THE DESEGN PARAME'EER‘S OF A POWERED GRASS-DWEDER That: for flu; Dogma o§ M. S. MICBIGAN STATE UNIVERSITY Gary W. Ash 1962 THESIS ’- / " ‘ L I B R A R Y Mfi‘hiéan Scam L? mvcrsity _._J THE DESIGN PARAMETERS OF A POWERED GRASS-DIVIDER by Gary w. Ash AN ABSTRACT Submitted to the Colleges of Agriculture and Engineering, of Michigan State University of Agriculture and Applied Science in ‘ partial fulfillment of the require- ments for the degree of MASTER OF SCIENCE IN AGRICULTURAL ENGINEERING Department of Agricultural Engineering 1962 Approved by(53%E;Eééé;:I/fzi;fé§;252Z:;;://’ {7%fi?2§%?t{9%f22_~ ABSTRAOT GARY w . ASH A mechanism for reducing the stOppages encountered at the inner and outer shoe of a mower bar was studied. The construction and testing of a powered grass divider are described. The divider was a high speed pick up reel 15 in. long with fingers that oscillated in and out of a drum surface as the drum revolved. The divider was mounted above the outer shoe of the mower cutter bar and was driven by a hydraulic motor. Tests were run at three different rotational speeds and four different reel settings of angularity with line of travel and tilt from the horizontal. Alfalfa stalks were tagged and their displacement measured after the divider operation. Corresponding stalk displacements were averaged and plotted to show the dis- tribution pattern. The plotted data show that the forage experiences a separation effect. The inner end of the reel throws forage farther forward than does the outer. end. The amount of separation is not significantly affected by changes in reel speed. The mean of the distribution pattern shifts from a forward to a rearward position in relation to the initial stalk position with an increase of reel speed. The distribution was not affected significantly by changes in reel positions in the forage used for qualitative tests. | GAR! W. ASH The width of the distribution pattern was approx- imately 25 ft. and the width of path cleared by the reel was from 11 to 15 in. THE DESIGN PARAMETERS OF A POWERED GRASS-DIVIDER by Gary w. Ash A THESIS Submitted to the Colleges of Agriculture and Engineering, of Michigan State University of Agriculture and Applied Science in partial fulfillment of the require- ments for the degree of MASTER OF SCIENCE IN AGRICULTURAL ENGINEERING Department of Agricultural Engineering 1962 GEES? ‘H‘HH ACKNOWLEDGEMENTS The author wishes to express his sincere apprecia- tion to the following: Dr. Wesley Buchele, the author's major professor, not only for his encouragement and interest, but, more importantly, for his imparting to the author a perspective of the horizons accessible by the media of ideas. Buchanan Steel Products Corporation, Buchanan, Michigan, who provided the funds that made this research possible. The International Harvester Company, the Branch Office, Lansing, Michigan, who supplied the use of a mowing machine and tractor for the duration of this research. Dr. Bill Stout for his personable influence to undertake graduate studies and for serving on the author's guidance committee. Dr. Frank Tse for serving on the author's guidance committee. June, the author's wife, for her encouragement and patience, and for her willingness to accept the many long husbandless evenings. TABLE OF INTRODUCTION . . . . . . . . LITERATURE REVIEW . . . . . APPARATUS . . . . . . . . . PROCEDURE . . . . . . . . . QUALITATIVE TESTING . . . . RESULTS AND DISCUSSION . . . SUMMARY . . . . . . . . . . CONCLUSIONS . . . . . . . . RECOMMENDATIONS . . . . . . APPENDIX . . . . . . . . . . REFERENCES . . . . . . . . . CONTENTS Page 0 O O O O O O O O O O O 1 . . . . . . . . . . . . . 3 . . . . . . . . . . . . . 7 .............20 LIST OF FIGURES Figure Page 1. Schematic of non-uniform spacing of conditioner rolls . . . . . . . . . . . . 6 2. Tractor and mower with powered grass d1V1d°r O O O O O O O O 0 O O O O O O O O 8 3. Finger assembly and eccentric mounting Shaft O O O O O O O O O O O O O O O O O O 8 u. "Arc positioner' mounted on the end of the reel 0 O O O O O O O O O O O O O O O 10 5. View of drum, drum slots, retainer and . stabilizing bushing . . . . . . . . . . . 1o 6. Powered grass divider assembly . . . . . . 12 7. Mounting_position of the hydraulic motor and enclosure of hydraulic lines . . . . 12 8. General field Operation of the divider . . 15 9. Distribution width after divider Operation e e e e e e e e e e e e e e e'e 15 10. Rubber strips mounted on the drum . . . . . 17 11. Operation of the divider in previously cut material . . . . . . . . . . . . . . 17 12. Shielding the hydraulic motor to prevent "rapping eeeeeeeeeeeeeeee 18 13. Method of tagging alfalfa stalks (arrows indicate tags) . . . . . . . . . . . . . 18 14. Measurement of displacement of alfalfa Stalks O O O O O O O O O O O O O O O O O 22 15. Reel Operation in tagged stalks . . . . . . 22 16. Avera e alfalfa stalk displacement; reel at 5° angle-0° tilt; reel speed of 400, 500, and 600 R.P.M. . . . . . . . . 24 Figure Page 17. Average alfalfa stalk displacement; reel at 30° angle-30° tilt; reel speed Of “'00, 50°, and 600 R.P.H. e e e e e e e e 25 18. Distribution pattern of tagged alfalfa stalk after divider operation (see painter) O O O O O O O O O O O 0 O O O O 28 19. Area of distribution pattern before and after reel Operation . . . . . . . . . . 30 Table I. II. III. IV. VI. VII. VIII. IX. XI. XII. XIII. LIST OF TABLES Average displacement of alfalfa stalks for comparative stalk position at 45° angle- 00 t11t O O O O O O O O O O O O O C O O 0 Average displacement of alfalfa stalks for comparative stalk position at 45° angle- 300 tilt O O O O O O O O O O O O O O C 0 Average displacement of alfalfa stalks for comparative stalk position at 30° angle- 00 t1 1t 0 O O O O O O O O O O O O O O O 0 Average displacement of alfalfa stalks for comparative stalk position at 30° angle- 00 tilt O O O O O O O O O O O O O O O O 0 Displacement of alfalfa egalks at reel speed of 400 B.P.M., 45 angle-0° tilt . Displacement of alfalfa egalks at Seal speed of 500 R.P.M., #5 angle-0 tilt . Displacement Of alfalfa stalks at reel speed of 600 R.P.M., 45° angle-0° tilt . Displacement of alfalfa stalks at reel speed Of #00 R.P.M., u5° angle-30° tilt . Displacement Of alfalfa stalks at rael speed of 500 R.P.M., u5° angle-30 tilt . Displacement of alfalfa stalks at reel speed of 600 R.P.M., h5° angle-30° tilt . Displacement of alfalfa stalks at reel speed of 400 R.P.M., 30° angle-0° tilt . Displacement of alfalfa sgalks at reel speed of 500 R.P.M., 3o angle-0° tilt . Displacement of alfalfa stalks at reel speed of 600 B.P.M., 30° angle-0° tilt . Page 37 38 39 no 41 #2 43 “5 as A7 48 “9 Table XIV.' vii Page Displacement of alfalfa stalks at reel speed of 000 R.P.M., 30° angle-30° tilt . . 50 Displacement of alfalfa stalks at reel speed of 500 R.P.H., 30° angle-30° tilt . . 51 Displacement of alfalfa stalks at reel speed or 600 B.P.M., 30° angle-30° tilt . . 52 INTRODUCTION Forage and cereal crops are removed by cutting from approximately 70% of the 360 million acres of crop land each year in the United States. Ray is cut from two to six times per season and accounts for about 72 million acres each year in the United States. The mowing machine .is primarly used to cut the hay crop. The mower is also used to control weeds in pastures, fence lines, and road right—aways. Because of its extensive and repeated use, the mower covers more acres each year than any other farm machine. Mower development was closely associated with that of the reaper; the first machines were used to out both grain and grass crops. Ketchum, in the 1840's, market- ed the first mowers that were distinct from reapers. Except for the use Of awpower-take-cff shaft to deliver the tractor power to Operate the mowing machine, few significant improvements were designed into the mower until the late 1940's. The production of a double knife mower was followed by the dynamically-balanced mower. Recent mover research has been primarily concerned on drive mechanisms, cutting energies, and cutting action. The purpose of this research was to increase the usefulness and reduce stoppages of the mower by the design and development of a mechanism to replace the swath board and grass stick presently employed at the outer shoe Of the cutter bar. The information, so gained, can be used in the improvement of mower design, thereby increasing their utilization by reducing stoppages under a wider range of conditions .' LITERATURE REVIEW In 1833 the principle of the reciprocating sickle knife and slotted guards was patented by Hussey.(l) Blaauw states that this.is still the major'mechanism for mowing forage crops. Smith (2) reported a 1856 patent granted to Cornelius Aultman contained the basic principles of mowers (the rachet-pawl drive). _ In the early 1900's the horse-drawn mower tongue was cut Off and the mower was pulled by a tractor. The manufacturing of tractor mounted mowers began about 1920. Mowers underwent few changes as to increased . effectiveness until in the late l9h0's and early 1950's the double-knife mower was produced.‘ According to Blaauw (1), this idea was not new; it was patented in 1833. This was even before an efficient machine had been produced; they experienced difficulties with clogging and drive mechanism balancing. The double-knife mower has no guards; consequently, the knives dull rapidly in gravelly soils and a poor Job results. In addition, this mower tends to ride up on thick or matted crops, as there are no guards to give suction. Elfes (3) discussed the design Of a dynamically balanced, pitmanless, minimum vibration mower capable of many more cutting-strokes per minute. Both of the above mowers were capable of Operating with the cutter bar in any position from the vertical to “50 degrees below the horizontal. Scarnato (b) reported on the counter balancing of a mover drive to facilitate smoothness of operation, absorb the change of balance encountered with Optional length knives, and be.capable of enduring a continuous crank speed of 1000 R.P.M. Feller (5) studied the effect of knife angle on cutting energy. Prince and Wheeler (6) investigated ener- gies and velocities required to cut forage crops. 8 Personal field experiences and Observations, as well as farmer comments, indicated that one of the major deficiencies of the modern mower*was the swath board and graSs stick. The operation of the swath board limits the overall effectiveness of the mower in many applications. The present swath board, consisting of a divider board and/or grass stick, has undergone little change from the earliest mowers. This lack of improvement can be, in part, attributed to the cheapness Of the present board. The present-day functional requirements of the swath board are two-fold. First, it must effectively clear a path for the inner shoe to travel in the next cut around. Failure to clear the strip Of swath next to the uncut crop causes stoppages at the inner shoe on the next round. In many cases of long, viney forage, the stems drape over the board and are dragged along by the grasS'stick. This causes a stoppage of the mower, and requires the Operator to dis- mount to remove the hay from the grass board and stick. The second requirement of the swath board and stick is that the divider arrangement should distribute the transferred forage over the swath rather than winwmaw it on tOp of the outer edge. There are two reasons for this requirement. First, when the forage is deposited in a narrow strip on top of the swath, that portion dries slowly because of the double layer. Secondly, the double layer tends to plug hay conditioners. To minimize plugging the condi- tioner, the rolls are often adjusted with a non-uniform tension in springs or spacing between rollers. This per- mits greater clearance at the end where the double layer of forage is conditioned. Not only does poor conditioning result to the double thickness of material, but also, because of the tapered roll spacing, the forage passing between the rolls adjacent to the two-layer area is not adequately conditioned. This is shown schematically in Figure l. The present swath board aggravates the situation by accumulating under certain conditions small bunches of hay and dropping them onto the swath. This increases swath thickness and non-uniform drying. POOR CONDITIONING . . ~.£!E?%£Sfiififi Ci . , AEITIONER ROLL [DOUBLE LAYER OF FORAGE Fig. 1. Schematic of non-uniform spacing of conditioner rolls. Secondary requirements Of the grass divider were that it be light in weight and positive in action. -APPARATUS A powered grass divider was designed, constructed, and mounted above the outer end of the cutterbar as shown in Figure 2. Basically, this device was a high speed pickup reel. . Sixteen pickup-fingers were free to rotate about their mounting shaft, which was mounted eccentrically in a 6 in. diameter drum. The drum rotated about its concentric axis. The fingers were spaced 13/16 in. apart laterally, but so arranged that they protruded through the drum surface at 90° intervals. The drum rotation forced the fingers to rotate and move in and out, relative to the drum surface. The maximum extension of the fingers beyond the drum was 3 in. Fingers were held by holders made from tubing. The tubing wall was drilled perpendicularly to its concen- tric axis, and the finger pressed into the hole. The fingers were then brazed to the tubing. An Oilite bronze bearing was pressed into the tubing to complete the holder. See Figure 3. The eccentric mounting shaft was made by off- setting the finger shaft from the bearing support shafts with two pieces of i in x l in. flat steel. This is shown in Figure 3. The offset is 1% in. The support shafts were held in two upright mounting brackets. The inner bracket was “L" shaped and extended behind the reel before dropping Fig. 2. Tractor and mower with powered grass divider. I , .. y _ ‘ 3713.137. L .’ I . I“? 1- Fig. 3. Finger assembly and eccentric mounting shaft. down to fasten to the mower bar. This was done to avoid forage catching on the inner bracket. The outer bracket was fastened to the outer shoe. The reel could be adjusted in the vertical and horizontal planes as well as be Operated at various angles to the direction of travel. The are positioner was a part of the outer mount- ing bracket. The positioner was composed of a hub welded to a semi-circle of flat steel. Adjusting holes were drilled On an are close to the perimeter. The positioner was pinned to the support shaft with a split key and a bolt through an adjusting hole secured the positioner to the support bracket. See Figure A. Rotating the positioner moves the mounting shaft inside of the drum, which changes the maximum reach position as well as the ”flipping“ position. x ' ’ The drum consisted of a 15 in. length of a 6 in. outside diameter aluminum tubing (wall thickness 1/16 in.). Sixteen 5/16 in.by l} in. slots were cut into the drum wall to provide clearance for the fingers to are as they rotate. Each slot was 90° apart on the drum periphery at a lateral distance of 13/16 in. apart. Stabilizing bushings for the fingers to slide in were constructed from i in. diameter wood-doweling. These bushings were rocked in their retainers as the fingers oscillated. 10 'IU-A 24-1”; 'L-l) ' 'mf“ .5. ' .. In: Fig. h. "Arc positioner“ mounted on the end of the reel. ' . -u’ BUSHING-j 1— RETAINER Fig. 5. View of drum, drum slots, retainer and stabilizing bushing. 11 Retainers were built from 3/8 in. standard pipe. Each retainer was 1% in. long, reamed to i in. inside dia- meter. An end—mill was then used to slot them laterally, the length of slot equal to the i in. inside diameter. The slot width was 5/16 in. See Figure 5. Two self-tapping metal screws positiOn each re- tainer on the inside Of the drum directly under each drum slot, as shown in Figure 5. Reel ends were built from 1/8 in. flat steel with a i in. long piece of l in. outside diameter tubing, welded to the center for increased bearing support. The tubing was then chucked in a lathe, ends turned to 5 7/8 in.diameter, and tubing and plate drilled and reamed for Oilite bronze bearings. Clips were welded even with.the outside diameter to provide mounting tabs to join drum and ends. The ends fit flush into the drum. The power sprocket was pressed Cover the bronze bushing and fastened to the outer reel end. Figure 6 shows the completed reel. The pickup finger tips travel in a true arc, but tip velicity is not constant, as the mounting shaft is eccentric in the drum. At the I'in" position, tip velo- city is identical with drum velocity. At the extended posi- tion, tip velocity is equal to 3 1/8 times drum velocity. As the fingers approach the fully extended position, the tips are accelerated rapidly, and have a flipping effect. To insure positive action, independent of forward travel, the divider was chain-driven from a hydraulic Fig. 6. Powered grass divider assembly. Fig. 7. Mounting position of the hydraulic motor and enclosure of hydraulic lines. 13 motor, Char-Lynn, Model A-lO. The motor was positioned directly behind the drum, as shown in Figure 7. The hydraulic motor was driven by the tractor's hydraulic system, using the tractor's control valve. The hydraulic lines to the motor were enclosed in a sheet metal case, and positioned right behind the cutterbar. Drum speed was controlled by tractor engine speed, and by changing sprocket sizes. Drum speed ranged from 260 R.P.M. to 600 R.P.M.. giving a peripheral drum velocity of #08 F.P.M. and 9&2 F.P.M., respectively. The ratio of peripheral velocity to ground speed was between 2 and 3 to l. PROCEDURE Initial field tests revealed that forage caught on the left mounting bracket of the reeI, and caused stop- pages. The inner mounting bracket was removed, and the support shaft machined flush with the end plate. The outer mounting bracket was rebuilt to support the entire divider. NO further plugging occurred at the inner end of the reel. The mounting was built from 3/4 in. diameter shaft- ing and setscrew collars. The reel was adjustable in the vertical and horizontal planes, and could also be positioned at various angles to the line of travel and tilted from the horizontal position. The chain and sprockets were tightly shielded to prevent grass entanglement. The divider scattered a narrow strip of cut material, adjacent to the uncut forage. Lateral adjustment of the divider, to permit the outer end Of the reel to skim the uncut grass, eliminated this loss. During high speed Operation, the fingers broke loose from the holders. Fingers were replaced and arc- welded in the holders. The path width and the distribution pattern were unsatisfactory below reel speeds of 400 R.P.M. Consequently, a speed range of #00 to 600 R.P.M. was selected for quali- tative testing.‘ The operation or the divider was satisfac- tory in upright forage up to 2 ft. in height. General Operation .. “(I-’9‘. fl. ‘1? 3,. ' . j. t'. HIS-"1.1,“: ~ _. +.‘ .. a - I , A r . a - N __ ' . \ - " -4 Fig. 8. General field Operation of the divider. Fig. 9. Distribution width after divider Operation. 16 is shown in Figure 8. The forage underwent a rapid accel- eration, and eXperienced a trajectory sufficient to clear a path of 11 to 15 in., and be distributed over the swath in a width up to #0 in. See Figure 9. Although the bar would go through longer, slightly tangled forage without clogging, the forage did not receive a great enough acceleration to distribute it. The drum was roughened to increase the acceleration. Four 2% in. by 1a in. rough rubber strips were cemented longitudinally onto the drum. This is shown in Figure 10. Little improvement in the acceleration was noticed. Another interesting result was noticed. When cutting the last swath, or at any time the outershoe must pass through previously cut swaths, the outershoe and grass- board usually plug. The powered divider pulls the forage in an unbroken flow of material up and over the reel. (Figure 11) This Occurred in both-new and Old cuttings.l Some wrapping Occurred in long, viney, mature alfalfa. Wrapping started from forage being deposited on the hydraulic motor, and then being dragged between mOtor and reel. To eliminate this, the motor was remounted at a 450 angle below the horizontal from the reel. A sheet metal shield was also made to extend from the rear side of the drum, out over the motor. See Figure 12. This lessened wrapping, but did not completely eliminate it. 1? r SM“ ans—1 Fig. 10. Rubber strips mounted on the drum. \ l ' ‘.. ' \ Fig. 11. Operatic of the divider in prev- iously cut material. Fig. 12. Shielding the hydraulic motor to pre- vent wrapping. Fig. 13. Method of tagging alfalfa stalks (arrows indicate tags). 19 The motor was then mounted 200 from being dir- ectly under the reel. The shield was also utilized, but wrapping still occurred. The reel speed appeared to be adequate at 500 to 600 R.P.M; however, because of the length and tangled condition Of the forage (first cutting, mid- July), insufficient velocity was imparted to throw it clear of the reel. Reel and finger action were positive in that material was always carried over the reel, but not positive enough to impart to the forage a velocity approaching drum peripherial speed. When forage did wrap around the drum, a careful operator could quickly clear the reel by alternately chang- ing the rotational direction, by Operating the control valve. The relief valve, in the hydraulic circuit of the control valve, served as a safety clutch. When the divider became severely wrapped, the torque requirement increased rapidly, producing a high pressure surge, which caused the valve to return to neutral. Once wrapping started, the divider's rapid ro- tation would usually cause it to plug before the Operator could stop its rotation. QUALITATIVE TESTING Second cutting alfalfa of approximately 16 in. high was used for the following tests. TO conserve forage and ease of measurements. 1“ in. wide strips were out rather than full cutter bar width. Three 4 in. strips 10 ft. apart at right angles to the line of travel were marked with paint from an instant spray can." This facilitated the location of the hay after it was distributed. After the 14 in. strips were measured, the alfalfa stalks were tagged at 2 in. intervals beginning at the outside edge. This is shown by Figure 13. The tagged stalks were used to establish the distribution pattern after cutting and to analyze the trajectory. Each test consisted of three tagged strips. " Tests were run at reel speeds of #00, 500, and 600 R.P.M. The reel was set at angles or u5° and 60° with the line of travel. The reel was Operated level and at a tilt of 30° below the horizontal for each of the angled settings. All four conditions were repeated for the three reel speeds. The width of path cleared was measured for each test. The lateral and forward or backward position of each tagged stalk was measured with respect to the edge of the standing marked strip as shown in Figure 14. From this, the movement of the tagged stalks from their initial 21 positions could readily be determined. Figure 15 shows divider operation in tagged stalks. 22 [\a I Fig. 1h. measurement of displacement of alfal- fa stalks. Fig. 15. Reel operation in tagged stalks. RESULTS AND DISCUSSION The data discussed in this thesis were obtained by measuring the lateral and forward or rearward displace- ments of tagged alfalfa stalks. The displacements for all of the grass divider settings are recorded in Tables V thru XV. The settings were at h5° angle-0° tilt, 45° angle-30° tilt, 30° angle-0° tilt, and 30° angle-30° tilt with reel speeds of #00, 500, and 600 R.P.M. The 3 displacements for each replicated stalk position in each test were averaged and tabulated in Tables I to IV. Data that did not appear consistent was not in- cluded in the averages. The original positions of the stalk and the data from Tables I and IV, representing the averaged displacements for reel settings of 45° angle-0° tilt and 30° angles-30° tilt for the 400, 500, and 600 R.P.M. reel speeds, have been plotted to show the distri- bution pattern in Figures 16 and 17. Analysis of the graphs indicate the following: 1. The forage does not undergo uniform acceleration but suffers a severe separation. In relation to each other, the inner group of stalks is accelerated forward, but the outer portion is accelerated rearward. 2. 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