Abstract:
A boar cart for carrying a boar through alleyways of a sow insemination area for interaction with the sows during insemination is formed by a cage for containing the boar including a cage floor on which the boar stands, two sides each defined by vertical bars on a respective side of a longitudinal center line of the cage assembly for confining the boar so that the boar is maintained extending longitudinally of the cage, a front and a rear defined by vertical bars, at least one of which can be opened as a door to allow entry and exit. The cage is mounted on rear driving wheels and front steering/caster wheels. The cage is defined by a front portion and a rear portion connected together for pivotal articulated movement about one or two pivot couplings defining a vertical pivot axis arranged substantially at the center line such that the cage can articulate to the left and to the right for navigating left and right corners in the alleyways while the boar is retained in the cage. The length of the cage is reduced by bowing the front and rear bars. The front steering wheels can be set to direct the steering slightly to the left or right so as to tend to guide the cage along one or other side of the alley where it has rollers to run along a rail and hold the boar close to the sows on one side.

Description:
This invention relates to a boar cart for use in transporting a boar adjacent to a series of pens containing sows during insemination of the sows. 
     BACKGROUND OF THE INVENTION 
     In high intensity rearing of pigs, sows after farrowing are moved to an area where they are maintained in separate pens awaiting insemination at the suitable time of estrous. The sows are maintained in separate pens in rows on one or both sides of dividing alleyways so that the farm hand can move along the row of sows both at the front and rear to access the sows for insemination and for various other purposes. 
     The alleyways between the rows can range in width from 18 inches up to 36 inches in most cases and in some cases the alleyways are wider still. The alleyways are defined between rows of pens and of course at the end of the rows the alley turns through a right angle so that passage can be obtained along one end of the rows and then back between the next set of rows where another right angle turn is required. 
     It is well known in artificial insemination that it is desirable to bring a boar to the sows both for the purposes of stimulating the sows by close physical contact with the boar and for determining whether a particular sow is in estrous. The presence of the boar is known to improve the effectiveness of the artificial insemination both by allowing the farm hand to more accurately determine the presence of estrous and in addition to place the sow in a more accepting condition for the insemination. 
     Conventionally a boar is led along the front of the stalls so as to physically contact or approach each sow in turn while the farm hand takes the necessary actions for carrying out insemination of those sows found to be in estrous. This requires the manual handling of a very large powerful animal by one or more additional farm hands. 
     Attention has therefore been given to design a device which allows the boar to be moved or transported along the alleyway in front of the row of sows in their pens while the farm hand carries out the necessary actions for insemination. It is clearly desirable if such a device is remotely controllable so that the farm hand at the rear of the animal can operate the device to move the boar to the required position adjacent the sow involved. 
     SUMMARY OF THE INVENTION 
     It is one object of the present invention to provide an improved boar cart which allows improved control over the movement of the cart. 
     According to a first aspect of the invention there is provided a boar cart for carrying a boar through alleyways of a sow insemination area for interaction with the sows during insemination comprising: 
     a cage assembly for containing the boar including a cage floor on which the boar stands, two cage sides each on a respective side of a longitudinal center line of the cage assembly for confining the boar so that the boar is maintained extending longitudinally of the cage assembly, a cage front and a cage rear for confining the boar against forward and rearward movement; 
     the cage assembly having at least one door allowing entry and exit of the boar from the cage assembly; 
     the cage assembly being mounted on ground wheels for movement generally longitudinally along an alleyway carrying the boar within the cage assembly; 
     the cage assembly having a front portion for receiving the front feet and forward portion of the boar and a rear portion for receiving the rear feet and rearward portion of the boar; 
     the front portion being connected to the rear portion for pivotal movement about a vertical pivot axis to allow the cage assembly to navigate around a corner from one alleyway to another. 
     Preferably the pivotal movement is provided by a pivot coupling defining a vertical pivot axis arranged substantially at the center line such that the cage assembly can articulate to the left and to the right for navigating left and right corners in the alleyways while the boar is retained in the cage assembly. 
     Preferably the cage assembly includes a roof member parallel to the floor arranged at a top of the side walls and wherein the pivot coupling includes a first bearing member at the floor and a second bearing member at the roof member. 
     Preferably the side walls interconnect the roof member and the floor. 
     Preferably the side walls of the front portion are separate from the side walls of the rear portion such that the side walls have a change in spacing therebetween so that they move closer on one side and further apart on the other side as the portions articulate. 
     Preferably there are provided flexible confining members between the side walls to accommodate said change in spacing. 
     Preferably the side walls are defined by a plurality of vertical bars allowing access to the boar. 
     Preferably there is provided a second pivotal coupling thus allowing articulation about two parallel axes on the center line. 
     Preferably the pivot coupling includes a lock for locking the portions in an aligned position. 
     Preferably the rear portion includes at least one drive wheel for driving the cage assembly along the alleyways and the front portion includes at least one steerable wheel for guiding the cage assembly along the alleyways. 
     According to a second aspect of the invention there is provided a boar cart for carrying a boar through alleyways of a sow insemination area for interaction with the sows during insemination comprising: 
     a cage assembly for containing the boar including a cage floor on which the boar stands, two cage sides each on a respective side of a longitudinal center line of the cage assembly for confining the boar so that the boar is maintained extending longitudinally of the cage assembly, a cage front and a cage rear for confining the boar against forward and rearward movement; 
     the cage assembly having at least one door allowing entry and exit of the boar from the cage assembly; 
     the cage assembly being mounted on ground wheels for movement generally longitudinally along an alleyway carrying the boar within the cage assembly; 
     the cage assembly having a front portion for receiving the front feet and forward portion of the boar and a rear portion for receiving the rear feet and rearward portion of the boar; 
     the front portion and the rear portion being connected together for pivotal articulated movement about a pivot coupling such that the cage assembly can articulate for navigating corners in the alleyways while the boar is retained in the cage assembly; 
     at least one of the cage front and the cage rear being bowed outwardly such that a height thereof adjacent the boar projects outwardly relative to the cage floor to thus reduce the length of the floor relative to the total length of the cage assembly to assist in navigating corners. 
     Preferably the cage front and cage rear are both bowed. 
     Preferably the gate is arranged at one of the front and rear. 
     Preferably the front and rear are formed from bars only 
     According to a third aspect of the invention there is provided a boar cart for carrying a boar along an alleyway of a sow insemination area for interaction with sows on at least one of two sides of the alleyway during insemination comprising: 
     a cage assembly for containing the boar including a cage floor on which the boar stands, two cage sides each on a respective side of a longitudinal center line of the cage assembly for confining the boar so that the boar is maintained extending longitudinally of the cage assembly, a cage front and a cage rear for confining the boar against forward and rearward movement; 
     the cage assembly having at least one door allowing entry and exit of the boar from the cage assembly; 
     the cage assembly being mounted on ground wheels for movement generally longitudinally along an alleyway carrying the boar within the cage assembly; 
     the cage assembly including a guide arrangement arranged to cooperate with at least one member in the alleyway for guiding the cage assembly along a selected one of the sides of the alleyway and spaced from the other of the sides, the guide assembly being arranged to allow selection of said one side. 
     Preferably the ground wheels are arranged and adjustable to tend to direct the cage assembly toward a selected one of the sides of the alleyway and away from the other of the sides and wherein there is provided a guide assembly for guiding the cage assembly in movement along said selected one of the sides. 
     Preferably the ground wheels include at least one rear drive wheel connected to a motor for supporting the cage assembly and for driving the cage assembly along the alleyway and at least one front steering wheel for supporting the cage assembly and for guiding the cage assembly along the alleyway; said at least one front wheel being adjustable and lockable in a predetermined direction to tend to direct the cage assembly in movement toward a selected one of the sides of the alleyway; and the cage assembly having side guide members for contacting a guide element at the selected side of the alleyway such that the cage assembly is directed toward and runs along the guide element at the selected side. 
     Preferably there are two drive wheels. 
     Preferably there are two front wheels wherein the wheels are arranged such that, when directed to one side, one wheel is locked and one wheel casters. 
     Preferably both wheels are selectably lockable and both are free to caster when unlocked. 
     Preferably the guide members comprise rollers. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention will now be described in conjunction with the accompanying drawings in which: 
     FIG. 1 is a top plan view of a first embodiment of cart according to the present invention showing the cart in the straight ahead position. 
     FIG. 2 is a bottom plan view of the cart of FIG. 1 with the cart in its position turned to one side for navigating a right hand corner. 
     FIG. 3 is a side elevational view of the cart of FIG.  1 . 
     FIG. 4 is a bottom plan view similar to that of FIG. 2 showing more detail of the front steering/caster wheels. 
     FIG. 5 is a bottom plan view similar to that of FIG. 2 showing a second embodiment according to the present invention. 
     FIG. 6 is a top plan view similar to that of FIG. 4 showing a further embodiment according to the present invention. 
    
    
     DETAILED DESCRIPTION 
     A boar crate is generally indicated at  10  and includes a rear section  11  and a front section  12  which are articulated at a vertical pivot axis  13  allowing the front section to move from a straight ahead aligned position shown in FIG. 1 to either a left hand or right hand turned position, one of which is shown in FIG.  2 . 
     The pivot axis  13  is defined by a top bearing  14  in overlapping top panels  16  of the cart and a bottom bearing  15  in overlapping bottom floor panels  17  of the cart. 
     The front and rear portions can be locked in the straight ahead position shown in Figure, and preferably in the left and right turned positions, 1 by a pin lock system  18  including an arm  19  connected to the front portion which extends rearwardly over the rear portion to a pull pin  20  which engages into one of three separate holes  21  at the three separate positions. The pull pin  20  is spring biased into a locked position and is moved against the spring bias to a pulled position manually as required. 
     The rear section  11  is mounted on a pair of drive wheels  22  carried on an axle  23 . One or both of the drive wheels is driven by a motor  24  communicating through a drive chain  25  mounted at or beneath the floor  17 . The wheels  22  are mounted each on a respective side of a main longitudinal rail  26  of the section  11  with each wheel being covered at its position outside of the respective rail  26  by a fender  27 . The fenders  27  each extend between frame channel members  28  and  29  extending outwardly from the rails  26  to a respective side. Between the rails  26  is defined a floor on which the rear part of the animal and the rear legs of the animal stand. 
     The motor  24  is controlled by an electrical control system  30  provided within a housing on the top  16  of the cart. The electrical control system  30  includes an antenna  31  which receives communications from a remote control system using a suitable communication medium so that the farm hand can remotely operate the cart to drive the wheels  22  forwardly and rearwardly as required. The wheels  22  are not steering wheels and simply drive the cart forwardly and rearwardly. 
     The front section  12  includes a planar floor panel  17  which is supported by rails  32  and  33  extending rearwardly from a forward edge  34  of the floor panel and diverging outwardly so as to leave a rear area of the floor panel  17  at the bearing  15  which overlies a front rectangular section of the floor  17  of the rear portion of the cart. A rear edge of the floor panel  17  of the front section defines a semi circular rear line  17 A surrounding the bearing  15  and the axis  13  and this rear portion can therefore sweep over the top surface of the rear floor panel and moves in front of the wheels  22  and in front of the fenders  27 . 
     The front portion  12  is mounted on a pair of castor wheels  35  and  36  carried on the underside of a transverse brace  37  at the front edge  34 . Thus the direction of movement of the cart is controlled by the castor wheels as described hereinafter. 
     The rear channel members  28  of the rear section  11  each carry a bumper or guide roller  39  which is carried on a bracket  40  allowing rotation of the guide roller about a vertical mounting pin  41 . Similarly a bracket  42  on the brace  37  carries a front bumper roller  43  pivotal about a vertical pin  44 . The bumper rollers  39  and  43  are thus mounted at a common height on the front and rear portions and project outwardly therefrom slightly to each side and at a position in front of and rearwardly of respectively the front and rear edges of the floor panels  17 . 
     The bumper rollers  39 ,  43  are mounted at a height which coincides with a suitable rail on the pens at the side of the alleyway against which or adjacent which the cart is intended to run. 
     The pivot axis  13  is arranged so that it lies on or adjacent a center line  45  of the cart in its aligned position shown in FIG.  1 . The axis  13  is also approximately midway between the front edge  34  of the front portion and the rear edge of the rear portion. Thus the pivotal action provides articulation of the two portions to a position which the angle of the center line of the front portion is arranged approximately at 45° to the center line of a rear portion. This is of course symmetrical in both left and right directions in view of the fact that the pivot axis lies on the center line. 
     The cart is further formed by two side walls  50  and  51  the front wall  52  and a rear wall  53 . Each of these walls is formed by bars allowing visual and direct physical access to the animal within the cart over the full area of the cart both to the rear, the front and the sides. The side walls are divided into two sections such that the rear portion  11  has its own side wall section  50 A,  51 A and the front section has its own side wall section  50 B,  51 B. The side wall  51 A terminates at a front post  54  and the side wall  51 B terminates at a rear post  55  with those posts separated rearwardly and forwardly respectively of the pivot axis  13 . There is no direct rigid connection between the posts  54  and  55  so that the pivotal action about the axis  13  allows the post  54  and  55  to move closer together as the cart articulates to one side and to move further apart as the cart articulates to the other side. The post  54  and  55  are however connected by loose flexible chains  56  which have respective ends connected to the respective posts and which hang down as a loose connection bridging the space between the posts and acting the confine the animal in the area between the post to ensure that the animal is prevented from escape between the posts. 
     The side walls including the main mounting posts are attached to the floor so as to stand upwardly therefrom adjacent the outermost edge thereof and particularly the rear side walls stand upwardly from the outer edge of the portions  28  and  29 . The top of the side rails are connected by transverse bars  60  which maintain the side walls in fixed vertical position and also provide a top or roof structure again providing the animal and prevent it from jumping upwardly to attempt to escape over the side walls. The top bearing  14  is connected to overlapping panels  16 A and  16 B carried respectively by a rear rail  60 A of the front part and a front rail  60 B of the rear part. The cage assembly may include flat closed panels covering or replacing the bars for additional strength if required. 
     The front wall  52  and the rear wall  53  are both formed as separate pivotal elements attached to a front post  61  of the front section and to a rear post  62  of the rear section respectively. Thus the front wall  52  includes two side posts  63  which can be pinned to respective ones of the posts  61  to hold the front wall fixed in place. Similarly the rear wall  53  includes posts  64  which can be pinned to the post  62  to hold the rear wall in place. One of or both of the front and rear walls can be removed by simply removing the pins so that the wall can be totally removed or can be removed at one side or disconnected from its respective post and pivoted away from the other post to allow access for entry or exit of the animal. Preferably both the front and rear walls are pivotal for removal in this manner so as to allow the animal to enter from the rear and exit from the front. 
     The front and rear walls further include top and bottom rails  64  and  65  respectively which extend across horizontally and interconnect the posts. Furthermore, the front and rear walls further include confining bars  66  which extend generally vertically downwardly from the top rail  64  to the bottom rail  65 . Each of these bars  66  is bowed outwardly from the main plane containing the rail  64  and  65  so that a center section of the bars above the floor projects outwardly from the plane of the wall so as to increase the area within the cart which is accessible for the animal at the height of the rump and the nose of the animal which is approximately midway at the height of the cart and spaced upwardly from the floor. This bowing of the front and rear gates thus allows a reduction in the length of the whole of the cart thus reducing the distance between the front edge of the front section and the rear edge of the rear section and reducing the distance between the bumper rollers  39  and  43  so that the overall length of the cart is significantly reduced while the length of animal which can be accommodated between the outermost points of the bar  66  remains equal to the required length depending upon the size of the animal. 
     As shown in FIG. 1, the boar is schematically within the cart and, although the size of the boars used will of course vary, the cart is designed to take effectively the largest type of boar which would be used and this boar would wholly fill the cart so that its sides touch the side walls, its rump reaches the outwardly bowed section of the bar  66  at the rear of the rear section and its nose projects through or just reaches the bars  66  at the front of the front section. The animal is thus wholly contained and confined and the cart has dimensions which are significantly greater than the size of the animal itself. 
     Turning now to FIG. 4, further detail of the castor wheels  35  and  36  is shown. It will be noted firstly that the castor wheels are mounted on the underside of the cross brace  37  such that the normal forward direction  70  of the castor is offset at a slight angle to the longitudinal direction  71  of the cart which is parallel to the center line  45 . Thus the left hand castor wheel  35  is normally inclined slightly outwardly in a direction forwardly and outwardly as indicated at  72  and the castor wheels  36  is similarly inclined slightly forwardly and outwardly as indicated at  73 . 
     Each castor wheel can be locked in its normal forward direction by a locking pin  74  of a type which is commercially available so that the castor  35 ,  36  can be locked in its forward direction,  72 ,  73  or can simply castor as required depending upon the position of the lock  74 . 
     In operation, if it is required that the cart remain alongside the side rail  75  adjacent the castor  36 , the castor  36  is locked and the castor  35  is released to be free to castor. Thus both castor wheels will take up a position normally tending to move along the direction  73  thus tending to push the cart as it moves forwardly toward the rail  75  on one side of the alley  76 . 
     Therefore in a situation where there are sows on both sides of the alley  76 , the farm hand can select that side of the alley to which the cart tends to move by locking the wheel on that side and releasing the wheel on the other side. Thus as the cart moves forwardly it also tends to push toward one side so that the bumper rollers on that side tend to run along the rail  75 . 
     In some cases the alley is relatively narrow so that the cart in effect just fits between the rails and moves along the alleyway equidistant from each of the rails. In this case both wheels may be set to caster. 
     However in other arrangements, the alleyway may be significantly wider and it is therefore desired to hold the cart to the side adjacent those sows which are being operated upon by the farm hand. Thus this simple steering system avoids the necessity for remote controlled steering and simply ensures that the cart remains adjacent the required side of the alleyway. The bumper rollers hold the cart at the required position and gently guide the cart as it moves along the alleyway. It will be appreciated that the movement of the cart is very slow in that the cart is often maintained stationary for a period of time and then stepped forward to a next pen of the next adjacent sow. 
     Turning now to FIG. 5, there is shown an arrangement which is substantially identical to that of FIGS. 1 through 4 except that the front section  12 A is articulated relative to the rear section  11 A by two pivot axes  13 A and  13 B. This is effected by the provision of an intermediate section  80  defined by a floor panel  81  and two vertical posts  82  and  83  connecting to a top structure  85 . Thus the axes  13 A and  13 B are again defined by top and bottom bearings at the floor panel  81  and at the top panel  85 . 
     The double articulation arrangement of FIG. 5 thus allows an increased angle between the front section and the rear section in the articulated position and in particular an arrangement in which the center line  45 A of the front section lies at 90° to the center line  45 B of the rear section. This of course requires the animal to accommodate a larger angle of bend between its rear and its front section but this allows the cart to move more effectively around a right angle corner particularly where the alleyways are very narrow. 
     The arrangement has the advantage therefore that the animal can be maintained within the cart at all times while the cart is moved along alleyways and round corners onto the next adjacent alleyway and there is no necessity to remove the animal with the difficulty of returning it to its position should it have any reluctance. The animal is therefore always confined and can be handled by a single farm hand by the remote operation while the farm hand operates upon the sows in conventional manner. 
     In an alternative arrangement (not shown) the pivot coupling is offset from the center line but this arrangement is less advantageous in that it may be necessary to remove the boar from the cart to navigate certain or all corners. 
     Turning now to FIG. 6 there is shown in top plan view schematically an alleyway  90  having a first row of pens  91  on one side and a second row pens  92  on the other side of the alleyway. The width of the alleyway is greater than the width of the cart so that the cart can be adjusted so that it runs with one side  93  adjacent the pen  91  and the other side  94  spaced away from the pens  92  and by vice versa. 
     Various arrangements for guiding the movement of the cart along the respective selected side can be provided including the arrangement shown previously in FIG.  4 . However an alternative arrangement is shown in FIG.  6  and this includes a pair of guide tracks  95  and  96  which are provided in the alleyway at a suitable location and preferably adjacent the respective line of pens. The tracks  95 ,  96  and be provided by raised rails cast in or attached to the concrete of the alleyway or can be provided by another ridge or groove in the concrete which thus forms a continuous line or track along the concrete for holding the cart along a predetermined line adjacent the respective selected side. 
     In the embodiment shown, the track  95  or  96  is followed by a pair of rollers  97  which are attached to the cart on a bracket  98  which can be moved from the lefthand position shown to a righthand position  98 A to guide the cart along the selected one of the tracks  95 ,  96 . 
     Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without departing from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.