US3308611A - Mowing attachment - Google Patents

Description

March 14, 1967 c. F. BARBER 3,308,611

MOWING ATTACHMENT Filed Jan. 2Q, 1964 3 Sheets-Sheet l INVENTOR 6209.91.55 El /73:1?

ju y 494m ATTORNEYS March 14, 1967 c. F. BARBER MOWING ATTACHMENT 3 Sheets-Sheet 2 Filed Jan. 20, 1964 m T. m. V m

ATTORNEYS March 14, 1967 c. F. BARBER MOWING ATTACHMENT 5 Sheets-Sheet 5 Filed Jan. 20, 1964 INVENTOR 1 54954-7? United States Patent 3,308,611 MOWING ATTACHMENT Charles Frederick Barber, Cambridge, Ohio, assignor to Ni) Trim, Inc., Cambridge, Ohio, a corporation of 0 io Filed Jan. 20, 1964, Ser. No. 338,998 11 Claims. (Cl. 56-25) This invention relates to mowing attachments of the type carried by a tractor or the like and in particular to the mounting of such attachments in a manner to reduce the damaging effects of shocks produced during normal operation and when the attachment strikes an obstruction.

More particularly, the invention relates to improvements in the type of mowing attachment disclosed in the Stewart Patent No. 2,997,835. This type of attachment includes a vertical mast carried at the side of the tractor and mounted thereon for swinging movement about a vertical axis. A cutting head is supported from the mast through a series of articulated arms, the innermost of which is pivoted to the mast .in the manner of a boom for swinging movement in a vertical plane. The vertical swinging movement is controlled by means of a hydraulic piston and cylinder. In this type of arrangement considerable wear and tear on the hydraulic system and on the mountings for the mast are experienced when the cutting head meets an obstruction during for ward movement of the tractor. Even during normal operation considerable vertical shock forces and vibration are transmitted to the hydraulic system by the boom.

It is a primary object of the present invention to provide an improved mast and boom construction for mowing attachments which reduces the damaging effects of shocks which occur both during normal operation and upon striking of the cutting head against an obstruction.

It is a further object to provide an improved mast construction for mowing attachments which permits the mast and the elements supported thereby to swing rearwardly when the cutting head strikes an obstruction and which then automatically returns the mast to its normal operating position.

It is a further object to provide a mast construction for a mowing attachment in which the mast is releasably indexed at its operative position, and returned thereto after being displaced, by a spring-biased member held in contact with a cam member.

It is a still further object to provide a boom construction for a mowing attachment in which a piston and cylinder for controlling vertical movement of the boom coacts with the boom through a hoist lever which pivots independently of the boom and which acts on the boom through a resilient shock absorbing element.

The invention will be further understood from the following detailed description of a specific embodiment taken with the drawings in which:

FIGURE 1 is a perspective view of a tractor carrying a mowing attachment;

FIGURE 2 is a fragmentary plan view, partly in section, of the mast of the moving attachment of FIGURE 1;

FIGURE 3 is a fragmentary perspective view of the mast of the moving attachment of FIGURE 1;

FIGURE 4 is the same as FIGURE 3 with the mast rotated 90 degrees in which position the cutting head would be disposed in front of the tractor; and

FIGURE 5 is a fragmentary elevational view, partly in section, of the boom of the mowing attachment of FIGURE 1.

Referring to FIGURE 1 there is shown a tractor having attached to its right hand side a mowing attachment 12 which embodies the principles of the present invention. The attachment 12 includes as major elements its forward end to the tractor frame.

3,398,611 Patented Mar. 14, 1967 ice a cutting head such as a sickle bar assembly 14, an outer arm 16, a channel shaped inner arm or boom 18 and a channel shaped support stand or mast 20 which is pivotable about a vertical axis by means of an arrangement which is one of the features of the invention. The sickle bar assembly 14, which may be of any suitable construction is swivelly attached to the outer end of the outer arm 16 for rotation about the longitudinal axis of the outer arm 16 and about an axis 22 at right angles to the plane of the outer arm 16 and the boom 18. As shown in FIGURE 1 the sickle bar asembly 14 is disposed at the side of the tractor but it may also be disposed in front of the tractor by rotating the mast degrees. Complete details of the manner in which the assembly '14 may be mounted are set forth in the aforementioned Patent No. 2,997,835.

The inner end of the outer arm is provided with a pair of longitudinally extending ears 24- which are pivoted on the outer end of the boom 18 by means of a horizontal pin 26 passing through the ears 24 and through the flanged portions 18a, 18b of the boom 18. The other end of the boom 18 terminates between the upper ends of the flange portions 20a, 20b of the mast 20 and is pivoted thereto by a horizontal pin 28.

The attachment 12 is controlled and operated hydraulically by a system which includes a rotary hydraulic motor 30 carried by the outer arm 16 for operating the cutting mechanism of the sickle bar assembly 14 and three hydraulic cylinders 32, 34 and 36 for controlling movement of the articulated members. The cylinder 32 is carried by the outer arm 16 for rotating the sickle bar assembly 14 about the axis 22 through a sprocket and chain linkage (not shown). The cylinder 34 is disposed between and pivoted at 38 to the flange portions 18a, 18b of the boom 18. Its extensible piston arm 40 is pivoted by means of a pin 42 to the upper end of a short link 44 whose lower end is pivoted on a pin 46 carried by a pair of depending ears 4 7 on the boom 18. Another link 48 extends outwardly from the pin 42 to a pin 49 carried by the cars 24 on the outer arm 16.

The cylinder 36 is inclined upwardly and outwardly from a horizontal pivot pin 50 carried by the lower ends of the flange portions 20a, 20b of the mast 20. The extensible piston arm 52 of the cylinder 36 is connected to the central portion of a relatively short channel shaped hoist lever 54 by means of a horizontal pin 56 extending between the flange portions of the lever 54. The inner end of the lever 54 is pivoted on the pin 28 independently of the boom 13. Its outer end, which is offset downwardly from its inner end, cooperates with the adjacent portion of the boom 18 through a compression spring assembly 57 which with the lever 54 constitutes another feature of the invention.

The hydraulic system for operating the motor 30 and the cylinders 32, 34 and 36 also inclues a hydraulic pump (not shown) carried by the tractor 1i flexible hydraulic conduits (not shown) and control valves (not shown) which are controlled by the tractor operator in a manner known in the art.

As indicated above, one of the features of the invention is the manner in which the support stand or mast 20 is mounted for permitting the mower assembly 12, when carried at the side of the tractor, to break away or swing rearwardly when the sickle bar assembly 14- meets an obstruction. As seen in FIGURE 1, the supporting framework for the mast 20 includes an elongated vertical plate 58, the upper end of which is braced by means of a horizontal member 60 extending across the top of tractor 10 at a location above the rear of the engine hood and a forwardly and downwardly extending strut 62 secured at The end of the horizontal brace 60 opposite the support plate 58 is secured to a vertical side brace 64 which is reinforced by another inclined strut 66. As best seen in FIGURE the upper end of the mast is closed with a horizontal plate 68 which is pivoted to the end of the horizontal support member 60 by means of a vertical sleeve 70 passing through the member 60 and the plate 68. The sleeve 70 is retained in place by means of a ring 72 which is clamped against the upper end of the sleeve 7 0 by means of bolts 74 threaded into the upper surface of the member 60. It will be appreciated that other means may be provided for pivotally mounting the upper end of the mast 20; the sleeve arrangement is a convenient construction because it provides a passageway and retainer for the hydraulic lines (not shown) leading to the cylinders 32, 34 and 36 and the motor 30.

As best seen in FIGURE 3 the lower end of the vertical support plate 58 is secured, as by welding to an outwardly extending horizontal cam plate 76 which is mounted on top of a horizontal channel member 78 by means of screws 80, the heads of which are countersunk in the upper surface of the plate 76. The inner end of the channel member 78 is secured to the tractor frame 79 by suitable brackets illustrated at 81 and 82. A vertical pivot pin 84 lying on the axis of the sleeve 70 extends upwardly through the web portion of the channel 78, through the cam plate 76 and through a horizontal foot plate 86 which is welded between the lower ends of the flange portions 20a, 20b of the mast 20. A washer (not shown) is disposed around the pin 84 between the foot plate 86 and the cam plate 76 to provide bearing surfaces.

According to the principles of the invention the fixed cam plate 76 together with a movable cam engaging member such as a latch lever 88 and associated elements provide for the break-away feature referred to above. Referring particularly to FIGURES 3 and 4 it will be seen that the lever 88 depends from a horizontal pivot pin 90 which is mounted in the flange portions 20a, 20b of the mast 20 a short distance above the outer edge of the cam plate 76. The lower portion of the lever 88 extends through a guide slot 92 in the foot plate 86 and is engageable with the outer and forward edges of the cam plate 76. As best seen in FIGURE 2 the outer edge of the cam plate 76 has a generally V-shaped notch 94 into which the lever 88 is biased by a pair of spiral tension springs 96 disposed between the flange portions 20a, 20b of the mast 20. The springs 96 are hooked at their inner ends to a bracket 98 which is welded to the web portion of the mast 20' and at their outer ends to a bracket 100 which is welded to the lever 88. The mast 20' will thus be restrained by engagement of the lever 88 with the notch 94 against rotation about the vertical axis through the bolt 84 and the sleeve 70. However, when the sickle bar assembly 14 meets an obstruction during forward movement of the tractor torque will be applied to the mast to displace the lever 88 and allow the mast to rotate clockwise as viewed in FIGURE 2.

The portion of the outer edge of the cam plate 76 which is rearward of the notch 94, extends outwardly as well as rearwardly and forms a cam surface 104 on which the lever 88 rides when the mast is rotated during a break-away operation. After the lever 88 has been displaced from the notch 94 continued rotation of the mast slides the lever 88 rearwardly along the edge 104 and simultaneously moves its lower portion outwardly. This action continually increases the tension in the springs 96 so that continually greater restraint against rotation of the mast 20 is effected. The are through which the mast may rotate is limited by an upstanding stop member 105 welded to the latch plate 76 in a position to engage flange 20a at about 27 of rotation from the operative position. More important, however, is the effect of the outward angling of the edge 104 which assures that the force applied by the lever 88 to the edge 164 will tend to return the mast to its original position when the torque which produced its deflection is removed.

From FIGURE 2 it will be apparent that, by virtue of the relationship of the pivot bolt 84, the points of attachment of the springs 96 and the angle of the edge 104, the resultant force of the springs 96 on the mast 20 will tend to rotate it counterclockwise from positions in which the lever 88 engages the edge 104 of the cam plate 76. If the mast 20 should overshoot the notch 94 when it is being returned to its operative position the springs 96 will produce an opposite torque by virtue of the engagement of the lever 88 with a flat edge portion 106 of the plate 76 which extends forwardly of the notch 94. Stated in different words, it will be seen that the attachment of the springs 96 is such that they exert a pull substantially along a line passing through the axis of rotation of the mast 26 so that the force of the lever 88 on any straight edge such as the edges 104 and 186 produces a torque on the mast except when the straight edge is at a right angle to a line passing through the axis of rotation. While the arrangement of the parts in the illustrated embodiment is a preferred construction it will be apparent that the principles involved do not limit the arrangement to the one disclosed.

The forward edge of the cam plate 76 has generally V-sha-ped groove 108 which is disposed at a right angle to the groove 94. When it is desired to mow grass adjacent the front of the tractor 10, the mast 20 is rotated counterclockwise from the FIGURE 2 position until the lever 88 slips into the groove 108, as illustrated in FIG- URE 4. Then the sickle bar assembly 14 is rotated about the longitudinal axis of the arm 16 so as to be in a position to engage grass and the like upon forward movement of the tractor. Once the lever 88 has been displaced from the groove 94 and has negotiated the straight edge 106 very little force is necessary to continue to rotate the mast 20 because the major portion of the edge of the cam plate 76 between the grooves is curved in an arc 116 having a radius passing through the axis of rotation of the mast 20. To retain the mast in a forwardly facing position a removabie stop block 112 is disposed adjacent the outer flange 20a of the mast by attaching it to the cam plate 76 with a pair of screws 114 threaded into tapped holes 116. The same block may be used as a stop 118 to prevent forward rotation of the mast when the latter is in the position shown in FIGURES 1, 2 and 3 by attaching it to the cam plate 76 forwardly .of the groove 94 with screws 120 threaded into tapped holes 122.

According to another feature of the invention, the mechanism for raising and lowering the boom 18 includes the hoist lever 54 and the spring assembly 57 which is illustrated in detail in FIGURE 5. As shown, the assembly 57 includes a heavy compression spring 124 retained between the end of the hoist lever 54 and the boom 18 by means of two tubular members 126 and 128 which are secured as by welding to the boom 18 and to the hoist lever 54, respectively. The spring 124 resides primarily within the member 126, but normally projects from the lower end thereof a suflicient distance to support the boom 18 in spaced relation to the hoist lever 54. The upper end of the tubular member 126 is closed by an exteriorly threaded plug 136 which abuts the upper end of the spring 124 and which may be employed to adjust the compression of the latter. A bolt 132 extends through the plug to aid in aligning the spring 124 and is secured to the plug 139 as by welding so that the latter may be rotated with a wrench. As described before, the hoist lever 54 and the boom 18 are independently rotatable on the pin 28 so that the boom 18 may move against the action of the spring 124 even though the hoist lever is being held stationary by the hydraulic cylinder 36.

While not shown in the drawings it will be understood that the pivot pins for the various articulated members will be protected from excessive wear by suitable bushings and lubrication passages.

In using the mowing attachment 12 it is usually desired to dispose the sickle bar assembly 14 laterally to the side of the tractor 10, as shown in FIGURE 1. In this position the channel-shaped mast 20 faces outwardly and is releasably restrained against rearward rotation by .angagement of the latch lever 88 in the notch 94 of the cam plate 76. Forward rotation of the mast 20 is positively restrained by engagement of the mast 20 with the stop 118. The tractor operator then drives the tractor forwardly and manipulates the hydraulic control valves (not shown) to position the sickle bar assembly 14 for a cutting operation either parallel to and close to the ground or in an elevated angular position for trimming bushes, hedges and small tree branches. Raising and lowering of the boom 18 is effected by the hydraulic cylinder 36 and the hoist lever 54, but the boom may also move independently of the cylinder 36 and lever 54 by virtue of the spring 124. Thus minor vibrations of the boom 18 and slight vertical movements thereof are accommodated and absorbed by the spring 124 and are not transmitted to the hydraulic system.

If during forward movement of the tractor 10 the sickle bar assembly 14, the outer arm 16 or the boom 18 meet an obstruction such as a stump, rock, large tree branch or road sign, the resulting torque about the vertical pivot axis of the mast 20 will displace the latch lever 88 from the slot 94- in the cam plate 76. The mast 20 together with the articulated members carried thereby then rotate rearwardly against the action of the tension springs 96 in the manner already described. Simultaneously the compression spring 124 will absorb at least part of any vertical shock transmitted to the boom 18. While the direction of the shock will be primarily toward the rear of the tractor, the shape of the obstruction and the position of the sickle bar assembly 14 may also tend to move the boom 18 upwardly or downwardly.

When the mowing attachment 12 clears the obstruction either by way of passing over it or, in severe cases, by the operators stopping and reversing the tractor 10, the tension springs 96 return the mast 20 to its normal cutting position in the manner already described.

It will be appreciated that the shock absorbing and automatic return features of the invention effect several advantages of safety and economy. The resilient connection between the hydraulic cylinder 36 and the boom 18 reduces the transmission of normal vibration and normal oscillation of the boom 18 to the hydraulic system and thereby reduces wear and tear on the latter. The same connection together with the break-away construction reduce the possibility of damage or breakage .of the articulated parts in the event that an obstacle is encountered during forward movement of the tractor. The breakaway feature is also a safeguard for the tractor operator who might be injured by the breaking of parts of the attachment or, in severe cases, upsetting of the tractor. The possibility of either of these occurrences is much reduced because the operator can stop the tractor or make other adjustments as soon as the break-away feature goes into operation. The automatic return after a break-away requires no attention by the operator and thereby places the equi ment in position for immediate use as soon as the obstruction is cleared.

While a preferred form of the invention has been described and illustrated modifications thereof will be apparent to those skilled in the art without departing from the principles of the invention. Therefore it is not intended that the details of the described embodiment be limiting except as they appear in the appended claims.

What is claimed is:

1. In a mowing attachment for use in combination with a tractor or the like; a vertical support mast rotatable through an are about a vertical axis; a boom member pivoted at one end to said mast for rotation in a vertical plane; a cutting head supported from the other end of said boom member; a hoist lever disposed below said boom member and pivoted at one end to said mast; a piston and cylinder device disposed below said hoist lever and pivoted at its ends to said hoist lever and said mast; a compression spring between said hoist lever and said boom member for reducing transmittal of vibration and vertical shock forces from said boom member to said piston and cylinder device; a cam member having a notch therein and a cam surface adjacent said notch, said cam surface extending in a plane which is at right angles to the axis of rotation of said mast; a movable cam engaging member, one of said members being fixed with respect to said mast and the other being carried by said mast; a spring urging said cam engaging member into engagement with said cam member so as to releasably latch said mast against rotation when said member resides in said notch, said cam surface having a contour which when engaged by said member, converts part of the force of said tension spring into torque on said mast in a direction to pivot said mast toward a position in which said member resides in said slot.

2. In a mowing or cutting attachment for use in combination with a tractor or the like: a vertical support mast rotatable through an arc about a vertical axis; a cutting head; means connecting said cutting head with said mast for rotation therewith about said vertical axis; means for releasably restraining said mast against pivotal displacement caused by the engagement of said cutting head with an obstruction during movement of the tractor and for restoring said mast to its former position after displacement, said means including a cam member having a notch therein and a cam surface adjacent said notch and a cam engaging member, one of said members being fixed with respect to said mast and the other carried by said mast and further including means biasing said cam engaging member into contact with said cam member whereby engagement of said cam engaging member in said notch releasably latches said mast in a predetermined position, said cam surface having a configuration which converts at least a portion of the force of said biasing means into torque which tends to pivot said mast toward at position in which said cam engaging member resides in said slot.

3. Apparatus as in claim 2 wherein said cam member includes a horizontal plate, an edge of which defines said cam surface, said plate being with respect to said mast and wherein said cam engaging member is carried by said mast.

4. Apparatus as in claim 3 wherein said biasing means includes a tension spring carried by said mast, said spring exerting pull on said cam engaging member along a line generally through said vertical pivotal axis of said mast.

5. Apparatus as in claim 3 wherein said plate has a second notch therein at a right angle to said first-mentioned notch whereby said mast may be latched in a second position.

6. In a mowing attachment for use in combination with a tractor or the like: a cutting head; a boom member carrying said cutting head at one end; means pivoting the other end of said boom member for rotation in a vertical plane; power means cooperating with said boom member intermediate its ends to support said boom member and to move the same upwardly and downwardly in said vertical plane, said boom member being free to move upwardly with respect to said power means without corresponding movement of the latter; and shock absorbing means for reducing the transmittal of vibration and vertical shock forces from said boom member to said power means over a wide range of positions of said boom member, said shock absorbing means being disposed between engaging said power means and said boom member whereby said boom member can move upwardly relative to said power means when said cutting head strikes an obstruction without transmitting shock to said power means and whereby during normal operation vibration and vertical shock forces to said power means are reduced.

7. Apparatus as in claim 6 wherein said power means includes an extensible piston and cylinder element, a lever rotatable in a vertical plane by said piston and cylinder element, said shock absorbing means including a 7 resilient member disposed between one end of said lever and a downwardly facing surface on said boom member; and pivot means supporting the other end of said lever for said rotation.

8. Apparatus as in claim 7 wherein said resilient member is a compression spring.

9. In a mowing attachment for use in combination with a tractor or the like: a vertical support mast; a boom member pivoted at one end to said mast for rotation in a vertical plane; a cutting head; means connecting said cutting head and the other end of said boom member; a hoist lever disposed'below said boom member and pivoted at one end to said mast for rotation in a vertical plane; a piston and cylinder device disposed below said hoist lever and pivoted at one end to said mast for rotation in a vertical plane, the other end of said piston and cylinder device being pivoted to said hoist lever intermediate the ends thereof; and a compression spring disposed between said hoist lever and said boom member.

References Cited by the Examiner UNITED STATES PATENTS 5/1957 Allen et a1. 5625.4 7/1962 Shelter 56-25.4

ABRAHAM G. STONE, Primary Examiner.

RUSSELL R. KINSEY, Examiner.

Claims (1)

1. IN A MOWING ATTACHMENT FOR USE IN COMBINATION WITH A TRACTOR OR THE LIKE; A VERTICAL SUPPORT MAST ROTATABLE THROUGH AN ARC ABOUT A VERTICAL AXIS; A BOOM MEMBER PIVOTED AT ONE END TO SAID MAST FOR ROTATION IN A VERTICAL PLANE; A CUTTING HEAD SUPPORTED FROM THE OTHER END OF SAID BOOM MEMBER; A HOIST LEVER DISPOSED BELOW SAID BOOM MEMBER AND PIVOTED AT ONE END TO SAID MAST; A PISTON AND CYLINDER DEVICE DISPOSED BELOW SAID HOIST LEVER AND PIVOTED AT ITS ENDS TO SAID HOIST LEVER AND SAID MAST; A COMPRESSION SPRING BETWEEN SAID HOIST LEVER AND SAID BOOM MEMBER FOR REDUCING TRANSMITTAL OF VIBRATION AND VERTICAL SHOCK FORCES FROM SAID BOOM MEMBER TO SAID PISTON AND CYLINDER DEVICE; A CAM MEMBER HAVING A NOTCH THEREIN AND A CAM SURFACE ADJACENT SAID NOTCH, SAID CAM SURFACE EXTENDING IN A PLANE WHICH IS AT RIGHT ANGLES TO THE AXIS OF ROTATION OF SAID MAST; A MOVABLE CAM ENGAGING MEMBER, ONE OF SAID MEMBERS BEING FIXED WITH RESPECT TO SAID MAST AND THE OTHER BEING CARRIED BY SAID MAST; A SPRING URGING SAID CAM ENGAGING MEMBER INTO ENGAGEMENT WITH SAID CAM MEMBER SO AS TO RELEASABLY LATCH SAID MAST AGAINST ROTATION WHEN SAID MEMBER RESIDES IN SAID NOTCH, SAID CAM SURFACE HAVING A CONTOUR

Images