Abstract:
A mower has features that allow it to mow directly over a flexible marker shaft without damage to the shaft. The mower has front and rear rollers mounted directly in front and behind each blade. These rollers engage the ground in rolling contact and support the housing. The rollers are spaced together a distance less than the height of the marker. The front roller contacts the marker and causes it to bend over. Before the front roller leaves the marker, the rear roller will be in contact with the marker to keep it in a prone position until the mower passes from the marker.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of application Ser. No. 190,482, filed May 5, 1988, now U.S. Pat. No. 4,862,823. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates in general to equipment for mowing grass, and in particular to a lawn mower which is capable of mowing over flexible markers. 
     2. Description of the Prior Art 
     Large grassy areas that require mowing often have numerous obstacles. Markers are one type of obstacle. For example, on a golf course, markers and signs are used for tee boxes, out-of-bounds areas, hazards and distance indicators. Right-of-way areas next to highways also utilize various markers. 
     When cutting the grass, these markers have to be cut around or pulled up, then replaced. If cut around, the appearance will be unsightly and even can obscure the marker unless further trimming is done. This requires additional equipment and is time-consuming. 
     In application Ser. No. 190,482, filed May 5, 1988, a flexible shaft is disclosed for use in these areas. This shaft will bend at the point where it enters the ground to a position substantially flush with the ground. This allows a reel-type mower to mow directly over the marker. The mower blade contacts the marker and pushes it downward as the mower moves over it. 
     While the above-identified patent application describes a satisfactory method of use with reel-type mowers, there is no discussion of how such would work with other types of mowers. For example, with rotary mowers which use a blade that rotates in a horizontal plane, the blade would destroy the marker. Also, a flail-type mower which utilizes a number of cutting elements rotated around a horizontal shaft, would damage or destroy the marker. In addition, these types of mowers do not have any means for causing the marker to begin bending as the mower contacts it. 
     SUMMARY OF THE INVENTION 
     In this invention, mowers are fitted with front and rear guard members. Each guard member is a solid curved surface extending transversely across each blade. One of the guard members will be located in front of the blade and one in the rear. The front guard member causes the marker to bend and holds it down until the rear guard member begins to contact it. The spacing of the front and rear guard members is such that the rear guard member will be in a position to hold the stake down by the time the front guard member leaves the marker. 
     In the preferred embodiment, the guard members comprise cylindrical rotatable rollers. Also, preferably, each roller contacts the ground and supports the housing of the mower. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic side elevational view illustrating a mower constructed in accordance with this invention, shown prior to contacting a marker. 
     FIG. 2 is a schematic side elevational view of the mower of FIG. 1, showing the marker in a horizontal position underneath the mower. 
     FIG. 3 is a perspective view of the lower side of the mower of FIG. 1. 
     FIG. 4 is an enlarged perspective view illustrating one of the mounts for one of the rollers of the mower of FIG. 1. 
     FIG. 5 is a schematic lower perspective view illustrating a second embodiment of a mower constructed in accordance with this invention. 
     FIG. 6 is a bottom plan view of a third embodiment of a mower constructed in accordance with this invention. 
     FIG. 7 is a schematic side elevational view of the mower of FIG. 6. 
     FIG. 8 is a perspective view of a third embodiment of a mower constructed in accordance with this invention. 
     FIG. 9 is a bottom perspective view of the mower of FIG. 8. 
     FIG. 10 is a side elevational view of the mower of FIG. 8. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, marker 11 is a stake or shaft driven into the ground 13. Marker 11 may have a sign, symbol or some other type of indication on it. Marker 11 is preferably of a type as shown in U.S. Pat. Application Ser. No. 190,482, filed May 5, 1988, all of which material is hereby incorporated by reference. Marker 11 may be located in an area having grass 15. 
     Mower 17 is a type of a mower that will have a downward facing housing 19. A drive means 21 will be mounted to the upper side of the housing 19. Alternately, the mower 17 could be pulled by a tractor, which also serves as a drive means. A chute 23 extends out the side of the housing 19 for discharging clippings. As shown in FIG. 3, the drive means 21 rotates a vertical drive shaft 25. Drive shaft 25 rotates a blade 27 which is horizontal and has generally flat ends for cutting the grass as the blade 27 rotates in a generally horizontal plane. 
     A guard member or front guard roller 29 will be mounted to the forward end of housing 19. A rear guard roller 31 will be mounted to the rearward end of the housing 19. Each roller 29, 31 is a cylindrical member that extends completely across the width of the housing 19. Each roller 29, 31 is oriented perpendicular to the direction of travel of the housing 19. The width of each roller 29, 31 is slightly greater than the width of the blade 27. 
     As shown in FIG. 4, each roller 29, 31 has bearings (not shown) which rotate on an axle 33. The axle 33 is urged downward by a spring 35. A plate 37 locates between the spring 35 and axle 33. The spring 35, plate 37, and the end of the axle 33 locate within a mounting body 39. A mounting bracket 41 secures the mounting body 39 to the housing 19. The end of the axle 33 extends in a longitudinal slot 42 in the body 39. This allows the axle 33 to move up and down within the slot 42 to accommodate uneven terrain. The rollers 29, 31 support the mower 17 for rolling contact with the ground 13. 
     The distance between the axles 33 of the rollers 29, 31 is less than the height that the marker 11 protrudes above the ground 13. As shown in FIG. 2, this is necessary so that when the upper end of the marker 11 is released from its contact with the front roller 29, the rear roller 31 will already be a significant distance on the marker 11. The rear roller 31 prevents the marker 11 from springing back up after the front roller 29 passes from it. 
     In operation, mower 17 will move directly into contact with marker 11. The front roller 29 will cause the marker 11 to bend at its base. The front roller 29 will roll on top of the marker 11, causing it to assume a prone position, substantially flush with the ground. The weight of the mower 17 will hold the marker 11 in the horizontal position as the blade 27 passes over it. Before the front roller 29 releases its contact with the marker 11, the rear roller 31 will also roll onto the marker 11. As the front roller 29 releases contact, the rear roller 31 will be on the marker 11 a distance sufficient enough to maintain it in the prone position. This prevents the marker 11 from flexing up into contact with the blade 27. Once the rear roller 31 leaves the marker 11, it will spring back to the vertical position shown in FIG. 1. 
     In the embodiment of FIG. 5, the housing 19&#39; has the same front and rear rollers 29&#39;, 31&#39;. In addition, it has an intermediate roller 43. The intermediate roller 43 is located parallel to the front and rear rollers 29&#39;, 31&#39;. It is located halfway between the front and rear rollers 29&#39;, 31&#39; and substantially underneath the shaft (not shown) of the blade 27&#39;. The intermediate roller 43 will serve to maintain the marker 11 prone in the case of markers which are not greater in length than the longitudinal distance between the front and rear rollers 29&#39;, 31&#39;. 
     In the embodiment of FIG. 6, the same principle is applied to a gang-type mower 44. Mower 44 has a housing 45. Housing 45 will contain a number of blades rather than just one. In the embodiment shown, there is an offset blade 47 which is located in the forward portion of the housing 45. Aligned blades, 49, 51 are located in the rearward portion of the housing 45. The aligned blades 49 each are located on a line perpendicular to the longitudinal axis of the housing 45. The offset blade 47 is located forward of the aligned blades 49, 51. It is located on the longitudinal axis. The aligned blades 49, 51 are laterally spaced apart from each other in a direction perpendicular to the longitudinal axis of housing 45. The offset blade 47 will be located forward of and equidistant between the aligned blades 49, 51, overlapping slightly at the edges. 
     Each of the blades 47, 49, 51 is mounted on a vertical drive shaft 53, which rotates the blades 47, 49, and 51 in horizontal planes. A front roller 55 locates just forward of the cutting tip of the offset blade 47. A rear roller 57 locates just rearward of the cutting tip of offset blade 47. A front roller 59 locates immediately forward of the cutting tip of aligned blade 49. A front roller 61 locates immediately forward of the cutting tip of aligned blade 51. The rollers 59, 61 are located rearward of the cutting tip of rear roller 57. A rear roller 63 locates immediately rearward of the aligned blade 49. A rear roller 65 locates immediately rearward of the aligned blade 51. 
     The axial width of each roller 55, 57, 59, 61, 63, 65 is only slightly greater than the width of each blade 47, 49, 51. Each roller 55, 57, 59, 61, 63, 65 is connected to a rotatable mount 67 which is similar to the mount shown in FIG. 4. Each of the rollers 55, 57, 59, 61, 63, 65 will contact the ground and support the housing 45 for rolling contact with the ground. As shown in FIG. 7, each of the blades 47, 49, 51 has a drivehead 69 which is connected by a drive shaft 71 to a tractor 73. A tow bar 76 will connect the housing 45 to the tractor 73. 
     In the operation of the embodiment of FIGS. 6 and 7, the rollers 55, 59, and 61 overlap each other such that regardless of alignment, if the mower 44 passes over a marker 11, one of the rollers 55, 59, 61 will cause it to deflect downward. The rear rollers 57, 63 and 65 are spaced closely enough to the front rollers 55, 59, 61 respectively, so as to contact the prone markers 11 before they are released from one of the front rollers. This avoids the marker 11 from springing up into contact with one of the blades 47, 49 or 51. 
     In the embodiment of FIGS. 8-10, a flail-type mower 75 is shown. Flail mower 75 is a conventional type of mower having a housing 77. A plurality of cutting elements 79 are mounted to a horizontal shaft 81. The cutting elements 79 are sharp discs or blades that rotate in vertical planes as the shaft 81 rotates. 
     The guard means for flail mower 75 will comprise a front roller 83 and a rear roller 85. Rollers 83, 85 will extend the full width of the shaft 81. The rollers 83, 85 are solid cylindrical members that support the housing 77 in rolling contact with the ground. As shown in FIG. 10, the longitudinal spacing between the rollers 83, 85 is less than the height of the marker 11. This assures that the rear roller 85 will be holding the marker 11 down as the front roller 83 passes from the upper end of the marker 11. 
     The invention has significant advantages. The guard members will force a flexible marker down and hold the marker down as the mower housing passes over it. The guard members prevent the marker from springing back into contact with a blade which would otherwise damage it. These guard members allow mowers with rotary and flail-type blades to be used without having to trim around a marker. 
     While the invention has been shown in only four of its forms, it should be apparent to those skilled in the art that it is not so limited but is susceptible to various changes without departing from the scope of the invention.