US2318562A

US2318562A - Damming device

Info

Publication number: US2318562A
Application number: US348120A
Authority: US
Inventors: Walter H Silver; John I Cantral
Original assignee: Deere and Co
Current assignee: Deere and Co
Priority date: 1940-07-29
Filing date: 1940-07-29
Publication date: 1943-05-04
Anticipated expiration: 1960-05-04

Description

y 4 w. H. SILVER EI'AL 2,318,562

DAMMING DEVICE Filed July 29, 1940 4 Sheets-Sheet 1 INVENTORS. WALTER'H. SILVER &

May 4, 1943. w. H. SILVER HAL DAMMING DEVICE 4 Sheets-Sheet 2 Filed July 29, 1940 a W mu v w n ITZQA m H m Mm w I w 4 She'ets-Sheet 5 INVENTORS.

TTORNEYS.

May 4, 1943.

w. H. SILVER r AL DAMMING DEVICE Filed July 29, 1940 M y 1943. w. H. SILVER ETAL 2,318,562

DAMMING DEVICE Filed July 29, 1940 4 Sheets-Sheet 4 INVENTORS. WALTER H. SILVER &

Patented May 4, 1943 UNITED STATES Q 'DAMMING DEVICE Walter H. Silver and John I. Cantral, Molina, Ill,

assignors to Deere & Company, Molina, 111., a corporation of Illinois Application July 29', 1940, Serial No. 348,120

41 Claims.

"The present invention relates generally to agricultural implements and is more particularly concerned with damming devices.

The object and general nature of the present invention is the provision of certain new and useful improvements in the connecting and controlling means for damming devices of this general character. More specifically, it is a feature of this invention to provide controlling means especially adapted for use with damming tools of the type which include rotatable blades which successively accumulate soil to form dams in the furrow along which the tool is drawn. Still further, it is a feature of this invention to provide a shiftable member successively engageable with oneblade or a set of blades to prevent the rotating tool from moving so as to hold another blade or set of blades in operating position, with toggle means controlled by a member that re-' sponds to the height of the accumulated soil to permit the latching member to move out of engagement with the tool.

An additional feature of this invention is the provision of means for automatically restoring the latching member into its locking position before the next blade or set of blades move into a position to engage the locking member, and still further, another feature of this invention is to provide means for adjusting the toggle links to provide the proper response and release.

Further, another feature of this invention is the provision of a pair of approximately parallel links connecting the front end of the dam-forming device with suitable supporting means, such as a lister plow, and it is also a feature of this invention to provide means for limiting the downward movement of the dam-forming unit. Specifically, it is a feature of this invention to provide connecting links which are not exactly parallel but converge slightly in a forward direction, thereby providing a virtual connection with the supporting means that lies well ahead of the actual or physical connection. An additional feature of this invention is to provide means for cushioning the connection between the damforming unit and the supporting means, and more particularly it is a feature of this invention to provide means for resiliently connecting the dam-forming unit with its supporting means whereby, when the latter is raised toelevate the dam-forming means, and also any furrow forming tools associated therewith, into a transport position, said dam-forming unit is resilientlysupported by a cushioning connection. It is also a feature of this invention to provide connections which ailord a limited amount of lateral flexibility or cushioning.

Still further, another feature of this invention is the provision of a damming unit of the type having a pair of rotatable members each provided with a plurality of blades, with means for yieldingly causing said rotatable members to rotate together so that each blade section on one member acts with the companion section on the other member to form, in effect, a single damforming blade, while the spacing between each blade section and its companion section affords ample clearance for the frame of the dam-forming unit and associated parts.

These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings.

In the drawings:

Figure 1 is a side view of one form of the present invention, showing the sameas embodied in a damming unit adapted to be fixed behind each tool of a tractor listerof the trailing type;

Figures Zand 3 are top and side views, respectively, of the damming unit shown in Figure 1, Figures 2 and 3 including certain modifications relating to the shape of the blade tips and the means for limiting the downward movement of the unit;

Figure 4 is a sectional view taken generally along the line 44 of Figure 3;

Figure 5 is a perspective View of another form of damming unit embodying the principles of the present invention;

Figures 6 and 7 are sections taken, respectively, along the lines 6-6 and 1-! of Figure 5; and

Figure 8 is a side View, taken at a reduced scale, of the damming unit shown in Figures 5-7, showing the means for limiting the downward swinging movement of the damming unit so that when the supporting frame is raised the damming units are also raised, the form of the invention shown in Figures 5-8 being adapted to be attached behind the tool or tools of a lister of the integral or tractor-mounted type.

Referring now more particularly to Figures l3, the lister with which the damming unit of the present inventionis used is indicated in its entirety by the reference numeral I and is constructed generally along the lines of the lister shown in the patent, No. 1,813,207, which issued July '7, 1931, to Walter H. Silver, to which reference may be made if necessary. Briefly, thelister l includes a number of lister units, disposed in transverse alignment, the number being immaterial so far as the present invention is concerned, there being one damming unit for each of the lister furrow openers. Each lister unit includes a lister beam 5, the lower end of which extends downwardly to form a tool-receiving section 6 to which a lister tool 1 is fixed in any suitable manner, preferably by standards 8 connected with the section 6 by a pair of bolts 9. The several lister beams are connected to, or form a part of, a main frame which is indicated by the reference numeral ID and which comprises a transversely extending front frame bar H and a rear cross bar 12, together with two or more longitudinally extending frame bars IS. The latter converge forwardly and receive suitable hitch plates (not shown) by which the implement I may be connected in trailing relation to a tractor. The implement l is particularly adapted for tractor operation, but it is to be understood, so far as the present invention is concerned, the latter is not to be limited to any particular type or kind of propelling means, whether draft animal or tractor power.

The lister I is provided with a pair of supporting wheels 2| which are journaled for rotation on the forwardly extending ends of a crank axle 22, the intermediate portion of which is mounted for rocking movement in brackets 23 suitably fixed to the intermediate lister beams 5. The crank axle 22 is rocked to raise and lower the frame relative to the supporting wheels by means of a half-revolution clutch mechanism 26 driven from the left hand ground wheel 2|. The clutch trip lever is shown at 24, and the depth of operation is controlled by a hand lever connected in the usual manner. When the half-revolution clutch 25 is tripped, the crank axles 22 swing downwardly which raises the frame l6 generally bodily upward, lifting both the lister bottoms l and the damming units associated therewith out of engagement with the ground, as will be referred to below.

Referring now to the damming units with which the present invention is more particularly concerned and one of which is disposed behind each of the lister bottoms 1, each damming unit is indicated in its entirety by the reference numeral 30 and in general, each damming unit includes a frame 3| and a rotatable blade assembly indicated in. its entirety by the reference numeral 32. The frame of each unit 3| comprises a pair of

bars

34 and 35 which at their forward ends are connected together by an integral loop section 36, best shown in Figure 2. A bracket 31 is fixed, as by welding, to the loop section 36 of the frame 3| and forms upper and lower lugs or

bracket sections

38 and 39. The rear ends of the

bars

34 and 35 are secured, as by rivets 4|, to the opposite sides of a forwardly extending section 42 of a casting 40, the rear portion of which is formed as a transverse sleeve 43 in which the rotatable blade assembly .32 is mounted for rotation, as best shown in Figure 4. The manner of supporting the rotatable blade unit will be described below.

centrally of the associated sleeve section 48, as best shown in Figure 2. The link is apertured, as in 52, to receive the lower end of an adjusting eye bolt 53, the upper end 54 of which is threaded and which passes through a trunnion 56 pivotally connected, as at 51, to the upper and rear ends 59 of a pair of standards 60. A pair of nuts 6| are carried at the upper threaded end 54 of the adjusting bolt 53 and serve as stop means engageable with the trunnion 56 to limit the downward swinging of the frame 3|. A pair of upper and lower

parallel links

63 and 64 are connected, respectively, with the pivot bolts 49, carried by the member 41, and the bolts 9 which, as described above, secure the lister bottom standards 8 to the lister beam 6 associated therewith. Each of the

links

63 and 64 comprises a pair of laterally spaced straps 61, 68, as best shown in Figure 2, the

straps

67 and 68 diverging forwardly, as best shown in Figure 2, so as to provide the required spacing so as to embrace the lister standards 8. A pair of cushion-rubber bushings H are disposed about the connecting bolts 46 and serve as resilient means connecting the damming unit with its supporting means, both in lowered operating position and in raised transport position. When in the former position the upper bushing 'II is under compression and yieldingly holds the damming unit to its work, and when the damming unit is raised into its' inoperative or transport position, the lower bushing H is under compression, due to the overhanging weight of the unit itself, thereby cushioning the damming unit and permitting the same as lim ited amount of oscillation in its transport position and thereby relieving the supporting means of jars, vibrations, and the like when travelling across a field or along a road.

As best shown in Figure 2, each damming unit blade assembly 32 consists of two sets of rotatable blades, the right hand unit being indicated by the reference numeral '15 and the left hand unit being indicated by the reference numeral 16, the units being identical in construction except that one is a right hand unit and the other is a left hand unit. Each blade assembly unit consists of a plate 11 to which three angles 19 are fixed, as by rivets 19. The angles 16 are fixed to one side of the associated plate 11. On the other side of the latter is another set of three angles 8|, fixed to the plate 11 by the same rivets The upper and

lower lugs

38 and 39 of the 19. Each pair of angles 18 and 8| carries a damming blade 82 of the configuration shown best in Figure 2.

Referring now to Figure 4, a bearing sleeve 86 is disposed within the sleeve section 43 of the casting 40 and is rotatable therein. The ends of the bearing sleeve 86 extend slightly beyond the ends of the sleeve section 43, and the sleeve 86 is apertured to receive a bolt 81 that extends therethrough. The bolt 81 also extends through apertures in the plates H, the latter being loosely mounted on the ends of the bolt 81. A dust cap 88 is disposed between each plate 11 and the inner end of the

sleeves

43 and 86, each cap 89 being clamped between the associated plate and the end of the sleeve 86, with clearance between the cap- 88 and the end of the mounting sleeve section 43. The clamping means preferably consist of a rubber washer of'substa-ntial thickness disposed between each plate Hand the outer end ofthe bolt, with a backing washer between the outer face of the rubber bushing, which is indicated by the reference numeral 89,

and the head, or-the attaching nut, of the 'bolt 87. The backing washer is indicated by the reference numeral 95.

It will be noted, therefore, that, in effect, the blade units I and 76 are caused to rotate together by the frictional connection that is established when the bolt 81 is tightened and presses through the washers 89 against the plates 1! and associated caps 88. This construction permits one blade unit I5 or I6 to rotate relative to the other if ground conditions require such action, but normally they rotate together and are periodically locked against rotation by locking mechanism that acts against both blade units at the same time, as will now be described.

The mechanism for controlling the rotation of the blade units of each damming device is made to respond to the amount of soil accumulated in front of the damming blades in operative or soil-scraping position. Referring now more particularly to Figure 3, a bracket IUI, preferably consisting of two upstanding bars I92 and I I33 (Figure 2), is secured, as by Welding, to the frame bars 3 3 and 35 generally midway between the ends thereof. The upper ends of the bars I62 and I03 are apertured to receive a pivot I04 which swingably supports a rotation controlling member I'05. At its outer or upper end the latter carries a transverse pin or shaft I56 upon which a pair of rollers IE! and I58 are supported. Preferably, the pin or shaft I55 is welded to the member I05. The member I05 is extended, as at II 0, to form an arm to which a toggle link HI, consisting of a pair of straps, is" pivoted, as at H2. The lower end of the link I I I is pivoted at H3 to the upper end of an arm H4 which is pivoted at II 5 to the frame bars 34 and 35. The arm H4 extends below the pivot H5 and receives the forward end of a shoe II! which extends rearwardly and which preferably consists of a pair of angles IE8 and H9 welded to the lower ends of the arm I I4 at their forward ends and at their rearward ends are welded to a bracket I2I which extends upwardly between the frame bars 34 and 35. A cotter key- I22 is disposed at the upper end of the bracket I2I and serves as means limiting the downward movement of the shoe I I1. As best shown in Figure 2, the shoe II'I, together with the frame 3! and associated parts, is disposed, and the blade units 75 and 16 are spaced apart, so that the blades 82 clear the shoe and frame when the units rotate. Normally, however, they are held against rotation by virtue of the engagement of the outer or tip ends of the blades 82 with the rollers I81 and IE8 when the member IE5 is disposed in the position shown in full lines in Figure 3. In this position the link III and the arm H4 serve as toggle links and are disposed in over-center position so as to prevent the member I55 from swinging in a clockwise direction, the arm or toggle link H4 being prevented from swinging in a counterclockwise direction about its pivot II5 by virtue of the fact that the shoe bracket IZI prevents the shoe II! from swinging downwardly, since in the full line position the cotter key I22 acts as a stop against the frame bars 34 and 35.

The operation of the damming device as described above will best be understood by referring to Figure l, which shows a damming device, 1

constructed according to the principles of the present invention, attached in place behind the furrow opener of a lister of the trailing type. Normally, the lister crank axles 22 are swung u'pwardlyand forwardly in order to permit the lister frame In to lower, this action also lowering the damming units which are mounted rearwardly of the lister bottoms I so that the lower blades of each damming unit operate to scrape soil from the sides of the furrow to accumulate enough soil to form a dam substantially filling the furrow. In order to have the blades scrape soil effectively they must, of course, be held against rotation during the stage of accumulating soil, and this is done according to the present inventionby the toggle lock mechanism described above, consisting of the member I 05 and the toggle links Hi, H5. As long as the toggle links Iii, H4 remain in the position in full lines in Figure 3, the member m5 is held against rotation and, in turn, locks the blade units I5, I6 against rotation, by virtue of the fact that the upper blades engage the rollers I08 and I5! and therefore hold the lowermost set of blades 82 in soilaccumulating position. As the accumulated soil builds upin front of the blades, the soil presses against the shoe Ill and eventually swings the same upward about the pivot H5. This movement swings the arm H4 forwardly, thereby breaking the toggle I I I, I i l by shifting the pivot H3 to the right of a line connecting the pivots I I2 and I I5. The pressure of the soil against the lowermost or working blades 82 acts at all times to tend to rotate the damming blade units, but this is not permitted to occur until the toggle I I I, II 4 .is released, whereupon the pressure of the upper blades'against the rollers It]? and I58 immediately forces the member I05 into the position shown in broken lines (Figure 3) The damming blade units are then free to rotate, being no longer locked against rotation. The rotation of the damming units causes the latter to clear the dam already formed by the accumulated soil, leaving the same intact in the furrow, and the*- next succeeding pair of damming blades'82 move down into operating position, this movement of course bringing the following blades 82 into a position to engage the rollers 15? and Q03. Thus, as to each pair of blades, the other pairs constitute ground-engaging means that restores the tool to dam-forming position. As soon as the machine passes beyond the accumulated soil, the shoe III drops down into the full-line position shown in Figure 3, thus restoring the locking member I to locking position before the next oncoming set of blades reach a position to engage the member I 65. It is important to restore the locking member I05 to locking position immediately after the toggle lock is released in order to insure that the next succeeding set of blades 'will begin accumulating soil immediately after the last dam has been completed. When the end of the field is reached, or if for any other reasons it is desired to place the machine in transport position, the operator trips the power-lift clutch, causing the crank axles 22 to swing downwardly and raise the lister frame. Since the damming units are connected with the lower ends of the beams 5, which are rigidly connected 'to or form apart of the implement frame, the damming When the implement is raised into its transport position, the lowermost nut 6I on the link 53 engages the collar 56 and prevents the damming unit from moving downwardly, yet when in operation each darnrning unit is floatingly connected with its associated supporting means as is essential to secure uniform operation,

Figure l discloses certain modified arrangements, as compared with the construction shown in Figures 2-4, and referring now more particularly to Figure 1, it will be noted that the plate 41 is mounted so that the lug is disposed in a lower position, rather than in an upper position as shown in Figure 3. This requires a somewhat longer link, indicated in Figure 1 by the reference numeral 53a, but the upper threaded end passes through the collar 56 the same as is shown in Figure 3, and receives nuts BI which limit the downward movement of the associated damming unit. Where the lug 5I is disposed in a lower position and the longer link 53a is used, a spring I38 is disposed about the link 53a between the collar 56 and a setscrew collar I 3! adjustably fixed to the link 5311. The spring I38 bears upwardly against the collar 56 at its upper end and at its lower end bears against the collar I3I, thereby acting through the link 53a to hold the damming unit down in a working position, thus augmenting the Weight of the damming unit itself. Also, as shown in Figure 1, the ends of the blades 82 may be bent, as indicated at 820., so that a somewhat greater component of force is available for moving the locking member I05 quickly out of locking position after the toggle HI, II is released. Normally, however, the blades 82 are flat as shown in Figures 2 and 3, but they may be bent, as at 82a, to provide a somewhat quicker release, as may be necessary under certain conditions and/or for higher tractor speeds.

Figures 5-8 show another form of the present invention, wherein the damming unit is particularly constructed so as to be easily attachable to a lister of the integral or tractor-mounted type. In this form of the invention as disclosed in Figures 5-8, inclusive, the tractor is indicated by the reference numeral I58 and is provided with a power-lift unit I5I which includes power lift arms I52 which have extensions I53. The lister frame is indicated in its entirety by the reference numeral I55 and is pivotally connected, as at I56, to a hitch I51, preferably of the spring or cushioned type, including a swinging link arrangement I58 and one or more cushioning springs I59 connected at the forward ends with the forward portion of the tractor I58. The lister frame includes rearwardly extending bars I6I which, at their rear ends, are secured in any suitable manner to a transverse cross member or tool-receiving bar I62. One or more standards I63 are adapted to be secured to the bar I62 in any suitable manner, the lower end of the standard receiving a tool, preferably in the form of a lister bottom, indicated as I64. Preferably, as best shown in Figure 5, each lister standard I63 is clamped to the bar I62 by a cap I66 and a pair of clamping bolts I61. As shown in Figure 5, the standard I63 is of the friction-release type substantially the same as the beam construction shown in Figure 1, each beam or standard I63 including tool-receiving parts I69 which are pivoted, as by a pivot bolt I'II, adjacent the bar I62 and, when the bottom I64 meets obstruction, swingable rearwardly relative to the upper U-shaped part I72 of the standard I63. A clamping bolt I14, together with associated locking members, serves to hold the beam plates I69 against movement relative to the beam section I12 during normal operation.

The details of the damming unit itself, as shown in Figure 5, are substantially the same as described above in connection with Figures 1-3, and for all parts that are identical with those described above the same reference numerals have been used.

The frame 3ia of the damming unit, indicated in its entirety in Figure 5 by the reference nume'ral I88, differs slightly from the frame 3| described above in that the frame bars 340, and

. 35a are not integrally connected at the forward ends, but, instead, are riveted, as at I8I, to a pair of bracket plates I82 and I83. The lower ends of these plates are disposed one against the other, as best shown in Figure 7, while their upper portions I82a and I830. are spaced apart laterally, as best shown in Figures 5 and 6, to receive a collar I85 therebetween, the collar being supported for pivotal movement relative to the bracket sections I82a and I83a by trunnions E86 (Figure 6). Like the damming um'tshown in Figure 3, the damming unit I88 of Figure 5 is swingably connected with the lister beam I63 by means serving as a pair of substantially parallel links I88 and I89. While, in Figure 3, the

links

63 and 6 3 are substantially exactly parallel, in Figure 5, the links I88 and I89 are slightly out of parallelism, being arranged, as best shown in Figure 8, in forwardly converging relation. The upper link I88, as best shown in Figure 6, comprises a threaded shank I8I and a- U-shaped yoke I92, the ends I93 and I96 of which are apertured and pivotally mounted on the lister beam clamping bolt I'M. Preferably, the threaded shank I9I is welded to the yoke I92. A pair of nuts I86 and I9? is threaded onto the shank ISI, and two pairs of rubber bushings I88 and I99 are mounted on opposite sides of the collar I85 between the latter and the nuts I96 and I91. The purpose of this arrangement is to provide flexibility in a generally vertical direction between the damming unit and its supporting standard; that is to say, when the unit is in operating position, the front rubber bushings I99 may be under slight compression in order to hold the unit down to its work, but when the implement is raised into its transport position, as shown in Figure 8, the rear rubber bushings I98 are under compression and resiliently or yieldingly connect the damming unit with hitch supporting means so as to cushion the transmission of jars, Vibrations, and the like to the implement frame.

The connection between the damming unit frame 3Ia and the lower link E89 is also a cushioned connection, this connection affording cushioning in a lateral direction. The lower parallel link I89 consists of apair of straps 28I and 202, which at their forward ends are pivoted on a bolt 283 carried by the standard I63 and at their rear ends are pivoted on a transverse bolt 204', as best shown in Figure '7. A rubber bushing 285 is disposed on the inside of each of the link members 28I and 202, between these links and the frame bracket sections I82 and I83. Yielding of the rubber bushings 265 affords lateral cushioning, and of course the collar I85 fits over the threaded section IQI of the upper link I88 with sufficient looseness that some lateral swinging of the damming unit is permitted, but such movement is cushioned not only by the lower cushioning rubber bushings 205 but also the upper bushings I98 and I99. In other words, each damming unit may swing laterally about a generally vertical axis at the front end of the frame, as permitted by the yielding rubber bushings. Also, by virtue of the yielding of the upper rubber bushings the unit I89 may oscillate vertically about a generally transverse horizontal axis, and the lateral yielding of the lower rubber bushings 265 permits a certain amount of oscillation of the associated damming unit about a generally longitudinal axis.

In the construction shown in Figures 1 and 3, the damming unit is limited in its downward swinging movement, as permitted by the parallel link connection, by a generally vertically extending link which, in effect, is anchored to the supporting means. In Figures and 8 the damming unit is limited in its downward swinging movement, as permitted by the substantially parallel links I88 and I89, by a ground-contacting gauge member which is indicated in its entirety by the reference numeral 2I6. This member includes a downwardly and rearwardly carried rod 2I I having its upper end 2I2 received in a yoke casting 2I3, the latter having a sleeve section 2I4 to accommodate the rod 2. The sleeve section 2 I4 is provided with a setscrew 2 I 5 by which the rod member 2 may be fixed to the casting 2I3. The latter is provided with a pair of laterally spaced arms 2!! and 2I8 which are disposed'on opposite sides of the beam standard I63 and are apertured to receive the same bolt 203 to which the lower parallel link members I and 262 are connected. Also, the yoke casting 2I3 is formed with a lower section 22I. This section is provided on opposite sides with ears 222 which are adapted to engage against the rear edges of the lister beam plates I69. Further, the casting 2I3 also has an ear 225 on each side which is adapted to engage underneath the associated link member 20I or 262, whereby the member 2I3 serves to act through the lower parallel link I89 to limit the downward movement of the damming blades. A projection 226 is also formed on the casting member 2I3 and, when employed with a lister beam of the type shown at I63 in'Figure 5, is adapted to enter into the space between the plates I69. However, with other types of lister beams, such as the solid type, the end of the projection 226 may serve to engage the lister beam and, acting through the ears 225, serve to limit the downward movement of the damming unit.

The form of the invention shown in Figure 5 difiers, also, from the form shown in the preceding figure in that, instead of a rigid standard I2I and a cotter key I22 for limiting the downward movement of the shoe 1, a rod 230 is fixed at its lower end to the shoe I I! in between the angles H8 and H9 and extends upwardly between the frame bars 34a and a. A bushing 23I surrounds the lower portion of the rod 230 and a spring 232 is disposed above the bushing 23I and at its upper end receives a washer 233, also loosely mounted about the rod 238. The upper end of the latter is threaded and receives a pair of lock nuts 234. The engagement of the latter with the upper edges of the frame bars 34a and 35a serves to limit the downward movement of the shoe II! and therefore determines the over-center position of the toggle links III, H4. The provision of the adjusting nuts 234 instead of the cotter key I22, shown in Figure 3,

has the advantage that the over-center position 'of the toggle mechanism may be adjusted 'to secure the action desired. The function of the spring 232 is to facilitate the return as from a position corresponding to the position shown in broken lines in Figure 3, so as to insure under all operating conditions and speeds that the looking member I will be in a position to intercept the next succeeding pair of plates 82 following a release of the toggle'mechanism in response to the accumulation of sufiicient soil to form a dam.

The operation of the damming device shown in Figures 5-8 is substantially the same as the damming device shown in Figures 1-4. The forwardly converging links I88 and I89 provide, in effect, a virtual hitch point for the damming unit I which lies at the intersection of the forwardly extended center lines of the links I88 and I89, which in all normal position of the dammer is well forwardof the actual physical connection between the damming unit and the associated supporting means. This provides a slow floating action for the damming unit and permits the latter to follow irregularities in the ground surface. .When suflicient soil is accumulated in front of. the lower plates 82, the shoe I I1 is pressed upwardly by the soil until (the spring 232yields and permits the soil pressure acting againstthe shoe III tobreak the toggle and permits the soil pressure acting against the plates to rotate the blade assemblies, forcing the latching member I05into a position corresponding to the position shown in broken lines in Figure 3. This action may be facilitated, if desired, b'y forming the outer tips of the blades .82 with a backward bend as indicated in Figure 1 by the reference numeral 82a. The blades 82 are spaced apart so as to move on opposite sides of the gauge rod 2I 1', whereby the presencejof the latter will not interfere with the proper turning of the blade assemblies whenever the toggle mechanism is released. The movement of the gauge rod 2 along the bottom'of the furrow prevents the blades from scraping away too much soil at any one point and serves to secure uniform action.- Whenithe tractor power lift I5I is actuated the arms I52, I53 are raised, and since the arm sections I53 are connectedhwith the lister frame I55 by a chain or chains, as shown in Figure 8, the lister frame and the damming units attached thereto areraised out of ground-engaging position. The engagement of the yoke casting 2I3 withjthe lister beam. plates. I69 limitsthe downward swinging movement of each damming, unit relative to the associated lister beam'I63, and the support of, the damming'units on thalister beams I63 is cushioned by the rubber bushings I98, I99, and 205, whereby the tractor and implement frame are not subjected to objectionable jars and the likewhen transporting the damming units from place to place. s V

While we have shown and described above the preferred structure in which the principles of the present invention have been incorporated, it is to beunderstood that our invention is not to be limited to theparticular details shown and described, ,but' that, .in fact, widely, different meansmaybeemployed in the practice of the broader aspects of'ourinvention.

What we cla'im,.therefore, and desire to secure by Letters Patent is:

1. A damming device comprising an earthengaging tool movable into and out of earthengaging position, mechanism operative to hold said tool in earth-engaging position whereby to formv a dam, means responsive to the" formation of a dam ahead of said tool for tripping said mechanism to release said tool, and means movable separately from and independently of said tool following its release for moving said mechanism into its tool locking position.

2. A damming device comprising an earthengaging tool movable into and out of earthengaging position to alternately accumulate soil in front of the tool, as the latter advances, and deposit said soil in a pile to form a dam, toggle link mechanism, means responsive to the height of the earth accumulated in front of said tool for tripping said toggle link mechanism, means serving as a one-way connection between said toggle link mechanism and said tool, whereby said toggle mechanism is effective to hold said tool in operative position until enough earth for a dam has accumulated, said one-way connection means providing for the return of said toggle link mechanism to its tool holding position before the tool returns to its earth-engaging position.

3. A damming device comprising an earthengaging tool movable into and out of earth-engaging position, toggle link mechanism operative to hold said tool in earth-engaging position whereby to form a dam, means responsive to the formation of a dam ahead of said tool for tripping said toggle link mechanism to release said tool, and means engageable with the ground for restoring the tool to operative earth-engaging position.

4. A damming device comprising an earthengaging tool movable into and out of earthengaging position, toggle link mechanism operative to hold said tool in earth-engaging position whereby to form a dam, means responsive to the formation of a dam ahead of said tool for tripping said toggle link mechanism to release said tool, means for restoring the tool to operative earth-engaging position, and means independent of the position of said tool following its release for restoring said toggle link mechanism into its tool-locking position. i

5. A damming device comprising a rotatable tool having a plurality of parts adapted to successively engage the ground and form a dam, a member movable successively into and out of a position engaging said tool to prevent rotation thereof, shiftable mechanism operative to hold said member in'a position successively engaging different portions of said tool for locking the latter against rotation for positioning said parts successively in operating position, and means engageable with the tops of the dams and responsive to the height of the latter for shifting said mechanism to release said tool for rotation.

6. A damming device comprising a rotatable tool, a member movable successively into and out of a position engaging said tool to prevent rotation thereof so as to hold the tool in earth-engaging position so as to accumulate soil in front of said tool, toggle mechanism for moving said member, a pivoted part adapted to be engaged by the accumulated soil and operatively connected with said toggle mechanism for trip- ,ping the latter and releasing said tool when enough soil to form a dam is collected, and biasing means acting through said pivoted part against said toggle mechanism for returning said movable member to a position to engage said tool.

7. A damming device comprising aframe, an earth-engaging tool rotatively supported by said frame and having'a plurality of dam-forming earth-engaging parts, a member movably carried by said frame and movable successively into and out of a position engaging said tool to prevent rotation thereof so as to hold each of said parts successively in earth-engaging position so as to accumulate soil in front of said tool, a part pivoted to said frame and adapted to be engaged by the accumulated soil in front of said tool, said pivoted part being operatively connected with said member for moving the same from one position to the other and operative to release said tool when enough soil to form a dam is collected, and spring means acting between said frame and said pivoted part for returning said movable member to a position to engage said tool following the release of the latter by an accumulation of soil acting said pivoted part.

8. A damming device comprising a rotatable tool having a plurality of dam-forming earthengaging parts, a member movable successively into and out of a position to engage one of said parts so as to hold another part in dam-forming position, a toggle link mechanism for holding said member in a position to prevent rotation of said tool, and means responsive to accumulation of earth ahead of the earth-engaging part of said tool for tripping said toggle link mechanism and releasing said tool for rotation so as to deposit the accumulated earth to form a dam. I

9. A damming device comprising supporting means, a frame, a pair of links connecting said frame with said supporting means for generally vertical movement relative thereto, a dam-form ing tool carried at the rear end of said frame and movable into and out of earth-engaging position, releasable toggle link mechanism for holding said tool in earth-engaging position so as to accumulate soil to form a dam, and means responsive to the height of soil accumulated in front of said tool for tripping said toggle link mechanism.

10. A damming device comprising supporting means, a generally longitudinally disposed frame, a pair of links for connecting the forward end of said frame with said supporting means for generally vertical movement relative thereto, an earth-engaging tool carried at the rear thereof and movable into and out of earth-engaging position, releasable means for holding said tool in earth-engaging position, and groundengaging means cooperating with at least one of said links for limiting the downward movement of said frame relative to said supporting means.

11. A damming device as defined in claim 10, further characterized by a one-way connection between said ground engaging means one of said substantially parallel links. Y

12. A damming device as defined in claim 10, further characterized by said limiting means comprising a ground-engaging member operatively fixed to one of said links for limiting the downward movement of said damming device.

13, A damming device comprising a longitudinal frame member, a rotatable damming tool carried at the rear of said frame and including a plural ty o eart r nsa ins pa t a ta da carried by said frame, a member movably supported on said standard and movable into and out of engagement, successively, With said earthengaging parts, a link connected with said member, and an arm pivotally connected with said frame adjacent said bracket means and including a section cooperating with said link to form toggle mechanism releasably looking said tool against rotation, said arm having a ground:

engaging portion operative upon the accumulation of a predetermined amount of soil in front of one of said tool parts for releasing said tool for rotation so as to deposit the accumulated soil in the form of a dam, and means for limiting the downward movement of said frame.

14. A damming device comprising supporting means, a frame, an earth-engaging dam-forming tool connected with the rear end of the frame and normally disposed so as to engage the soil at a predetermined working angle, and a pair of links spaced apart vertically and connecting said frame with said supporting means for generally vertical movement relative thereto about a virtual pivot point in advance of said supporting means.

15. A damming device as defined in claim 14, further characterized by means for adjusting the effective length of one of said links.

16. A damming device as set forth in claim 14, further characterized by a yoke pivotally connected with said supporting means adjacent the lower of said links, said yoke having portions adapted to engage said lower link to limit the downward movement of the latter relative thereto, and ground-engaging element adjustably carried by said yoke.

17. Controlling mechanism for a movable earth-engaging dam-forming member, comprising frame means upon which said member is movably supported, a bracket carried by said frame means, an arm pivoted on said bracket and releasably engageable with, said member for periodically holding the same against movement relative to said frame, toggle links pivotally con nected with each other and said member and frame, respectively, and a shoe fixed to move with said toggle links and responsive to the height of soil accumulated in front of said damforming member for releasing said toggle links.

18. Controlling mechanism as defined in claim 17, further characterized by adjustable means determining the over-center position of said toggle links. I

19. A damming device comprising supporting means, a damming unit including tool means adapted to form a dam, means for raising said supporting means for lifting said tool out of engagement with the ground, and cushioning means connecting said damming unit with said supporting means for resiliently supporting said unit therefrom when said supporting means is raised,

20. A damming device comprising supporting means, a damning unit including a, frame and tool means carried thereby, said frame having upper and lower lugs and cushioning means connecting said frame with said supporting means including upper and lower connectors limiting the outward movement of said frame relative to said supporting means and a pair of compressible rubber bushings surrounding said connectors and accommodating, by virtue of their compressibility, a limited amount of cushioned movement of said unit relative to said supporting means.

21. A damming device comprising supporting means, a damming unit including a frame and tool means carried thereby, means connecting said frame with said supporting means including a pair of compressible rubber bushings accommodating, by virtue of their compressibility, a limited amount of cushioned movement of said unit relative to said supporting means, said frame means including upper and lower lugs at its forward end, said cushioned connecting means including a link pivotally connecting the lower lug with said supporting means, and a connector for the upper lug pivotally connected with said supporting means and with said upper lug, said pair of rubber bushings being disposed between said upper connector and said upper lug and serving to cushion movement of said upper lug relative to said upper connector in both directions.

22. A damming device comprising supporting means, a damming unit including a frame and tool means carried thereby, means connecting said frame with said supporting means including a pair of compressible rubber bushings accommodating, by virtue of their compressibility, a limited amount of cushioned movement of said unit relative to said supporting means, said frame means including upper and lower lugs at its forward end, said cushioned connecting means including a link pivotally connecting the lower lug with said supporting means, a connector for the upper lug pivotally connected with said supporting means and with said upper lug, said pair of rubber bushings being disposed between said upper connector and said upper lug and serving to cushion movement of said upper lug relative to said upper connector in both directions, and a second pair of rubber bushings associated with the lower lug and providing for transverse cushioning in both directions.

23. A damming device comprising a pair of rotatable members,..and means frictionally engaging said members so as to cause them to rotatesimultaneously and to accommodate relative movement of one with respect to the other.

24; A damming device comprising a frame, a member rotatably' mounted thereon, a pair of rotatable damming'units, and means including a rubber bushingfo'r each unit ioryieldingly connecting said units with said member for rotation therewith. 1

25. A damming device comprising an earthengaging tool movable into and out of earthengaging position, a releasable member operativeto hold said tool in earth-engaging posi tion whereby to form a darn, a part adapted to be engaged-by the accumulated soil in'front of said tool, said part -being operativelyconnected with said member for moving the-same from one position to the other and. operative to release said tool when enough soil to forma dam is collected, and spring means a'cting'against said dam-engaging part for returning said movable member to a position to engagesaidtool following the release of the latter by an accumulation of soil acting against said part.v r

26. A dam forming device comprising a longitudinal frame member, dam forming tool means movably mounted adjacent the rear portion of said longitudinal frame member, a locking member for releasably holding said locking member in a dam forming position, toggle means reacting against said frame member for holding said locking member in tool-holding position, means responsive to theaccumulation of soil by said tool to actuate 'said toggle means for causing said locking member to release said tool, and means whereby the pressure of the soil against said tool following its. release moves the tool into a dam forming position.

27. A damming device comprising supporting means, a frame, means connecting said frame with said supporting. means for generally vertical movement relative thereto, a dam-forming tool carried at the rear end of said frame. and movable into and out .ofearth-engaging position,

and movable into and out of engagement, sue:

cessively, with said earth-engaging parts, a link connected with said member, and an arm pivotally connected with said frame adjacent said standard and including a first section adapted to be moved by the accumulation of earth in front of said tool and a second section cooperating with said link to form toggle mechanism releasably locking said tool against rotation.

29. A damming device comprising a frame, a rotatable damming tool carried at the rear of said frame and including a plurality of earthengaging parts, a standard carried by said frame, a member movably supported on said standard and movable into and out of engagement, successively, with said earth-engaging parts, a link connected with said member, and an arm pivotally connected with said frame adjacent said bracket means and including a section cooperat ing with said link to form toggle mechanism releasably locking said tool against rotation, said arm having a ground-engaging portion operative upon the accumulation of a predetermined amount of soil in front of one of said tool parts for releasing said tool for rotation so as to deposit the accumulated soil in the form of a dam.

30. A damming device comprising a frame, a movable damming tool carried at the rear of said frame, a standard carried by said frame, a member movably supported on said standard and movable into and out of engagement with said tool for holding the same in earth-engaging position, a link connected with said member, and an arm pivotally connected with said frame adjacent said bracket means and including a sec-. tion cooperating with said link to form toggle mechanism releasably locking said tool against movement, said arm. having a ground-engaging portion operative upon the accumulation of a predetermined amount of soil in front of said tool for releasing the latter so as to deposit the accumulated soil in the form of a dam.

31. A damming device comprising a pair of rotatable members, means yieldingly connecting said members together so as to cause them to rotate simultaneously and to accommodate relative movement of one with respect to the other, and means for bringing said members back into position with respect to each other after the occurrence of relative movement therebetween,

32. A damming device comprising a pair of rotatable members, means yieldingly connecting said members together so as to cause them to rotate simultaneously and to accommodate relative movement of one with respect to the other, and releasable rotation-preventing means periodically engageablewith said members for hold-. ing them against rotation and bringing them back into position with respect to each other, after the occurrence of relative movement therebetween.

33. A damming device comprising a longitudinal frame, a pair of members mounted on said frame at opposite sides thereof for rotation relative to the frame, and means yieldingly connecting said members together so as to cause them to rotate simultaneously and to accommodate relative movement of one with respect to the other.

34. A damming device comprising a longitudinal frame, a pair of members mounted on said frame at opposite sides thereof for rotation relative to the frame, means yieldingly connecting said members together so as to cause them to rotate simultaneously and to accommodate relative movement of one with respect to the other, and means on the frame and engageable with said members for bringing the latter back into position with respect to each other after the occurrence of relative movement therebetween.

35. A damming device comprising a longitudinal frame, a pair of members mounted on said frame at opposite sides thereof for rotation relative to the frame, means yieldingly connecting said members together so as to cause them to rotate simultaneously and to accommodate relative movement of one With respect to the other, and releasable rotation-preventing means movably mounted on said frame and periodically engageable with said members for holding them against rotation and bringing them back into position with respect to each other after the occurrence of relative movement therebetween.

38. A damming device comprising a longitudinalframe, a pair of members mounted on said frame at opposite sides thereof for rotation relative to the frame, means yieldingly connecting said members together so as to cause them to rotate simultaneously and to accommodate relative movement of one with respect to the other, and means on the frame releasably engageable with both of said members for holding them against rotation.

37. A damming device comprising a longitudinal frame, a pair of members mounted on said frame at opposite sides thereof for rotation relative to the frame, means yieldingly connecting said members together so as to cause them to rotate simultaneously and to accommodate relative movement of one with respect to the other, means on the frame releasably engageable with both of said members for holding them against rotation, and means responsive to the formation of a dam ahead of said members for releasing said releasable means.

38. A damming device comprising an earthengaging tool movable into and out of earthengagi-ng position to alternately accumulate soil in front of the tool, as the latter advances, and deposit said soil in a pile to form a dam, releasable locking means, means responsive to the height of the earth accumulated in front of said tool for releasing said locking means, means serving as a one-Way connection between said locking means and said tool, whereby said looking means is effective to hold said tool in operative position until enough earth for a dam has accumulated, said one-way connection means providing for the return of said locking means to its tool holding position before the tool returns to its earth-engaging position.

39. A damming device comprising a frame, an earth-engaging tool rotatively supported by said frame for movement about a fixed axis relative to said frame, said tool having a plurality of darn-forming earth-engaging parts, a member movably carried by said frame and movable successively into and out of a position engaging said tool to prevent rotation thereof so as to hold each of said parts successively in earth-engaging position so as to accumulate soil in front of said tool, a part pivoted to said frame forward of said tool and adapted to control said member, and spring means acting between said frame and said pivoted part for moving said member into a position to engage said tool following the formation of a dam independently of the position of said tool.

40. A damming device comprising supporting means, a generally longitudinally disposed frame, link means for connecting the forward end of said frame with said supporting means for generally vertical movement relative thereto, an earth-engaging tool carried thereby and movable into and out of earth-engaging position, releasable means for holding said tool in earthengaging position, and ground-engaging means cooperating with said link means for limiting the downward movement of said frame relative to said supporting means.

41. A damming device comprising supporting means, a damming unit including a frame and tool means carried thereby, said frame including upper and lower lugs at its forward end, a link pivotally connecting the lower lug with said supporting means, a connector for the upper lug pivotally connected with said supporting means and with said upper lug, and a pair of resilient parts disposed between said upper connector and said upper lug and serving to cushion movement of said upper lug relative to said upper connector in both directions.

WALTER H. SILVER.

JOHN I. CANTRAL.