Abstract:
A coulter assembly is provided to create furrows in a field, while at the same time reducing the amount of soil and debris which accumulates on the coulter disc. The coulter assembly has a disc for creating furrows, with a floating scraper blade on the inner side to keep the inner side of the disc free of debris. The scraper blade also assists in maintaining the furrow once it has been opened by the disc. The scraper blade has a leading edge constructed of carbide and inserts attached to the scraper blade for reducing wear on the scraper blade during operation. A tine extends across the outer side of the disc in a configuration that prevents soil from adhering to the outer side of the disc, and in trash covered fields, trash will wrap around the tine to act as an organic wear pad between the disc and the tine.

Description:
RELATED APPLICATIONS 
     This application is a continuation in part (CIP) of U.S. patent application Ser. No. 09/031,689 filed Feb. 27, 1998, now U.S. Pat. No. 6,024,179. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to agricultural implements and is particularly concerned with a coulter assembly with an inside floating scraper with a leading edge constructed of carbide. 
     BACKGROUND OF THE INVENTION 
     Farmers frequently plant crops in fields that have debris and waste material covering the field. Such material may consist of straw or old crops, which is frequently referred to as trash. In order to plant seeds or deposit fertilizer in such fields, coulter assemblies are tools that are used to create furrows or seed trenches in the soil. These coulter assemblies are typically attached, in a side-by-side configuration, to a frame which is then pulled behind a tractor to create a slot that allows the injection of agents, such as fertilizer and seed, into a field. 
     One problem that may occur with known coulter assemblies is an accumulation of dirt and debris between the discs and the struts as they rotate through the soil. If the soil is wet, it may stick and build up on the discs, which can inhibit rotation of the discs, cause poor disc penetration, excessive soil disturbance and create excessive draft forces. Conventional scrapers are made of steel and tend to wear relatively quickly and require a high scraper pressure when used in heavy, wet, clay soil. Once the scraper wears, the contact area between the scraper and the disc increases, further increasing the spring force that is required to keep the scraper in contact with the disc to keep the disc clean, which consequently increases the drag force on the coulter assembly. Moreover, if the field consists of sections of clay and sandy soil, the coulter assembly has less frictional force available to turn the coulter disc when it is pulled through the sections of sandy soil. The high spring force on the scraper blade may cause difficulties since the disc may stop turning when pulled through the sections of sandy soil, thereby causing operational problems. 
     In U.S. Pat. No. 493,182 issued Mar. 7, 1893, Platt teaches the use of a rod, which rotates freely about a spool between discs, to break up clogs of dirt and debris which form as the coulter discs create a furrow. The rod drags behind the discs and as soil accumulates, the rod rotates upward until the rod is stopped above the discs. The rod breaks the soil clumps which fall beside the disc. A scraper blade is also provided which is subject to a spring force to keep the scraper blade in contact with a surface of the coulter. As the coulter disc rotates, the scraper blade maintains contact with the surface to remove debris. 
     In U.S. Pat. No. 5,626,196 issued May 6, 1997, Hughes teaches the use of a blade which continuously contacts the surfaces of a coulter disc to scrape the disc and clean it as the disc rotates. In an embodiment, the scraper blade is made of plastic to permit flexibility, as it also bends when in contact with the soil. This scraper blade performs the dual role of acting as a scraper/cleaner and also as a closer. Once the disc opens a furrow in the soil, the scraper blade acts as a closer since it will force some of the soil back into the furrow after seeds have been deposited. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an improved coulter assembly, particularly one which utilizes a scraper blade on the inside of the disc to clean the disc as it rotates. 
     In accordance with one aspect of the present invention, there is provided a coulter assembly adapted to be mounted on a frame of a farm implement comprising: 
     a mounting bracket; a strut; means for connecting said strut to said mounting bracket; a two-sided disc, said two sides of said disc comprising an inner side and an outer side, said disc being rotatably attached to said strut; a torque arm pivotally attached to the strut; a scraper assembly slidably and rotatably mounted to the torque arm and facing the inner side of the disc; and resilient means mounted on the torque arm wherein said scraper assembly is urged against the inner side of the disc by said resilient means of said torque arm and whereby said scraper assembly cleans the inner surface of said disc during operation of the coulter assembly. 
     In accordance with another aspect of the present invention, there is provided a coulter assembly adapted to be mounted on a frame of a farm implement comprising: 
     a mounting bracket; a strut; means for connecting said strut to said mounting bracket; a two-sided disc, said two sides of said disc comprising an inner side and an outer side, said disc being rotatably attached to said strut; a torque arm pivotally attached to the strut; a scraper assembly slidably and rotatably mounted to the torque arm and facing the inner side of the disc, said scraper assembly comprising: a scraper blade having a leading edge attached thereto and constructed of carbide; and a hollow tubular member attached to the scraper blade, said tubular member adapted to matingly engage said torque arm and being slidably maintained thereon with a retaining means; and resilient means mounted on the torque arm wherein said leading edge of said scraper assembly is urged against the inner side of the disc by said resilient means of said torque arm and whereby said scraper blade cleans the inner surface of said disc during operation of the coulter assembly. 
     In accordance with another aspect of the present invention, there is provided a coulter assembly comprising a coulter assembly adapted to be mounted on a frame of a farm implement comprising: a mounting bracket; a strut; means for connecting said strut to said mounting bracket; a two-sided disc, said two sides of said disc comprising an inner side and an outer side, said disc being rotatably attached to said strut; a torque arm assembly fixedly attached to the strut, said torque arm assembly including a torque arm; a scraper assembly slidably and rotatably mounted to the torque arm and facing the inner side of the disc, said scraper assembly comprising: a scraper blade having a leading edge attached thereto and constructed of carbide; and a hollow tubular member attached to the scraper blade, said tubular member adapted to matingly engage said torque arm and being slidably maintained thereon with a retaining means; and resilient means mounted on the torque arm wherein said leading edge of said scraper assembly is urged against the inner side of the disc by said resilient means of said torque arm assembly and whereby said scraper blade cleans the inner surface of said disc during operation of the coulter assembly. 
     In accordance with another aspect of the present invention, there is provided a coulter assembly comprising: a substantially vertically oriented mounting bracket having a lower end and an upper end; a strut, having an upper end and a lower end; a torque arm assembly fixedly attached to the strut, said torque arm assembly including a torque arm; a coupling attached to the upper end of the strut and pivotally connected to the lower end of the mounting bracket; a disc, rotatably attached to the lower end of the strut whereby an inner side of the disc faces the strut; a scraper assembly slidably and rotatably mounted to the torque arm and facing the inner side of the disc, said scraper assembly comprising: a scraper blade having a leading edge attached thereto and constructed of carbide; and a hollow tubular member attached to the scraper blade, said tubular member adapted to matingly engage said torque arm and being slidably maintained thereon with a retaining means; and resilient means mounted on the torque arm wherein said leading edge of said scraper assembly is urged against the inner side of the disc by said resilient means of said torque arm assembly and whereby said scraper blade cleans the inner surface of said disc during operation of the coulter assembly; and 
     a spring connected between the mounting bracket and the coupling whereby the coupling will rotate upon elevation of the strut to avoid obstacles when in operation. 
     In accordance with another aspect of the present invention, there is provided a coulter assembly comprising: a strut, having one end adapted to be mounted to the frame of a farm implement; a two-sided disc having an inner side and an outer side rotatably attached to said strut; a scraper attached to the strut having a leading edge attached thereto facing the inner side of the disc, said leading edge constructed of carbide; wherein said leading edge of said scraper is resiliently biased against the inner side of the disc to clean the inner side of the disc during operation of the coulter assembly. 
     In accordance with another aspect of the present invention, there is provided a scraper for use in a coulter assembly having a disc with an inner side; said scraper having a leading edge for scraping an inner side of a disc wherein said leading edge is constructed of carbide. 
     Advantages of the present invention include: increased wear resistance of the scraper blade when the coulter assembly is used to create furrows in fields; reduced scraper pressure required to keep the coulter disc clean in operation, and reduction in drag on the coulter assembly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be further understood from the following description with references to the drawings in which: 
     FIG. 1 is a perspective view of a coulter assembly according to an embodiment of the invention; 
     FIG. 2 is a side view of the coulter assembly of FIG. 1; 
     FIG. 3 is a perspective view of the coulter assembly of FIG. 1; 
     FIG. 4 is a side view of the coulter assembly of FIG. 1; 
     FIG. 5 is a top view of the coulter assembly of FIG. 1; 
     FIG. 6 is an enlarged perspective view of the strut, spindle, housing an d bracket of the coulter assembly of FIG. 1; 
     FIG. 7 is an enlarged perspective view of the strut, spindle, housing and bracket of the coulter assembly of FIG. 1; 
     FIG. 8 is a perspective view of the coulter assembly of FIG. 1; 
     FIG. 9 is a front view of a scraper assembly according to an embodiment of the invention; and 
     FIG. 10 is a side view of the scraper assembly of FIG.  9 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Certain terminology is used in this description for convenience and reference and is not intended to be limiting. For example, the words “forward”, “rear”, “up”, “down” and derivatives thereof will refer to directions in the drawings to which reference is made. In FIGS. 1 to  10 , the direction indicated by the arrow in FIG. 1 will be referred to as “forward”. 
     Referring firstly to FIG. 1, a coulter assembly according to an embodiment of the invention is generally indicated by  10 . 
     Disc  20  is substantially circular with an outer perimeter  22  that is bevelled to a sharp edge to permit disc  20  to easily enter soil to create a furrow or a seed or fertilizer trench during field operations. Disc  20  is preferably made of steel and is approximately 45 cm. in diameter. There is a bore (not shown) in the center of disc  20  to permit the mounting of disc  20  on hub  40 . Disc  20  has two sides which will be referred to as an inner side  24 , seen in FIGS. 1 and 2, and an outer side  26 , seen in FIGS. 3 and 4. 
     Spindle  30  is a member that acts as an axle to support hub  40 . As shown in FIGS. 6 and 7, spindle  30  comprises section  31 ,  32  and  34 . Sections  31  and  32  are solid, co-axial rodshaped sections and section  32  has a smaller diameter than section  31 . Section  34  is a threaded section extending from section  32  and is co-axial with section  32 . 
     Hub  40  is a one-piece member, shown in the top view of the coulter assembly in FIG. 5, having a conical shaped section  42 , a tubular section  44 , and a shoulder  46 . Hub  40  has a bore (not shown) through its center, and hub  40  slides over spindle  30 . Hub  40  acts as a mount for disc  20 . 
     As shown in FIG. 5, disc  20  slides over the shoulder  46  of hub  40  until the inner side  24  of disc  20  abuts against conical shaped section  42  of hub  40 . Disc  20  is secured to hub  40  with bolts  60 . As shown in FIGS. 4 and 5, four bolts  60  pass through holes (not shown) in disc  20 , and bolts  60  are threaded into holes in hub  40  that are adapted to receive bolts  60 , as shown in FIG.  2 . As a result of this configuration, disc  20  is secured on hub  40 , and disc  20  is free to rotate about spindle  30  via hub  40 . 
     As shown in FIGS. 3 and 5, a dust cap  70  is attached to spindle  30  against shoulder  46  to prevent dust and debris from interfering with rotation of disc  20 . As shown in FIGS. 3 and 4, a dust cap shield  72  is attached to the outer side  26  of disc  20  to provide further protection to the dust cap  70  and spindle  30 . In the illustrated embodiment, dust cap  70  is semi-spherical. As shown in FIGS. 3 and 4, dust cap shield  72  is a rectangular steel plate with two ends attached to the outer side  26  of disc  20 . Two of the bolts  60  pass through the ends of dust cap shield  72  to secure dust cap shield  72  to the outer side  26  of disc  20 . The remaining plate is bent in a configuration which adapts to the exterior of shoulder  46  and along the semi-spherical shape of dust cap  70 . 
     Referring to FIG. 2, spindle  30  extends beyond the hub  40  on the inner side  24  of disc  20  and is attached to strut  80 , preferably by a weld between section  31  of spindle  30  and strut  80 . Strut  80  is located opposite the inner side  24  of disc  20 , and as shown in FIG. 2, strut  80  is welded at a first end  82  to the circular surface of section  31  of spindle  30 . As shown in FIG. 1, strut  80  extends upward and forward from spindle  30  such that a second end  84  of strut  80  is located outside the outer perimeter  22  of disc  20 . 
     As shown in FIGS. 6 and 7, strut  80  preferably includes a one-piece steel hollow member  81  with a rectangular cross-section. Attached at the second end  84  of strut  80  is a coupling  86 , which is a tubular shaped member. As shown in FIG. 1, coupling  86  rotates about pin  88 , which is fixed at either end to plates  92  and  93 . In FIG. 1, pin  88  is shown to be secured to plate  93  with a nut  91 . As shown in FIG. 4, pin  88  is welded to a plate  97 , which is located directly above pin  88  on plate  92 . Plate  97  is shown as a rectangular plate with a notch adapted to receive pin  88 . Directly above plate  97  is a substantially rectangular stub  160 , which is welded to plate  92 . As a result of this configuration, pin  88  is restrained from rotation when mounted between plates  92  and  93 . Plates  92  and  93  are rectangular plates which extend substantially vertically from the location where they are fixed to the ends of pin  88  until they reach mounting bracket  90 . 
     As shown in FIG. 1, mounting bracket  90  extends substantially vertically from plates  92  and  93 , and is used to attach coulter assembly  10  to an agricultural instrument, such as a horizontal beam (not shown) pulled behind a tractor. Accordingly, a number of coulter assemblies  10  may be arranged in a side-by-side configuration along the beam. As shown in FIG. 1, mounting bracket  90  is preferably a member with a square cross-section, defined by two sides  94 , a rear section  95  and a front section  96 , which is shown in FIG.  8 . As shown in FIG. 3, a portion of plates  92  and  93  overlap a portion of sides  94  of mounting bracket  90 , and preferably, welds are employed in the overlap region  99  to attach plates  92  and  93  to sides  94  of mounting bracket  90 . As shown in FIG. 1, two adjustment plates  100  are attached to the front section  96  of mounting bracket  90  for a length of approximately 35 cm measured from the top of mounting bracket  90 . Adjustment plates  100  have two opposing long edges, one of which is indicated as  102  in FIG. 2, and adjustment plates  100  are attached to mounting bracket  90  with a weld between one of the long edges  102  and rear section  95 . The plates  100  are spaced apart from each other and attached to rear section  95  so that adjustment plates  100  are substantially parallel to sides  94  of mounting bracket  90 . 
     As shown in FIG. 2, each adjustment plate  100  contains a number of apertures  98 , positioned along the length of plates  100 . Apertures  98  are used to connect mounting bracket  90  to a beam. The number of apertures  98  permits a setting that allows various depths of soil trenches to be created with disc  20 . In the embodiment, apertures  98  are shown as key-shaped, but it is understood that a hole or other aperture may perform the same function. 
     As shown in FIG. 2, a torque arm assembly  110  is attached to strut  80  and to section  31  of spindle  30 , and spindle  30  is shown as extending past inner side  24  of disc  20 . Scraper torque arm assembly  110  comprises a housing  114 , which is shown in the embodiment to be a box-shaped section, rectangular in cross-section, and extends from a point below and rearward of spindle  30  to a position forward and above spindle  30 . Preferably, scraper torque arm assembly  110  is attached to strut  80  and spindle  30  by welding housing  114  to both spindle  30  and strut  80  at the location identified as  112 . 
     As shown in FIG. 5, spacer  116  is semi-circular in shape and lies under spring  122  and properly positions spring  122  on torque arm  120 . Spacer  116  includes at least one hole to secure it in position with bolt  123 . Bolt  123  secures both spring  122  and spacer  116 . Washers  118  are attached at either end of housing  114 . A torque arm  120  is inserted through the center of spacer  116  and co-axial with the spacer. As shown in FIG. 2, torque arm  120  extends beyond the forward end  115  and rearward end  113  of spacer  116  and torque arm  120  is free to rotate relative to housing  114 . 
     As shown in FIG. 5, a bolt  123  attaches torsion spring  122 , or other resilient means, to torque arm  120  and spacer  116  by pressing one end  124  of torsion spring  122  against the exterior surface of spacer  116 . There is a hole (not shown) extending transversely through torque arm  120 , which aligns with a hole (not shown) in the spacer  116  to receive bolt  123  at the forward end  115  of spacer  116 . Torsion spring  122  is shown in FIG. 2 as a helical spring enclosing spacer  116  and torque arm  120 , extends downward and rearward toward housing  114 . The second end  126  of torsion spring  122  is attached to strut  80 , as shown in FIG. 1, via a hooked member  128  which is attached, preferably by welds, to strut  80 . Alternatively, the second end  126  of torsion spring  122  may be attached to the housing  114  or another section of the torque assembly  110 . 
     As shown in FIG. 2, at the lower end of housing  114 , torque arm  120  bends at right angles away from the long axis of housing  114 , and at the same time extends toward the inner side  24  of disc  20 . The lower end of torque arm  120  is attached to the scraper assembly  131 . The scraper assembly  131  is constructed of a tubular member  133 , scraper blade  130  and leading edge  132 . Preferably, the tubular member  133  and scraper blade  130  are made of steel and joined together with arc welds. As shown in FIG. 2, torque arm  120  is attached to the scraper assembly  131  via the tubular member  133 . Torque arm  120  is inserted into the tubular member  133  and secured thereto to prevent the scraper assembly  131  from sliding off the torque arm  120  and at the same time, scraper assembly  131  may rotate about the torque arm  120  until the scraper assembly  131  contacts the inner side  24  of disc  20 . A number of connections can be located at the end of the section of torque arm  120  that slides through the tubular element  133  to retain the torque arm  120 , such as, for example, a nut and a bolt, a spring pin or a roll pin. 
     As shown in FIG. 2, scraper blade  130  has a leading edge  132  that is constructed of carbide material. This carbide material is generally described as a cemented hard carbide of which there are many grades. The configuration of the torsion spring  122 , spacer  116 , torque arm  120 , and housing  114  results in torque being exerted on the torque arm  120 , and as a result, the leading edge  132  of scraper blade  130  is urged against and maintains contact with inner side  24  of disc  20 . 
     In the illustrated embodiment, insert  200  is attached to scraper blade  130  to improve the scraper blade&#39;s resistance to wear. As shown in FIGS. 9 and 10, insert  200  extends through an opening (not shown) in scraper blade  130  and is attached to scraper blade  130  with arc welds. Preferably, insert  200  is constructed of cast iron, but any wear resistant material may be used. Although insert  200  is shown as protruding past both sides of scraper blade  130 , it may extend past only one of the sides of scraper blade  130 . 
     As shown in FIGS. 2,  6  and  7 , a bracket  140  is attached to the top of the housing  114 , preferably with a weld. As shown in FIG. 1, bracket  140 , shown in the embodiment as L-shaped, joins housing  114  to tube holder  150 . Tube holder  150  is located on the inner side of disc  20  in a position to deposit seeds or fertilizer in the trench created by disc  20 . Preferably, tube holder  150  is a trapezoidal shaped container with an open top  152  and bottom  154 . Seeds or fertilizer will feed into the top  152  of tube holder  150  from one or more tubes (not shown) and exit tube holder  150  at the bottom  154  where they will fall into a furrow created by disc  20 . As shown in FIGS. 1 and 5, tube holder  150  has a flange  156  extending transversely from tube holder  150 . As shown in FIG. 5, flange  156  is attached to bracket  140 , preferably with bolts  158  and nuts  159 . 
     As shown in FIGS. 2,  6  and  7 , an arm  160  is attached to coupling  86 , preferably with a weld, and arm  160  extends forward and upward from coupling  86 . Arm  160  contains a hook shaped feature  162  (see FIGS.  6  and  7 ). As shown in FIG. 2, near the top of mounting bracket  90 , a tab  164  is attached to front section  96  of mounting bracket  90 , preferably with a weld. Tab  164  extends horizontally, and contains an aperture (not shown). An eyebolt  166  is inserted through the aperture in tab  164  and secured with nuts  168 . As shown in FIG. 2, a spring  170  with an upper end  172  and lower end  174  is positioned between arm  160  and tab  164 . Upper section  172  is inserted through the aperture in eyebolt  166 , and lower section  174  is secured in the hook shaped feature  162  in arm  160 . Accordingly, spring  170  is substantially vertical. As shown in FIG. 8, a stop-tab  165  is attached, preferably with welds, between plates  92  and  93  at a position above arm  160 , such that stop-tab  165  stops arm  160  from moving upward. Accordingly, spring  170  is in tension, pulling upward on arm  160 , but stop-tab  165  acts as a “stop” to define the position shown in FIG.  2 . If arm  160  moves downward due to clockwise rotation of coupling  86 , spring  170  exerts greater tension between arm  160  and tab  164 , thereby urging arm  160  back to a position against stop-tab  165 . 
     As shown in FIGS. 2 and 6, a cylindrical shaped bushing  163  is attached, in a substantially vertical direction, to the outer side of arm  160 . As shown in FIG. 2, a tine  180  has a first end which is inserted inside bushing  163 . Tine  180  then extends downward from coupling  86  while remaining outside the outer perimeter  22  of disc  20 , then tine  180  bends at substantially a right angle so that tine  180  passes from the inside of disc  20 , as shown in FIGS. 2 and 8, to the outside of disc  20 , as shown in FIG. 4, resulting in a substantially horizontal section  185  as shown in FIGS. 5 and 8. Once tine  180  passes the outer side  26  of disc  20 , it bends downward and rearward in a path that extends across the outer side  26  of disc  20 , shown as sections  186  and  188  in FIG.  4 . Section  186  of tine  180  is substantially equidistant from the outer side  26  of disc  20 , then tine  180  extends downward, rearward, and toward the outer side  26  of disc  20  in section  188  such that the second end  184  of tine  180  terminates on outer side  26  of disc  20 , but inside outer perimeter  22 . The second end  184  of tine  180  touches the outer side  26  of disc  20 . In the illustrated embodiment, tine  180  is shown to be a continuous elongate member with a circular cross section. While this embodiment is preferred, it is understood that a similar device may be used, for example, a bar with a square or hexagonal cross-section, while still achieving the advantages of the invention. 
     As shown in FIGS. 2 and 7, a cylindrical shaped bushing  191  is attached, preferably by a weld, to a face of strut  80  that is opposite the inner side  24  of disc  20 . A tine mount rod  190 , as shown in FIG. 2., is inserted into bushing  191 . Tine mount rod  190  has a hooked end  192  and a straight end  193 . Bushing  191  is oriented on strut  80  such that the hooked end  192  of tine mount rod  190  engages the substantially horizontal section  185  of tine  180  to support the tine. Straight end  193  extends through bushing  191  and a nut  194  fits over the end  193  to secure tine mount rod  190  to bushing  191 . 
     In operation, the coulter assembly  10  is pulled in the direction indicated by the arrow in FIG.  1  and disc  20  creates a furrow in the soil. The leading edge  132  of scraper assembly  131  is in direct contact with the inner side  24  of disc  20 , resulting from the torsion exerted by spring  122  on torque arm  120 . Leading edge  132  of scraper assembly  131  is preferably constructed of carbide, resulting in improved hardness and wear resistance of the scraper blade  130 . Accordingly, inner side  24  of disc  20  is kept clear of debris and the disc  20  does not become jammed by an accumulation of debris between disc  20  and scraper blade  130 . Scraper blade  130  also acts to keep the furrow open while seeds or fertilizer are deposited. Tube holder  150  is attached to one or more tubes (not shown), and seeds or fertilizer are transferred into tube holder  150 . Fertilizer or seeds subsequently fall out the bottom  152  of tube holder  150  into the furrow. 
     If the coulter assembly is used in wet or sticky soil, large sods or clumps of soil may be carried with the disc  20  as it rotates, but the sods will be broken on the outer side  26  by tine  180 . Accordingly, tine  180  allows operation of the coulter assembly to continue normally. Outer side  26  of disc  20  is not necessarily kept clean down to its metal surface. If coulter assembly  10  is used in a field which has not been cleared, straw and trash will wrap around tine  180 , forming an organic wear pad between tine  180  and disc  20  to prevent wear on the outer side  26  of disc  20 . If rocks or other obstructions are encountered in the field, tine  180  will be elevated. Since tine  180  is attached to coupling  86 , if the remote end  184  of tine  180  is forced upwards, coupling  86  will rotate and arm  160  will move downward, placing spring  170  into tension and at the same time permitting strut  80  and scraper assembly  131  to elevate since strut  80  and tine  180  are both attached to coupling  86 . After the obstruction is passed, tine  180  and strut  80  will return to their original position since arm  160  will move upward until stopped by stop-tab  165 . 
     Numerous modifications, variations, and adaptations may be made to the particular embodiments of the invention described above without departing from the scope of the invention as defined in the claims.