US3863403A

US3863403A - Blade sharpening device for rotatable chopping cylinders including hydraulic drive means

Info

Publication number: US3863403A
Application number: US445677A
Authority: US
Inventors: Philip F Fleming
Original assignee: Gehl Co
Current assignee: Manitou Equipment America LLC
Priority date: 1974-02-25
Filing date: 1974-02-25
Publication date: 1975-02-04
Anticipated expiration: 1992-02-04

Abstract

A blade sharpening device for a rotatable chopping cylinder for a forage harvester or the like, which cylinder has a plurality of circumferentially spaced and generally parallel blades that are of a generally spiral shape. The device includes a carriage that moves along parallel to the cylinder and has a sharpening tool extending from it for contact with the blades, guide means connected directly to the carriage for guiding abuttment with a succeeding blade whereby as the carriage moves along the axis of the cylinder, and a compact hydraulic motor for driving the grinding wheel. A hydraulic system for such a blade sharpening device.

Description

Feb. 4, 1975 United States Patent [19] Fleming BLADE SHARPENING DEVICE FOR ROTATABLE CHOPPING CYLINDERS Primary Examiner-Al Lawrence Smith Assistant Examiner-Nicholas P. Godici Attorney, Agent, or FirmJames E. Nilles .s S W A m Me B E! VS R ow Cn Um Uh MF F W m GP N ea mew m Nm II [57] ABSTRACT A blade sharpening device for a rotatable chopping [73] Assignee: Gehl Company, West Bend, Wis.

Feb. 25, 1974 [22] Filed:

cylinder for a forage harvester or the like, which cylinder has a plurality of circumferentially spaced and generally parallel blades that are of a generally spiral 21 Appl. No.: 445,677

52 us. 51/249,51/1345 F, 59610245407, Shaw The device includes a carriage that moves along parallel to the cylinder and has a sharpening tool extending from it for contact with the blades, guide means connected directly to the carriage for 4 7 154 M 4 b ,4 HM 2 B 2 M 3 86 M45 9 B5 MUZ NW7 n4 ""2 "0 m r "a e "S .1 0 d .l Mk IF 1] loo 55 ll.

guiding abuttment with a succeeding blade whereby as the carriage moves along the axis of the cylinder, and

References Cited UNITED STATES PATENTS a compact hydraulic motor for driving the grinding wheel. A hydraulic system for such a blade sharpening device.

2,166,940 7/1939 Conradson.......................... 2,839,874 6/1958 Maker....... 3,724,139 4/1973 Leverenz PATENTED v 1.863.403

- sum 1 or 6 PATENTEDFEB I I 3863.403

SHEET 2 OF. 6

PATENTED FEB 4|975 FIG. 6

SHEET GDP 6 ii? I I 14o F M LL51! l Mel A30 OPEN SYSTEM CLOSED SYSTEM 1 BLADE SHARPENING DEVICE FOR ROTATABLE CHOPPING CYLINDERS INCLUDING HYDRAULIC DRIVE MEANS BACKGROUND OF THE INVENTION This invention pertains to apparatus for sharpening the blades of a cylindrical rotor of a forage harvester, or the like, and without the necessity of removing the knives from the harvester. It is an improvement over the sharpener shown in US. Pat. No. 3,724,139, issued Apr. 3, 1973 and assigned to an assignee common with the present invention.

SUMMARY OF THE INVENTION The present invention provides a blade sharpening device for a rotatable chopping cylinder of the type having a series of circumferentially spaced, generally parallel and spiral shaped blades. The device includes a carriage that moves parallel to the axis of the cylinder and has a grinding wheel for engagement with one of the blades as it moves longitudinally of the cylinder, and a guiding element that contacts the succeeding blade and thereby guides the wheel in an exact manner over the blade to be sharpened.

The invention also includes a compact hydraulic motor which permits complete adjustment of the grinding wheel relative to the blade so that minimal relief grinding of the blade is assured. The invention also includes a hydraulic circuit for driving the hydraulic motor, the circuitry being such that the sharpening apparatus and circuitry can be used with various tractor systems including open center or closed center systems, fluid pressure sources of varying output capacity, tractive units having different engine speeds and other variables.

The arrangement is such that an excess flow check valve located in the pressure line from the source of fluid pressure will automatically shut off the motor when excessive flow passes through the check valve, and in this manner, the motor is prevented from overspeeding and thereby its attached grinding wheel will not break apart due to centrifugal forces but on the other hand, the wheel will not be under speed to thereby grind inefficiently. The circuitry is such that the operator can easily determine the maximum speed of the grinding wheel which can be attained without popping the excess flow valve. Another aspect of the invention relates to an adjustable needle valve which controls the delivery of the closed center system pump by varying the downstream pressure of the pump.

These and other objects and advantages of the pres ent invention will appear hereinafter as this disclosure progresses, reference being had to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a portion of aforage harvester embodying the present invention I showing certain parts being swung away from their normal operating position and other parts being shown as broken away or removed for the sake of clarity in the drawings;

FIG. 2 is an end elevational view of the device shown in FIG. 1, but on an enlarged scale and showing certain parts being broken away or removed for the sake of clarity, and showing the grinder carriage in the position when it commences its sharpening travel at one end of the knife;

FIG. 2a is a sectional view taken generally along the line 2a-2a in FIG. 2, certain parts being shown as broken away or removed for the sake of clarity;

FIG. 3 is a view taken generally along the line 33 in FIG. 4, certain parts being shown as broken away for the sake of clarity, and showing the carriage at one extreme end of its travel, before contact with a knife to be sharpened;

FIG. 4 is a sectional, plan view taken generally along the line 44 in FIG. '2, but showing the carriage when about half-way through a sharpening pass over the knife, certain parts being shown as broken away or removed for the sake of clarity;

FIG. 5 is an enlarged, exploded view of the fluid motor and grinding wheel and its mounting and adjustment to the carriage;

FIG.'6 is a circuit of an open center system hydraulic circuit usable with the present invention; and

FIG. 7 is a circuit diagram of a closed center system usable with the present invention.

DESCRIPTION OF A PREFERRED EMBODIMENT The general organization of the invention as applied to a forage harvester is shown in FIG. 1, the forage harvester including a housing H supported on ground engaging means such as the wheel means W, a blower B attachable to the housing for receiving the cut crop from the housing via the blower opening 1. The blower includes a fan F rotatable mounted therein which delivers the cut crop to the tangentially extending chute C in the known manner. The blower B has been shown for purposes of clarity as being swung to the rear of the housing, but it will be understood that in operation, the blower B will be swung snugly against the housing so that the opening 1 is in immediate adjacency with the housing for receiving cut crops therefrom. Furthermore, when the machine is operating in the field, another cover (not shown) would enclose the top of the chopping cylinder 5, to be described.

A conventional chopping cylinder 5 is rotatably mounted in the housing and rotation in the direction indicated by the curvilinear arrow in FIG. 2. The cylinder has a series, for example six shown, of blades ll, l2, l3, l4, l5 and 16 which are circumferentially spaced and generally parallel to one another, and are mounted on the cylinder rotor frame 18. These Conventional blades are arranged to define the periphery of the cylinder and are generally spiral in form. The blades include a front sharpening edge defined by the respective bevelled portions, for example Ila of the blade 11 which is shown in the position for being sharpened. These edges must be reground periodically to insure sharpness of the blade. The cylinder 5 also includes a plate-like member 20 rigidly fixed to the outer end of the cylinder shaft 21 and located on the outside of the housing H. This plate-like member has a series of projections 22 arranged around its periphery, one for each of the blades. As shown in FIGS. 1 and 2, spring loaded means 25 are provided to act between the housing H and the plate-like member so as to bias the cylinder in the direction of rotation indicated by the curvilinear arrow in FIG. 2. More specifically, the spring loaded means 25 includes an extensible strut 26 which is pivoted at 27 to the housing and which has a clevice 28 fixed by a bolt means 29 to the other end of the extensible strut 26. A spring 30 acts between an anchor 31 on the strut and the extensible end 32 of the strut to thereby urge the bolt means into firm contact with the projections 22 and consequently bias the cylinder in the direction of rotation noted, for a purpose that will hereinafter appear.

Guide track means in the form of

parallel rods

40 and 41 are mounted on the housing and are arranged in parallelism with the cylinder axis and adjacent the top opening 42 in the housing. One of said rods is mounted on each side of the housing and extend generally coextensively in length therewith.

A travelling carriage 50 is slideably mounted on each of the

guide rods

40 and 41 so that the carriage can be slid from one end of cylinder to the other, more specifically across the full length of the cylinder 5. A sharpening tool in the form of a rotatable grinding wheel 52 extends from a hydraulic motor 53 so that the latter can drive the wheel 52 through its drive shaft 54.

The grinding wheel 52 and the associated hydraulic motor 53 are adjustable as a unit relative to that blade of the cylinder to be sharpened, as follows. The hydraulic motor in turn is rigidly carried on the carriage by a motor mounting plate 55 which has a generally vertically extending torque arm 56 rigidly fixed thereto (FIG. 5). The torque arm is slideably mounted in aperture 57 formed in a motor support 58.

The motor support 58 is pivotally mounted on the carriage 50 by means of two

stub shafts

59 and 60 which extend through aligned

holes

58a and 50a of the support 58 and carriage 50, respectively.

A threaded member 61 is rotatably mounted at one end in mounting plate 55 and is then in threadable engagement at 62 with the support 58. A hand adjusting knob K is fixed at the end of threaded member 61.

A link 65 is connected by pin 63 to the support 58 and by an eccentrically movable bolt 64 to the carriage 50.

The above construction permits the arm 58, motor 53 and wheel 52 to be adjustable in a generally vertical direction relative to the blade to be sharpened, and this is accomplished by rotating the knob K in one direction or the other. Adjustment of the eccentric bolt 64 varies the angle of the motor 53 and its grinding wheel 52 relative t0 the blade to insure that the proper angle is ground for the bevel edge 11a.

Guide means 70 are provided for insuring that the cylinder rotates the proper amount as the carriage moves axially thereover, so that the grinding wheel is at all times properly positioned in respect to the blade 11 being sharpened and that the proper edge is formed on the blade. This guide means includes an arm 71 which is rigidly fastened by bolts 73 (FIG. 4) to the carriage proper, which arm extends rearwardly from the grinding wheel 52. The guide means includes a pair of rollers 76 at its lower end. The rollers are adapted to roll along the inner side 77 (FIGS. 2 and 4) of the blade 16 which succeeds or follows the blade 11 being sharpened. The guide means also includes a shoe 78 having a curved or angled leading edge 79 so that when the carriage is at one extreme end of the cylinder and the guide means is about to make contact with the corresponding end of blade 16, the guide means will make proper contact with the blade 16 to properly orientate the guide means and carriage in respect to the cylinder prior to the sharpening pass of the wheel 52 over the blade.

As previously mentioned, the spring loaded means 25 is provided for biasing the cylinder in the direction of rotation indicated in FIG. 2 by the curvilinear arrow, and the blade 16 is held snugly against the rollers 76 of the guide means as the sharpening tool 52 moves axially along the cylinder. Thus, as the sharpening wheel 52 moves along the length of the cylinder to sharpen the blade 11, the cylinder must also rotate sufficiently, because of the spiral nature of the blade shape, to insure that the wheel 52 is presented at the proper attitude to the blade along its entire length.

Manually operated drive means are provided for driving the carriage 50 along the length of the guide track means 40, 41 in either direction. This drive means includes a crank which can be continuously rotated by the operator so as to reciprocate the carriage along the guide track means. More specifically, the crank has a relatively small sprocket 92 fixed thereto and over which the endless chain 93 is trained. A shaft 94 is fixed within the housing and has a pair of sprockets 95 while another endless flexible member in the form of a roller chain 97 is trained around sprocket 96. Another shaft 98 is also mounted in the housing and has a sprocket 99 mounted thereon and over which the chain 97 is also trained.

A drive chain pin 100 (FIGS. 3 and 4) is carried by the chain 97 and extends from the side thereof, a plate member 101 is fixed to the carriage and has a vertical slot 102 formed therein for the reception of the chain pin 100. Thus the pin 100 travels in an orbital path with the chain 97 when the operator turns the crank 90. The pin 100 consequently carries the carriage with it via the connecting slotted plate 101. At either end of travel of the carriage, the pin moves vertically in the slot 102 and continued rotation of the crank 90 then causes the pin to reverse its travel, carrying with it the carriage. As a result, continuous rotational motion of the crank 90 by the operator in one direction is translated into reciprocating motion of the carriage. Thus the grinding wheel 52 can be caused to make various passes, in either direction, over the blade being sharpened.

HYDRAULIC CIRCUIT The hydraulic circuit used in the present invention are shown by way of example in FIGS. 6 and 7. Generally, fluid pressure conduits 130 and 13] extend from the hydraulic motor 53 and to a source of pressure fluid, such as a fluid pump 114 carried on the harvester or a propelling vehicle (not shown).

The fluid motor 53 has two

check valves

116 and 117 therein. Valve 116 allows the motor to coast to a stop when the pressure is suddenly shut off by a control valve 120 and check valve 117 prevents the motor 53 from being driven backward due either to improper connection of the hydraulic conduits and 131 or operating the tractor control valve in the wrong direction.

Referring more specifically to FIG. 6, this illustrates an open center hydraulic system and has a fixed displacement pump 114 whose output varies depending on the speed of the engine of the propelling vehicle (not shown) for the harvester and also depending on the size of the pump of any particular propelling vehicle. The four-way control valve 120 is of the conventional type and is controlled by the operator from the cab of the propelling vehicle, such as a tractor and this four-way control valve has three positions as schematically indicated. Moving the valve to the left as viewed in FIG. 6 delivers pressurized fluid to the right hand line 130 and of course moving the valve spool to the right pressurizes the left hand line 131. With the invention as above described, the valve 120 is shifted only to the right so that pressurized fluid enters the left conduit 131.

The closed center system shown in FIG. 7 uses a variable displacement pump ll4a whose delivery is independent of the tractor engine speed, but this pump varies its output by sensing the downstream pressure. In this manner, the four way valve 120 is shown in the closed position wherein no fluid is being delivered to the system and the pump is de-stroked. Positioning the control valve 120 to the left or to the right produces the same effect as in the open center system of FIG. 6, while the pump strokes itself to produce flow of pressurized fluid.

With either the above open or closed systems, no two tractors or different models or manufacture will in all probability deliver the same output per minute while running at rated engine speed. Furthermore the revolutions perminute of the fluid motor 53 of the grinding wheel is directly proportional to the gallon per minute of fluid pressure delivered to it. Therefore, in accordance with the present invention, excess flow check valve 140 is provided in the line and adjustable needle valve 142 in the same line is also provided, that is between the flow control valve 120 and the fluid motor 53.

The grinding wheels such as are used with the present invention must not run excessively fast or they will break and disintegrate due to centrifugal force. On the other hand these wheels must not be under-speeded or they will not grind efflciently. To assure that the various tractors usable with the present invention will deliver the proper amount of fluid to the motor 53, the excess flow check valve 140 is placed in the pressure line l3l and this valve automatically functions to shut off the line when the flow of fluid in the line is in excess of a predetermined amount, thereby stopping the fluidmotor 53 and preventing its overspeeding.

With open center type hydraulic tractors, the operator starts the hydraulic pump 53 at low engine speeds and gradually increases that speed, thereby increasing delivery of the pressure fluid and consequently increasing motor speed until the excess flow check valve 140 closes. The operator can then note the tachometer setting of the tractor engine set to a particular point. Then the operator can restart the engine again at low speed and bring the tachometer which reads engine speed up to a point just below relief setting of the valve 140 which he has just noted. The operator is then ready to perform the grinding function at the proper hydraulic motor speed. ln this case, he does not use the adjustable needle valve 142 and instead it is left in the wide open position.

With most closed center system tractors, the operator sets the tractor engine speed and having set the adjustable needle valve 142 to the fully shut position before starting, he then gradually opens the needle valve 142 until the excess flow check valve 140 closes. The operator then closes the adjustable needle valve 142 slightly, then restarts the engine and is then operating the motor at just the correct speed. The adjustable needle valve 142 is thus a device which controls the delivery of a closed center system pump by varying the downstream pressure of the pump.

Once the needle valve 142 is set as above indicated and the tachometer reading is noted, the adjustments 5 described above are no longer necessary when using the same tractor for operating the hydraulic motor 53.

The present circuitry is capable of accommodating all existing tractor systems regardless of their output capacity, and results in a simple system for controlling the speed of the hydraulic motor 53 with both open or closed center supply systems.

I claim:

1. A blade sharpening device for use with a forage harvester having a housing and a cutting rotatably retained within the housing and having a plurality of circumferentially spaced spiral shaped cutting blades, the sharpening device comprising: guide track means supported on said housing, a carriage movably supported on said track means for movement generally parallel to the cylinder axis, a grinding wheel on the carriage and engagable with one of said cylinder blades, a hydraulic motor connected to and for driving said grinding wheel, and a hydraulic circuit for supplying controlled pressure fluid to and from said motor, said circuit including a fluid pressure pump, a control valve for receiving pressure fluid from said pump and delivering it to said motor, and an excess flow check valve and also and adjustable needle valve both located between said control valve and said hydraulic motor.

2. The device set forth in claim 1 including a motor assembly which includes said grinding wheel and said hydraulic motor, a motor support pivotally mounted on said carriage, said assembly having means for being shiftably mounted on said support, an adjustable connection between said support and said assembly for varying the grinding wheel relative to a blade being sharpened.

3. The device set forth in claim 2 including eccentric adjusting means between said carriage and said support to vary the angle of said grinding wheel relative to said blade being sharpened.

4. A blade sharpening device for use with a forage harvester having a housing and a cutting cylinder rotatably retained within the housing, the cylinder being composed of a plurality of circumferentially spaced and substantially parallel, peripheral and spiral shaped cutting blades supported on a frame, the sharpening device comprising; guide track means supported on said housing and dispositioned parallel to the cylinder axis, a movable carriage supported on said track means for movement parallel to the cylinder axis, a motor support pivotally mounted on said carriage, a motor assembly including a fluid motor and a grinding wheel drivingly connected therewith, said assembly having means for being shiftably mounted on said support and also having an adjustable connection with said support for varying the grinding wheel relative to a blade being sharpened, an eccentric adjusting means between said carriage and said support to vary the angle of said grinding wheel relative to said blade being sharpened and a hydraulic circuit for supply controlled pressure fluid to and from said motor, said circuit including a fluid pressure pump, a control valve for receiving pressure fluid from said pump and delivering it to said motor,-an excess flow check valve and an adjustable needle valve located between said control valve and said hydraulic motor.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 863, 403 Dat d February 4, 19 7 5 Inventor (5) Philip F. Fleming It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

COLUMN 6, line 14, after "cutting", insert ---cyIinder--- Bigncd and Salad this Thirtieth Day of November 1976 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner of Parents and Trademarks

Claims

4. A blade sharpening devIce for use with a forage harvester having a housing and a cutting cylinder rotatably retained within the housing, the cylinder being composed of a plurality of circumferentially spaced and substantially parallel, peripheral and spiral shaped cutting blades supported on a frame, the sharpening device comprising; guide track means supported on said housing and dispositioned parallel to the cylinder axis, a movable carriage supported on said track means for movement parallel to the cylinder axis, a motor support pivotally mounted on said carriage, a motor assembly including a fluid motor and a grinding wheel drivingly connected therewith, said assembly having means for being shiftably mounted on said support and also having an adjustable connection with said support for varying the grinding wheel relative to a blade being sharpened, an eccentic adjusting means between said carriage and said support to vary the angle of said grinding wheel relative to said blade being sharpened and a hydraulic circuit for supply controlled pressure fluid to and from said motor, said circuit including a fluid pressure pump, a control valve for receiving pressure fluid from said pump and delivering it to said motor, an excess flow check valve and an adjustable needle valve located between said control valve and said hydraulic motor.