Calf puller
When delivering animals of their young and particularly cows of their calves, the cow frequently needs assistance in the delivery through the medium of external pulling forces applied to the calf, particularly if the calf is not positioned properly. In addition, the calf must frequently be turned to provide the best delivery possible, all of which is difficult to do manually. As a result, some mechanical devices have been developed over the years to assist in pulling the calf from the mother, but each of the prior art devices developed to date have one or more deficiencies, and it is the general object of this invention to remedy many of these deficiencies by providing an improved calf pulling device. In many of the prior art devices, one of the primary difficulties in their design is that they either have no means for quickly releasing the tension on the calf or, if provided with some form of quick release mechanism, such mechanism is either too slow or too inconvenient to operate and normally requirers the use of two hands, which sometimes is quite difficult if only one person is assisting the delivery. Oftentimes, the calf may be strangled or otherwise injured during the delivery unless the tension is instantaneously released. Therefore, one of the most important objects of this invention is to prrovide a calf puller with a foolproof quick release mechanism which provides instantaneous and total release of tension and which can be operated by the use of only one hand in a convenient manner. 
     Another problem encountered with devices presently available is that the jack mechanism is capable of slipping, or at least tends to slip, during use and operation, which not only means that the operator is inconvenienced during use and requires more time than would otherwise be necessary, but also results in an erratic delivery which can be harmful or at least unduly painful to both the cow and the calf. Another important object of this invention, therefore, is to provide a calf puller with a novel jack mechanism which will not slip during use. 
     Still another problem associated with these devices is that the majority of them require the use of cables, which are bulky to handle and transport and inconvenient to use, and also present problems during use since they have a tendency to kink. Another object of this invention is to provide a calf pulling device which does not require the use of any cables whatsoever. 
     The cow can be most effectively assisted by working as close to the cow as possible. To date, most devices require that the work be done a substantial distance from the cow, and it is an object of this invention to provide a device which is not only simple in operation, but is compactly designed so that the work can be done close to the cow. 
     Still another problem with many available devices is that they are expensive to make and difficult to manipulate and transport and are oftentimes difficult to repair, requiring servicing at a special shop or factory outlet. 
     Another object of this invention is to provide a calf pulling device that is comprised of separate parts of lightweight construction which can be readily disassembled and compactly arranged for transport and storage and which can be quickly and easily assembled into its original form and which generally speaking can be repaired by the user without being taken to a specialty shop, and wherein only that part which needs servicing or repair can be taken in, with the remainder being left behind for convenience of transporting and handling. 
     Still another object of this invention is to provide a device which will permit a calf to be maneuvered during delivery and which provides a positive and steady rearward pull on the jack itself and the rotating spanner to provide the type of pulling tension and pulling angle considered most desirable during delivery. 
     Still another object is to provide a device whereby obstetrical chains can be used directly from the jack mechanism to the calf with no intermediary means required so that the chain can be hooked or connected directly to the pulling device. 
    
    
     These and other objects will be more fully understood and appreciated by an evaluation and reading of the following description made in conjunction with the attached drawings in which: 
     FIG. 1 is a top plan view of one preferred embodiment of this invention, illustrating actual use thereof during delivery while in engagement with the hindquarters of a cow; 
     FIG. 2 is a perspective view on an enlarged scale of the completely assembled jack mechanism portion of the calf pulling device illustrated in FIG. 1; 
     FIG. 3 is a side elevational view of the device with the locking tongues released for free travel of the jack mechanism on the supporting shaft; 
     FIG. 4 is a side elevational view of the device of this invention with the handle in a partially raised pulling position with the primary locking and levering tongue engaged with the supporting shaft to pull the slide on the shaft and prevent movement of the jack mechanism relative thereto, with the secondary locking tongue not yet engaged; 
     FIG. 5 is a side elevational view with the handle raised further than in FIG. 4, with the secondary locking tongue in locking engagement with the stationary shaft to prevent slippage; 
     FIG. 6 is a top plan view of the device on an enlarged scale minus the breech spanner; 
     FIG. 7 is a cross sectional view taken along the line 7--7 of FIG. 3; 
     FIG. 8 is a longitudinal sectional view of the rotational connection between the breech spanner and the shaft as taken approximatetly along the line 8--8 of FIG. 1; 
     FIG. 9 is a cross sectional view taken along the line 9--9 of FIG. 8, and 
     FIG. 10 is a perspective view of the breech spanner. 
    
    
     Although the use and application of the device of this invention is described and illustrated herein as applied to assisting in the delivery of a calf at birth, it will be understood that the use of the invention is not limited thereto, and its use as a mechanical jack can be utilized in any field of endeavor where such a device is needed, with or without modification, as the exigencies dictate. 
     REferring to the drawings, the calf puller illustrated therein includes a rectangular shaft or tube 10 which is preferably formed of square metallic tubing (preferably steel) with holes or openings 11 bored in one wall thereof and evenly spaced along the center line of one side, preferably the top thereof. The forward or proximal end (the end closest to the cow) of the shaft 10 is provided with a piece of round tubing 12 (preferably metallic) which is secured by any suitable means such as welding to the interior wall of the forward end of the shaft 10, said tubing 12 being adapted to receive the breech spanner 13 in a manner hereinafter described. 
     During use, the shaft 10 is stationary longitudinally, to provide the resistance against which the pulling portion of the device must work, although said shaft 10 is free to rotate 360° about its longitudinal axis. 
     The breech spanner 13 is preferably formed of a length of flat spring steel, said spanner consisting of a medial portion 13a and a pair of distal ends 13b disposed at an approximately 60° angle with respect to the medial portion 13a, with each of the distal end portions having a slightly rounded outer end 13c. 
     The medial portion 13a has affixed thereto by any suitable means a short length of round metallic stock forming a round shaft 14 (preferably steel) which extends in the opposite direction from the distal end portions of the spanner, the round shaft 14 being adapted to be removably inserted into the round tubular portion 12 of the shaft 10 whereby the spanner and the shaft are adapted to rotate freely relative to one another through 360° in a plane perpendicular to the shaft 10. 
     The spanner 13 is designed to span the rear of the cow with the ends 13b engaging and at least partially wrapping around the hindquarters of the cow, to hold the shaft 10 stationary longitudinally during delivery. In other applications, the spanner can be replaced by another type of shaft support which will be suitable for anchoring the shaft to the particular supporting base structure. 
     Thus, when not in use, the spanner 13 can easily be detached from the shaft 10 for compact packaging and storage. 
     The jack mechanism is mounted on the shaft 10 and includes an elongate slide or sleeve 15 formed of rectangular metal tubing, said slide functioning as a sleeve which rides on the shaft 10 and telescopically receives the same interiorly thereof. The interior dimensions of the slide 15 correspond approximately to the exterior dimensions of the shafat 10 whereby the shaft 10 and slide 15 are freely movable longitudinally with respect to each other and yet have minimum play or lateral movement therebetween. The top wall of the slide 15 has elongate slots 16a and 16b formed therein which extend longitudinally thereof and in alignment with the holes 11 of the shaft 10, a slot being provided for each of the locking tongues hereinafter described. Said slots 16a and 16b communicate with the interior of the slide 15 so that the locking tongues may enter the holes 11 disposed below said slots and engage the shaft 10 either to provide the leverage necessary to move the slide relative to the shaft away from the cow, or hold it against movement towards the cow. 
     Adjacent one (distal) end of the slide, a pair of upstanding handle or lever supporting and guide members 17 are provided which are rigidly secured to the sleeve in any suitable fashion. The members 17 are laterally spaced apart to receive the lever handle 18 therebetween as well as levering tongue 19 which constitute a part of the lever member, said members 17 not only supporting the handle but also serving to guide the vertical movements of said handle and said levering tongue 19, which also is a levering element. 
     The lever supporting members 17 are provided with aligned openings in which openings is installed a threaded pivot pin 21, with a fastener such as a nut 22 being used to removably secure said pivot pin to said members 17. 
     The handle 18 has a bifurcated end portion consisting of the opposing spaced apart arms 18a having aligned openings formed therein which also receive the pivot pin 21 for free rotational movement of the handle 18 and said arms 18a relative to said pivot pin about the longitudinal axis of said pivot pin, which serves as the fulcrum for the lever. 
     The tongue 19 is pivotally attached to the bifurcated end of the handle by means of a pivot pin 24 installed in aligned openings with the bifurcated portions 18a of the handle which extends transversely of the arms 18a with the tongue 19 being swingably disposed in the space between the arms 18a for swinging movement about pin 24. A helically coiled contracting spring 25 is provided, the upper end of which is secured to a cross bar 26 attached to and extending between the arms 18a, the other end of said spring 25 being attached to said tongue by installing the loop of the lower end thereof in an opening 27 in tongue 19 whereby the tongue 19 is continually biased or pulled downwardly and forwardly towards said slide 15 and shaft 10 under the influence of said spring. 
     The tongue 19 is provided with a pointed or tapered lower end or tip 19a which points or faces downwardly and is disposed in alignment with the slot 16a and intended to selectively engage the holes 11 in the shaft 10. The upper edge of the tongue 19 is provided with an elongate elevating bar 28 which extends laterally or transversely of said tongue and is adapted to engage the leading edge or track surface 17a of the members 17 so that the rearward (counterclockwise as seen in the drawings) throw of the handle 18 towards the cow elevates the levering tongue 19 thereby causing it to disengage from the shaft 10. 
     It will be understood that the tongue 19 is an essential part of the lever or leverage system comprising the handle 18 and the tongue 19, for it is the action of tongue 19 against the stationary shaft 10 under the influence of the handle 18 swinging forwardly away from the cow (clockwise in the drawings) which causes the sleeve 15 to slide forwardly away from the cow and exert a pulling force on the obstetrical chain 20, the ends of which are attached to the calf (normally to the front feet) to assist in pulling it from the cow. 
     A second group of locking mechanisms similar to, but slightly smaller than that previously described is provided adjacent the middle portion of the slide and includes a pair of upstanding spaced apart opposed tongue supporting members 29 which are similar to members 17 but substantially smaller and shsorter in height, said members 29 being rigidly attached to sleeve 15 to pivotally or swingably support a locking tongue 30 therebetween, the pivotal mounting of said tongue on said members being provided by a pivot pin 31 which may be a bolt or some other form of pivot pin extending through aligned openings in the tongue supporting members 29 and in the locking tongue itself, the pivot pin 31 being removably secured to the members 29 by means of any suitable fastener such as the threaded nut 34. 
     A second helically coiled contracting spring 35 is provided, one end of which is attached to a cross bar 36 affixed to and extending transversely of the members 29, and the other end of said spring being attached to the tongue by installation in an opening 37 provided therein whhereby the tapered and pointed end or tip 30a of the tongue is continuously biased or pulled downwardly and forwardly away from the cow towards the slide 15 and shaft 10 by means of said spring 35. 
     The tongue 30 is strictly a locking member, and plays no part in exerting any leverage or pulling force on the slide 15. The lower tip 30a thereof is intended to insert itself in one of the openings 11 in the shaft 10 as the tongue 19 is inserted in another of the openings 11 ahead of the opening in which tongue 30 is inserted. When the tongue 19 is lifted from engagement with shaft 10, tongue 30 remains in its opening and in engagement with shaft 10, preventing the sleeve from slipping or sliding backwards and thereby losing some of the distance already gained. Although the tongue 30 prevents retractive movement towards the cow, it is adapted to freely release itself from the shaft 10 anytime there is a forward movement of the slide 15 relative to shaft 10 (as used herein, the term &#34;forward&#34; refers to a direction away from the cow and base support and &#34;rearward&#34; means movement towards the cow or base support). 
     The end of locking tongue 30 opposite that of the pointed end is provided with a dog 38, the top surface 38a thereof being adapted to be engaged by a releasing member 39 which is affixed to and extends from the handle 18 to release the tongue 30 from engagement with the shaft 10 when the handle 18 is lowered to a position approximately paralleling the slide 15 and shaft 10 as illustrated in FIGS. 2 and 3, which is the fully retracted or starting position of the handle 18. 
     Thus, if for any reason the tongue 30 must be unlocked, or the slide 15 returned to free sliding capabilities in both directions, or if the tension on the calf or obstetrical chain needs instant relief or release, this can be immediately accomplished by quickly swinging handle 18 back to the starting position of FIGS. 2 and 3, thereby releasing both tongues 19 and 30 and unlocking the slide 15 for free longitudinal movement on shaft 10 in either direction. 
     Release member 39 works against the biasing action of spring 35, and swings the tongue upwardly (clockwise as illustrated) away from engagement with shaft 10. Thus, the operator can single-handedly release the entire mechanism or progressively jack or pull the calf while his other hand is used to position and steady the distal end. 
     The other end portion of the slide 15 is provided with an obstetrical chain hook 40 which is designed so as to provide both a loop hook 40a and a grab hook 40b for added versatility for the use of obstetrical chains with this device. 
     FIGS. 3, 4 and 5 illustrate the progressive steps and incremental movements of the device during one forward swing of the handle 18. FIG. 3 shows the component parts in their initial completely unlocked position, with the tongues 19 and 30 completely disengaged and the handle 18 in fully retracted starting position, and the sleeve 15 free to move longitudinally in either direction on the shaft 10. Note that the tips 19a and 30a of the tongues are above the top level of sleeve 15 and aligned with their respective slots 16a and 16b. 
     FIG. 4 shows the device and its components after the handle 18 has been partially raised and swung forwardly (clockwise). This movement has pushed the tip 19a of tongue 19 downward through slot 16a in sleeve 15 into opening 11a in shaft 10 with elevating bar 28 controlling the downward movement through its engagement with edges 17a, the bar 28 being held against the edges 17a by the biasing action of spring 25. 
     This same movement has lifted release member 39 from engagement with dog 38, permitting tongue 30 to come under the influence of spring 35, which has pulled it downwardly through its sleeve slot 16b into engagement with the portion of the top wall or side of shaft 10 immediately preceding shaft opening 11b. 
     The openings 11 are smaller than the major portion of tongue 19, but larger than tips 19a (and 30a) so as to permit end 19a to penetrate sufficiently to make adequate levering engagement with shaft 10. When tip 19a can penetrate no further, then the levering or pulling action begins. 
     FIG. 5 illustrates the device during the levering or pulling action, the handle 18 having been lifted forwardly still further from its position in FIG. 4. As the handle continued its movement from its FIG. 4 position, the levering tongue 19 was anchored against shaft 10, so that continued movement of handle 18 forced members 17 forwardly to the position of FIG. 5, pulling sleeve 15 the same distance, as illustrated by the incremental distance X. This movement has also brought tip 30a of tongue 30 into alignment with opening 11b in the shaft, and spring 35 has pulled tip 30a downward into opening 11b and into engagement with shaft 10, so that the sleeve 15 cannot slip rearwardly if handle 18 is released by the operator, or if handle 18 is swung rearwardly to initiate another pulling movement, tongue 30 holding the sleeve against any such movement. 
     To repeat the operation, the handle is swung rearwardly (counterclockwise) preferably to a point just short of engagement of release member 39 with dog 38, and then swung forwardly again to move the slide and the calf the distance X. As this movement is repeated, tongue 30 automatically disengages itself from opening 11b under the influence of the sleeve moving forward, and moves towards the next opening 11c in the series, as tongue 19 moves towards its next adjacent opening 11d in the series. 
     In use and operation, the breech spanner is positioned against the hindquarters of the cow, and the ends of the chain 20 are attached to the front legs of the calf, with the medial portions of the chain engaging the hook 40. 
     The operator then begins operating handle 18, moving it back and forth as illustrated and hereinbefore described moving the calf the distance X each time. If problems arise, or if for any reason the tension on the calf must be alleviated, the operator can immediately move the handle to starting position, lifting both tongues out of engagement with the shaft 10 and permitting sleeve 15 to slide rearwardly to whatever degree is necessary to eliminate the problem. 
     It will be noted that pivot pins 21 and 31 are self-explanatory and it will also be noted that the pivot pin 24 is located on one side (forwardly) of the pivot axis provided by pivot pin 21, and that the elevating bar 28 is located on the opposite (rearward) side of the pivot axis of pin 21, and it will further be noted that said pivot pin 24 and elevating bar 28 are also located on opposite sides of the lever supporting members 17. These relative locations of these parts enables the elevating bar 28 to engage the track surfaces 17a and raise the levering tongue 19 from engagement with the main supporting shaft 10 when the handle is swung rearwardly (counterclockwise) towards starting position. Thus, it will be appreciated that this invention includes a unique and effective leverage system comprising the handle 18 and the tongue 19 and the various supporting structure therefore, the design of said leverage system providing maximum leverage and ease of operation of the jack mechanism within a relatively small range of movement of the handle so that the operator can maintain a position close to the calf being born during substanatially the entire delivery operation. 
     It will also be understood that parts of the description which indicate a directional orientation such as up, upstanding, down, etc., and specific directions of movemennts such as forward, rearward, counterclockwise, etc., have relevancy only insofar as the device is presented in the accompanying drawings and it is not intended that the invention or the claims be limited insofar as these specific directional descriptions or limitations are concerned, but only insofar as they relate to the remainder of the structure and the functioning thereof. 
     Thus, considering the invention in its broader aspects, it involves a force exerting mechanism which includes a supporting means such as the tube 10, movable means such as sleeve 15 supported by said supporting means, means including the leverage system involving the handle 18 and tongue 19 for moving said movable means relative to said supporting means, attachment means such as the hook structure 40 carried by the movable means, the attachment means being adapted for connection to the object on which the force is to be exerted (such as the calf to be delivered) by any suitable pulling means such as the obstetrical chain 20 and having locking means including the tongue 30 for holding the supporting and movable means against movement relative to one another with release means such as the release member 39 for releasing the locking means in response to the actuation of the handle portion of the moving means with the supporting means having a series of detents such as the openings 11 formed therein and also including base means such as the breech spanner 13 for supporting and holding the supporting means against movement in at least one direction, which in this case is towards the cow itself. 
     Thus, the entire jack mechanism can be continuously and progressively cranked outwardly away from the cow without any danger of slippage and yet can be quickly and instantaneously released from connection with the supporting shaft 10 so as to immediately and instantaneously relieve the tension on the obstetrical chain 20 and on the calf itself to prevent any injury thereto. 
     It will, of course, be understood that various modifications, variations and changes may be made in the form, details, proportions, dimensions and arrangements shown and set forth herein without departing from the spirit and scope of the invention hereof, which scope is defined by the claims attached hereto and included herein, and the appended claims should be construed as broadly as possible in view of the prior art, the specific embodiments described herein being given by way of example only for clearness of understanding, and no unnecessary limitations should be derived therefrom.