Abstract:
A hand operated meat tenderizer comprising a generally semicircular housing having an elliptical horizontal cross-section opening with an axle mounted across the opening. A rotary blade assembly comprising at least one blade segment is arranged on a common axis on the axle There is further a means for retractably shielding the blade assembly.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to meat tenderizers. More particularly, the invention relates to a compact, hand-held mechanical meat tenderizer which uses a series of knives arranged around a common axle that imparts a tenderizing action on a piece of meat as the tenderizer is rolled across the meat&#39;s surface. 
         [0003]    2. Background 
         [0004]    Several devices have been invented to mechanically tenderize meat. These devices generally operate using one of two principles—either plunging of the tenderizing functionality into the meat or rolling of a spiked spindle across the meat. Early meat tenderizers used a mallet with a figured or spiked head. The user would strike the meat forcing the tenderizing elements to puncture the meat. Recent improvements on this concept are found in U.S. Pat. Nos. 7,182,685 issued to Gorowski, 4,199,841 issued to Jaccard, and D545,644 issued to Deni, all of which place the striking elements within a spring-loaded handle. The user pounds the meat with the handle which compresses a spring causing the blades to extend into the meat. As the user lifts the apparatus, the spring relaxes and the blades retract into the handle increasing user safety. One advantage of this approach is the tenderizer can be used in one hand, while the other hand handles the raw meat. One-handed operation minimizes the opportunities for contaminating the work area with harmful bacteria. However, this striking of the meat leads to user fatigue as the tenderizer must be lifted and transferred to another portion of the meat to repeat the piercing process while also causing the natural juices to be forced out of the meat yielding a less tender final product. 
         [0005]    Examples of the second approach to mechanical meat tenderizers—rolling pins—are found in U.S. Pat. Nos. 6,159,090 issued to Thompson and D365,971 issued to Brockman. This approach modifies a smooth pastry rolling pin by replacing the smooth portion with a figured or spiked portion between the two handles. This type of tenderizer is less strenuous on a user as it is easier to roll the pin back and forth rather than lifting and plunging as with the striking type tenderizers. Rolling also minimizes the amount of downward force applied to the meat allowing more of the natural juices to remain within the meat leading to a more tender final product. However, this rolling pin apparatus requires two hands for proper operation, leading to an increased chance of contamination from touching the raw meat and then handling the rolling pin handle. U.S. Pat. Nos. 4,380,850 issued to Coburn and D481,268 issued to Hibbert modify the two-handed roller by adding a handle such that the roller looks more like a stirrup. The user is then able to operate the tenderizer with one hand. However, disadvantages of any of the rolling pin-based tenderizers are their bulk (requiring a lot of space in a kitchen drawer) and the possibility of owner injury because, even when not in use the tenderizing elements (spikes or knives) are unsecured raising the chance that an owner may be cut or punctured by inadvertently touching or grabbing the tenderizer. 
         [0006]    Thus it is readily apparent that there is a long felt need for a compact, single-hand operated, rolling meat tenderizer which can be safely used and stored which also minimizes possibilities of bacterial contamination. 
       SUMMARY OF THE INVENTION 
       [0007]    It is accordingly a primary object of the present invention to provide a compact, single-hand-operated rolling meat tenderizer for use in home kitchens. 
         [0008]    Another object of the invention is to provide a rolling meat tenderizer which tenderizes the meat by using a plurality of discs, each of which contains numerous knife edges to puncture the meat. 
         [0009]    A further object of the invention is to provide a compact rolling meat tenderizer possessing a cover which protects the owner from injury during use and also a protective cap for the knife-edged discs for use when the tenderizer is in storage. 
         [0010]    The above and other objects are accomplished in accordance with the present invention which comprises a compact, hand-held mechanical meat tenderizer having a first generally semicircular housing formed of two components having a diameter and thickness to fit comfortably in a user&#39;s hand. An axle is located at the center of the housing&#39;s diameter and has a plurality of disc shaped blades with each disc having numerous knife edges and being spaced roughly evenly apart upon the axle. A spring-loaded comb is mounted onto the housing for being slidably movable into and out of the housing and contains a plurality of flow through grooves for passage of the disc shaped blades. Preferably, a second generally semicircular housing which complements the first housing to form a completed circle is removably affixed to the first housing to protect the user from injuries and the knife edges from damage while the tenderizer is in storage. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The present invention and the manner in which it may be practiced is further illustrated with reference to the accompanying drawings wherein: 
           [0012]      FIG. 1  is a perspective view of one embodiment of a meat tenderizing device of the present invention. 
           [0013]      FIG. 2  is a side view of one embodiment of a meat tenderizing device of the present invention showing the blade cover being removed. 
           [0014]      FIG. 3  is an end view of one embodiment of a meat tenderizing device of the present invention, taken generally along line  3 - 3  of  FIG. 2 . 
           [0015]      FIG. 4  is a bottom view of one embodiment of a meat tenderizing device of the present invention, taken generally along line  4 - 4  in  FIG. 3 . 
           [0016]      FIG. 5  is an exploded view of one embodiment of a meat tenderizing device of the present invention. 
           [0017]      FIG. 6  is a perspective view the wheel assembly of one embodiment of a meat tenderizing device of the present invention. 
           [0018]      FIG. 7  is a cross-sectional view of one embodiment of a meat tenderizing device of the present invention showing the spring-loaded comb in a down position, taken generally along line  7 - 7  in  FIG. 3 . 
           [0019]      FIG. 8  is a cross-sectional view of one embodiment of a meat tenderizing device of the present invention showing the spring-loaded comb in an up position, as when the device is being used. 
           [0020]      FIG. 9  is an illustrative example of one embodiment of a meat tenderizing device of the present invention just prior to being used for tenderizing. 
           [0021]      FIG. 10  is an illustrative example of one embodiment of a meat tenderizing device of the present invention being used for tenderizing. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    At the outset, it should be clearly understood that like reference numerals are intended to identify the same structural elements, portions, or surfaces consistently through out the several drawing figures, as may be further described or explained by the entire written specification of which this detailed description is an integral part. The drawings are intended to be read together with the specification and are to be construed as a portion of the entire “written description” of this invention as required by 35 U.S.C. §112. 
         [0023]    The meat tenderizing device of the present invention is suitable as a rolling style single-hand operated mechanical meat tenderizer. In operation, the protective housing of the meat tenderizer is removed to expose the spring-loaded comb. While holding the blade housing, the spring-loaded comb rests on the surface of the meat. Pressure is then applied to the housing allowing the comb to recede into the blade housing and expose the knife edges. The knife edges penetrate the meat. The housing is then rolled across the meat surface causing the knife blades to rotate on the blade axle as the tenderizer is rolled. Successive knife edges pierce the meat as the tenderizer is rolled along the meat surface. Rolling the device allows the knives to puncture the meat without tearing or gouging the meat surface. When the user lifts the tenderizer from the meat, the tension on the springs is released from the comb and the comb re-covers the knife edges. Preferably, the tenderizer housing and axle are constructed of a durable plastic or lightweight metal such as aluminum while the disc blades and knife edges are made of a rigid material capable of maintaining a sharp edge such as stainless steel. 
         [0024]    Adverting now to the drawings, with reference to  FIGS. 1 and 2 , a preferred embodiment of the present invention is indicated generally by numeral  10  showing a meat tenderizer with a generally semicircular blade housing with an additional lobe formed of two components  12   a  and  12   b  (collectively blade housing  12 ), circular axle covering  14 , blade assembly  30 , a spring-loaded comb  20  mounted within the blade housing operatively arranged to be slidably movable into and out of the blade housing and possessing a plurality of flow through grooves for passage of the disc shaped blades, and optionally, a complementary generally semicircular blade covering  18 . Circular axle covering  14  conceals and protects the junction between housing  12  and blade assembly  30 . 
         [0025]      FIGS. 3 and 4  show different views of a preferred embodiment of a meat tenderizer of the present invention.  FIG. 3  is an end view of one embodiment of a meat tenderizing device of the present invention, taken generally along line  3 - 3  of  FIG. 2 .  FIG. 4  is a bottom view of one embodiment of a meat tenderizing device of the present invention, taken generally along line  4 - 4  in  FIG. 3 . 
         [0026]      FIG. 3  is an end view while  FIG. 4  is bottom view of a preferred embodiment of a meat tenderizer of the present invention. As shown, the blade housing is comprised of two halves  12 A and  12 B having a rounded-over top edge. During use, spring-loaded comb  20  is pushed upward into blade housing  12  exposing the knife blades  32  of the tenderizer. The ergonomic rounded edge increases user comfort and safety when holding the blade housing during use. When the device is pushed toward the meat during use there are no sharp edges pressing against the user&#39;s hand. Circular axle coverings  14  project exterior the blade housing and cover the fastening means of the axle to the blade housing (not shown). Circular axle coverings  14  are aesthetic appendages and are not required for proper functioning of the tenderizer. The semicircular housing  12  is ergonomically shaped with a generally elliptical horizontal cross-section and is designed to fit comfortably in a user&#39;s hand. It should be understood by those skilled in the art that meat tenderizers can be constructed having other shapes, but that the semicircular shape of the preferred embodiment was chosen to maximize user comfort while simultaneously minimizing storage space requirements. 
         [0027]      FIG. 5  is an exploded view of a preferred embodiment of a meat tenderizer of the present invention. The blade housing is composed of two generally semicircular halves  12 A and  12 B which are attached by threading screws  15  through a hole on first semicircular half  12 A into a corresponding receptacle  16  on second semicircular half  12 B. Although screws are used to hold the two halves together, it should be understood that other fastening means can be used, such as but not limited to a clip and groove arrangement or a glue or cement. When combined, the blade housing forms a shell having an elliptical cross section. Each half  12 A and  12 B has an additional semicircular lobe  13  depending downwardly from the straight edge diameter of each half  12 A or  12 B. Semicircular lobe  13  has a smaller diameter than  12 A or  12  B and possesses the same center point as the larger semicircle. Each lobe  13  has a through-hole  17  through which passes axle end shaft  39 . Circular covering  14  snaps onto each half of blade housing and covers through-hole  17 . Covers  14  are aesthetic appendages and are not required for proper functioning of the tenderizer. When combined,  12 A and  12 B create channel  24  which houses spring  22 . Extension  21  of spring-loaded comb  20  is operatively arranged to slide within channel  24 . Spring loaded comb  20  contains flow through grooves for passage of knife blades  32  during use of the meat tenderizer. Semicircular blade covering  18  complements the blade housing  12  to form a completed circle and is removably affixed to the blade housing to protect the user from injuries and the knife edges from damage while the tenderizer is in storage. In as further depicted in the view of  FIG. 6 , blade assembly  30  comprises axle  35  having a fixed nut  38  proximate one end and threaded portion  37  proximate the other end. Axle  35  has threadless cylindrical extensions  39  at each end which fit operatively within holes  17  of blade housing  12  such that axle  35  will rotate freely during use of the meat tenderizer. Threaded nut  36  is positioned onto the threaded portion  37  and, in conjunction with fixed nut  38 , prevents knife blades  32  and spacers  34  from moving laterally along axle  35 . 
         [0028]      FIG. 6  shows blade assembly  30  as a complete unit. Knife blades  32  alternate with spacers  34 . In one embodiment, three knife blades and two spacers are used. However, it is envisioned that any number of blades and spacers can be used depending on the width of the blade housing and thickness of the blades and spacers. In one preferred embodiment, the axle shaft is cylindrical in shape with a round external surface. Knife blades  32  and spacers  34  can contain a round internal through-bore which slides over the shaft. The round shaft and round through-bore allow each of the knife blades to rotate on the shaft individually. In a separate embodiment, the axle shaft (apart from smooth cylindrical portions  39 ) has a polygonal (preferably hexagonal) external surface. The knife blades  32  and spacers  34  have a corresponding through-bore which slides over the shaft. The non-round shaft prevents the knife blades from rotating individually. The knife blades will turn as a single unit as the roller is moved across the surface of the meat. 
         [0029]    As shown in  FIGS. 7 and 8 , spring-loaded comb  20  extends into blade housing  12  and rests within channel  24 .  FIG. 7  is a cross-sectional view of one embodiment of a meat tenderizing device of the present invention showing the spring-loaded comb in a down position, taken generally along line  7 - 7  in  FIG. 3 . Spring  22  is positioned within channel  24  and passes into a channel formed within the comb&#39;s extension. Spring-loaded comb  20  is free to float within channel  24 . In use, downward pressure, illustrated by arrow  60  in  FIG. 8 , is exerted on housing  12  causing comb  20  to compress spring  22 . This spring compression causes comb  20  to partially enter channel  24  thereby exposing the edges of knife blades  32  as the blades pass through the flow through grooves in the comb as shown in  FIGS. 8 and 10 . When the tenderizer is not in use, spring  22  is relaxed allowing comb  20  to cover the tips of the knife blades  32  as shown in  FIGS. 7 and 9 . 
         [0030]      FIGS. 9 and 10  illustrate a meat tenderizer of the present invention just prior to use ( FIG. 9 ) and during use ( FIG. 10 ). As shown in  FIG. 9 , blade housing  12  is positioned so that comb  20  rests on the surface of the meat  50 . Comb  20  covers knife blades  32 . During use, as shown in  FIG. 10 , blade housing  12  is pushed downwardly, as shown by arrow  65 , and comb  20  is directed upwardly into blade housing  12  by compressing springs (shown in  FIG. 8 ). The upward movement of comb  20  exposes the edges of knife blades  32 , and combined with the downward pressure on blade housing  12 , presses the edges of knife blades  32  into the meat surface  50 . Moving blade housing  12  back and forth, as shown by arrows  70 , causes the axle/blade assembly to rotate on the axle, as shown in  FIG. 8  by arrow  72  and arrow  74  in  FIG. 10 . The rotation of the axle allows successive knife edges to penetrate and tenderize the meat surface. 
         [0031]    In operation, minimal downward pressure is needed to expose the knife edges and cause them to penetrate the meat. The minimally-applied pressure alleviates loss of the natural fluids found in the meat allowing for a more tender and flavorful product. The successive knife edges prevent tearing of the surface as the meat is tenderized. After use, as pressure is removed from blade housing  12 , the stored energy in the compressed springs (shown in  FIG. 8 ) is released causing comb  20  to return to its relaxed position covering the knife blades  32  (shown in  FIG. 7 ). Thus, when not in use the sharp edges of the knives are covered, preventing a user from accidentally cutting or puncturing himself or herself while also protecting the sharp edges from damage. For added security, the blade covering (as shown in  FIGS. 2 and 3 ) can be employed, particularly during storage in a kitchen drawer. 
         [0032]    Although the invention has been described with reference to certain preferred embodiments, it will be appreciated by those skilled in the art that modifications and variations may be made without departing from the spirit and scope of the invention. It should be understood that applicant does not intend to be limited to the particular details described above and illustrated in the accompanying drawings. In this regard, the term “means for” as used in the claims is intended to include not only the designs illustrated in the drawings of this application and the equivalent designs discussed in the text, but it is also intended to cover other equivalents now known to those skilled in the art, or those equivalents which may become known to those skilled in the art in the future.