Patent Document

REFERENCE TO RELATED APPLICATIONS 
   This application is a division of copending U.S. application Ser. No. 10/803.583, filed Mar. 18, 2004 now U.S. Pat. No. 7,100,854. 

   BACKGROUND 
   This application relates to systems for chopping or comminuting food stuff and, in particular, to hand-operated choppers of the reciprocating types. 
   Various types of reciprocating food choppers have heretofore been provided. They typically include some type of housing which, either alone or in combination with some underlying support surface, confine food item to be chopped by means of a vertically reciprocating chopping blade which is moved within the housing by a vertically reciprocating plunger/handle assembly, which may be spring-loaded to a raised position. The plunger assembly may be provided with an indexing mechanism which rotates the blade assembly slightly during each up/down cycle of the plunger assembly. Such choppers may be subjected to rather severe shocks and vibrations, particularly when chopping relatively hard food stuffs, such as nuts or the like. The repeated shocks of the engagement of the blade assembly with the food stuff and/or with the underlying support surface can cause damage to the structure of the chopper and may also be painful or uncomfortable for a user. 
   The prior choppers are often of relatively complex and expensive construction and may be difficult to assemble. 
   SUMMARY 
   There is disclosed herein an improved chopper which avoids disadvantages of prior choppers while affording additional structural and operating advantages. 
   In an embodiment, there is provided a food chopper comprising a housing for receiving a food item, a blade assembly including a blade and moveable within the housing for chopping the food item, a shaft attached to the blade assembly for movement therewith, a plunger assembly coupled to the shaft for effecting reciprocating and rotational movement thereof, and a shock absorber disposed between the plunger assembly and the shaft. 
   In an embodiment, the shaft may be threadedly connected to the blade assembly. 
   Also, in an embodiment, the chopper may include a stripper fixed to the housing and responsive to movement of the blade assembly for removing food from the blade, and first and second guide structures respectively on the blade assembly and the stripper for guiding coupling of the blade assembly to the stripper. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For the purpose of facilitating an understanding of the subject matter sought to be protected, there are illustrated in the accompanying drawings embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages should be readily understood and appreciated. 
       FIG. 1  is a front elevational view of a chopper; 
       FIG. 2  is a right-hand side elevational view of the chopper of  FIG. 1 ; 
       FIG. 3  is a top plan view of the chopper of  FIG. 1 ; 
       FIG. 4  is an enlarged sectional view taken along the line  4 — 4  in  FIG. 3 ; 
       FIG. 5  is an exploded perspective view of the chopper of  FIG. 1 ; 
       FIG. 6  is an enlarged, fragmentary, perspective view in vertical section of the upper body of the housing and portions of the plunger assembly of the chopper of  FIG. 1 ; 
       FIG. 7  is a enlarged, fragmentary, perspective view in vertical section of portions of the chopper of  FIG. 1 ; 
       FIG. 8  is an enlarged, top perspective view of the blade assembly of the chopper of  FIG. 5 ; 
       FIG. 9  is an enlarged front elevational view of the shaft of the chopper of  FIG. 5 ; 
       FIG. 10  is a sectional view taken along the line  10 — 10  in  FIG. 9 ; 
       FIG. 11  is an enlarged top plan view of the assembled shaft and blade assembly of the chopper of  FIG. 5 ; and 
       FIG. 12  is a sectional view taken along the  12 — 12  in  FIG. 11 . 
   

   DETAILED DESCRIPTION 
   Referring to  FIGS. 1–5 , there is illustrated a food chopper, generally designated by the numeral  20 , which includes a housing  21 , which may be a two-part housing, including an upper body  22  and a lower body  40 , which may each be of unitary, one-piece construction and may be molded of suitable plastic materials. The upper body  22  has an upwardly and radially inwardly tapering, somewhat bullet-shaped outer wall  23  having a sinuous or undulating lower edge  24 . The inner surface of the outer wall  23  is recessed just above the lower edge  24  to define an annular shoulder  25 . Referring also to  FIGS. 6 and 7 , the recessed portion of the inner surface has a pair of diametrically opposed detent recesses  26  formed therein and has a plurality of circumferentially spaced-apart latch ribs  27  projecting laterally inwardly therefrom a slight distance below the shoulder  25 . The outer wall  23  terminates at an upper edge  28 . 
   Integral with the outer wall  23  at the upper edge  28  and depending therefrom is an outer cylindrical wall  30  (see  FIGS. 4 ,  6  and  7 ) integral at its lower edge with a radially inwardly extending annular bottom wall  31  which is, in turn, integral with an upstanding inner cylindrical wall  32  which is coaxial with the outer cylindrical wall  30  and extends a slight distance upwardly above the upper edge  28 . Formed in the outer cylindrical wall  30  are equiangularly spaced-apart and axially extending guide slots  33 , each communicating at its lower end with a circumferentially extending latch slot  34  just above the bottom wall  31 . The portion of the bottom wall  31  which extends radially inwardly beyond the inner cylindrical wall  32  defines an annular shoulder  35  having circumferentially spaced teeth  36  formed on the upper surface thereof (see  FIG. 6 ). Formed in the inner surface of the inner cylindrical wall  32  and extending the length thereof are a plurality of equiangularly spaced-apart helical or spiral grooves  37 . Formed through the outer wall  23  just below the upper edge  28  and communicating with the space between the outer wall  23  and the outer cylindrical wall  30  are two diametrically opposed pairs of apertures  38  for a purpose to be explained below. A helical compression spring  39  (see  FIG. 4 ) is disposed in the space between the inner and outer cylindrical walls  32  and  30  and is seated on the bottom wall  31 . 
   The lower body  40  is generally cylindrical in shape and terminates at a circular lower edge  41  and a circular upper edge  42  (see  FIG. 4 ). The outer surface of the lower body is recessed adjacent to the upper edge  42  to define a sinuous or undulating shoulder  43 . Formed on the recessed surface above the shoulder  43  are a plurality of spacing ribs  44  and two diametrically opposed detent beads  45 . In use, the lower body  40  is adapted to mate with the upper body  22  so that the sinuous lower edge  24  of the upper body  22  seats against the sinuous shoulder  43  of the lower body  40 , and with the detent beads  45  respectively seating in the detent recesses  26  to resiliently retain the parts in their assembled condition. For disassembly, relative rotational or twisting movement of the upper and lower bodies  22  and  40  creates a camming action along the sinuous mating surfaces to facilitate separation of the parts. 
   As can be seen in  FIGS. 2 and 3 , an elongated plastic scraper  46  may be mounted on the outside of the housing  21 , the scraper  46  being provided with a pair of hooks  47  (see  FIG. 4 ) adjacent to its upper end for being received in one pair of the apertures  38 , the scraper  46  being dimensioned to follow the external contours of the housing  21  so that it fits snugly against the outer surface thereof, as can best be seen in  FIGS. 2 and 3 . The scraper  46  is easily removable and is formed of a suitable relatively flexible plastic material and can be used to facilitate scraping food contents from the interior surfaces of the chopper  20 . 
   Referring in particular to  FIGS. 4–7  a plunger assembly  50  is mounted in the upper end of the housing  21 . The plunger assembly  50  includes a plunger  51  including a cylindrical wall  52  closed at the upper end thereof by a slightly domed top wall  53 , which extends laterally outwardly beyond the cylindrical wall  52  to define a peripheral lip  54  having diametrically opposed pairs of projections  55  projecting radially outwardly therefrom. The top wall  53  may be covered by a cap  56  formed of a suitable flexible and resilient frictional gripping material, such as that sold under the trade name Santoprene, the cap  56  fitting over the lip  54  and having apertures therethrough through which the projections  55  may extend so as to be visible in use. A plurality of equiangularly spaced-apart latch tabs  57  project radially outwardly from the cylindrical wall  52  adjacent to its lower edge. Depending from the inner surface of the top wall  53  are two diametrically opposed, part cylindrical guide arms  59  which lie along an imaginary cylinder coaxial with the cylindrical wall  52 , but have a much shorter axial extent. Also depending from the inner surface of the top wall  53  radially inwardly of the guide arms  59  are a plurality of equiangularly spaced-apart latch arms  60 , each provided at its lower end with a latch hook  61 . Depending from the inner surface of the top wall  53  centrally thereof is an elongated post  62  having a short axial bore  63  formed in its lower end and having mounted thereon a bumper pad or shock-absorber  64  formed of a suitable elastomeric material and having a neck  65  which seats in the bore  64 . 
   Referring now in particular to  FIGS. 4 ,  5  and  9 – 12 , the plunger assembly  50  also includes an elongated shaft  70  having a cylindrical main body  71  provided with an external thread  72 . Integral with the main body  71  intermediate the ends of the shaft  70  is a radially outwardly extending annular flange  73  provided on its lower surface with a set of circumferentially spaced lower teeth  74  and on its upper surface with a plurality of circumferentially spaced upper teeth  75 . The lower end of the shaft  70  defines a bifurcated post  76  forming a pair of arms  77 , respectively provided at their lower ends with radially inwardly tapered projections  78 . The upper end of the shaft  70  defines an upper post  79  having an axial bore  80  formed in the upper end thereof. Integral with the upper post  79  at its upper end is an radially outwardly extending latch flange  81  defining an annular lip  82 . Projecting radially outwardly from the shaft  70  immediately above the flange  73  are equiangularly spaced and axially extending spacer ribs  83  joined at their upper ends by a ring  84 . 
   Referring in particular to  FIGS. 4–7 , the plunger assembly  50  also includes an indexer sleeve  85  having an inner cylindrical wall  86  joined at its lower end by a radially outwardly extending annular web  87  to an outer cylindrical wall  88 , which is much shorter than the inner cylindrical wall  86 . Formed on the underside of the annular web  87  are plurality of circumferentially spaced teeth  89 . Formed on the outer surface of the outer cylindrical wall  88  are a plurality of equiangularly spaced-apart keys  89   a  designed to respectively ride in the spiral grooves  37  of the housing  21 . 
   In assembly, the indexer sleeve  85  is fitted down over the upper end of the shaft  70 , with the teeth  89  disposed for engagement with the upper teeth  75  of the shaft  70 . Then the shaft  70  is installed in the plunger  51 , the latch flange  81  of the shaft  70  being snap-fitted between the latch arms  60  of the plunger  51  so that the hooks  61  latch under the lip  82  to hold the shaft  70  in place. During this assembly, the plunger post  62  is received in the bore  80  of the shaft  70  so that the bumper pad  64  engages the shaft  70  at the inner end of the bore  80 , as can best be seen in  FIG. 4 . When thus assembled, the inner cylindrical wall  86  of the indexer sleeve  85  fits up coaxially within the guide arms  59  of the plunger  51 , the indexer sleeve  85  being capable of axial movement which is limited by engagement with the lower ends of the guide arms  59  and by engagement with the flange  73  of the shaft  70 . 
   When the plunger assembly has thus been assembled, it is then mounted in the housing  21 . More specifically, the upper end of the spring  39  is received between the cylindrical wall  52  and the guide arms  59  of the plunger  51 , the plunger assembly  50  being pushed down into the housing  21 , compressing the spring  39 , with the shaft  70  and the indexer sleeve  85  being fitted down within the inner cylindrical wall  32  of the housing  21 , and the cylindrical wall  52  of the plunger  51  being fitted between the outer and inner cylindrical walls  31  and  32  of the housing  21 . The latch tabs  57  snap past the upper edge  28  of the housing  21  and respectively into the longitudinal guide slots  33  for latching the plunger assembly  50  in an assembled condition on the housing  21 , the spring  39  resiliently urging the plunger assembly  50  upwardly to a raised position (not shown) wherein the latch tabs  57  are stopped at the upper ends of the guide slots  33 . As the plunger assembly  50  is fitted into the housing  21 , the keys  89   a  of the indexer sleeve  85  respectively enter and ride in the spiral grooves  37  of the housing  21 . 
   It will be appreciated that the plunger assembly  50  may be reciprocated up and down between the normal raised position and a lowered position, wherein the cylindrical wall  52  of the plunger  51  bottoms against the annular bottom wall  31  of the housing  21  (see  FIG. 4 ). The plunger assembly  50  may be latched in this lowered position by rotating the plunger  51  about ⅛ of a turn to move the latch tabs  57  into the latch slots  34  of the housing  21 , in a known manner. 
   Referring now in particular to  FIGS. 4 ,  5 ,  8 ,  11  and  12 , the chopper  20  includes a blade assembly  90  having a flat, generally circular base plate  91  having formed on its underside a depending elongated linear boss in a serpentine shape, which receives and has embedded therein the upper edge of a serpentine blade  93  having a cutting edge  94  at its lower end. Upstanding from the base plate  91  at diametrically opposed locations, along parallel chords, are guide flanges  95 , each having an axial slot or groove  96  formed therein. The serpentine blade  93  is symmetrical about an axis passing through the grooves  96 . The blade assembly  90  includes a hollow cylindrical neck  97  projecting axially upwardly from the base plate  91  centrally thereof and provided at its upper end with internal threads  98 . Formed in the lower end of the neck  97  is a conically tapered seat  99 , having a diametrical slot  99   a  formed thereacross (see  FIG. 8 ). 
   In assembly, the lower end of the shaft  70  is received in the cylindrical neck  97  of the blade assembly  90 , the threads  72  on the shaft  70  threadedly engaging the internal threads  98  in the neck  97 . When the parts approach full threaded engagement, which may be after about ½ turn, the tapered projections  78  on the shaft arms  77  enter the tapered seat  99  in the neck  97 , compressing the arms  77  together until the projections  78  snap into the slot  99   a . This resiliently holds the parts together and inhibits inadvertent unscrewing thereof. This threaded connection permits the blade assembly  90  to be easily removed for cleaning by simply rotating it about ½ turn. 
   The chopper  20  also includes a stripper  100  including a generally circular base plate  101  having a serpentine slot  102  formed therein for receiving the serpentine blade  93 . Integral with the base plate  101  at its outer edge and upstanding therefrom is a generally cylindrical side wall  103  which is, in turn, integral with a pair of upstanding, diametrically opposed, generally oval-shaped guide arms  104 , respectively provided with laterally inwardly extending guide ribs  105  extending longitudinally along the entire axial extent of the guide arms  104 . Depending from the base plate  101  at its outer edge is a scraper arm  106  (see  FIG. 5 ). The upper edge of the side wall  103  is provided with a radially outwardly projecting latch flange  107 . 
   In assembly, the guide arms  104  of the stripper  100  are fitted up inside the lower body  40  of the housing  21 . To facilitate this insertion in the correct orientation, the guide arms  104  are aligned with the guide flanges  95  of the blade assembly  90  so that the guide ribs  105  are respectively received in the grooves  96 . This will orient the parts so that the serpentine blade  93  will be aligned with and fit cleanly through the serpentine slot  102  of the stripper  100 . Insertion continues until the latch flange  107  snaps into engagement above the upper edge  42  of the housing lower body  40  (see  FIG. 4 ) for resiliently holding the stripper  100  in place. Because of the symmetry of the blade  93 , the stripper can be inserted in either of the two orientations 180° apart. 
   Referring in particular to  FIGS. 1–5 , the chopper  20  also includes a circular base plate  110  having an upstanding cylindrical side wall  111  at its periphery. Projecting radially outwardly from the base plate  110  is a circumferential rib  112 . An elastomeric seal ring  113  is fitted over the outer edge of the base plate  110 , having a pocket which receives the rib  112 . The seal ring  113  completely covers the outer peripheral surface of the base plate  110  and is stepped to define an annular shoulder  114 . In use, the base plate  110  and the seal member  113  are so dimensioned that the cylindrical wall  111  and its seal member covering may be fitted snugly up inside the lower end of the lower body  40 , so that the lower edge  41  of the housing lower body seats on the annular shoulder  114 , as can best be seen in  FIG. 4 . Thus, in use, food items may be disposed in the housing  21 , which may then be closed by the base plate  110  so that the food items rest on the base plate  110  as they are being chopped by the reciprocating movement if the blade assembly  90 , all in a known manner. Alternatively, the lower edge  41  of the housing could be seated on any suitable underlying support surface, such as a countertop, chopping block or the like, for confining the food items being chopped. However, the base plate  110  has the advantage of providing a ready-made container so that, after chopping is complete, the lower body  40  need simply be detached from the upper body  22  and the chopped food is then contained within the lower body  40 . 
   The chopper  20  is also provided with a cap  115  which is formed of a flexible and resilient material and is dimensioned so that, when not in use, it can be fitted over the base plate  110 , as illustrated in  FIGS. 1–4 . The cap  115  has a circular end wall  116  and is provided at its periphery with an upstanding outer cylindrical wall  117  having a sinuous or undulating upper edge  118 . A handle tab  118   a  projects radially outwardly from the upper end of the cylindrical wall  117 . There is also provided an inner cylindrical wall  119  which is upstanding from the end wall  116  a slight distance radially inwardly from the outer cylindrical wall  117  and coaxial therewith. 
   When the cap  115  is not in use, the raised portions of the outer cylindrical wall  117  fits snugly around the seal ring  113  of the base plate  110  so that it does not become misplaced. After food is chopped upon the base plate  110 , the lower body  40  may be detached, as explained above, and the cap may be fitted on the upper end thereof for closing the container of chopped food items. In this regard, the inner cylindrical wall  119  of the cap fits down inside the upper edge  42  of the lower body  40 , while the outer cylindrical wall  117  fits along the recessed outer surface of the lower body  40  so that the sinuous edge  118  mateably engages the sinuous shoulder  43  on the lower body  40 . Detent recesses (not shown) may be provided on the inner surface of the outer cylindrical wall  117  for respectively receiving the detent beads  45  on the lower body  40  to assist in retaining the cap  115  in place. 
   It will be appreciated that, in use, the plunger assembly  50  is reciprocated up and down, carrying with it the blade assembly  90  for chopping food items disposed in the lower body  40 , all in a known manner. As the shaft  70  moves downwardly to its lowermost position, wherein the serpentine blade  93  bottoms on the base plate  110 , as seen in  FIG. 4 , the shaft flange  73  separates from the indexer sleeve  85 , which is retarded by the spiral grooves  37  and stopped at the lower ends of those grooves. Upon the return stroke of the plunger assembly  50 , the upper teeth  75  on the shaft flange  73  reengage the teeth  89  on the indexer sleeve  85  and carry the indexer sleeve  85  back upwardly with the plunger assembly  50 . However, since the indexer sleeve  85  is keyed in the spiral grooves  37  it rotates as it rises, causing the shaft  70  and blade assembly  90  to also rotate, approximately ⅛ turn. Thus, for each down/up plunger cycle the blade assembly  90  rotates slightly to effect an even chopping action on the food item, all in a known manner. As the blade assembly  90  reciprocates up and down, the stripper  100  serves to wipe food items from the blade  93 , again in a known manner. It is significant that the elastomeric bumper  64  between the post  62  and the shaft  70  serves to absorb shock and vibration during the reciprocating chopping action, thereby minimizing user stress and minimizing the chance of cracking or otherwise damaging the chopper  20 . 
   From the foregoing, it can be seen that there has been provided an improved chopper which is of relatively simple and economical construction, permitting easy disassembly of all of the parts which come in contact with the food items during use, to facilitate cleaning and easy reassembly by a user. In a constructional model of the chopper  20 , the spring  39  and the blade  93  may be formed of suitable metals, such as suitable steels, while all of the rest of the parts may be formed of suitable plastic materials. If desired, the lower body  40  of the housing  21  may be formed of a light-transmitting plastic material, such as a transparent plastic, to facilitate viewing the food items being chopped and to permit ready identification of items which are stored in the lower body  40 . 
   The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of applicants&#39; contribution. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.

Technology Category: b