Reel mower conditioner

A computer controlled all-in-one reel mower sharpener and roller alignment system can be rolled under a mower to be conditioned. No removal of the cutting unit is needed. A linear voltage displacement transducer (LVDT 715 or a mechanical dial indicator 7155; alternatively a friction wheel 7150 with a rotary encoder 7151 may be used, or any combination of sensors 715, 7155, 7151) or equivalent instructs the machinist how to align the front and rear rollers in parallel. A laser scanner or probe determines the location for the cutter, and then the machining head sharpens each blade automatically. A separate cutter sharpens the bed knife. Most all mowers can be conditioned based on the laser or probe calibration of the blade size. The laser or probe measures the height of cut by sensing the blade location.

FIELD OF INVENTION

The present invention relates to providing maintenance to golf course reel mowers by using a laser based scanner or a probe to align the frame components, setting the height of cut and using a linear voltage transducer or equivalent to level the front and rear rollers, and using various machining cutters for sharpening the blades and the bed knife, all by computer control.

BACKGROUND OF THE INVENTION

Maintaining golf course grass is a science. A clean cut on each blade of grass is preferred because a ragged cut stunts growth and weakens the grass. When the grass is weakened it becomes prone to disease. Diseased grass is attacked by weeds. When weeds develop costly chemicals are needed to kill the weeds. In order to cut the grass cleanly, reel mower blades need to be sharpened frequently. Most prior art sharpening systems require removing the reels from the mower frame to perform the sharpening process. This removal and re-installation of the reel blades is costly in terms of labor costs as well as downtime for the expensive power lawnmower.

A brief summary of the prior art sharpeners follows below. Dieck et al. '581 claims to perform both the “true” grind of the reel tips and the “relief” grind of the trailing edge of each blade without the removal of the reel from the mower.

U.S. Pat. No. Re 28,200 (1974) to W. E. Witt et al. discloses a reel lawnmower sharpener, wherein a motorized grinder is mounted to the frame to sharpen the blades.

U.S. Pat. No. 4,148,158 (1979) to Hewitt discloses a lathe-type machine, which receives the frame of a reel mower, and mechanically grinds each blade.

U.S. Pat. No. 4,192,103 (1980) to Sousek discloses a reel lawnmower grinder that has an automatic indexing device to advance the cutter reel blades into the grinder.

U.S. Pat. No. 4,485,591 (1984) to Bolin discloses a portable, ground mounted motorized grinder on a frame which can connect to the underside of a reel type mower.

U.S. Pat. No. 4,746,330 (1988) to Johnson discloses a reel mower blade sharpener with a pulley system to rotate the blades in synch with the sharpener.

U.S. Pat. No. 5,012,617 (1991) to Winstanley discloses in FIG. 4 a reel mower blade assembly mounted on a dual purpose grinder for sharpening both the rotating blades and the fixed bottom blades.

U.S. Pat. No. 5,321,912 (1994) to Neary et al. discloses a tabletop spin grinder for a reel type mower, wherein the perfect cylindrical shape of the blade is assured.

U.S. Pat. No. 5,879,224 (1999) to Pilger discloses a tabletop grinder for a reel mower, with an automatic blade indexer.

U.S. Pat. No. 5,549,508 (1996) to Searle et al. discloses a tabletop grinder for a reel mower, with an indexer and a dampening mechanism to minimize grinding vibrations.

U.S. Pat. No. 5,725,415 (1998) to Bernhard discloses a portable grinder for the bed knife or bottom blade of a reel mower.

U.S. Pat. No. 6,010,394 (2000) to Dieck et al. discloses a tabletop reel grinder with sophisticated blade indexing to reduce manual adjustments after initial first blade setup.

U.K. Patent No. 2 170 740 A (1986) discloses a tabletop reel grinder with a single hydraulic actuator for the traverse means for the grinder and the blade rotator is provided.

U.S. Pat. No. 6,290,581 B1 (2001) to Dieck et al. is assigned to Foley-Belsaw Company. The invention features a tabletop grinder for a reel blade. Both the “true” grind and the “relief” grind steps and automatic indexing are provided. A mechanical sensor (FIG. 7, 42) senses the blade position which controls the vertical positioning of the grinding head.

Each reel has a front and a rear roller which need to be parallel and set to a proper height. All known methods are manual to align these rollers.

Height adjustments for a golf course are complex. Generally the deep rough is set at 1½ to 2 inches. The intermediate rough is set at 1 to ¼ inch. The fairway is set at ½ to 1 inch. The greens are set at 3/32– 3/16 inch. The tees are set from 3/16–½ inch. Height adjustments are set to 0.001 inch for precision.

The present invention is rolled under a power lawnmower which is usually lifted on a power lift. No removal of the cutting units is necessary. A laser or a mechanical probe, an encoder, and a cutter based system is operated by the machinist using an on-board computer controller. The rollers are aligned using the encoder. The reel blades are sharpened using a machining head with end cutter. The bed knife is sharpened using the machining head with back facing cutter. The height adjustment is measured by the laser scanner or encoder probe to the exacting requirements of each height setting. Additionally the reel cylinder axis is measured by the laser scanner or encoder probe.

The overall benefits to the golf course owner are a very precisely conditioned reel mower which reduces costs to maintain the grass. The precise conditioning is also achieved in less time, thus reducing maintenance costs for the golf course. The system offers benefits to any grass mowing maintenance operation.

SUMMARY OF THE INVENTION

The primary aspect of the present invention is to provide a reel mower conditioning system that sharpens the blades and aligns the rollers—all without removing the cutting units from the chassis of the mower.

Another aspect of the present invention is to provide a laser scanner to direct the positioning of a power cutter used for sharpening the blades and the bed knife.

Another aspect of the present invention is to use an accurate means to align the front and rear rollers in parallel.

Another aspect of the present invention is to use the laser scanner or a probe to precisely set the cutting height.

Another aspect of the present invention is to use a mechanical feeler to precisely set the cutting height.

Another aspect of the present invention is to provide a blade end cutter that has a guide which keeps the blade edge centered on the cutter, thereby allowing the blade edge to be sharpened in one pass instead of a typical two pass “true and relief” method.

Another aspect of the present invention is to provide a computer controlled, menu driven screen to guide the machinist through the various tasks.

Another aspect of the present invention is to align the rollers to the axis of the reel cylinder.

DETAILED DESCRIPTION OF THE DRAWINGS

Glossary

Cutting Unit: reel, roller, knife assembly of a reel mower.Blade: one of several cutting edges of reel cylinder on a cutting unit.Reel Cylinder: assembly of several blades which spins to produce cut.Bed Knife: fixed cutting edge which provides second half of scissor cutting.Grinding: abrasive metal removal other (existing) technology.Machining: single point metal removal (new technology disclosed herein).Machining Head: drive system for cutters used to sharpen by machining.Linear Voltage Displacement Transducer (LVDT) Assembly: a rocker arm assembly is connected to a LVDT transducer which senses proper parallelism of a front roller to a fixed rear roller after the fixed rear roller has been adjusted parallel to the reel cylinder.

Referring first toFIG. 1a front perspective view of a preferred embodiment reel mower conditioner1shows a machinist3using the touch screen13. A cutting unit2is shown mounted on the machining sub-assembly6. The machining sub-assembly6is supported on the base7. The base7has wheels10, a frame9and a battery and electronics housing8. The wheels10enable the machinist3to roll the conditioner1under a power lawnmower and raise the machining sub-assembly6up to meet the cutting unit2. The raise/lower mechanism11controls the height of the machining sub-assembly6. One roller4can be seen locked into fixed roller supports18,180. The second roller is supported by a rocker arm assembly3400attached to the mechanical dial indicator7155; alternatively a friction wheel7150with a rotary encoder7151may be used, or any combination of sensors715,7155,7151whose operation is described inFIG. 31, wherein these devices may be characterized as level position sensing devices. Alternatively an LVDT could work with circuitry to accommodate ambient temperatures and voltage fluctuations. Another equivalent to the mechanical dial indicator715would be a linear encoder with a shaft connected to the rocker arm assembly3192. The blades(s)5of the cutting unit2can also be seen. The blades5are rotated by the reel drive system and clutch assembly17. The roller4is locked in place by the roller4clamp12after the left roller position adjuster14and the right roller position adjuster15are adjusted to accommodate the particular cutting unit2size.

The machining head assembly19holds various machining cutters for the true and relief cuts of the blades5and the sharpening of the bed knife. The traverse drive1616moves the machining head assembly3333after the machining requirements are calculated by a laser or a probe3200type blade analyzer (FIG. 33) which is also moved by the transverse drive1616.

Referring next toFIG. 2a front perspective view of an equivalently functioning reel mower conditioner20to that of the conditioner1ofFIG. 1is shown. The front roller23, rear roller4and blade5of the cutting unit2can be seen. The conditioner20consists of a base22having a frame25and wheels10to enable the conditioner to be rolled under the power lawnmower201. The cutting unit2remains mounted in the power lawnmower201.

The first step for conditioning is frame alignment. In referring toFIG. 13the reel cylinder1359is measured to be in perfect alignment with the frame of the cutting unit2. The roller4in our illustration is a rear roller that can be set by hand to parallel with the reel cylinder1359. The roller4is resting on fixed, non-movable columns30,31. To ensure parallelism of the roller4to the reel cylinder1359, a laser beam or a mechanical probe mounted on the machining head assembly36is set at the left end of the roller, near the roller support30,FIG. 8number30. The laser beam or the probe measures the distance up to the shaft of the reel cylinder. Next the process is repeated on the right side by the right roller support,FIG. 6Anumber31. Next the roller support brackets94are adjusted as shown inFIG. 9until the two above mentioned measurements are the same. Now the rocker arm assembly3400in conjunction with the level position sensing device described inFIG. 31is used to align the (front) roller23to the (rear) roller4as described in the discussion ofFIG. 7. This step completes the frame alignment process.

The machining sub-assembly21has a touch screen13, a pneumatic supply hose26and an AC power cord27. A raising/lowering mechanism50(FIG. 5) raises the conditioning assembly51. The reel is controllably rotated by the reel drive system with a slip clutch28, which is shown attached to the reel inFIG. 8. The transverse drive29consists of an electric motor to turn the transverse screw291which is located between the support guides292,293.

The left roller support column30, and the right roller support column31support the rear roller4. Roller clamps34,35lock against the roller4before any conditioning steps begin. Rear stops294,295brace the roller4against the roller clamps34,35. Rear rocker arm columns32,33support the front roller23. These rocker arm columns32,33are part of the rocker arm assembly3400that are connected to the mechanical dial indicator7155; alternatively a friction wheel7150with a rotary encoder7151may be used, or any combination of sensors715,7155,7151via a magnification arm3190as shown inFIG. 31andFIG. 7B. The rocker arm columns are labeled3200and3100respectively, as better seen inFIG. 4. Alternatively a LVDT could work with circuitry to accommodate temperature and voltage fluctuations. Another equivalent to the mechanical dial indicator715would be a linear encoder sensing the position of the rocker arm assembly3400. The machining head assembly36, best shown inFIG. 2, includes a machining head37that holds various cutting/grinding tools, a laser38that calibrates the blade edges for machining, and a motor39. The machining head assembly36moves along the support guides292,293via the traverse screw drive29.

Referring next toFIG. 3the electronics/control compartment30has a front door33. The roller clamps34,35are run by a pneumatic control valve31. The DC power supply329feeds all electronic components including the computer, (preferably a pc based imbedded computer, however a PLC can be used)34. All other powered parts are run from battery.

Referring next toFIG. 4the machining head assembly36is moved all the way left to allow the open roller clamps34,35to receive a cutting unit as shown inFIG. 5. Electric housing401houses the wiring402to the machining head assembly36. The housing440supports the calibration adjustment knob439for setting zero deviation of the rocker arm assembly3400as best shown inFIGS. 7A,7B.

Referring next toFIG. 5the raising mechanism50has raised the conditioning assembly51which has received the cutting unit2.

Referring next toFIG. 7A, the cover for the level position sensing device described in discussion ofFIG. 4,31transducer housing has been removed to expose the LVDT715a mechanical dial indicator7155; alternatively a friction wheel7150with a rotary encoder7151may be used, or any combination of sensors715,7155,7151. The calibration adjustment knob439adjusts the level position sensing device length to establish a zero deviation from the plane of the fixed roller supports (18,180inFIG. 1). InFIG. 31the roller23rests on the tops3200,3100of rocker arm columns32,33. Bearings3191allow the arc segment3192to slide to reflect the tilt, if any, of roller23. The magnification arm3190translates the displacement at juncture3195to the top3196of the level position sensing device transducer715.

FIG. 7Bis the same view asFIG. 5with a cut-a-way of the frame showing front roller supports32,33with rocker arm3192supported on roller bearings3191. Also shown is magnification arm1390and connection to LVDT715or a level position sensing device described in discussion ofFIGS. 4,31.

Referring next toFIG. 8the base800of machining head assembly36has a stationary nut inside which moves the base800as the screw291is powered by the screw drive29.

Referring next toFIG. 9the machinist3adjusts the roller4to reel cylinder axis alignment in a known manner using an open end wrench90on roller end91and loosening nut93on the bracket94that supports the roller4.

Referring next toFIG. 10the laser38shines a beam1001to the cutting edge1002of the blade5. The computerFIG. 3,34stores the distance d1(height of cut, H.O.C.) of the cutting head in relationship to the plane of the rollers.

Referring next toFIG. 11the touch screen13displays H.O.C., d1ofFIG. 10, as 0.109 inch. Field1119indicates a zero deviation from parallel between the front and rear roller as described above in the frame alignment paragraph. Field1120showing “NEXT” allows the machinist to proceed to the next step.

Referring next toFIG. 12the roller clamps34,35are closed. The machinist3is adjusting the height of cut (H.O.C.) by moving the front roller23up or down using knob1212. The opposing knob (not shown) must be set at the same H.O.C. in order for the rocker arm top3100to be level with rocker arm top3200, thereby providing a perfect alignment signal from the level position sensing device as described in discussion ofFIGS. 4,31.

Referring next toFIG. 13the rollers4,23and the reel cylinder1359must be all parallel. The arrows up (U), down (D) forward (F), and back (B) indicate the manual adjustments potentially available on the cutting unit2.

Referring next toFIG. 14the touch screen13is displaying the choose function screen with the primary function options displayed.

Referring next toFIGS. 15A,15B,15C the touch screen13shows the sequence the machinist uses to instruct the computer that the cutting unit has eight blades and is21inches long. The machinist touched NO inFIG. 15A, NEXT inFIG. 15Buntil8was displayed, and entered21in the same manner (not shown) asFIG. 15B, which resulted in a ready screen,FIG. 15C.

InFIG. 16the machining head assembly36has been moved left, L, until the laser beam1001is located at the left end1600of the reel blade5. InFIG. 17the touch screen13shows the H.O.C. as1563field1790when the laser beam is at the left end1600of the reel blade5. If the machinist moved the laser beam more left by touching field1791, then the laser beam would reflect off a much higher surface and show a much bigger H.O.C.

The machinist moves the laser beam1001to the right by touching field1792.

Referring next toFIG. 18the cutting assembly1850is a unique invention. A base1856is mounted to the cutting head assembly36,FIG. 2. A blade guide1851has a left half1852and right half1853which push against the blade5. A bolt1857locks the halves1852,1853to the base1856.

The end cutter1854rotates so that cutter tips1860,1861,1862machine the edge of the blade5sharp. The blade guide1851keeps the edge of blade5right over the point of metal removal1863of the end cutter1854.

InFIG. 19the machinist adjusts the cutting assembly1850against the blade5at the start of the cutting process with the adjusting knob1879, and raising/lowering the spindle1855, alternatively he uses hand wheel16shown inFIG. 1.

InFIG. 20the edge2000of the blade5is being held exactly over the point of metal removal1863by tip1860of the end cutter1854by the blade guide1851. The end cutter1854could have from2or more blade tips. A portion2293(FIG. 23) of the top of the blade guide1851acts as a stop for blade5as the cutting assembly1850moves left, L, and the reel cylinder1359is rotated by the reel drive system with slip clutch28.

Referring next toFIG. 21the reel rotation direction R forces the blade5edge2000to sweep past the bed knife2121at its tip2029. The cutting action takes place at the confluence of the leading edges of the bed knife and the reel blade,2030and2040respectively. The bed knife relief angle Z may be different than the reel blade relief angle X.

Referring next toFIG. 22the end cutter1854has end points1860,1861,1862as shown inFIG. 18. Point1863is the point of metal removal because the end cutter1854is slightly tilted relative to the arc of the blade5as best shown inFIG. 24. The cutting force F, against the blade5is resisted by the blade guide force F2, and ideally the point of balance between forces F1, F2occurs along axis1869, which passes though the longitudinal axis A of the end cutter1854at its tip2069.

Referring next toFIG. 23this top plan view describes the forces shown inFIG. 22. The end cutter1854rotates in direction CR. The forces F1, F2are equalized at the point of metal removal1863.

Referring next toFIG. 24the cutting assembly1850is slightly tilted at angle T (range from about 3 to about 20 degrees) so as to have the cutting tips1860,1861,1862contact the blade edge2000at point1863. There exists a gap G at point2401between the end cutter1854and the blade5.

This angle T tilts the cutting head of the tool1854, thereby forming a concave relief (FIG. 22A,2101); additionally the leading cutting edge2100appears to stay sharper longer with this concave relief. The cutting assembly1850may be a high speed (circa 20,000 rpm) machining head having a carbide cutting tool.

Referring next toFIG. 25the touch screen13field2501displays the status that a sharpening process is proceeding. Field2500has automatically advanced from blade1to blade5via computer control.

Referring next toFIG. 26this end perspective view shows the blade5pushed against the blade guide1851by the rotational force of the reel drive system with slip clutch28. The machining head assembly36could be moving away from the viewer into the page or vice versa for a sharpening process.

Referring next toFIG. 27the cutting assembly1850is mounted to the machining head assembly19as shown inFIGS. 1,33B at a fixed angle (ranging from about 1 to 15 degrees) sufficient to put a relief cut in the blade edge, see number X,FIG. 21.

Referring next toFIG. 28the setup for the bed knife sharpening process has been done. The bed knife cutting tool2803has been fastened into the spindle assembly1855in place of the end cutter1854. The cutting edge2804is located on the bottom face of the bed knife cutting tool2803. The threads2802of the spindle assembly1855can be seen which enable the height h1of the spindle1855to be adjusted by knob1879. The locking lever2801tightens the base1856to the outside of the spindle assembly1855.

Referring next toFIG. 29the machinist3is adjusting the height h1of the bed knife cutting tool2803using adjusting knob1879or alternatively using hand wheel16shown inFIG. 1so as to make the cutting edge2804touch the bed knife2121at its tip2029as seen inFIG. 21. This adjustment and the angle X seen inFIG. 27machines an angle Z ofFIG. 21.

Referring next toFIG. 30, the base22has a car battery3000to run the electronics, other than the computer. A solid state power supply could be used. A motor3001powers a screw shaft3002to provide the raise/lower action for the machining sub-assembly51ofFIG. 2. The AC/DC power supply3004runs the computer, (preferably a PC based imbedded computer, however a PLC can be used)34.

Referring next toFIG. 32the roller clamp35is closed by pressurizing an air cylinder3119via air supply3120. The piston3123is returned to the up position as shown by spring3124. The piston3123is attached to the rod3121which in turn is attached to the linkage3122which in turn is attached to the roller clamp35.

Referring next toFIGS. 33A,33B a probe assembly3200can be substituted for the laser assembly38. A housing3201is mounted to the machining head assembly36, forming machining head/probe assembly3333. Arm3212as shown is pivoted to allow the magnet3203to attach to the arm3212. In this position the operator can finely adjust the probe3202with the manual machining head adjustment16. The operator can measure the cutter position h1as shown inFIG. 33B. When the arm3212is pivoted away as shown by arrow P, the probe3202can be operated independently as described below. The probe3202is slidably mounted inside the housing3201. The tip3203of the probe3202comprises a magnet having a flat top surface3204to engage a blade edge2000or the core of the reel cylinder1359, the core usually consists of a shaft on which the blades5are mounted. The handle3205is attached to the probe3202and is manually lifted by the machinist for the measuring operations. The purpose of the magnet in the tip3203is to enable the probe3202to stick to the measured surface, thereby allowing the machinist to free up both hands.

Referring toFIG. 33Bthe preferred embodiment of the machining head/probe assembly3333is shown. Base332contains a stationary nut that moves the base332as screw337is powered by1616best shown onFIG. 1. The machining head19is powered by motor335. The machining head19is attached to slide334by bolts338. The slide engages left guide330and right guide331that are bolted to the base332by bolts339. The slide334contains a stationary nut336which engages screw333which is turned by means of hand wheel16. The position of the machining head19can be finely positioned shown by arrow h1using the hand wheel16. Also attached to the base332is a manually movable arm3212which pivots as shown by arrow p by means of pivot3213. Additionally the probe assembly3200is bolted to base332by bolts not shown. With the arm3212in position over the magnet3203of the probe assembly3200, the position h1of the machining head19can be determined by the probe assembly3200and displayed to touch screen13best shown onFIG. 1. With movable arm3212not positioned over magnet3203the probe can be manually operated by means of handle3205as described in discussion ofFIG. 33A.

The chain3206is continuous and is wound around the upper sprocket3207and the encoder sprocket3208. The probe3202is attached to the chain3206by a link3209. In operation the probe3202is lifted to the blade edge2000, thereby turning the encoder sprocket3208which in turn generates an electric signal from the encoder3210which signal is transmitted via wire3211to the computer (preferably a PC based imbedded computer, however a PLC can be used)34. Equivalent probe assemblies could use automatically extending probes.

Referring next toFIG. 34a schematic of the input, output and control functions is shown in a modular layout.

Referring next toFIGS. 35A,35B a control logic schematic of the mower conditioner20is shown. Block3500requires entry of an identification number for a particular cutting unit. Block3501requires entry of the cutting unit parameters including blade count. Block3502designates the start of the conditioning of a chosen cutting unit. Block3503mounts the cutting unit onto the conditioner. Block3504provides the machinist with the choose function screen.

Block3505represents starting the frame alignment process (seeFIG. 14). Block3506represents positioning the probe or laser at the first (left) roller support. Block3507represents measuring the distance to the reel cylinder core. Blocks3508,3509represent positioning and measuring the distance to the reel cylinder core at the second (right) roller support. Block3510displays any difference in distances from the left to the right ends of the reel cylinder to allow the machinist to adjust the roller to eliminate any difference.

Block3511starts the height of cut (H.O.C.) process by adjusting the height of the opposite roller that is set in the frame alignment process (seeFIG.12). Block3512indicates positioning the probe or laser at one end of a cutting unit. Block3513indicates the machinist setting his desired H.O.C. Block3514shows theFIG. 11touch screen wherein the machinist has leveled the opposite end of the roller which has been set at the desired H.O.C.

Block3515starts the bed knife sharpening process. Block3516instructs the machinist to install the bed knife cutting tool (seeFIG. 28). Block3517instructs the machinist to rotate the reel blade5out of the way. Block3518instructs the operator to position the bed knife cutter to the bed knife (seeFIG. 29). Block3519sharpens the bed knife. Block3520indicates the first sharpening pass is done, and the machinist can feel the bed knife and decide whether to repeat the process.

Block3521starts the reel blade sharpening process. Block3522instructs the machinist to mount the end cutter1854(seeFIG. 18). Block3523instructs the machinist to adjust the height of the end cutter (seeFIG. 19). Optional block3524automatically rotates the blade5away from the end cutter, then Block3525automatically moves the end cutter outbound from the end of the blade5, then Block3526automatically powers up the end cutter to rotate, then Blocks3527,3528move the end cutter toward the blade slowly, then senses the powered rotation of the reel cylinder1359stopped by the blade guide1851, leaving the end cutter outbound from the blade5. Now Block3529automatically traverses the end cutter across the length of the reel blade.

Block3530automatically measures the traverse of the end cutter and compares the traverse to the known length of the reel blade. When the end cutter reaches the end of the reel blade, then the reel cylinder rotation is stopped, thereby leaving the reel blade at a known rotational position. The end cutter continues to traverse. Block3531automatically stops the traverse when the blade guide clears the end of the reel blade, thereby enabling a rotation of the reel cylinder to index to the next blade position as indicated by Block3532. Block3533indicates the counting of the blades to automatically repeat the sharpen blade process until all blades are sharpened. Block3534allows the machinist to feel the blades and decide if another sharpening cycle should be done.