps to maintain the light-weight nature of assembly  10  according to the present invention, to conserve material, and to nevertheless provide a device which has sufficient structural rigidity. Further, the gap or central opening between halves defines a second strap end connecting structure and can be used to secure a strap to be tensioned as is well known in the art. 
     Locking structure  66  is advantageously provided as two cylinder halves  70 ,  72 , each of which has an outwardly extending collar  74  which is beveled or sloped at the distal end of the device. This structure is sized to snapingly engage through hole  34  of base  12  during assembly. 
     Thus, during assembly of the apparatus  10  according to the invention, handle  14  is positioned relative to base  12  with holes  54 ,  56  aligned with holes  32 ,  34 . In this position, ratchet wheel  16  is inserted with locking structure  66  first through larger holes  32 ,  54  and then through hole  56  of handle  14  and into snapped engagement with hole  34  of base  12 . In this position, ratchet assembly  10  is ready for use as desired. 
     The teeth of ratchet wheel  16  are preferably designed such that surfaces are either parallel to or perpendicular to the other surfaces of this structure, specifically the split-half portions of shaft  62 . This assists in the plastic injection molding of ratchet wheel  16  by allowing for a part which can be manufactured with two mold halves in a simple and efficient manner. In order to accomplish this, several approaches can be taken. One approach would be to utilize wheels having only four teeth and utilizing a handle member  14  designed to pivot sufficiently to advance one tooth per stroke. Alternately, a wheel  16  can be used have more than four teeth while the mold part line and angles of wheel  16  are nevertheless selected to simplify molding. Of course, while these are two specific examples of preferred embodiments of the invention, other embodiments and variations can be used well within the broad scope of invention. 
       FIG. 4  shows a sectional view of ratchet assembly  10  in accordance with the present invention in an assembled and closed position. As shown, in this position, handle  14  rests against up-standing central rib  38  with stabilizing member  40  engaged into opening  60 . This is a rest position and is the proper position in which ratchet assembly  10  should be left when not in use for winding a strap. 
       FIG. 5  shows an enlarged cutaway portion of  FIG. 4 , and further illustrates the interaction between advancing ratchet  58 , ratchet teeth on ratchet wheel  16 , and holding ratchet  36  according to the invention. As made clear from this illustration, ratchet wheel  16  is locked against rotation in clockwise manner when handle  14  is pivoted up and away from base  12 . This prevention of rotation is due to the engagement of holding ratchet  36  with teeth on ratchet wheel  16  during such motion. 
     When handle  14  is then brought back through a downward stroke, advancing ratchet  58  engages with teeth of ratchet wheel  16  and rotates ratchet wheel  15  in a counter-clockwise manner while holding ratchet  36  rides along the sloped back-facing surfaces of the teeth of ratchet wheel  16 . It should be readily apparent that this structure advantageously allows for a strap winding device wherein the closing or force-requiring motion is the downward stroke, which is more ergonomically appropriate for use of the device. 
     Referring back to  FIG. 3 , ratchet assembly  10  is illustrated in a position of use, connected between two ends  100 ,  102  of a strap. One end  100 , as discussed above, is connected at structure  18  of base  12 , while the other end  102  is connected to ratchet wheel  16 , preferably by being threaded through the gap between the halves of shaft  62 . In this configuration, during winding, end  102  of the strap is incrementally wound upon ratchet wheel  16  as desired in accordance with the present invention. 
     It should be readily appreciated that ratchet assembly  10  in accordance with the present invention is advantageously a light-weight and economically manufactured assembly which is perfectly well suited to light-duty use environments, for example in backpacks and other types of gear. Assembly  10  is advantageously manufactured of plastic materials, and is most preferably manufactured through injection molding to allow for efficient and reliable manufacture of the three components of the assembly. 
     It should be appreciated that while the assembly as illustrated in  FIGS. 1-5  results in strap tightening during a downward stroke, it is within the broad scope of the present invention to reverse the orientation of teeth and wind the strap during an up-stroke. 
     It should also be appreciated that although the broad invention certainly includes use of a single advancing ratchet and a single ratchet wheel on ratchet structure  16 , a more stable and thereby preferred structure has two spaced ratchet wheels on ratchet wheel structure  16 , and two advancing ratchets  58  adapted to engage therewith. This serves to spread the stress of tightening of the strap across the entire ratchet wheel  16 , rather than concentrating this stress in one point. 
     It should be appreciated that the present invention is particularly well suited to light-duty environments of use, and thereby presents a desirable alternative to conventional metallic strap winding devices when light-duty uses are called for. 
     It should finally also be appreciated that the present disclosure is made in terms of a preferred embodiment, and that the details provided herein are not to be considered limiting on the broad scope of the present invention, but rather are intended as illustration of examples of one embodiment of the invention.