Abstract:
A scraper for removing debris from the floor of an animal stall is provided with a first motorized drum, a second motorized drum, a cable extending between the first and second drums, a scraper and a switch tripper carried by the cable. The switch tripper actuates a switch in communication with the first motorized drum to stop and reverse direction of the scraper and cable.

Description:
RELATED APPLICATION 
   This application claims the benefit of co-pending provisional Application Ser. No. 60/444,053, filed 31 Jan. 2003. 

   This invention relates to equipment for animal husbandry. More specifically the invention relates to a scraper device particularly suited for clean up of cattle confinement areas such as barns, free stalls and pits. 
   BACKGROUND OF THE INVENTION 
   Various scraper devices have heretofore been utilized for the clean up of cattle stalls and barns. Typically such devices employ some type of scraper blade. With conventional blades, however, clean up efficiency is reduced by the fact that if a straight blade encounters an irregularity in the floor surface, a one piece blade is caused to rise up and thus leave areas which are not scraped clean. 
   One type of scraper assembly is shown in U.S. Pat. No. 4,243,137 wherein a pair of scraper blades are hingedly connected to a frame. However, to allow the blades to move vertically the device of that patent requires that the blades be formed of several components which are loosely bolted together, thus reducing the ability to maintain downwardly directed scraping forces. 
   A need has existed for improved scraper devices for use in cleaning up of animal manure from floor surfaces that enable improved cleanup of floor surfaces that are characterized by various surface irregularities. 
   SUMMARY OF THE INVENTION 
   The present invention relates to an improved scraper mechanism particularly useful in cleaning up of stalls such as free stalls wherein animals are free to roam within the stall structure. 
   Alley scrapers of the present invention keep barn alleys clean. Clean alleys contribute to better animal health with fewer foot problems and a better overall barn environment. Clean alleys also provide safer conditions for both animals and workers with better footing. Clean alleys mean less animal stress, fewer muscle strains, and fewer fall downs. Healthy, less stressed animals give better milk production. Alley scrapers are easy to install in new barns or retrofitted to existing barns, with or without guide grooves in the floor. Pre-wired terminal boxes and unitized construction make installation of the present invention in barns quite simple. 
   A device for cleaning animal waste from stalls is disclosed, the device having a first motorized drum; a second motorized drum; a cable extending between said first and said second motorized drums; a scraper carried by said cable; a switch tripper carried by said cable; a switch in communication with said first motorized drum; said switch responsive to said switch tripper to perform at least one of the following: moving the cable in a first direction, moving the cable in a second direction, and stopping movement of said cable. 
   In preferred embodiments, the switch is carried by a housing, which also carries an override stop between the switch and the first drum. 
   A method of operating an alley scraper is also disclosed, wherein a time-independent switch is operable to slide said alley scraper a predetermined distance. 
   Longer alleys can be cleaned by adding more scraper blades. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a top view of one embodiment of a scraper device of this invention; 
       FIG. 2  is a top view of an alternate embodiment of the present invention; 
       FIG. 3  is a side view of an embodiment of a drum housing; 
       FIG. 4  is a side view (from another side) of an embodiment of a drum housing; 
       FIG. 5  is a side view of an embodiment of a limit switch housing. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIG. 1 , there is seen a scraper assembly  10  of the present invention. Assembly  10  comprises first and second drum houses  20 , a wire  30 , a scraper  40 , a draw bar  50 , and wheels  60  if the user desires a multiple alley configuration. 
   The wire  30  runs between the two drum houses  20 , around two wheels  60  in the displayed configuration, although more or less wheels  60  may be used in accordance with a desired configuration. 
   When one of the drums  80  within one of the drum housings  20  is operated in a forward direction (pulling cable) the second drum is allowed to operate in a reverse direction (feeding out cable) by disengaging a motor driving the reverse direction drum. Because of the gearing described later, the dead motor and drum will provide a sufficient drag on the scraper assembly  10  such that the cable  30  will be kept desirably taught. 
   In the preferred embodiment, two switch trippers  90  are provided closest in proximity to limit switch housings  70  relative to any scraper  40  in the direction of cable travel. As will be described later, the switch trippers  90  serve to trip switches in communication with the motorized drums  80 , to first move the cable  30  (and all scrapers attached to the cable  30 ) in a first direction toward one of the drums  80 , next to stop the cable  30  and scrapers once the switch trippers  90  reach a portion of a limit switch housing  70 , and next to reverse direction of the cable  30 , so that the cable  30  is moving away from the first drum  80  and being drawn into the second drum  80 . 
   This embodiment also allows for less than half of the entire cable length to be placed on a single drum  80 , whereas the prior art mainly required a single drum has to be large enough to hold all of the cable at once. 
   In a preferred embodiment, an axis of the drum  80  (or the entire housing  20  carrying the drum) is canted at a slight angle Ø from perpendicular between the direction of the cable  30  and the axis of the drum  80 , such that winding the cable  30  onto the drum  80  is promoted in an orderly winding fashion. This angle Ø thus allows (but does not require) the user to forego use of a cable winder as is present in the prior art, as rotating of drum  80  winds cable  30  onto the drum promoted along the axis of the drum  80 . 
   Referring now to  FIG. 2 , a top view of an alternate embodiment of the present invention is shown. In this embodiment, the scraper assembly  10  is equipped without wheels  60 , for a single alley configuration. 
   Referring now to  FIG. 3 , a side view of the drum housing  20  and the limit switch housing  70  is shown. 
   In commercial embodiments, an efficient drive unit comprises an electric motor  130  through a ratio heavy duty gear box, comprising driving belt  140 , in turn driving wheel  150 , in turn driving (next components displayed on  FIG. 4 ) high speed sprocket  160 , in turn driving a chain  155 , in turn driving a larger, slower sprocket  170 , in turn driving a chain  155 , in turn driving a larger, slower sprocket  180 , in turn driving a chain  155 , in turn driving a larger, slower sprocket  190 , until finally a chain  155  (remaining components shown in  FIG. 3  again) drives drum  80  at a rate reduced from the turning speed of the motor  130 . In a preferred embodiment, an approximately 1750 to 1 reduction is provided, meaning one revolution per minute of the drum  80  for every 1750 revolutions per minute from the motor  130 . Also preferred, wheels  190  mounted on a pivot with springs keep slack out of the roller chains  155 . 
   In a preferred embodiment, this arrangement transfers power to the drive drum  80  via #60 roller chain for a safe scraper speed of preferably 6 feet per minute, although preferred speed may be application specific. The drive unit also preferably features easily accessible, greaseable 1½″ ball bearings  210 , carried by cross bar  200 , to support the drive drum  80 . The thrust of the bearing  210  is taken by the cross bar  200  a preferable 45° angle so there is no pull on it. 
   In commercial embodiments, the cable capacity of the drum will approximate 360 feet of ⅜″ cable, as one scraper blade stroke has been found to efficiently clean 300 feet of alley, although again preferences may be application specific. Of course, larger or smaller mechanical components could be used and this is also application specific. 
   For control of the unit  10 , several control boxes/switches are designated throughout the drawings at CB/S, where typically controls such as stop, go, reverse and forward can be advantageously provided to manually control the unit  10 . 
   Referring now to  FIG. 5  a side view of an embodiment of a limit switch housing  70  is shown. As can be seen, when the switch tripper  90  approaches the housing  70  along cable  30 , the switch tripper  90  will engage limit switch operating arm  75  sending a control to CB/S by actuation of switch  72 . It is preferred that switch  72  stop cable  30  upon actuation and then reverse direction of switch tripper  90  (and the scrapers behind it). 
   When two switch trippers  90  are used in conjunction with two housings  70  and two limit switch operating arms  75 , such as shown in  FIGS. 1  or  2 , it will be understood that the scrapers will can run in a continuous mode continuously reversing direction of travel toward and away from one of the drum housings  20  to automate alley scraping. 
   Alternatively, the system can be equipped with sufficient controls at one of the CB/S to operate in a single-cycle mode, wherein the switch tripper  90  will travel through a single cycle from its start position, through a reversal, and then return to its start position, providing a single alley sweep. In this respect, the present invention differs from the prior art in that the prior art primarily operated continuously, or through a time-dependent setting such as 15 minute run time. The single cycle mode is thus considered time-independent. 
   Still referring to  FIG. 5 , a fail-safe is provided at fail-safe arm  77  actuating fail-safe switch  76 , which is intended to be a system shutoff. Referring now to  FIGS. 3 and 4 , in conjunction with  FIG. 5 , if fail-safe arm  77  should fail to actuate fail-safe switch  76  and shut the system down, a secondary failsafe door  100  is provided that is pivotally coupled to the housing  20 , and communicatively coupled with secondary fail-safe rod  120 , intended to shut down the system through secondary fail-safe switch  130 . 
   In an alternative embodiment (not shown), a speed change switch may be provided so that at start-up of the system, if slack is present such as if the scraper is on frozen manure, the speed change switch can account for the slack or speed change from start winding to run winding. With a single phase motor provided, cable  30  may be impreferably tight enough that when switch tripper  90  gets to limit switch housing  70 , cable  30  could relax and turn one of the motors  130  backwards. A centrifugal on a shaft carrying one of the sprockets may be provided. Alternatively, an overrunning clutch could be provided on the motors  130 . 
   The configurations described above may be modified by inclusion of any number of drum houses or wheels, to fit the application or as a user desires. In this manner, one or more drum houses  20  may be used in conjunction with zero, one or more wheels  60  to configure a scraper system. 
   Further modifications and variations of the invention will be apparent to those skilled in the art. Thus, the invention should be considered limited only by the scope of the following claims and including equivalents thereof.