Abstract:
A plastic clip comprising two jaws united at one end by a hinge permitting them to swing between open and closed positions. The hinge may suitably be of the box type including a hinge blade associated with one jaw that is mounted between opposed cheeks associated with the other jaw by a hinge pin received in an elongated bearing opening in the cheeks, and along which the pin may travel to adjust the nip of the jaws. A spring latch at the opposite end of the jaws preferably permits a plurality of latching positions so as to permit the nip of the jaws at that end to be varied. The elongated bearing opening may permit the assembly of the jaws even where the box structure is relatively rigid and where the pin is integrally formed with the hinge blade.

Description:
FIELD OF INVENTION  
       [0001]     This invention relates to clips, which may be used, for example, to releasably close storage bags.  
       BACKGROUND OF THE INVENTION  
       [0002]     Clips in the general nature of those to which this invention relates are exemplified in patent documents WO 02/076836 and 99/19223, of common inventorship herewith. In general, such clips comprise a pair of axially elongated jaws which are hinged together adjacent one axial end thereof to permit them to swing between a closed position in which the jaws are mutually confronting substantially along their length, and an open position, and a latch disposed adjacent the opposed axial end for releasably retaining the jaws closed about a bag or the like as desired.  
         [0003]     The bags with which such clips may find use may vary considerably in their characteristics, for example from thin, single ply polymer film to thick, multi-ply paper. Although clips of several different sizes are available, and a user will normally select a clip having an appropriate size, variations in the bag thickness for any given size of bag are such that they will have a limited range of use.  
         [0004]     While bag clips are not normally manufactured to be disposable items, particularly where they are intended for use in larger size bags having a capacity of about 50 kg (about 100 lbs) or more, they are none-the-less required to be inexpensive, and accordingly any improvements should not incur any significant change in cost, thereby effectively precluding highly engineered solutions.  
         [0005]     A further problem with bag clips, particularly of the larger sizes, is that the hinge elements are exposed to substantial levering forces, which tend to spring the hinge elements apart where these are of a type using a hinge pin, and skew the jaws.  
         [0006]     Known bag clips often use a box hinge comprising three generally orthogonally connected walls forming an axially aligned channel associated with one jaw, having bearing openings in the facing walls of the channel. The other jaw may be provided with a hinge bearing unitarily formed therewith, which snaps into the bearing openings when the channel walls are resiliently deformed. Although this type of hinge is cost effective, it is prone to separating under heavy loads, due either to the use of cup and ball type bearings which engender a wedging apart of the cheeks under the influence of loading forces, or due to the channel walls being too easily deformed in a resilient manner. To overcome these tendencies, hinge pins must be used to the exclusion of cup and ball arrangements, and the channel walls of the hinge may be made substantially more rigid, for example by increasing the thickness thereof, and/or by providing a fourth wall, which interconnects the channel walls substantially along the height of these walls. However, this has heretofore prevented the snap engagement of the fixed hinge pin into the bearing openings, and it has been necessary to use a separately formed hinge pin, thereby increasing manufacturing costs, or to use a hook-together arrangement which reduces the integrity of the hinge.  
         [0007]     It is an object of this invention to provide improved bag clips that may more readily accommodate different sizes of bags.  
         [0008]     It is another object of this invention to provide bag clips that are economic to produce and easily adjustable.  
         [0009]     It is yet another object of this invention to provide adjustable bag clips that are capable of resisting normal forces to which they may be exposed.  
         [0010]     It is still another object of this invention to provide bag clips with an economic, two piece hinge structure that is not easily separable under heavy loads.  
       SUMMARY OF THE INVENTION  
       [0011]     In accordance with a broad aspect of this invention, in a bag clip comprising a pair of axially elongated jaws, and hinge means disposed adjacent one axial end thereof about which the jaws are movable between closed and open positions, and latch means adjacent the opposed axial end for releasably retaining the jaws closed, the hinge means and the latch means are each adjustable to permit the spacing between the jaws to be varied, so as to permit the clip to accommodate bags having significantly different thicknesses. Suitably and preferably, the adjustable hinge means and latch means should permit a relatively uniform change in the spacing between the jaws to be achieved, where this is desired.  
         [0012]     Also suitably and preferably, the hinge means and the latch means are independently adjustable without necessitating the demounting of the jaws and disassembly of the clip.  
         [0013]     In accordance with preferred aspects of the invention, the clip comprises only two parts that may each be molded as unitary items, thereby reducing manufacturing costs.  
         [0014]     The adjustable hinge means comprises a pair of transversely spaced apart, axially aligned cheeks associated with one of said jaws; each of the cheeks has a generally vertically oriented elongated opening therein; a hinge pin unitarily formed with the other jaw is slidable along the opening. The opening is provided with a plurality of detents for arresting the sliding movement of the hinge pin, thereby permitting the spacing between the jaws at the hinge end of the clip to be adjusted as desired.  
         [0015]     The detents may comprise bearing recesses, each of which communicates with an arcuately formed slot. Where there are two hinge bearing recesses in each cheek, the hinge bearing opening will generally have a cardioid shape, wherein all diametric chords have the same dimension. The hinge pin disposed on the other of the jaws is slidable along the slot so as to be engageable in any desired bearing openings.  
         [0016]     The cheeks of the hinge means are in accordance with a first embodiment of the invention united by a top wall and by an end wall, together forming in essence a relatively rigid six-sided box structure that is open in its forward and bottom faces. Notwithstanding the relatively rigid nature of the box portion of the hinge, the elongated nature of the hinge bearing opening permits the snap engagement of the hinge pin within the opening. This is achieved by partially rotating the other jaw about its longitudinal axis so as to cant the hinge pin, and with the jaws of the clip open, engaging the uppermost end of the hinge pin in the opening of one cheek adjacent the upper end thereof. The other jaw is then counter-rotated, forcing the lower end of the hinge pin between the cheeks, until it can commence to enter into the bearing opening. The hinge pin at this point will still be slightly canted, but as it engages fully into the bearing opening of the other cheek, it will assume a horizontal condition, at which time it may be adjusted by sliding along the bearing opening and urged into the bearing recesses of choice.  
         [0017]     In accordance with a second embodiment, the detents comprise a gear rack and the hinge pin is provided with a pawl selectively movable between interfering and non-interfering relationship with said rack, to permit the adjustment of the spacing between the jaws of the clip at the hinge end thereof.  
         [0018]     Suitably, the adjustable latch means comprises a plurality of ratchet teeth associated with one of the jaws, and at least one ratchet tooth associated with the other jaw. The ratchet teeth associated with one of the one jaw are mounted on a spring finger forming a part of that jaw, so as to be selectively cooperatively engageable with at least one tooth provided on the other of the jaws. It will be understood that the one tooth may be resiliently mounted and the plurality of teeth may be fixed, or that all teeth may be resiliently mounted as may be desired according to particular circumstances.  
         [0019]     The above aims, objects and advantages of the invention, together with still further advantages thereof, will become more apparent from a consideration of a preferred, non-limiting embodiment thereof, taken in conjunction with the drawings forming a part hereof 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     In the drawings  
         [0021]      FIG. 1  shows a clip in accordance with the invention in side elevation, with hidden detail shown in dashed outline, with the clip in a first position of adjustment;  
         [0022]      FIG. 2  is similar to  FIG. 1  but shows the clip in a second position of adjustment;  
         [0023]      FIG. 3  is a cross-section on enlarged scale taken along line  3 - 3  of  FIG. 1 , and shows in addition a portion of a bag;  
         [0024]      FIG. 4  is similar to  FIG. 3 , but is taken along line  4 - 4  of  FIG. 2 ;  
         [0025]      FIG. 5  is a fragmentary, exploded plan view of a portion of the hinge detail;  
         [0026]      FIG. 6  is a schematic elevational view on enlarged scale of the hinge bearing path;  
         [0027]      FIG. 7  is similar to  FIG. 6 , but shows a hinge bearing path with two bearing openings;  
         [0028]      FIG. 8  is a front elevation of the clip of  FIG. 1 ;  
         [0029]      FIG. 9  is a fragmentary view of the hinge portion of the clip illustrating the manner in which the jaws of the clip are assembled together;  
         [0030]      FIG. 10  is a side elevational view of the hinge end of a clip in accordance with a second embodiment of the invention, with the jaws in confronting position;  
         [0031]      FIG. 11  is similar to  FIG. 10 , but shows the jaws in their open position; and  
         [0032]      FIG. 12  shows in rear elevation a portion of the hinge of the second embodiment on enlarged scale. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0033]     Referring to the drawings in detail, a clip in accordance with a first embodiment of the invention is identified globally therein by the numeral  10 . In the ensuing description, the terms upper, lower, forward, rearward and the like are used to facilitate the description of the drawing and are not to be construed as having an absolute meaning unless the context clearly indicates otherwise.  
         [0034]     Clip  10  comprises an upper jaw  12 , which includes side walls  14  joined along their length by a top wall  16  and at the rearward end by rear wall  18 , to provide a relatively stiff, hollow beam structure. Clip  10  further comprises a lower jaw  20  having an upper surface  22  formed with an undulating profile to provide a plurality of crests  22   a  and troughs  22   b  therealong, with side shoulders  24  and a flange  26  extending substantially along the length thereof. As thus far described, clip  10  has elements in common with the clip described in the above referred to WO Patent document 02/076836, the contents of which are incorporated herein by reference thereto as fully as if they were set forth at length herein.  
         [0035]     Clip  10  includes a hinge  30  to permit jaws  12  and  20  to move between a closed position, such as is shown in  FIG. 1 , and an open position (not shown). Hinge  30  includes a hinge blade  32  formed on jaw  20  to project rearwardly from flange  26 , and which terminates in a transversely disposed hinge pin  34 . Hinge  30  further comprises a pair of cheeks  36 , which are spaced apart so as to accept blade  32  snugly therebetween. Each cheek  36  is provided with an elongated bearing opening  38 . Each bearing opening  38  has three detent recesses  40   a ,  40   b  and  40   c , therein which are centered on a notional axis A-A orthogonal to the axis of clip  10 , with a cusp  44  between each adjacent pair of recesses. Bearing opening  38  and hinge pin  34  are dimensioned such that the hinge pin is a good fit in the bearing recesses  40   a ,  40   b  and  40   c , and may be urged under the influence of a small, manually applied force, from one pair of bearing recesses to another pair as desired. Suitably, a small wall  46  circumscribes bearing opening  38  on the outer wall surface of cheeks  36 , serving both as a reinforcement and to increase the area of contact between the hinge pin  34  and the bearing recesses. Cheeks  36  are united along their upper end by top wall  16  and adjacent their rearward edge by rear wall  18 , which extends substantially along the whole of the height of cheeks  36 . The upper portions of the forward edge of cheeks  36  are united with side walls  14  of jaw  12 , but the lower portions are spaced apart from side walls  14  by a cut  48 . The open box-like structure formed by cheeks  36  and connecting walls  16 ,  18  provides a relatively rigid structure, and cheeks  36  are not readily forced apart particularly in the vicinity of bearing recesses  40   a ,  40   b  and  40   c.    
         [0036]     Considering now the manner in which jaws  12  and  20  are initially assembled together to form hinge  30 , this step is suitably performed when cheeks  36  are warm and susceptible to resilient deformation. The assembly of jaws  12 ,  20  is effected by rotating the lower jaw  20  slightly about its longitudinal axis, thereby canting hinge pin  34 . The uppermost, or leading end of hinge pin  34  is then passed between cheeks  36 ; in view of the bearing opening  38  having a dimension appreciably greater than the diameter of the hinge pin, this leading end of the hinge pin may be engaged in the bearing opening while subtending a substantial angle to cheek  36 , sufficient to permit the trailing end of the hinge pin to pass between cheeks  36  as the lower jaw is counter rotated, without necessitating the application of a destructive force. Continued counter-rotation of the lower jaw  20  ultimately causes the trailing end of hinge pin  34  to snap into position in the bearing opening of the other of the cheeks. Surprisingly, provided that hinge pin  34  is not permitted to cant, it is difficult to disengage the hinge pin, and jaws  12 ,  20  remain united even under heavy loads.  
         [0037]     Clip  10  further comprises a latch  50  at the axial end thereof opposed to hinge  30 . Latch  50  comprises a downwardly dependent tongue  52 , which is resiliently rooted to jaw  12  adjacent top wall  16  at the forward end thereof, so as to be capable of spring movement. Tongue  52  carries thereon a number of ratchet teeth  54  which are conveniently equal in number and spacing to the number and spacing of the detents provided in bearing opening  38 , which is to say in this embodiment bearing recesses  40   a ,  40   b  and  40   c . A cooperating ratchet tooth  56  is formed on lower jaw  20 . Lower jaw  20  at the forward end includes a forwardly projecting frame  60 , which serves to locate tongue  52  laterally, and reduce the possibility of the disengagement of latch  50  when under load. Suitably, the width of tongue  50  is progressively diminished on approach to the distal end  62  of the tongue in order to facilitate the entry of the distal end of the tongue into frame  60  as clip  10  is closed when under load.  
         [0038]     Considering now the operation of clip  10 , when it is intended to use the clip to close a bag constructed of relatively thin material such as uniply film shown schematically in  FIG. 3  and identified therein as F 1 , hinge  30  is adjusted, with the jaws  12 ,  20  in their open position, so that hinge pin  34  is engaged in the upper ones  40   a  of the bearing recesses. The jaws  12 ,  20  are then moved towards their closed position causing the ratchet teeth  54 ,  56  to engage progressively so as to create a uniform gripping pressure on film F 1  therealong. Assuming now that it is desired to close a bag with thicker multiply walls such as is identified as F 2  in  FIG. 4 , clip  10  will be adjusted so that hinge pin  34  is engaged in an inferior pair of bearing recesses such as  40   c . Accordingly, when jaws  12 ,  20  are moved to their closed position, they will engage to a lesser extent, so as to provide for a suitable clearance for bag wall F 2 . It will be understood that the ratchet teeth  54 ,  56  of latch  50  will be engaged appropriately so as to provide a suitable and uniform pressure on bag wall F 2 .  
         [0039]     It will be appreciated that the number of detents in either or both the hinge portion and the latch portion of clip  10  could be varied from that shown, and where for example the clip is intended for use with medium size bags, a bearing opening  38 ′, as shown in  FIG. 7 , may preferably comprise two bearing recesses and have a cardioid form. Such form may be shaped and constructed wherein all diametric chords have the same dimension, which will be selected to provide a good fit on hinge pin  34  and reduce any tendency of jaws  12 ,  20  to skew when the jaws are opened and the hinge pin is not seated in bearing recesses.  
         [0040]     Considering now a second embodiment of the invention, a clip at the hinge end thereof is identified by the numeral  110 . It is to be understood that this clip may suitably be provided with a latch that is generally identical to the latch  50  of the clip  10  of the first embodiment. Clip  110  includes an upper jaw  112  and a lower jaw  120 , and a hinge  130  about which the jaws may rotate between open and closed positions. Hinge  130  includes a hinge blade  132  which is associated with jaw  120 , from which blade there projects a hinge pin  134  which is conveniently and preferably formed unitarily with the blade. Hinge pin  134  has a finger-like pawl tooth  135 , which projects upwardly and rearwardly from the hinge pin.  
         [0041]     Hinge  130  further comprises a pair of hinge cheeks  136 , which are transversely spaced apart sufficiently to permit the passage of hinge blade  132  therebetween. Cheeks  136  each have a bearing opening  138  therein, which is vertically elongated. Opening  138  has a plurality of detents therein, in the form of a saw-toothed gear rack  140 .  
         [0042]     The jaws of clip  110  are assembled together in an analogous manner to that in which the jaws of clip  10  are united, which is to say that the lower jaw  120  is partially rotated about its longitudinal axis so as to cant hinge pin  134 , and the most upwardly tip of the hinge pin is then engaged in an upper portion of the bearing opening  138  in one cheek  136 . Lower jaw  120  is then counter-rotated to force the lower tip of hinge pin  134  between cheeks  136 , and ultimately to enter bearing opening  138  in the other of the cheeks.  
         [0043]     Bearing opening  138 , hinge pin  134  and finger-like pawl  135  are dimensioned such that when jaws  112 ,  120  are closed, the tip  135 ′ of pawl  135  will be fully engaged with one of the teeth of rack  140 , which will prevent the hinge pin from moving downwardly in the bearing opening under the influence of a load applied to jaws  112 ,  120  when an object is clamped between the jaws. However, should it be desired to decrease the spacing D between the jaws, this is easily effected by applying a compressing force F in the vicinity of hinge  130 , as suggested in  FIG. 10 . Assuming now that it is desired to increase the spacing D between jaws  112 ,  120 , the jaws are moved to their open position; this causes hinge pin  134  to rotate, and to raise pawl  135 , whereby ultimately it will not interfere with rack  140 , as will be seen in  FIG. 12 , thereby permitting hinge pin  134  to be lowered to any desired position in bearing opening  138 .