Abstract:
The head-separating tool is a pair of pivoted blades, each having two sections. The section closest to the pivot comprises a wedge on each blade positioned so that the wedges come together in nearly point-to-point contact to engage in the beef neck&#39;s Atlas joint to separate the joint. The portions of the blade farther from the pivot are shears which overlap when closing to cut the soft neck tissue below the Atlas bone. The blades are power-actuated to disjoint at the Atlas joint with substantially no bone chipping.

Description:
FIELD OF THE INVENTION 
     This invention is directed to a power tool to be employed for separating the head from a beef carcass on a slaughterhouse production line. 
     BACKGROUND OF THE INVENTION 
     In a beef slaughterhouse production line, the carcass is suspended by its hind legs, is drained and gutted. The hide is stripped off, and the hanging carcass has a beef head still attached to it. In prior practice, the muscles surrounding the neck in the ear and jaw area must be cut by a manually operated knife. In addition, a knife cut is made directly at the base of the head to expose the Atlas joint. The Atlas joint is the joint between the occipital skull bone and the Atlas vertebrae, which is the first cervical vertebrae. The worker must turn and rotate his wrist back and forth through various angles while working the knife into the Atlas joint and cutting tendons so that the weight of the head will force the joint apart and, thus, facilitate separation of the head from the carcass. This repetitive movement of the worker&#39;s wrist, hand and elbow places excessive strain on the operator&#39;s muscles and tendons. When repeated often, this results in carpal tunnel syndrome. This is an ailment which is extremely painful and debilitating. 
     When a scissors-type power tool with conventional shear blades is used to cut through the Atlas joint and nearby tissue, the cut can be made quickly with little effort to eliminate the difficult hand-work portion of separating the head. However, these shear blades have sharp edges, and often the blades do not find the way between the joint. This causes bone chips which enter the meat to result in a less desirable product. The bone chips require additional labor to find and remove those bone chips. The prior manual methods resulted in disability, and the prior power tool methods resulted in bone chips in the meat. As a result, there is need for an improvement. 
     SUMMARY OF THE INVENTION 
     In order to aid in the understanding of this invention, it can be stated in essentially summary form that it is directed to a beef carcass head-separating tool which has a pair of pivoted blades. The portion of the blades close to the pivot are wedges which directly approach each other, and the portions of the blades which are farther away from the pivot are in the form of shears which pass each other to cut the soft tissue. As a result, the wedges separate the joint at the same time the adjacent soft tissue is sheared. 
     It is, thus, an object and advantage of this invention to provide a beef carcass head-separating tool which is a power tool which quickly and easily separates the head at the Atlas joint and also cuts the adjacent tissue to separate the head with minimal effort and minimal remaining bone chips. 
     It is a further object and advantage of this invention to provide a beef carcass head-separating tool which has a wedge for separating the beef head at the Atlas joint and which has adjacent shears for cutting the soft tissue adjacent thereto. 
     It is a further object of this invention to provide a beef carcass head-separating tool which separates the beef head in a manner such as to minimize bone chips in the meat so as to meet USDA requirements. 
     The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may be best understood by reference to the following description, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of the beef carcass head-separating tool of this invention shown in use. 
     FIG. 2 is a plan view of the blades of the separating tool with the power cylinder and support removed, showing the blades in closed position in full line and in open position in dashed line. 
     FIG. 3 is a sectional view, as seen generally along line 3--3 of FIG. 2. 
     FIG. 4 is a sectional view, as seen generally along line 4--4 of FIG. 2. 
     FIG. 5 is a sectional view, as seen generally along line 5--5 of FIG. 2, showing the Atlas joint in dashed lines. 
     FIG. 6 is a perspective view of the pivoted blades shown in the partly closed position, with parts broken away and the pivot pin taken in section. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The beef carcass head-separating tool of this invention is generally indicated at 10 in FIG. 1. The tool comprises an actuator 12, a support 14, and one or more positioning and control handles 16. The actuator is preferably a fluid actuator, such as a hydraulic cylinder, in order to keep electricity away from the work place. The positioning and control handles are mounted on the actuator so that the operator can position the tool and cause its actuation. Support 14 is a counter-balancing structure to carry the weight of the tool while the operator positions it. While the actuator 12 is a hydraulic cylinder, other types of actuators such as pneumatic or electrically-powered actuators are feasible. Mounted on and extending from the actuator are upper and lower arms 18 and 20. These arms extend forward and carry pivot pin 22 therethrough, see FIGS. 2 and 6. Piston rod 24 is driven by a hydraulic piston in actuator 12 and causes the tool to be operated. 
     FIGS. 2-6 best show the two blades 16 and 28. Blade 26 has bearing face 30 which faces upwardly, while upper blade 28 has bearing face 32, see FIGS. 3, 4 and 6 which faces downwardly. These faces lie against each other and are preferably lubricated because they slide. Pivot pin 22 engages in pivot pin openings in the two blades at these bearing faces 30 and 32. The blades rotate with respect to each other around the pivot pin, and these bearing surfaces define a shear plane. The upper and lower arms 18 and 20 respectively engage upon pivot pin 22 above and below blades 26 and 28 to fix the position of the pivot pin with respect to the tool 10. Actuating links 34 and 36 are pivoted on the forward end of piston rod 24 on pivot pin 38 and are respectively pivoted on the outer rear corner of the blades 28 and 26 on pins 40 and 42. By motion of the actuator piston rod, the blades move from the open position shown in dashed lines in FIG. 2 when the actuator piston rod is rearward to the closed position shown in full lines in FIG. 2 when the actuator piston rod 24 is in the forward position. 
     The blades have two operative sections or portions. The forward portions of the blades are shear portions 41 and 43, which have surfaces which lie on the shear plane so that they can pass over each other. In the closed position, the shear portions 41 and 43 are overlapped, as shown in FIG. 2. The shearing action is shown in FIG. 4. The edge of the shear portion 41 has a cutting face 44, which is preferably at about 45 degrees to the shear plane, and a clearance face 46, which is preferably at about 15 degrees to the shear plane. The shear portions of the blades are directed toward each other so that they overlap when in the closed position, as seen in FIG. 2. The angle of the shear portions with respect to the center line is about 26 degrees when closed. The shear portion 43 of upper blade 28 has the same cutting face 48 and clearance face 50. The overlapping angle of 26 degrees from the center line in the closed position, as seen in FIG. 2, is such that, when the jaws are full open in dashed lines, the shear portions diverge from each other for easy positioning about the carcass neck. Furthermore, this angle is such that, with an average beef carcass being cut, these blades are substantially parallel to each other when cutting engagement of the blades into the beef carcass occurs. 
     The separating portions of the blades 26 and 28 are generally indicated at 52 and 54, respectively. The separating portions extend from forward of the pivot to the back of the shear portion. The separating portions do not touch in the closed position, but are closely spaced (about 1/8 inch apart) in the closed position shown in FIG. 2. The stop in this position is caused by the limit of motion of the actuator. In the closed position, the separating portions 52 and 54 are parallel to each other. As seen in FIGS. 3 and 5, the separating portion 54 has a first face section wedge 56 with substantially 90 degrees total included angle. It is followed by a second fare section wedge 58 with about a 30 degree total included angle. These angles are the same as those in the shear portions. The length from the pivot pin 22 to the far end of the blades, to the right end shown in FIG. 2, is sufficient to engage at the Atlas joint 60 (see FIGS. 1 and 5) of a hanging steer with the shear blades cutting through to the trachea and the separating wedges reaching the Atlas joint 60. 
     In use, the beef carcass is hung, bled, gutted and skinned. A knife cut is made through the soft tissue in one straight cut on each side of the neck to expose the Atlas joint. Only exposure of the joint is necessary. There is no need to cut ligaments or pry about the bone joint. There is no difficult cutting. The hanging carcass is in tension so that a cut at the proper point on each side of the neck of the beef carcass easily exposes the Atlas joint. Since this type of manual knife operation does not require twisting of the knife blade, carpal tunnel syndrome injuries are avoided. Next, the tool 10 is brought into position with respect to the hanging beef carcass. With the blades in the open position, the blades are engaged at the Atlas joint with the pivot pin substantially parallel to the Atlas bone. The opened blades are thrust forward into position in line with the exposed Atlas joint, and the tool is actuated. The forward moving piston rod causes closure of the blades. The shearing portion cuts through the trachea and the adjacent flesh substantially back to the Atlas joint by overlapping shear action. The opposing wedge shaped separating portions readily engage in the joint. The first wedge portion 56 is the first to engage and enter the joint and separates it, while the second wedge portion 58 pries it apart. The bluntness of the first wedge portion 56 finds the joint rather than shears the bone so as to avoid bone chips. When the blades are fully closed, a small gap remains between the separating portions 52 and 54 to avoid blunting of the wedge portions. This structure and function of the separating portions 52 and 54 results in a reduction in bone chips in the product and less stress on the blades. 
     This invention has been described in its presently contemplated best modes, and it is clear that it is susceptible to numerous modifications, modes and embodiments within the ability of those skilled in the art and without the exercise of the inventive faculty. Accordingly, the scope of this invention is defined by the scope of the following claims.