Patent Publication Number: US-2017360000-A1

Title: Squeeze chute with livestock restraints

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application, pursuant to 35 U.S.C. 111(b), claims the benefit of the earlier filing date of provisional application Ser. No. 62/352,042 filed Jun. 20, 2016 and entitled “Pneumatic Squeeze Chute” and provisional application Ser. No. 62/375,070 filed Aug. 15, 2016 and entitled “Squeeze Chute with Livestock Restraints.” 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This invention is related to a squeeze chute having at least one restraint mechanism for temporarily confining an animal while it is being inspected or treated. More particularly, the present invention is related to a squeeze chute having a pair of side grippers and a rear pusher, wherein both the side grippers and the pusher are horizontally and vertically extensible and retractable from the top rail on which they are mounted. 
     Description of the Related Art 
     Ranchers and livestock producers must manage their herds in a manner that is safe for the livestock manager, the livestock, and the veterinarian. Restraining mechanisms such as a squeeze chute facilitate the handling of livestock, especially during veterinary operations such as pregnancy examinations, tagging, inoculations and the like. 
     The safe and effective restraining of an animal during veterinary operations has always been a problem for the animal, rancher and/or veterinarian. currently available squeeze chutes have either a manual or hydraulic mechanism to squeeze or constrict the animal from the lower side panels. In order to effectively restrain the animal for invasive procedures, the lower panels can exert enough pressure on the thoracic cavity of the animal to cause internal injury to the animal being constrained. Furthermore, none of the available squeeze chutes have a rear pusher that can effectively prevent the animal being constrained from backing up. 
     A need exists for a squeeze chute that is safer for the animal, rancher and/or veterinarian while the animal is undergoing inspection or treatment. 
     SUMMARY OF THE INVENTION 
     Embodiments of the invention include a squeeze chute for temporarily confining an animal while it is being inspected or treated, wherein the squeeze chute has a pair of side grippers and a rear pusher that cooperate to restrain the movement of the animal within the squeeze chute. Certain embodiment of both the side grippers and the pusher are horizontally and vertically extensible and retractable from the top rails on which they are mounted. 
     Embodiments of the present invention provide an animal restraining chute having: a) a rectangular chute having an entrance, an exit, an interior, a top, a first side and a second opposed side, wherein the first and second sides include a tubular top rail; b) a first side restraint mechanism mounted on the top rail of the first side and a second side restraint mechanism mounted on the top rail of the second side, wherein each restraint mechanism is rotatable about the top rail that it is mounted on, the side restraint rotatable between a substantially horizontal position away from the interior of the chute to a substantially vertical position closer to the interior of the chute and wherein each side restraint has a gripper that is vertically extendable or retractable for adjusting a distance between a distal end of the gripper to the top rail on which the restraint mechanism is mounted; and c) a pusher mounted on a horizontal cross-rail that is transverse to the top rails of the first and second sides, wherein the pusher is rotatable about the horizontal cross-rail that it is mounted on, the pusher is rotatable between a substantially horizontal position away from the interior of the chute to a more vertical position closer to the interior of the chute and wherein the pusher is movable toward and away from the interior of the chute along a longitudinal axis of the chute. 
     One embodiment of the present invention is an animal holding chute including: a) a rectangular chute having an entrance gate, an exit gate, an interior, a top, a first side and a second opposed side, wherein the first and second sides include a tubular first and second top side rail; and b) a first restraint mechanism mounted on the first top side rail and a second restraint mechanism mounted on the second top side rail opposite the first restraint mechanism, wherein each restraint mechanism having a tubular gripper support encircling a segment of the top side rail on which the restraint mechanism is mounted on, a gripper, a gripper extender having a first end attached to the gripper support and a second end attached to the gripper, wherein the extension or retraction of the gripper extender adjusts the distance between the gripper support and the gripper, and a gripper rotator having a hydraulic cylinder mounted on the top of the chute and a cylinder rod attached to the gripper support, wherein the extension or retraction of the cylinder rod rotates the restraint mechanism about the top rail on which it is mounted between a substantially horizontal position away from the interior of the chute to a substantially vertical position closer to the interior of the chute. 
     Another embodiment of the present invention is an animal holding chute including: a) a rectangular chute having an entrance gate, an exit gate, an interior, a top, a first side and a second opposed side, wherein the first and second sides include a tubular first and second top side rail; and b) a pusher rotatably mounted on a horizontal cross-rail that is transverse to the first and second top side rails, the pusher having a tubular pusher support encircling a segment of the cross-rail; a pusher body having a proximal end mounted on the pusher support and an opposed distal end; a pusher rotator having a hydraulic rotator cylinder mounted on a first end to the pusher support and a second end mounted to the cross-rail, wherein the extension or retraction of a rotator cylinder rod rotates the restraint mechanism about the cross-rail between a substantially horizontal position away from the interior of the chute to a substantially vertical position closer to the interior of the chute; and a pusher placement mechanism having a hydraulic placement cylinder mounted on the top of the chute wherein an extendable rod end of the cylinder is attached to the cross-rail and wherein each end of the cross-rail is transversely mounted to a tubular section having a bore that encircles one of the top side rails thereby rendering each tubular section slideable along an adjustment length of the top side rail that it encircles wherein the extension or retraction of the rod end of the placement cylinder moves the pusher toward and away from the interior of the chute along a longitudinal axis of the chute. 
     Yet another embodiment of the present invention is an animal holding chute including: a) a rectangular chute having an entrance gate, an exit gate, an interior, a top, a first side and a second opposed side, wherein the first and second sides include a tubular first and second top side rail; b) a first restraint mechanism mounted on the first top side rail and a second restraint mechanism mounted on the second top side rail opposite the first restraint mechanism, wherein each restraint mechanism has a tubular gripper support encircling a segment of the top side rail on which the restraint mechanism is mounted on, a gripper, a gripper extender having a first end attached to the gripper support and a second end attached to the gripper, wherein the extension or retraction of the gripper extender adjusts the distance between the gripper support and the gripper, and a gripper rotator having a hydraulic cylinder mounted on the top of the chute and a cylinder rod attached to the gripper support, wherein the extension or retraction of the cylinder rod rotates the restraint mechanism about the top rail on which it is mounted between a substantially horizontal position away from the interior of the chute to a substantially vertical position closer to the interior of the chute; and c) a pusher rotatably mounted on a horizontal cross-rail that is transverse to the first and second top side rails, the pusher having a tubular pusher support encircling a segment of the cross-rail; a pusher body having a proximal end mounted on the pusher support and an opposed distal end; a pusher rotator having a hydraulic rotator cylinder mounted on a first end to the pusher support and a second end mounted to the cross-rail, wherein the extension or retraction of a rotator cylinder rod rotates the restraint mechanism about the cross-rail between a substantially horizontal position away from the interior of the chute to a substantially vertical position closer to the interior of the chute; and a pusher placement mechanism having a hydraulic placement cylinder mounted on the top of the chute wherein an extendable rod end of the cylinder is attached to the cross-rail and wherein each end of the cross-rail is transversely mounted to a tubular section having a bore that encircles one of the top side rails thereby rendering each tubular section slideable along an adjustment length of the top side rail that it encircles wherein the extension or retraction of the rod end of the placement cylinder moves the pusher toward and away from the interior of the chute along a longitudinal axis of the chute. 
     Another embodiment of the present invention is a livestock holding chute comprising: a rectangular chute having an entrance, an exit, a first side and a second opposed side, wherein the first and second sides include a tubular top rail having a top rail outer diameter; a restraint mechanism mounted on the top rail of the first and second sides, wherein the restraint mechanism includes a tubular restraint support having a bore with an inner diameter larger than the rail outer diameter, wherein the inner diameter of the bore of the restraint support encircles a portion of the length of the top rail of the first and second sides; an arcuate gripper; a gripper extender having a first end attached to the restraint support and a second end attached to the gripper, wherein the extension or retraction of the gripper extender adjusts a distance between the top rail and the gripper; a gripper swivel that attaches the gripper to the gripper extender, wherein the gripper swivel allows the gripper to vertically rotate about the second end of the gripper extender; and a gripper rotator having a hydraulic cylinder mounted on a first end to the tubular support and a second end mounted to the top rail encircled by the tubular support; and a pusher assembly mounted on a horizontal cross-rail that is a transverse to the top rails of the first and second sides, wherein the pusher assembly includes a tubular pusher support having a bore with an inner diameter larger than the cross-rail outer diameter, wherein the inner diameter of the bore of the tubular support encircles a portion of the length of the top rail of the first and second side; a pusher body; a pusher extender having a first end attached to the pusher support and a second end attached to the pusher body, and a pusher rotator having a hydraulic cylinder mounted on a first end to the pusher support and a second end mounted to the cross-rail encircled by the pusher support. 
     The foregoing has outlined rather broadly several aspects of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed might be readily utilized as a basis for modifying or redesigning the structures for carrying out the same purposes as the invention. It should be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
         FIGS. 1A, 1B and 1C  are plan views of embodiments of a holding chute framework. 
         FIG. 2A  is an oblique view of the inwardly facing side of one embodiment of the restraint mechanism. 
         FIG. 2B  is an oblique view of the outwardly facing side of the embodiment of the restraint mechanism shown in  FIG. 2A . 
         FIGS. 2C and 2D  are oblique views of the outwardly facing side of the embodiment of the restraint mechanism shown in  FIG. 2B  where the gripper is extended in a downward direction. 
         FIG. 3A  is a side sectional view of one embodiment of the gripper extender. 
         FIG. 3B  is a side view of one embodiment of the restraint mechanism. 
         FIG. 4  illustrates a side view of a restraint mechanism mounted on a top side rail of the holding chute. 
         FIG. 5  is a schematic cross sectional view of the opposed grippers abutting the sides of an animal being restrained in the holding chute. 
         FIG. 6A  is a plan view of one embodiment of a pusher assembly mounted on a transverse top rail of the holding chute. 
         FIG. 6B  is a side view of one embodiment of a pusher assembly mounted on a transverse top rail of the holding chute having an open entrance gate. 
         FIGS. 7A and 7B  illustrate a couple of embodiments of a pusher assembly. 
         FIGS. 7C and 7D  illustrate a couple of embodiments of a pusher body. 
         FIG. 8  is rear view of the holding chute showing one embodiment of an exit gate. 
         FIG. 9  illustrates the closed exit gate shown in  FIG. 8  with a cow head protruding through an opening in the exit gate. 
         FIG. 10  illustrates one embodiment of a head positioner. 
         FIG. 11  illustrates a cow being restrained and lifted within one embodiment of the squeeze chute. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the invention include a squeeze chute for temporarily confining an animal, both domesticated and wild, while it is being inspected or treated. Embodiments of the squeeze chute have at least one restraint mechanism for restraining the movement of an animal held in the chute. Preferable restraint mechanisms include a pair of side restraints, a rear pusher and restraint and/or a head positioner. The restraint mechanism cooperate to restrain the movement of the animal within the squeeze chute. Certain embodiments of both the side grippers and the pusher are horizontally and vertically extensible and retractable from the top rails on which they are mounted. 
     It is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention in any appropriately detailed structure. 
     Referring now to the drawings, and initially to  FIGS. 1A and 1B , it is pointed out that like reference characters designate like or similar parts throughout the drawings. The Figures, or drawings, are not intended to be to scale. For example, purely for the sake of greater clarity in the drawings, component size and spacing are not dimensioned as they actually exist in the assembled embodiment. 
     The Holding Chute 
       FIG. 1A  is a schematic outline of one embodiment of a basic rectangular holding chute framework  100 . The holding chute framework  100  has an entrance  105 , an exit  110 , a first side  112 , and a second side  114 . The chute has four tubular top rails that are joined into a top rectangle and four bottom rails joined into a substantially similar bottom rectangle, where the top and bottom rectangles are joined at their four corners with end posts  160 . The top rail  116  for the first side  112  and the top rail  118  for the second side  114  are in a top plane and have substantially identical circumferences and outer diameters. Typically, the rails are steel tubes and are welded together. The rectangular framework  100  generally rest on a base  120 . The first side  112  and the second side  114  typically have multiple vertical bars  137  that connect the top and bottom rectangles and multiple horizontal bars  135  that connect the vertical bar  137  and the end posts  160 . Optionally, the chute framework  100  has one or more transverse horizontal tubes  170  that span the top rails  116  and  118 . 
       FIG. 1B  illustrates another embodiment of the holding chute framework  150  with a base  120  incorporated into the framework. Typically, the structural elements of the framework  150  are steel and are typically joined by arc welding. The structural base  120  is composed primarily of steel tubing and plate mounted on a horizontal rectangular steel base plate  125  which rests on a flat ground surface. The chute framework  150  has two sides with each side having two end posts  160 . Each side typically has multiple vertical bars  137  and horizontal bars  135  that provide the basic structure of the sides. The chute framework  150 , like the chute framework  100 , has one or more optional transverse horizontal tubes  170  that span the top rails  116  and  118 . 
     The chute framework  150  has at least two (with four being shown in  FIG. 1B ) tubular transverse loops  130 . The loops  130  are generally positioned parallel to each other and spaced along the long axis of the base plate  125 . The transverse loops  130  resemble an inverted “U” with curved legs welded on one end to the top end of opposed vertical bars  137  of the two sides of the chute framework. The other end of the curved legs are directed towards the center of the chute framework and are joined by horizontal bars  185  to form the inverted “U” shape. Typically one U-shaped tubular loop  130  is mounted each end of the chute framework  150  (i.e., the entrance  105  and the exit  110 ). 
       FIG. 1C  illustrates yet another embodiment of the holding chute framework  190  that is similar to the chute framework  150 . The major differences being that in one section of the chute framework  190 , proximal the exit  110  of the chute, the horizontal bars  185  are absent on the two sides except for the top rails  116  and  118 . The other major difference illustrated is that the framework  190  has a raised offset transverse loop  175 . The raised loop  175  illustrated in  FIG. 1C  is a “U” shape loop positioned horizontally with each leg of the “U” welded to a vertical extension that is welded to the opposed top rails  116  and  118 . However, the raised loop  175  can be a variety of shapes and sizes and is typically used to mount components of the squeeze chute. 
     On each side of both the entrance and the exit of the various chute frameworks, a vertical cylindrical tubular gate support post  140  is outwardly positioned from each end post  160 . Typically, each gate support post  140  is welded to the base plate  125  at its lower end and similarly attached by a short upper horizontal tubular support  155  to at an upper end by welding. The individual gate support posts  140  provide support for a pair of swing gates at the entrance  105  and the exit  110 . A variety of sizes and shapes of swing gates may be selected for the entrance  105  and the exit  110 . 
     The chute framework  100 ,  150  or  190  serves both to laterally confine animals within the holding chute and to provide a mount for other components of the squeeze chute. 
     The Side Restraint Mechanism 
       FIG. 4  illustrates a side view of a squeeze chute with a pair of substantially identical restraint mechanisms  200  mounted on the top rails  116  and  118  of the opposed sides of the chute framework  190 . Embodiments of such restraint mechanisms are illustrated in  FIGS. 2  A-D and  FIGS. 3A-B . 
     Embodiments of the restraint mechanism have a gripper attached to a top rail of the squeeze chute framework and are designed to be vertically and horizontally extensible and retractable. A simple design of the restraint mechanism  270 , shown in  FIG. 3B , has a gripper  220  that only extends and retracts in a vertical and horizontal direction; whereas a more complex design of the restraint mechanism  200 , shown in  FIGS. 2A-D , has a gripper  220  that extends and retracts in a vertical direction, extends and retracts in a horizontal direction, pivots about the top rail on which it is mounted, and pivots about its attachment to a gripper extender  230 . 
     One embodiment of the restraint mechanism  200 , shown in  FIGS. 2A-C , includes a tubular support  210  that encircles a top rail  116 , 118 ; an arcuate gripper  220  designed to conform to a section of the animal to be constrained by the restraint mechanism  200 , a gripper extender  230  connecting the gripper  220  and the tubular support  210 ; a gripper swivel  224  attaching the gripper  220  to the gripper extender  230 ; and a restraint rotator  240  mounted on a first end to the tubular support  210  and on a second end to the top rail  116 ,  118  encircled by the tubular support. The restraint mechanism  200  and its component parts are described in more detail below. 
     The tubular support  210  is a tubular structure having a bore with an inner diameter that is slightly larger than the outer diameter of the top rails  116 ,  118 . Prior to welding the top rails  116 ,  118  into the chute framework, the outer circumference of the top rail of each side, is threaded through the bore of at least one tubular support  210 . Thus, each tubular support encircles and is rotatable about a top rail  116 ,  118 . 
     A preferred embodiment of the gripper  220  has an arcuate inner surface  222  that will grip one part of the anatomy of the animal confined, such as the rib cage and/or abdomen of a cow as schematically indicated in  FIG. 5 . The inner surface  222  is optionally padded and is typically designed to conform to the portion of the anatomy of the animal to be constrained by the restraint mechanism  200 . The gripper  220  is optionally replaceable with other sizes and shapes of gripper depending on the animal to be constrained in the squeeze chute. The ability to swap different types and contours of grippers  220  allows the squeeze chute to be adapted for use with a variety of animals. For example, the gripper  220  shown in  FIG. 2D  is wider than the gripper  220  shown in  FIG. 2A  and the gripper  220  shown in  FIG. 3B  is not arcuate. 
     Embodiments of the gripper  220 , shown in  FIGS. 2A and 3A , has a pivot about which it can rotate as indicated by the arrows. One embodiment illustrated in  FIGS. 2A-2D  has a bifurcated arcuate extension  226  extending from its back surface  223  with a swivel pin  224  connecting the two sides of the arcuate extension  226 . Another embodiment shown in  FIG. 3  has a pivot point  225  attached to the back surface  223  of the gripper  220 . Alternatively, the gripper  220  shown in  FIG. 3B  does not have a pivot about which it rotates, but is positioned in a single position such as the vertical position illustrated. 
     A gripper extender assembly  230  has a first end attached to the tubular support  210  and a second end attached to the gripper  220 . One embodiment of the gripper extender  230  is shown in  FIGS. 2A-2D . This embodiment has a hydraulic cylinder  235  attached at a first end to the tubular support  210  and a second end attached to the swivel pin  224  of the gripper  220 . As the hydraulic cylinder  235  is extended or retracted, it adjusts the distance between the top rail and the gripper  220 . The embodiment shown in  FIGS. 2A-2D  has two telescoping support tubes  232  attached to the swivel pin  224  such that whenever the support tubes are rotated with the tubular support  210  the swivel pin  224  is rotated and the gripper  220  is moved either inwardly toward the center of the chute  100  or outwardly away from the center of the chute.  FIG. 2C  shows the inner arms  237  of the two telescoping arms  232  and the rod  233  of cylinder  235  extended. 
     The restraint mechanism  200  also includes a restraint rotator  240 , as illustrated in  FIGS. 2A and 2D , that includes a hydraulic cylinder  241  mounted on a first end to a rigid cylinder mount  242  that is mounted on or welded to the top rail  116 ,  118  and attached on a second end to rigid cylinder mount  244  that is mounted on the rotatable tubular support  210 . Thus, as the cylinder  241  is extended the cylinder mount  244  is pushed downward and rotates the tubular support  210 , the support tubes  232  and the swivel pin  224  to move the gripper  220  inwardly toward the center of the chute  100 . On the other hand, as the cylinder  241  is retracted the cylinder mount  244  is pulled upward and rotates the tubular support  210 , the support tubes  232  and the swivel pin  224  to move the gripper  220  outwardly away from the center of the chute  100 . Thus, the extension and retraction of the cylinder rod moves the gripper  220  in a predetermined arc that is preferably between 80 and 120 degrees. As the gripper  220  passes through this arc, the gripper goes from a substantially horizontal position with the inner surface  222  of the gripper pointing downward toward the ground to a more vertical position such that the inner surface  222  of the gripper moves inward toward the center of the chute to rest against the side of the animal constrained in the squeeze chute. 
     A second embodiment of a gripper mechanism  250  with a different embodiment of a gripper extender is shown in  FIG. 3A . This embodiment has a cylindrical cover  236  attached at a first end to the tubular support  210  with an internal hydraulic cylinder  232  having an attached extension tube  234  with a pivot point  225  attached to the gripper  220 . The internal extension tube  234  telescopes in and out of the cylindrical cover  236  as the hydraulic cylinder is extended or retracted. As the internal extension tube  234  telescopes in and out of the cylindrical cover it adjusts the distance between the top rail and the gripper  220 . 
     A third embodiment of a gripper mechanism  270 , illustrated in  FIG. 3B , has a vertical extender  235  that is similar to that illustrated in  FIG. 3A . The vertical extender  235  has a cylindrical cover attached at a first end to the tubular support  210  with an internal hydraulic cylinder having an attached extension tube that is attached to a horizontal extender  272 . The internal extension tube telescopes in and out of the vertical extender as the hydraulic cylinder is extended or retracted. As the internal extension tube telescopes in and out of the cylindrical cover  235  it adjusts the distance between the top rail and the gripper  220 . This gripper mechanism  270  also has a horizontal extender  272 . The horizontal extender  272 , like the vertical extender  235 , has a cylindrical cover attached transversely to the vertical extender with an internal hydraulic cylinder having an attached extension tube  274  that is attached to the gripper  220 . The internal extension tube  274  telescopes in and out of the horizontal extender as the hydraulic cylinder is extended or retracted. As the internal extension tube telescopes in and out of the cylindrical cover it adjusts the distance between the internal surface of the gripper  220  to the center of the squeeze chute. In the embodiment shown in  FIG. 3B , the internal surface of the gripper  220  is covered with a padded surface  252 . 
     A Pusher and Rear Restraint 
       FIGS. 6A and 6B  illustrate a pusher and rear restraint, also referred to as a prod or pusher, mounted on top of the squeeze chute. An embodiment of the pusher and rear restraint  700  is shown on a transverse horizontal top rail  715  which is attached at each end to a slideable tube  790  or  795 . Each slideable tube  790  and  795  encircles a top rail  116  or  118  of the opposed sides of the chute structure. The transverse top rail  715  of the pusher assembly is positioned substantially parallel to the top rail  113  of the entrance  105  and is typically located either about midway along the length of the holding chute (i.e., the distance between the entrance and the exit of the chute) or closer to the entrance  105  than the exit  110  of the chute structure. The hydraulic cylinders for operating components of the pusher, such as the pusher rotator and the placement mechanism, are also mounted on the top of the squeeze chute. Typically, the hydraulic cylinders are mounted on one of the top rails  116 ,  118  or on one or more transverse top rails  170  attached to the top rails  116  and  118 . 
     Two embodiments of the pusher and rear restraint  700  and  725  are seen in  FIG. 7A  and  FIG. 7B  respectively. Each pusher assembly has a pusher body, a pusher rotator and a pusher placement mechanism as described in more detail below. The pusher rotator rotates about the top rail  715  from a basically horizontal position to within a 30 degree angle of a vertical position. The pusher rotator governs the angle at which the pusher moves into or out of the chute. The placement mechanism governs the selective movement of the pusher into or out of the chute along the longitudinal axis of the squeeze chute. The selective rotation and placement of the pusher is used to urge the animal all of the way forward in the chute and to prevent the animal from backing up or laying down. Currently available prods or pushers are not fitted and held right up to the hind end and rear legs of the animal in the squeeze chute so that the animal is not constrained sufficiently to prevent it from backing up and/or laying down thereby rendering the animal, livestock manager or veterinarian susceptible to injury. 
     The pusher  700  and  725  include a support tube  710  that encircles the transverse horizontal rail  715 ; a slideable tube  790  that encircles a top rail  116  or  118 ; a slideable tube  795  that encircles the opposed top rail  116  or  118 ; a pusher body  720  respectively; a pusher rotator mechanism; and a pusher placement mechanism. 
     Slideable tubes  790  and  795  are tubular structures having bores with an inner diameter that is slightly larger than the outer diameter of the top rails  116  and  118 . Prior to welding the top rails  116  and  118  into the chute framework, the outer circumference of top rail  116  is threaded through the bore of slideable tube  790  or  795  and the outer circumference of top rail  118  is threaded through the bore of slideable tube  790  or  795 . Generally, the top rails  116  and  118  are positioned parallel to each other and are the same diameter such that the slideable tubes  790  and  795  could encircle either top rail  116  or  118 . The tubular support  710  is also a tubular structure having a bore with an inner diameter that is slightly larger than the outer diameter of the transverse horizontal top rail  715  that the tubular support  710  encircles. Prior to welding the two ends of the horizontal rail  715  to the slideable tubes  790  and  795 , the outer circumference of the support tube  710  is threaded over the transverse top rail  715 . Thus, the support tube  710  is rotatable about the transverse top rail  715  and the pusher  700  or  725  is slideable along a portion of the length of chute by sliding along the length of the top rails  116 ,  118 . 
     Although the pusher body  720  in  FIG. 7A  is shown as a loop that is narrower at the top than at the bottom, the pusher body  720  can be any shape and size such as the embodiments shown in  FIGS. 7B-7D . Thus, an appropriate size and shape of the pusher body  720  can be selected depending on the animal and the particular area on the animal to be examined or treated. The ability to swap different types and contours of pusher body  720  allows the pusher to be adapted for use with a variety of animals and for a variety of uses. For example, the pusher body  720  may be arcuate in shape or custom designed to fit more closely to the rear end of the animal and its hind legs. The pusher body  720  may also be padded to make its interaction with the rear end of the animal less traumatic for the animal. 
     Preferred embodiments of the pusher body  720  have an opening  728  in the pusher body  720 , such as shown in  FIGS. 7A-7D  to allow operating room for a livestock manager or a veterinarian to perform certain task at the rear end of the animal without the animal being able to back up or lay down. For example, an opening in the pusher body designed to be used at the rear of a pregnant cow allows a veterinarian access to determine the size and position of her fetus. One embodiment of the pusher body, shown in  FIG. 7D , allows the operator to adjust the size of the pusher opening and/or the height of the pusher body  720  by expanding or retracting the length of one or more sections or sides of the pusher body. The example shown in  FIG. 7D  has two vertically extending sides, where the length of each side can be adjusted. Each side has a tubular cover  732  attached at a first end to the support tube  710 . The tubular cover  732  has an internal cylinder attached to an extension tube  734  that telescopes in and out of the tubular cover  732  as the cylinder is extended or retracted. 
     The pusher rotator of the pusher  700  and  725  is illustrated in  FIGS. 7A and 7B  respectively. The pusher rotator includes a hydraulic cylinder  741  mounted on a first end to a rigid cylinder mount  744  that is welded to a plate  762  that is welded to the transverse top rail  715 . A second end of the cylinder  741  is attached to a rigid mount  780  welded to the rotatable tubular support  710 . Thus, as the cylinder rod  742  is extended the cylinder mount  780  is pushed toward the chute entrance and thereby rotates the tubular support  710  to move the pusher body upward to a substantially horizontal position. On the other hand, whenever the cylinder rod  742  is retracted the cylinder mount  780  is pulled toward the center of the chute and thereby rotates the tubular support  710  to move the pusher body downward to place the bottom end of the pusher body in a more vertical position so that it can be aligned with the rear end of the animal. 
     Alternatively, if the pusher  700  is turned over as it is mounted on the chute framework then the hydraulic cylinder  741 , the cylinder mount  744  and the cylinder mount  780  would be on the top side of the pusher and the extension of the cylinder rod  742  would rotate the pusher body downward toward the interior of the chute and the retraction of the cylinder rod would rotate the pusher body upward away from the center of the chute. The pusher rotator rotates the support tube  710  around the transverse horizontal rail  715  to move the pusher body  720  in a predetermined arc that is preferably between 60 and 120 degrees. As the pusher body passes through this arc, the pusher body goes from a substantially horizontal position with the bottom of the pusher body pointing away from the center of the chute to a more vertical position such that the bottom of the pusher body moves inward toward the center of the chute. 
     The placement mechanism of the pusher governs the movement of the lowered pusher body  720  from the entrance of the chute towards the middle of the chute to align with the rear end of the animal and to urge the animal forward toward the exit of the chute. Once the animal is properly positioned within the chute the pusher body is pushed gently up against the animal&#39;s hind end thereby constraining the animal and preventing it from backing up or laying down. 
     A plan view of the pusher  700  mounted on the top of the squeeze chute is shown in  FIG. 6A . The placement mechanism of the pusher  700  includes a hydraulic cylinder  770  mounted on a transverse horizontal rail  170  with a cylinder rod attached to a rigid cylinder mount  774  welded to the plate  762 . Thus, as the cylinder  770  is extended the cylinder rod  772  pushes the pusher  700  away from the center of the chute toward the entrance of the chute. On the other hand, whenever the cylinder rod  772  is retracted the pusher  700  is pulled toward the center of the chute and thereby can be aligned with the rear end of the animal. 
     A side view of the pusher  725  mounted on the top of the squeeze chute is shown in  FIG. 6B . The pusher  725  is shown in  FIG. 7B . Pusher  725  is similar to pusher  700  with the exception of the shape of the pusher body and the location of the placement mechanism. The pusher body  720  of the pusher  725  consists of a loop with a narrower top than bottom and a bottom end having a pair of mirror image leg engagement loops  730 , and a central leg separator loop  750  joining the outer ends of the leg engagement loops  730 . 
     The placement mechanism of the pusher  725  includes two cylinder rod mounts  797 , where one cylinder rod mount is welded on a top side of each slideable tube  790  and  795 . Two hydraulic cylinders (only one seen in the side view of  FIG. 6B ) are mounted on the top of the opposed sides of the chute, typically on the top rails  116  and  118  and their cylinder rods are attached to the mounts  797 . Thus, as the cylinder rods are extended the cylinder rods push the pusher  725  away from the center of the chute toward the entrance of the chute. On the other hand, whenever the cylinder rods are retracted the pusher  725  is pulled toward the center of the chute and thereby can be aligned with the rear end of the animal. 
     The Chute Gates 
     The squeeze chute has both an entry gate assembly  800  and an exit gate assembly  900 . As illustrated in  FIGS. 1A-1C and 6B , a vertical cylindrical tubular gate support post  140  is outwardly positioned from each end post  160  on each side of both the entrance and the exit of the squeeze chute. Typically, each gate support post  140  is welded to the chute base at its lower end and similarly attached by a short upper horizontal tubular support  155  at an upper end by welding. The individual gate support posts  140  provide support for a pair of swing gates at the entrance  105  and the exit  110 . A variety of sizes and shapes of swing gates may be selected for the entrance  105  and the exit  110 . 
     One embodiment of the entrance gate assembly  800  is shown in an open position in  FIG. 6B . The entry gate  800  includes mirror image right hand and left hand halves, which are mounted to have a rotational fit on the entrance support posts  140 . As illustrated in  FIG. 6B , each gate half has a vertical gate support tube  820  with an internal diameter that is larger than the outer diameter of the support posts  140 . Before the support posts  140  are welded into the entrance end of the chute framework, the bore of a gate support tube  820  is threaded over the outer surface of one of the two entry support posts  140 . The horizontal finger tubes  810  are made of tubes having a diameter that is the same or smaller than the vertical gate support  820 . The finger tubes  810  are coped on one end to permit them to be closely fitted and welded to the vertical gate support  820 . The other end of the finger tubes  810  have a hemispherical closure cap to avoid injury to the animal passing through the entry gate. The finger tubes  810  are typically mounted in a regularly spaced vertical coplanar array along the length of the vertical gate support  820 . The length of the finger tubes  810  is such that when the mounting planes of the finger tubes of a pair of mirror image gate halves are mutually rotated about 45 degrees from their fully open position, the rounded ends of the finger tubes nearly touch. This arrangement allows only one animal to enter the gate at one time. If another animal is following closely behind the animal that is entering, the gently closing finger tubes of the two halves of the entry gate will act as a warning to the second animal not to enter the chute. Thus, only the one animal is allowed entry into the squeeze chute at a time. 
     One embodiment of the exit gate assembly  900  in a closed position is shown in  FIG. 8 . The exit gate  900  includes mirror image right hand and left hand halves which are mounted to have a rotational fit on the exit support posts  140 . Each gate half has at least two tubular segments  945  with an internal diameter that is larger than the outer diameter of the support posts  140 . Before the support posts  140  are welded into the exit end of the chute framework, the bore of a tubular segment  945  is threaded over the outer surface of one of the two entry support posts  140 . The tubular segments  945  can rotate around the support posts  140 , but are held in their vertical position on the support posts by a weldment protrusion on the support posts beneath the tubular segments  945  to prevent their sliding down the support posts. 
     An internal frame  940  of the gate half is rotatably mounted onto a support post  140  by welding each tubular segment  945  to the outside side of the internal frame that faces the support post  140 . The embodiment of the exit gate assembly  900  illustrated in  FIG. 8  shows an internal frame  940  that is basically an elongated oval with a notch  960  indenting a central portion of the internal side of the frame  940  that faces away from the support post. The tubular frame  940  of the exit gate has a sheet filler  950  that fills the majority of the open space  955  within the interior of the frame  940 . When the two gate halves are mounted on opposed exit support posts  140 , the notch of each gate half faces the notch of the other gate half forming an opening  970  in the closed exit gate  900 . When an animal fully enters the squeeze chute, the head of the animal passes through this opening which provides support for the animal&#39;s head as shown in  FIG. 9 . Some animals will run toward the exit of the chute towards the notch in the gates and hit the internal frame with force. Since the animal&#39;s head will protrude through the notch opening  970 , the interior surface of the notch  960  is optionally padded to protect the animal from injury when it hits the internal frame. 
     Once the two halves of the entrance gate  800  and the exit gate  900  are rotatably mounted on the entrance  105  and the exit  110  of the chute respectively, each half of the entry gate and the exit gate is connected to a swing gate cylinder. In one embodiment of the gate opening/closing mechanism a pair of horizontal cylinder mounts  165  are attached to the top rails  116  and  118  at the entrance and exit of the chute. One end of a swing gate cylinder  668  is attached to each cylinder mount  165  on the top rails of the chute and the other end of the swing gate cylinder  668  is attached to one half of one of the swing gates (i.e., the entry gate or the exit gate). Whenever the swing gate cylinder rod extends, the connected swing gate rotates about its support post  140  and opens and whenever the cylinder rod retracts the swing gate closes. 
     An alternative gate opening/closing mechanism utilizes one or more cylinders mounted on each side of the entry or exit gate with the cylinder rod attached to a rotatable tubular segment (such as tubular segment  945  illustrated in  FIG. 8 ). In this case, whenever the swing gate cylinder rod extends it pushes the rotatable segment  945  forward and the connected swing gate rotates about its support post  140  and closes the gate and whenever the cylinder rod retracts the swing gate opens. 
     The Head Positioner 
     Each exit gate half has an associated rotatable head positioner  1010  as illustrated in  FIG. 8 . One head positioner is attached to each half of the exit gate  900 . There is a notch  1020  in the head positioner, such that when the head positioner is mounted on a gate half the notch  1020  of the head positioner and the notch  960  in the gate half overlap. Thus, when the two gate halves are closed, the notch  960  of one gate half faces the notch of the other gate half forming the opening  970 . Similarly when the two head positioners are mounted on the two closed gate halves, the notch  1020  in the two head positioners face each other to form an opening that is similar in size and shape to the gate opening  970 . Whenever an animal has entered the squeeze chute and its head passes through the gate opening  970  (see  FIG. 9 ), the animal&#39;s head is also passing through the opening formed by the two head positioner notches  1020 . 
     One embodiment of the head positioner  1010  is shown in  FIG. 10  that has a rotatable tubular segment  1030  welded to a top end and a bottom end of the head positioner  1010 . The top and bottom rotatable tubular segments  1030  are fitted over the external circumference of the gate tubular frame before it is welded closed. A cylinder rod connection point  1040  is mounted on an external surface of the top rotatable tubular segment  1030 . A hydraulic cylinder  1050  is mounted on an outside surface of each exit gate half on the exterior of the squeeze chute. 
     The rod of the cylinder  1050  is attached to the rod connection point  1040  of the head positioner such that when the cylinder rod is extended, the head positioner rotates about the gate frame  940  so that the notch of the head positioner is biased against the head or neck of an animal with its head sticking out of the squeeze chute through the opening  970  of the chute and the opening between the two head positioners. One head positioner is rotated at a time. Whenever the cylinder rod retracts the head positioner is moved back so that it lies next to the notch  960  of the gate frame that the head positioner is attached to. 
     The head positioner is used to assist a livestock manager or veterinarian to constraint any excess movement of the head of the animal and allow the treatment or inspection of the face, neck, ears or eyes of the animal. The gentle constraining of the animal&#39;s head during routine procedures, such as vaccinations, allows the procedure to be done quicker and safer. 
     The Control Module 
     The control module  1200 , such as illustrated in  FIG. 6A , provides the hydraulic power to operate the squeeze chute. Internal details of the control valving and provision of hydraulic power are well understood by those skilled in the art and hence are not described in detail. The box of the control module typically contains a hydraulic reservoir, a electric motor driven pump, control valving, a return line filter, pressure gauges, and hydraulic connections to the cylinders such as those operating the gates, the pusher, the restraint mechanisms, and the head positioners. The hydraulic connections to the double acting cylinders are by means of hydraulic tubing and jumper hoses. The control valves are bidirectional with closed center positions provided so that the cylinders will not “drift”. One valve controls each gate, one valve controls the pusher, one valve controls each of the restraint mechanisms, and one valve controls each of the head positioners. The electric power for the electric motor driven hydraulic unit can be either DC from truck batteries, AC commercial line power, or possibly from a combination of batteries and rectified AC power for battery recharging. 
     Operation of the Squeeze Chute 
     Embodiments of the squeeze chute will typically have a pair of restraint mechanisms  200  attached to opposed top rails  116 ,  118  and a pusher  700  attached to a horizontal tube  715  that is slidable along the top rails  116 ,  118  as seen in  FIG. 7A . 
     The squeeze is typically operated as follows. Initially, the entry gate  800  is opened and the exit gate  900  is closed, the pusher  700  is fully lifted so that the pusher body is almost parallel with the base of the chute, and the restraint mechanisms  200  are fully retracted so that the gripper is rotated outward away from the interior of the chute so an animal  10 . At this point the animal, such as a cow or horse, will have an unimpeded entry into the squeeze chute, but its exit will be blocked by the closed exit gate  900 . 
     When the animal  10  enters the interior of the squeeze chute, the entry gate  800  is then hydraulically closed to entrap the animal. The pusher  700  and the side restraints  200  are then positioned to constrain the penned animal so that the animal can be safely accessed by personnel. If the animal has its rump close to the entry gate  800 , the pusher  700  can be rotated to a more vertical position with the pusher rotator so that it is approximately aligned with the rear of the animal. The pusher body  720  is then moved forward along the longitudinal axis of the chute with the pusher placement mechanism to urge the animal forward. Once the animal is in place in the squeeze chute, the pusher body is gently moved forward to engage the rear end and/or legs of the animal, thus restraining the animal from backing up or laying down. The restrained animal provides a much safer environment for a veterinarian or rancher that desires to examine or treat the animal. 
     The opposed side restraint mechanisms  200  are then lowered and positioned on both sides of the animal as follows. The gripper extender  230  is extended to lower the opposed grippers  220  until the grippers are vertically aligned with the section of the animal&#39;s anatomy that the livestock manager desires to grip, such as the abdomen or rib cage of a cow. Once the inner surface  222  of the opposed grippers are at the desired height, then the hydraulic cylinder  241  of the restraint rotator  240  is extended which pushes the cylinder mount  244  downward and rotates the tubular support  210 , the support tubes  232  and the swivel pin  224  to move the gripper  220  inwardly toward the center of the chute. The gripper  220  is moved inwardly until the inner surface  222  of the opposed grippers abut the sides of the animal. As the inner surface  222  of the grippers  220  abut the sides of the animal the gripper can rotate such that the arcuate inner surface of the grippers conform to the contour of the sides of the animal as shown in  FIG. 5 . 
     The animal is then held securely by the side restraint mechanisms  200  to prevent the axial motion of the animal in the chute. If desired, the animal the grippers can be positioned so that a portion of the gripper is pivoted under the animal. By spreading out the force of the gripper along the sides and the underside of the animal&#39;s torso, the animal can be raised so that its feet do not touch the steel base plate as shown in  FIG. 11 . The side restraint mechanisms  200  can also be used to shift the torso of the cow laterally within the chute. At this point, the animal will generally be sufficiently immobilized to permit safe work on the animal, with rearward directed movement and/or kicking prevented and torso motion highly restrained. 
     Optionally, if the animal is constrained in the squeeze chute with its head protruding through the opening  970  in the exit gate  900 , one head positioner  1010  at a time can be rotated inward toward the center of the opening  970  and gently biasing the animal&#39;s head to move either to the right or to the left (depending on which head positioner is activated). The use of the head positioner allows the animals head and neck to be inspected or treated safely. 
     Following completion of operations on the animal, the exit gate  900  can be opened and the side restraint mechanisms  200  fully retracted. The animal can then exit the chute. 
     ADVANTAGES OF THE INVENTION 
     The squeeze chute of the present invention markedly improves the restraint of an animal enclosed within it, thereby rendering a much safer environment for the performance of veterinary or other procedures on the animal. In additionally, veterinarian or management procedures can be performed more speedily. The hydraulic operation of the squeeze chute is well suited to a dusty outdoor environment. Other advantages will be obvious to those skilled in the art. 
     A variety of modifications to the chute structure and function, as well as to the side restraint mechanism, the pusher, the entrance gate, the exit gate, and the head positioner can be made without departing from the spirit of the invention.