US3234671A

US3234671A - Land-forming apparatus

Info

Publication number: US3234671A
Application number: US351410A
Authority: US
Inventors: Eugene R Reynolds; Aaron G Reynolds
Original assignee: Reynolds Res and Mfg Corp
Current assignee: CONWAY TECHNOLOGIES Corp A CORP OF TX; Reynolds Res and Mfg Corp
Priority date: 1964-03-12
Filing date: 1964-03-12
Publication date: 1966-02-15
Anticipated expiration: 1983-02-15

Description

7 1966 E. R. REYNOLDS ETAL 3,234,671

LAND-FORMING APPARATUS 2 Sheets-Sheet 1 Filed March 12, 1964 Eugene Reyna/a6- Aaron 6 fleyfla/ J INVENTORJ ATTO/P/VEVJ Feb. 15, 1966 Filed March 12, 1964 E. R. REYNOLDS ETAL 3,234,671

LAND-FORMING APPARATUS 2 Sheets-Sheet 2 aye/7e ff Reyna/a: Aaron 6. fieyno/o J INVENTORJ ATTO/P/VEVJ United States Patent 3,234,671 LAND-FORMING APPARATUS Eugene R. Reynolds and Aaron G. Reynolds, both of McAllen, Tern, assignors to Reynolds Research and Manufacturing Corporation, McAllen, Tex., a corporation of Texas Filed Mar. 12, 1964, Ser. No. 351,410 8 Claims. (Cl. 37148) This invention relates generally to land forming apparatus, and particularly to improvements in apparatus for forming land to a predetermined rise or fall in elevation.

There are, of course, many and sundry types of equipment, including the ordinary bulldozer, with which an operator may form land to a desired grade by manipulation of the elevation of the blade or cutting edge of the equipment as it traverses the land. In raising or lowering the blade, the operator may be guided by grade stakes set at spaced-apart points over the land. In the alternative, he may be directed by rows which have been raised upon or lowered into the land surface by appara tus of the type shown and described in US. Patent No. 3,041,754, issued to Aaron G. Reynolds, on July 3, 1962. When the land is marked with these rows, they take the place of grade stakes, so that, in a subsequent operation, a bulldozer or other more conventional apparatus may be used to form the land to the grade marked by the rows.

The forming of land to grade by means of stakes has many obvious shortcomings, some of which are noted in the aforementioned US. patent. On the other hand, when a row is being formed in the manner described in the above noted patent, the instrument man is normally a substantial distance from the operator of the marking apparatus. Ordinarily, this presents no particular problem when the land is merely being leveled because, during the use of this apparatus, the instrument man merely guides the operator in' maintaining a target connected to and movable with the cutting edge of the blade in the line of sight of his level instrument. However, when the land is to be formed to grade so that the distance which the apparatus travels becomes a factor, the instrument man is ill equipped to guide the operator because of his inability to accurately determine this distance and thus the manner in which the cutting edge must be raised or lowered to maintain the grade.

It is the primary object of this invention to provide land-forming apparatus which permits the, instrument man to guide the operator of the device in forming the land to grade without having to determine the distance travelled by such apparatus.

Another object is to provide apparatus of this type which may be easily and readily adjusted for changing the grade to which the land is to be formed.

A further object is to provide such apparatus which may be adjusted for selectively forming the land to either a predetermined rise or fall in elevation, and more particularly which may be so adjusted by the operator of the apparatus from the position he ordinarily occupies in the use of same.

Still another object is to provide apparatus of this general type in which the operator has continuous visual indication of the elevation of the cutting edge of the blade, and further in which the operator may initially set the elevation of the cutting edge from his usual loca tion on the apparatus.

Yet another object is to provide such apparatus which enables the operator, again from his usual station, to reconcile the elevation of the cutting edge of the blade with elevations of design maps used in the forming of the land.

"ice

A still further object is to provide apparatus of the type described in one or more of the foregoing objects which is both simple and economical to construct.

These and other objects are accomplished, in accordance with the illustrated embodiment of the invention, by a target mountable on a grade line marker or other land-forming apparatus for movement with the cutting edge of the blade thereon. The blade is in turn mounted on the frame of the apparatus in such a manner that it may be raised and lowered with respect to the frame and the ground over which it moves. A part movable in response to movement of the frame over the ground is connected to the target in such a manner as to automatically change the elevation of the target relative to the blade cutting edge a predetermined amount for a given distance of frame movement. When the instrument man detects this rise or fall in the target, he is able to guide the operator of the land-forming apparatus in bringing the target back into the line of sight of his level instrument so as to raise or lower the blade edge accordingly. Of course, as this operation is repeated during movement of the apparatus over the ground, such ground is automatically formed to the desired grade.

For use in the initial setting of a blade edge to a desired level, an indicator is mounted on the frame for movement responsive to the target and relative to indicia on the frame. Also, there is a means for adjusting the elevation of the target relative to the blade cutting edge and independently of its movement responsive to movement of the frame over the ground. Thus, when the elevation of the line of sight has been determined, the target and thus the indicator can be moved and the location of the indicator relative to the indicia noted in order to determine the elevation of the blade cutting edge. At this time, the target may'be moved relatively to the frame and cutting edge to dispose the indicator in the desired position relative to the indicia, and the instrument man may then guide the operator in moving the blade cutting edge and thus the target back into the line of sight in order to set the cutting edge at the desired elevation.

Preferably, the indicia and indicator are so located on the apparatus as to be visible to the operator at his usual station relative to the apparatus. More particularly, when the operator station, and thus the indicator and indicia, are disposed at a location remote from the target, the means for adjusting the elevation of the target independently of frame movement is remotely operable at such location. In this manner, the operator has complete control over the use of the apparatus not only in the sense that he is at all times aware of the elevation of the cutting edge of the blade, but also inasmuch as he is in a position to initially set such elevation by adjusting the elevation of the target and indicator and then raising or lowering the cutting edge of the blade in accordance with directions from the instrument man. In a still further preferred embodiment of the invention, there is additional indicia on the frame which is located close to the first-mentioned indicia as well as the indicator and which is adjustable to permit it to be used in correlating the cutting edge elevation to map readings observed by the operator in his use of the apparatus.

In the illustrated form of the invention, the part which moves responsive to movement of the frame comprises a disc which is connected to a ground engaging wheel of the frame of the land-forming apparatus for rotation with it. In the case of a frame which is dragged over the ground, the wheel may be similarly connected to a non-supporting wheel. In either case, a drive mechanism is disposed between the rotating disc and target, a pin is mounted on the disc, and a pivotal arm is dis posed with one end in the path of the pin to be rocked thereby as the disc rotates and another end engageable with the drive mechanism to actuate it upon rocking of the arm. The drive mechanism is then connected to the target in a suitable manner, such as by means of an endless cord or cable, for automatically raising and lowering said target in response to its actuation by the arm.

More than one pin may be mounted on the disc so that the arm is rocked and the drive mechanism actuated just that much more often. Obviously, therefore, the extent to which the target is raised or lowered may be adjusted on the basis of the number of pins mounted on the disc. The drive mechanism is reversible so that it may be mounted between the target and rotating disc for selectively raising or lowering the target, whereby the apparatus is useful in forming the land to a r1s1ng or falling grade. In the preferred embodiment of the invention, the means for so reversing the drive mechanism is remotely actuatable by the operator from his usual station relative to the apparatus.

In the drawings, wherein like reference characters are used throughout to designate like parts:

FIG. 1 is a side view of a grade line marker broken away in part and having a device constructed in accordance with the present invention for forming the land to a predetermined rise in elevation during forward movement of the marker;

FIG. 2 is a horizontal sectional view of the grade line marker of FIG. 1, as seen along broken line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view of a portion of the device of FIG. 1, on an enlarged scale and as seen along broken line 33 thereof;

FIG. 4 is an elevational view of the device, as seen from the right-hand side of FIG. 3;

FIG. 5 is a side view of the device as shown in FIG. 1, but with parts thereof adjusted for forming the land to a predetermined fall in elevation during forward movement of the grade line marker; and

FIG. 6 is an elevational view of the front of the device, as seen along broken line 66 of FIG. 1, and showing among other things the indicator and 1nd1c1a visible to the operator.

With reference now to the details of the above-described drawings, and particularly FIG. 1, the grade line marker 10 may be similar in construction to that shown and described in the aforementioned US. Patent No. 3,041,754. Thus, it includes a frame 11 having laterally spaced-apart

sleds

12 and 13 for movement forwardly over the ground level G. For this purpose, the frame is adapted to be connected to a tractor (not shown) or the like for forward movement from right to left, as seen in FIG. 1. Obviously, the operator would normally be seated on the tractor and thus at a location close to the front or left end of the marker.

As more fully described in the aforementioned patent parallelogram type support 15 is pivotally mounted on an upstanding portion 11a of the frame for swinging about axes extending transversely to the direction of movement of the frame. A gathering member 16 comprising rearwardly converging, spaced-apart blades 16a (FIG. 2) is carried on a vertical member 58 at the front end of the support 15, while a digging member-17 comprising rearwardly diverging blades 17a connected at their forward ends (FIG. 2) is carried on a vertical member 59 at the rear end thereof. Thus, upon tilting of the front end of the support upwardly, as shown 1n FIG. 1, the cutting edges of the digging member blades 17a are lowered beneath the ground level, while the lower edges of the gathering member blades 16a are raised above such level. On the other hand, upon lowering of the front end of the support 15, the lower edges of the blades 17a are raised above the ground level, while the cutting edges of the blades of the gathering member 16 are lowered beneath such level. Obviously, and again as described in the patent cited, this movement of the support relative to the frame may be accomplished by any suitable means, such as an hydraulic actuator (not shown).

As described in the aforementioned patent, upon the abovedescribed raising of the gathering member and lowering of the digging member, the grade line marker 10 is operative to lower a row of the ground to the elevation determined by the lower edge of the blades of the digging member. On the other hand, upon raising of the digging member and lowering of the gathering member beneath the ground level, the rearwardly converging and spaced blades 16a of such gathering member will cause the earth to be plowed up and raised as it passes through them. This raised row is smoothed off to a desired grade by the blades 17a of the digging member, so that the grade line marker is operable to selectively raise or lower a row of the ground to a desired elevation.

Although the device to be describedis illustrate-d as being attached to and forming a part of this particular type of land-forming apparatus, it will be understood that such device is also useful in connection with other types of earth-working apparatus wherein a blade may be raised or lowered with respect to the frame movable over the ground level. Thus, although the invention is particularly useful in raising or lowering a marking row to a desired grade, it is also useful, in a broader sense, in forming an over-all plot of land to a desired grade, and the expression land-forming apparatus is used in the claims in this generic sense.

With reference now to the details of the device, a target 18 is carried from the support member 59 of the digging member 17 so that normally it will move with the cutting edge of the blades of the digging member and thereby indicate the level thereof, particularly with respect to the established elevation of the line of sight indicated in FIG. 1. The target 18 is connected as part of a continuous cord or cable 19 which is suspended above the target by a pulley 20 which is in turn suspended from a rearwardly extending flange of an upstanding rod 26 connected at its lower end to the rearward support member 59. Beneath the target 18, the cord extends downwardly about pulley 25 and then rearwardly to the pulley 23 (FIG. 3), both of which are carried on the side of frame member 59. From the pulley 20, the cord extends downwardly to another pulley 24 which, similarly to

pulleys

23 and 25, is carried by rear support member 59.

The front frame member 58 includes an upstanding portion 58a to provide a front face 50 having considerable vertical extent, as shown in FIG. 6. A .pulley 53 is mounted on the upper end of upstanding portion 58a, and another pulley 54 is mounted beneath the pulley 53 on the lower end of the front frame member 58. More particularly, and for a purpose to be described, the front sides of the pulleys 53 and '54 are substantially in alignment with the face 50 of the front frame member 58.

Additional pulleys

55 and 56 are mounted on the frame member 58 intermediate the

pulleys

53 and 54 and spaced somewhat rearwardly thereof. Thus, as can be seen from FIG. 1, cord 19 crosses itself in extending forwardly from pulley 24 to pulley 56 and forwardly from the pulley 2-3 to pulley 55.

From the

pulleys

55 and 56, the cord extends upwardly and downwardly, respectively, tothe pulleys 5 3 and 54, and then vertically between the front sides of the

pulleys

53 and 54. Since this extent of the cord is in substantial alignment with the front face 50 of the frame member 58, an indicator in the form of a pointer 57 connected as a part of the cord moves closely over a side edge of the front face 50 of the member 58. Inasmuch as the cord crosses itself as above described, the pointer 57 is caused to move upwardly or downwardly with the target 18, and particularly with a line indicator 18a on the target.

As shown in FIG. 1, there is indicia on the back side of the rod 26 which is visible to the instrument man and which provides a reference point for determining the elevation of the cutting edge of digging member 17. There is similar indicia 51 on the front face 50 of frame member 58 to provide a reference point visible by the operator of the grade line marker in making the same determination from his station. More particularly, the indicia on the rod 26 is disposed opposite the range of movement of the target indicator 18a, while the indicia 51 on the front frame member 58 is disposed opposite the range of movement of the indicator 57. As will be described to follow, either or both may be used in initially setting the elevation of the cutting edges in forming the land to the desired grade.

As shown in FIG. 6, there is additional indicia 52 which extends parallel to indicia 51 and is disposed between it and indicator 57 on the front face 50 of member 58. This latter indicia comprises a tape held between

rollers

60 and 61 at its upper and lower ends, respectively, for movement vertically across the front face 50. Thus, the operator may adjust the tape indicia 52 relative to the indicator 57 so as to correlate the elevation of the cutting edges of the marker to the elevations shown on the map of the plot of land being formed.

As best shown in FIG. 3, a hub 2301 on the pulley 23 extends through and is journaled within the frame member 59, and the outer end of the hub 23 has a square portion over which a worm :gear 64 is mounted. A shaft 27a on the side of a ratchet 27 extends through the pulley 23 as well as through the hub 23a on the pulley so as to rotatably mount the ratchet on support member 59 coaxially of pulley 23. The end of this shaft is threaded to receive a nut 65, and a spring 66 is compressed between the nut and the outer end of the hub 23a to urge the op positely facing sides of the hub and ratchet into engagement with the opposite sides of friction washer 67 which is also placed over the shaft 27a. Thus, there is a friction clutch between the ratchet wheel and pulley 23 which will, under normal loading, cause the pulley to rotate, and thus the cord 19 to move, with rotation of the ratchet wheel 27.

As best shown in FIGS. 3 and 4, a worm 68 is operably engageable with the worm gear 64 adjacent the side of rear frame member 59. More particularly, the worm is connected to a torque transmitting cable 72 received with a flexible sheath 69 and the sheath is held by means of a bracket 71 on the member 59 to position the worm for such engagement with gear 64. Th opposite end of the cable 72 extends toward the front of the grade line marker, as shown in FIG. 1, and is there mounted Within a bracket 74 on the left side of face 50 of front frame member 58 (FIG. 6). A knob 70 is connected to the forward end of the cable to enable the operator to turn the worm 68 in either direction. Obviously, when the worm is engaged with the gear 64, this rotation causes a corresponding rotation of the pulley 23. Thus, as will he described more fully hereinafter, the operator may manipulate the hand knob 70 for moving the cord and thus the target 18 relative to the frame. Furthermore, since the torque transmitting cable 72 is of greater length than the sheath 69, the cable may, if desired, be moved lengthwise relatively to the sheath so as to selectively engage or disengage the worm 68 with respect to the wheel 64.

The teeth about the ratchet wheel 27 are adapted to be engaged by a pawl 29 pivotally mounted on the upper end of an arm 30. The arm is in turn pivotally mounted on the front side of the ratchet wheel 27 by means of a threaded pin or bolt 63, as best shown in FIG. 3. More particularly, and as well known in this art of ratchet and pawl mechanisms, the pawl is spring pressed in any suitable fashion into a position in which its outer end normally engages against a tooth about the ratchet wheel 27.

An intermediate portion of the arm 30 on the side of the bolt 63 thereof opposite the pawl 29 is normally urged by a compression spring 34 into engagement with a stop 31 (see FIG. 3) mounted upon and extending outwardly from the front side of rear frame member 59. As shown diagrammatically in FIGS. 1 and 5, the end of the coil spring 34 may be carried on any suitable bracket 32 on the rear frame member.

As shown in FIG. 5, the arm 30 is normally disposed substantially vertically to dispose the end of the pawl 29 against the front side of a tooth on the ratchet wheel 27 However, upon swinging of the arm in a clockwise direction, as will be described to follow, the pawl 29 is caused to move other the back side of a succeeding tooth into a position on the front side of such succeeding tooth. Thus, upon return movement of the arm to its substantially vertical position shown in FIG. 5, the ratchet wheel 27 is caused to rotate in a counterclockwise direction. This will in turn rotate the pulley 23 in the same direction and thereby advance the cord 19 so as to raise the target 18 out of the line of sight.

When this occurs, and in the operation of the device to be described more fully hereinafter, the instrument man will indicate to the operator that the target should be lowered so as to bring its indicator 18a back into the line of sight and thereby lower the cutting edge of the blades 17. Consequently, upon continued forward movement of the frame of the grade line marker, the land will be formed to an elevation lower than the elevation to which it was previously formed. Thus, during a series of these changes in elevation of the cutting edge of the blades 17, the land will in effect he formed to a predetermined fall in elevation. If, on the other hand, it is desired to form the land to a predetermined rise in elevation, the position of the pawl 29 relative to the arm 30 is reversed. That is, the pawl is swung from the position shown in FIG. 5 to the position shown in FIG. 1, in which latter position it engages with the back side of a tooth of the ratchet wheel 27. Thus, swinging of the arm 30 in the previously described clockwise direction will move the pawl 29 against the back side of a tooth of the ratchet wheel 27 to move the ratchet wheel in a clockwise direction. Return swinging of the arm 30 will drag the pawl 29 over the front side of the preceding tooth and into engagement with its back side.

This clockwise rotation of the ratchet wheel 27 will, of course, rotate the pulley 23 in the same direction. Furthermore, this clockwise rotation of the pulley 23 will move the cord 19 in a direction to lower the target 18 with respect to the frame member. As a result, and as indicated above, this permits the apparatus to be used in forming land to a predetermined rise in elevation, because, after each such lowering of the target, the instrument man will indicate to the operator that the target is to be raised so as to bring its indicator 18a back into the line of sight, which of course will raise the cutting edge of the digging member 17.

In a preferred form of the invention, this reversal of the position of the pawl 29 may be accomplished by the operator from his usual station relative to the grade line marker. For this purpose, and as best shown in FIGS. 1 and 3, another cable 78 is extended from a position at the upper end of the rear frame member 59 to a position extending through the bracket 74 to one side of the front frame member 58. The forward end of this cable is connected to a hand knob 79 whereby it may be rotated in either direction by the operator at his normal station. As shown in FIG. 3, a crank 75 is formed on the rear end of the cable 78 and held in position for engaging pawl 29 by means of a bracket 77 which positions the sheath 76 surrounding the cable 78 at the upper edge of rear frame member 59 and with the axis of the crank aligned with the pivotal axis of pawl 29. As will be appreciated from the foregoing, rotation of the cable 78 will in turn rotate the crank 75 so as to engage the pawl 29 between its pivotal connection to the arm 30 and the teeth about ratchet Wheel 27.

The arm 30 is swung by the engagement with its lower end of a pin 35 located near the periphery of a disc 36 rotatably mounted upon a shaft 33 carried by the lower portion of support 59 (see FIG. 3). That is, during rtation of the disc 36 in a counterclockwise direction, as indicated in FIGS. 1 and 5, the pin 35 will be caused to engage the lower end of the arm 30 to swing it in the desired arc and then release it for return to the vertical position defined by the stop 31 under the urging of spring 34.

As previously described, this rotation of the disc 36 is directly proportional to the distance travelled by the leveling apparatus. For this purpose, the disc may, in the case of a wheeled apparatus, be attached for rotation with one of the wheels. Alternatively, in an apparatus which is dragged over the ground, as by means of the

sleds

12 and 13 of the grade line marker illustrated in the drawings in the present invention, rotation may be imparted to the disc by a wheel 37 freely swingable on an arm 38 extending rearwardly from the shaft 33. In this manner, the wheel 37 will engage the ground and thus rotate in the counter-clockwise direction indicated by the arrows of FIGS. 1 and 3 as the marker 10 moves over the ground G. This rotation of the wheel is in turn transmitted to the disc 36 by means of a chain drive 39 disposed about a sprocket wheel 42 keyed to a hub of the wheel 37 for rotation therewith and a sprocket 40 keyed to a hub extending from the disc 36, as shown in FIG. 2.

In the use of this apparatus, the instrument man will first sight through the level instrument upon an established height index, ordinarily a bench mark, in order to establish the elevation of the line of sigh of such instrument. He will then direct the line of sight toward the grade line marker and visually guide the operator in bringing the indicator 18a of the target 18 into the line of sight. For this purpose, the operator may raise or lower the target by means of the knob 70 adjacent his station at the front of the grade line marker. As previously described, if the worm 68 is out of engagement with worm wheel 64, the operator may push the knob toward the bracket 74 so that the cable 72 is extended rearwardly in order to bring about engagement of the worm 68 with the wheel. At this time, turning of the knob in the proper direction will rotate the wheel 64 and thus the pulley 23 in order to raise or lower the target. If this rotation of the pulley 23 is opposed to the engagement of the pawl 29 with a tooth of the ratchet wheel 27, the pulley will rotate freely of the ratchet wheel since it will slide relative to the friction disc 67.

When the indicator line 18a of the target has thus been brought into the line of sight of the level instrument, the instrument man may determine the elevation of the cutting edge of the grade line marker by observation of the position of line 18a relative to the scale on rod 26. Preferably, however, this is determined by the operator through reference to the indicator 57 relative to the scale 51 (see FIG. 6). That is, as previously described, the indicator 57 moves with and responsive to the target 18. If the operator is to follow a design map, he may align the bench mark reading on the map with the scale 52 by proper manipulation of the

rollers

60 and 61.

The operator then determines, from the design map or otherwise, the elevation to which the ground is to be formed, and accordingly moves the indicator pointer 57 with respect to the indicia. This, of course, causes an upward or downward movement of the target 18, so that in order to bring the cutting edge into such elevation, the instrument man again guides the operator in bringing the line 18a on the target back into the line of sight. In doing so, of course, the operator again manipulates the target by means of the knob 70.

With the above adjustment-s accomplished, it only remains to set the pawl 29 in the manner previously described to either raise or lower the target 18 conforming to the planned grade in the direction of travel of the apparatus. Then, during operation of the device, and as above described, the target 18 is moved a vertical distance, either up or down, proportional to the distance travelled .by a tooth of the ratchet wheel 27 and in response to the revolution of the wheel 37. Thus, during linear travel of the grade line marker equal to the circumference of the wheel 37, the indicator 13a of the target 18 Will be raised or lowered this distance. At that time, the instrument man, sighting through his level, will indicate to the operator of the grade line marker that he should either raise or lower the cutting edges of the blade 17a so as to bring the line 18a of the target 18 back into the line of sight. In this manner, the operator is able to conform the land to a desired grade.

As shown in FIGS. 1 and 5, there are a plurality of holes 43 about the disc 36 for receiving pins similar to pin 35. Thus, for example, if it is desired to change the grade at which the land is worked to twice the rate for which the device is adjusted in the illustrated drawings, a pin 35 would be disposed in the hole 43 diametrically opposed to the pin 35 already mounted in the disc 36. In this manner, the arm 30 would be swung in the manner described twice during each revol'ution'of the wheel 37. Consequently, the target would be moved, either up or down, the same amount as previously described, but during intervals of only one half that previously described.

This invention contemplates that grade need not be a constant. That is, the target need not be moved the same distance for each actuation of the pivotal arm 30. To the contrary, many common and well known mechanical movements may be employed for changing the elevation of the target at a varying rate if this is desired.

It is also contemplated that the imaginary line above described as a line of sight may instead be a beam of electric-magnetic energy for inducing certain responses in the target as it strikes various levels thereof. Thus, the elevation of the blade may be changed automatically in response to a signal from the target responsive to this earn.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereirrabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombin'ations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1. For use in combination with land-forming apparatus including a frame movable horizontally over the ground level, a blade on the frame, 'and means for adjusting the elevation of the cutting edge of the blade relative to the frame; a target movable vertically with the blade cutting edge, means including a part movable in response to movement of the frame over the ground for changing the elevation of said target a predetermined amount relative to said cutting edge upon movement of said frame a given distance, means for adjusting the elevation of the target independently of the means for changing the elevation of the target in response to movement of the frame over the ground, and means on the frame for indicating the elevation of the blade cutting edge relative to the elevation of the target.

2. Apparatus of the character described in claim 1, wherein said last-mentioned means comprises indici'a disposed along the range of independent adjustment of the target.

3. Apparatus of the character described in claim 1, wherein said last mentioned means comprises indicia disposed at a location remote from the target, and a pointer movable responsive to the target and along a path adjacent the indicia, said target adjusting means being operable from said remote location.

4. Apparatus of the character described in claim 3, including additional indicia extending parallel to the first-mentioned indicia and located close to said additional indicia and said pointer, and means for moving said additional indicia relative to said first-mentioned indicia and said pointer.

5. For use in combination with land-forming apparatus including a frame movable horizontally over the ground level, a blade on the frame, and means for adjusting the elevation of the cutting edge of the blade relative to the frame; a target movable vertically with as well as relative to said cutting edge, drive mechanism, a disc rotatable with respect to the frame in response to movement of the frame over the ground, a pin on the disc, a pivotal arm having one end in the path of the pin so as to be rocked thereby upon rotation of the disc and another end engageable with the drive mechanism to actuate same upon rocking of the arm, and means connecting the drive mechanism to the target for moving said target, upon actuation of said drive mechanism, so as to change the elevation of said target a predetermined amount relative to said cutting edge for each given distance of frame movement.

6. Apparatus of the character described in claim 5, wherein the disc has a plurality of holes therein to receive a selected number of pins.

7. Apparatus of the character described in claim 5, wherein said drive mechanism includes a ratchet, and said other end of the pivotal arm has a pawl for engagement with the ratchet for driving it in one direction only.

8. Apparatus of the character described in claim 7, wherein said ratchet is a wheel and said pawl is reversible to selectively raise or lower the target responsive to frame movement.

References Cited by the Examiner UNITED STATES PATENTS 332,042 12/ 1885 Blickensderfer. 1,491,168 8/ 1924 Prendergast. 2,651,280 9/1953 Justiss et al. 116-60 3,041,754 7/1962 Reynolds 37170 3,071,049 1/ 1963 Pizzarotti et al. 94-46 ABRAHAM G. STONE, Primary Examiner.

WILLIAM A. SMITH, III, Examiner.

Claims

1. FOR USE IN COMBINATION WITH LAND-FORMING APPARATUS INCLUDING A FRAME MOVABLE HORIZONTALLY OVER THE GROUND LEVEL, A BLADE ON THE FRAME, AND MEANS FOR ADJUSTING THE ELEVATION OF THE CUTTING EDGE OF THE BLADE RELATIVE TO THE FRAME; A TARGET MOVABLE VERTICALLY WITH THE BLADE CUTTING EDGE, MEANS INCLUDING A PART MOVABLE IN RESPONSE TO MOVEMENT OF THE FRAME OVER THE GROUND FOR CHANGING THE ELEVATION OF SAID TARGET A PREDETERMINED AMOUNT RELATIVE TO SAID CUTTING EDGE UPON MOVEMENT OF SAID FRAME A GIVEN DISTANCE, MEANS FOR ADJUSTING THE ELEVATION OF THE TARGET INDEPENDENTLY OF THE MEANS FOR CHANGING THE ELEVATION OF THE TARGET IN RESPONSE TO MOVEMENT OF THE FRAME OVER THE GROUND, AND MEANS ON THE FRAME FOR INDICATING THE ELEVATION OF THE BLADE CUTTING EDGE RELATIVE TO THE ELEVATION OF THE TARGET.