Patent Abstract:
A craft hoop assembly including a split hoop having a first end and a second end and a clamping mechanism connected to the first end, the clamping mechanism having a first pivot point and a second pivot point, the first pivot point associated with the first end, the second pivot point associated with the second end.

Full Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to craft hoops, and, more particularly, to a craft hoop clamp.  
           [0003]    2. Description of the Related Art  
           [0004]    Craft hoops also known as embroidery hoops or knitting rings, generally include concentric inner and outer hoops. The inner hoop has a fixed diameter and the outer hoop has an adjustable diameter. Material, such as fabric, is placed upon the inner hoop while the outer hoop is placed over the fabric and around the inner hoop. The outer hoop is then adjusted such that the outer hoop fits snugly against the material and the inner hoop so as to hold the material between the inner and outer hoops. Craft work is then undertaken on the fabric held between the inner hoop and outer hoop.  
           [0005]    Embroidery has been traditionally used to decorate clothing and household furnishings including such items as table linens, towels, bedding and decorative items. Most embroidered products are assembled from several individual pieces of fabric. Prior to assembling each piece of fabric, upon which an embroidered design or logo is to be placed, the fabric is inserted into an embroidery hoop and secured to the hoop. The hoop is then embroidered either by hand or with an embroidery machine.  
           [0006]    Embroidery hoops have been known and used in both home and in factories for many years. Spring type embroidery hoops are used for hand and machine operations. Spring type hoops tension the outer hoop entirely by the resilience of the spring. More commonly, embroidery hoops such as circular or oval shaped units have an outer threaded fastener that traverses the split in the outer hoop for tightening the outer hoop against the inner hoop.  
           [0007]    The problem with conventional embroidery hoops or craft hoops has been the difficulties with the tensioning mechanism. The screw type tensioning mechanism generally requires the use of two hands to position and tighten the threaded bolt with a wing nut. The disadvantage of the spring type embroidery hoop is that the tension is related only to the spring force and the force from the spring decreases as the hoop is drawn together.  
           [0008]    What is needed in the art is a tensioning device which is easily operable with one hand and adjustable to provide variable tension on a craft hoop.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention provides an adjustable tensioning device for a craft hoop assembly.  
           [0010]    The invention comprises, in one form thereof, a craft hoop assembly including a split hoop having a first end and a second end and a clamping mechanism connected to the first end, the clamping mechanism having a first pivot point and a second pivot point, the first pivot point associated with the first end, the second pivot point associated with the second end.  
           [0011]    An advantage of the present invention is that a split craft hoop can be secured around an inner hoop using only one hand.  
           [0012]    Another advantage is that a conventional outer hoop can be retrofitted with a kit of the present invention.  
           [0013]    Yet another advantage is that the craft hoop clamping method provides an adjustable over-center type mechanism for tensioning the outer hoop. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:  
         [0015]    [0015]FIG. 1 is a perspective view of an embodiment of a craft hoop clamping apparatus of the present invention;  
         [0016]    [0016]FIG. 2 is an exploded perspective view of the craft hoop clamping apparatus shown in FIG. 1;  
         [0017]    [0017]FIG. 3 is a partially sectionalized view of the craft hoop clamping apparatus shown in FIGS. 1 and 2;  
         [0018]    [0018]FIG. 4 is a partially sectionalized view of the craft hoop clamping apparatus shown in FIGS.  1 - 3 ;  
         [0019]    [0019]FIG. 5 is a partially sectionalized side view of the craft hoop clamping apparatus of FIGS.  1 - 4 ; and  
         [0020]    [0020]FIG. 6 is a view of another embodiment of the clamping apparatus in the form of a kit for a conventional craft hoop assembly. 
     
    
       [0021]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one preferred embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    Referring now to the drawings, and, more particularly to FIGS. 1 and 2, there is shown an embodiment of a craft hoop clamping apparatus  10  of the present invention, which generally includes split hoop  12  and over-center clamp mechanism  14 .  
         [0023]    Split hoop  12  is a generally circular hoop that has a split  16  along the circumference thereof. Split hoop  12  may be made from a variety of materials such as wood, plastic or carbon fiber. The inner surface, although shown as smooth in FIG. 1, may include ridges to better grip a fabric. Although split hoop  12  is shown as a circular hoop other shapes such as elliptical or quasi-rectangular may be incorporated as a part of craft hoop clamping apparatus  10 . Alternatively, more than one over-center clamp mechanism  14  may be applied along the circumference of a split hoop.  
         [0024]    Over-center clamp mechanism  14  includes retaining block  18 , recessed block  20 , over-center tensioner  22 , tensioning rod retainer  24 , tensioning rod  26 , rod spring  28  and expansion spring  30 . Retaining block  18  is attached to one end of split hoop  12  and retaining block  18  is aligned with recessed block  20 . Retaining block  18  includes an opening  36  through which tensioning rod  26  is disposed. Tensioning rod  26  is retained by retaining block  18  to thereby provide tension on split hoop  12 . Recessed block  20  is attached to another end of split hoop  12  and is aligned with retaining block  18 . Recessed block  20  includes elongated opening  38  through which tensioning rod  26  is disposed and recess  40  which serves as a bearing surface for tensioner  22 .  
         [0025]    Over-center tensioner  22  includes bearing surface  42 , handle  44  and slot  48 . Axis A and axis B denote two pivot points about which portions of over-center tensioner  22  rotate. Bearing surface  42  contacts recess  40  to provide pressure against recessed block  20 , thereby placing tension on split hoop  12 . Bearing surface  42  is part of a circumference of a substantially circular portion of over-center tensioner  22  that rotates about axis A. Handle  44  provides a mechanical advantage to over-center tensioner  22  and allows an operator to thereby put pressure on tensioning rod  26 . In a preferred embodiment of the present invention handle  44  exceeds two inches in length. Threaded portion  46  of tensioning rod retainer  24  engages tensioning rod  26  in an adjustable manner. Tensioning rod retainer  24  is retained in over-center tensioner  22  by the connection with tensioning rod  26 . Tensioning rod retainer  24  rotates about axis B such that when handle  44  is moved to a position adjacent to recessed block  20 , that tensioning rod  26  crosses axis A, thereby biasing handle  44  to remain adjacent to recessed block  20 . Such an arrangement is known as an over-center condition. Slot  48  allows space for tensioning rod  26  to travel when over-center tensioner  22  is rotated. Tensioning rod retainer  24  is positioned off center relative to bearing surface  42  to provide a camming type action as over-center tensioner  22  is rotated. Over-center tensioner  22  can be in the form of a cam clamp or a toggle clamp.  
         [0026]    Tensioning rod  26  includes a retaining end  32  in the form of a ball  32  on one end thereof and a threaded end  34  on an opposite end thereof. Retaining end  32  has a retaining surface for rod spring  28  to rest against. The portion of retaining end  32  directed away from tensioning rod  26  may include a tab that protrudes or a slot therein, thereby accommodating a rotational adjustment of tensioning rod  26 . Rod spring  28  is positioned on tensioning rod  26  prior to tensioning rod  26  being inserted into retaining block  18 . Rod spring  28  comes into contact with a surface of retaining block  18  and provides tension within over-center clamp mechanism  14  while it is unlatched. Tensioning rod  26  traverses the inner diameter of expansion spring  30 , which is positioned between retaining block  18  and recessed block  20 . Expansion spring  30  is positioned to cause split hoop  12  to part along split  16  when tension on tensioning rod  26  is released. Tensioning rod  26  also is disposed through elongated opening  38  of recessed block  20 . Threaded end  34  adjustably engages threaded portion  46  of tensioning rod retainer  24 . Tensioning rod  26 , also known as tensioning member  26 , may be embodied as a flexible member such as a cable with retaining end  32  connected thereto.  
         [0027]    Alternatively, over-center clamp mechanism  14  may be configured to provide a compressive force on an inner split hoop. The compressive force is exerted against an outer hoop.  
         [0028]    Now, additionally referring to FIGS.  3 - 5 , there is shown the operation of craft hoop clamping apparatus  10 . In FIG. 3 there is shown inner hoop  50  surrounded with craft hoop assembly  10  in an unlatched position. As handle  44  of over-center tensioner  22  is rotated in direction R tensioning rod  26  is drawn against retaining block  18  causing split  16  to narrow. As over-center tensioner  22  is rotated tensioning rod  26 , as shown in FIG. 4, is angularly offset. As shown in FIG. 5 over-center tensioner  22  is in a latched position, with tensioning rod  26  being slightly above centerline A thereby keeping over-center tensioner  22  in the latched position. Split  16  is substantially reduced in width when over-center clamp mechanism  14  is in the latched position, thereby causing split hoop  12  to be drawn tight against inner hoop  50 .  
         [0029]    Craft hoop assembly  10  is operated by placing over-center tensioner  22  in an unlatched position. Fabric is placed over inner hoop  50  and arranged as required by the user who may be an embroiderer or quilter. Outer hoop  12  is then placed over the fabric locating outer hoop  12  substantially concentric with inner hoop  50 . Over-center tensioner  22  is then rotated, thereby placing tension on tensioning rod  26 , causing split hoop  12  to close split  16  and securing tension against the fabric placed over inner hoop  50 . Over-center tensioner  22  is rotated until it is in a latched position to securely hold the fabric placed over inner hoop  50 . Retaining rod  26  is adjustable within tensioning rod retainer  24  thereby providing an adjustable amount of tension on split hoop  12 .  
         [0030]    Now, additionally referring to FIG. 6, there is illustrated another embodiment of the present invention in the form of a craft hoop clamping kit  110  shown with a conventional craft hoop. A conventional craft hoop includes outer split hoop  112 , protrusion  122 , protrusion  124  and a bolt with wing nut  126 . Protrusions  122  and  124  are respectively connected to an end of split hoop  112  and bolt/wing nut  126  is disposed therethrough, the combination thereby accommodating the tensioning of split hoop  112 . Craft hoop clamping kit  110 , which is substantially similar to over-center clamp mechanism  14 , is installed by first removing winged bolt  126  from protrusions  122  and  124 . Retaining rod  26  is unscrewed from tensioning rod retainer  24 . Tensioning rod  26  is then routed through protrusions  122  and  124  where bolt  126  had been and tensioning rod  26  is then re-threaded into tensioning rod retainer  24 . Retaining block  118  and recessed block  120  are shortened versions of retaining block  18  and recessed block  20  of the previous embodiment. The surface of recess block  120  that bears upon protrusion  124  is slidingly engaged to allow tensioner  22  to operate in a camming type manner.  
         [0031]    While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

Technology Classification (CPC): 3