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Publication numberUS3629977 A
Publication typeGrant
Publication dateDec 28, 1971
Filing dateDec 19, 1969
Priority dateDec 19, 1969
Publication numberUS 3629977 A, US 3629977A, US-A-3629977, US3629977 A, US3629977A
InventorsRobert L Holden
Original AssigneeNorton Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Work-feeding device
US 3629977 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

United States Patent [72} Inventor Robert L. Holden Westboro, Mass. [21] Appl. No. 886,578 [22] Filed Dec. 19, 1969 [45] Patented Dec. 28, 1971 [73] Assignee Norton Company Worcester, Mass.

[54] WORK-FEEDING DEVICE 10 Claims, 4 Drawing Figs.

[52] US. Cl 51/98 R, 90/21, 143/58, 51/165.77, 51/238 R [51] Int. Cl B241) 7/02 [50] Field of Search 51/98 R, 98 HK, 125,215, 165.77, 238 R; 90/21; 143/58; 144/154 [56] References Cited UNITED STATES PATENTS 1,422,749 7/1922 Dameron 51/98 1,477,151 12/1923 PiZZil'lO 51/238 2,686,994 8/1954 Wyborski 51/165.77 3,369,328 2/1968 Freerksetal. 51/216 Primary Examiner Lester M. Swingle Attorney-walter Fred ABSTRACT: A powered, adjustable, and pivotable elongated pressure bar for greatly assisting a snagging machine operator to feed at various feed rates workpieces such as foundry castings into a multipoint cutting tool such as a grinding wheel or abrasive belt to rapidly remove fins, gates and risers therefrom. A high-torque and slowly rotating drive means is coupled by a variable fluid pressure actuated friction clutch mechanism to a driven member which pivots the pressure bar held by the operator. A remote control is provided on the bar for the operator to actuate and control the friction clutch mechanism and thereby cause the pressure bar to exert the desired pressure against a workpiece placed between it and the cutting tool.

WORK-FEEDING DEVICE BACKGROUND OF THE INVENTION The invention relates to a work feeding device for abrading machines and the like. It pertains particularly to a pressure work feed device for assisting foundry floor stand grinder operators to remove fins, gates and risers rapidly from castings with a minimum of effort on their part.

In the past foundries have employed various means to help snagging grinder operators to apply pressure to a workpiece in order to clean and remove unwanted material from castings. For example, U.S. Pat. No. 1,422,749; No. 1,477,151; No. 2,277,559; No. 2,477,559 shows lever devices whereby an operator can exert various amounts of force on the workpiece. Also, fluid pressure devices, such as disclosed in US. Pat. No. 1,683,354; No. 2,686,994 and No. 3,369,328 have been employed.

Most of the prior art lever devices still required the operator to exert a substantial amount of force which became tiresome. Recently abrading machines and grinding wheels have been improved, strengthened greatly, and wheel speeds increased. Therefore, they now can withstand increased pressures which results in faster feed and material removal rates necessary to increase production and reduce grinding time. A fast cutting action produces clean, unburned and undistorted surfaces. The instant invention provides the advantage of being able to provide the increased pressures with a minimum of effort on the part of the operator. Yet, in instances where lighter pressures are sufficient the invention may be used in a manner whereby the operator can elect to apply the pressure without the aid of the power available to him.

Further, the operator can if he desires to, simultaneously apply both the power assist and his own strength to increase the pressure on the workpiece. However, it is the chief aim of the invention to relieve the operator of the task of applying the pressure to the workpiece being worked.

SUMMARY OF THE INVENTION A fixedly mounted base houses and has fixed thereto a high torque drive means consisting of a high speed motor driving a gear reducer. The output shaft of the gear reducer revolves at a slow rate and is coupled to drive an upwardly extending drive shaft rotatably mounted in an upper portion of the base. A driven member supporting a friction clutch mechanism thereon is rotatably supported on the upper portion of the base and around an upper end portion of the shaft passing therethrough.

A drive member is fixed to the end of the drive shaft and is adapted to be engaged by the clutch mechanism whereby the driven member is coupled to and driven by the drive member. Pivotably and slideably connected to the driven member is an adjustable elongated pressure bar which extends longitudinally above a work support table adjacent the cutting tool of a machine.

A remote control for actuating the clutch mechanism is provided on the free end portion of the bar. The remote control, such as a hand lever is manipulated by the operator to actuate a master cylinder piston of a closed fluid system. The master cylinder piston moves to exert pressure to move a column of fluid within a conduit leading to a second fluid cylinder having at least one piston which forces the friction clutch into engagement with the drive member. The amount of light pressure exerted by operator on the hand lever determines the degree of frictional engagement between the friction clutch and the slowly rotating drive member. Hence, the work feed rate or the amount of movement of the pressure bar and the pressure exerted on a workpiece placed between the bar and the cutting tool can be varied by the operator.

In another embodiment the remote control actuates a directional control valve to admit fluid under regulated pressure into a power assist fluid cylinder that exerts the force to move the master cylinder piston and actuate the friction clutch.

A conventional pressure regulating valve is provided and adjustable by the operator to provide the desired amount of frictional contact between the friction clutch and the drive member.

It is therefore the primary object of the invention to provide a powered pressure bar work feed device for assisting a machine operator to force a workpiece into a cutting tool with a minimum of effort on his part.

Another object of the invention is to provide a powered pressure bar work feed device which can be manipulated by the operator to vary the amounts of pressure applied to a workpiece.

A further object of the invention is to provide a powered pressure bar work feed device which is pivotable and adjustable to accommodate various sizes and shapes of workpieces.

A still further object of the invention is to provide a powered pressure bar work feed device having a high torque and slowly rotating drive means.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the work feed device of the invention fixedly positioned adjacent the grinding wheel of a floor stand grinder.

FIG. 2 is a front view of the work feed device partly in section taken approximately on line 2-2 of FIG. 1.

FIG. 3 is a sectional view of the closed fluid system for actuating the clutch mechanism of the work feed device.

FIG. 4 is a sectional view of alternate power assist means for actuating the fluid system and the clutch mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings there is shown a portion of an abrading machine 10 which is obviously only one of the many types of machines in combination with which the instant invention may be used. For example, the instant invention may be used to feed workpieces into sawing, milling, planning, polishing, sanding and other machines wherein a multipoint cutting tool moves at high speed and is able to withstand the additional pressure exerted by the instant invention.

As shown the abrading machine 10 is a conventional floor stand grinder machine such as that found in a foundry cleaning room. US. Pat. No. 863,643, No. 1,911,857, No. 2,003,495, and No. 2,763,103 disclose typical floor stand abrading machines utilizing either a grinding wheel or an endless abrasive belt as the cutting tool.

The abrading machine 10 comprises a driven abrading tool 12 which may be either a grinding wheel or an endless abrasive belt entrained over a conventional backup roll.

Preferably, a worktable 14 is provided for supporting a workpiece adjacent the abrading or cutting tool 12. The worktable 14 may be supported by the machine, by the work feed device of the invention, or be of any other suitable type such as a self-standing type extending upwardly from the floor to which it may be fixed if necessary. In some instances where the workpiece is light a worktable may be unnecessary. In this instance the worktable 14 is adjustable and fixed in an adjusted position on a support bar 16 fixed to and extending, at the right-hand side, from the machine base 18 of the machine 10. By loosening the screws 20 the work support 14 may be pivoted and or moved axially along the bar to the desired position necessary to support the workpiece. In FIG. 1 is shown, in phantom lines, a portion of the support bar 16, for supporting the table 14 and the base 18 which, on some machines, are located to the right of the cutting tool 12. Also, some machines may have a cutting tool 12 and a worktable 14 at each side thereof.

A work feed device 30 to which the invention pertains is provided for assisting a machine operator to force a workpiece W, such as a casting, into the cutting or abrading tool 12 whereby undesirable material such as fins, gates and risers are x rapidly removed therefrom. The work feed device comprises a base 32 fixedly mounted to a rigid support such as by bolting to the foundation or the floor 34 adjacent the machine 10. However, it is obvious that the base 32 could be an integral part of or fixed to, and supported by, the machine base 18. The base 32 extends upwardly from the floor 34 and has a lower portion 320 with a chamber 32b therein and an upper portion or housing 32c fixed to the lower portion 32a. Although the upper portion 32c is shown as a separate housing it could be made to be an integral part of the lower portion 320.

The upper portion or housing 32c extends upwardly to a position adjacent the abrading or cutting tool 12. An elongated drive shaft 36 is supported by the upper portion for rotation about a central axis thereof. The shaft 36 is rotatably mounted between its upper and lower ends, within shouldered bearings 38 supported by the upper portion or housing 32c. A pair of spaced thrust bearing or collars 40 are fixed in any suitable manner, such as by pinning them, to the shaft for engagement with oppositely positioned upper and lower shouldered surface of the bearings 38. As positioned the collar 40 prevent the shaft from moving axially beyond a predetermined allowable amount relative to the housing 320.

Drive means, fixed to the base 32 within the chamber 32b are provided for rotating the shaft about its central axis. The drive means comprises a conventional motor 42 having an output drive shaft 44 connected by a coupling 46 to the input shaft 48 of a commercially available speed reducer 50. The speed reducer 50 has an upwardly extending and relatively slowly driven output shaft 52 coupled to the lower end of the shaft 36 by a coupling 54.

Preferably the speed reducer 50 is one selected to produce a high torque and to reduce the high input speed of the motor 42 to about 0.5 to l.5 revolutions per minute at the output shaft 52.

A variety of suitable worm and worm gear reduction units are commercially available from the Boston Gear Works of Quincy Mass. Since torque produced at the output shaft is increased in the same proportion as the input speed is reduced. A V4 HP motor rotating at 1,750 rpm. which produces approximately 9 in.-lbs. of torque coupled to a reductor having a ratio of 3,000 to 1 would produce approximately 0.58 rpm. and disregarding frictional losses a torque of 27,000 in.-lbs, at the output shaft. However, it is estimated that this figure is reduced two-thirds by frictional losses and results in a torque of 9,000 in.-lbs. Also, torque is directly proportional to motor horsepower and therefore increases or decreases as the horsepower is increased or decreased. For example, a 1 HP motor has 4 times that of a A HP motor or 36 in.-lbs. of torque, therefore 4 times or 108,000 in.-lbs. of torque would be produced at the output shaft 36 with a speed reduction of 3,000 to l, disregarding friction.

Fixed to the upper end of the upper portion 32c is an end cap or flange 60 in which is fixed an annular bearing 62 having a shoulder bearing surface 62a. Rotatably mounted in the bearing and supported by the upper portion 32c is a clutch support or backing plate 64 having a central hole through which an end portion of the shaft 36 extends. The clutch support plate 64 is the driven member and has a shoulder or hearing surface at the upper end of a cylindrical portion, engaging the shouldered heavy surface 62a and an annular retaining flange or thrust bearing plate 66 fixed to its lower end. The bearing plate 66 has a diameter larger than that of the bearing mounting hole in the flange 60 and an upper surface which engages the lower end surface of the end cap 60 to prevent any excess axial upward movement of the clutch support or backing plate 64. Fixed within the central hole of the clutch support plate 64 is an annular sealed bearing 68 cooperating with the bearing 62, cap 60 and the base portion 320 to support and maintain the axial alignment of the upper end portion of the rotatable drive shaft 36.

Mounted on the clutch support or backing plate 64 and around the upper end portion of the shaft 36 is clutch mechanism 70 comprising conventional and commercially available automotive hydraulic brakecomponents. The components of the clutch mechanism 70 are assembled in and operated in substantially the same manner as are the components of an automobile brake assembly. The difference is that the clutch support plate 64 is not fixed as is the backing plate in an automotive brake and can be considered with the components mounted thereon and movable therewith to be the driven member. The clutch mechanism 70 comprises an anchor pin 72 fixed to and extending upwardly from the driven member or clutch support plate 64 a predetermined radial distance from the central axis of rotation of the shaft 36. A pair of conventional replaceable brakeshoes or arcuate friction elements 74 with suitable brake lining or friction material thereon each have one end thereof normally held in engagement with opposite sides of the anchor pin by springs 76 connected between the anchor pin and each of the friction elements 74. Between the opposite ends of the arcuate friction elements 74 is a conventional brakeshoe-adjusting screw mechanism 78 held in engagement therewith by a spring 80 connected at its opposite ends to the brakeshoes or friction elements 74. Also there are conventional holddown devices 82 each comprising a pin, spring, and a retaining washer for holding a side of each brakeshoe or friction element 74 downwardly against the clutch support plate 64.

Situated adjacent the anchor pin 72 and between the ends of the brakeshoes 74 is a conventional hydraulic fluid wheel cylinder 84 rigidly fixed to the clutch support plate 64. Within the fluid cylinder 84 is at least one but preferably a pair of spaced pistons 86 each of which engages a piston rod 88 extending between it and an abutment on each of the brakeshoes 74. A spring 90 extends between conventional seals engaging each of the pistons and normally bias the pistons apart to maintain the piston rods in engagement with the arcuate friction elements 74. The fluid cylinder 84 has an air bleeder valve screw 92 and an inlet part to which is connected to a flexible conduit 94.

A cylindrical drive member or brake drum is fixed and keyed to the upper end of the drive shaft 36 and is rotatable around an in close proximity to the arcuate friction elements 74.

It can be seen that when the fluid under pressure is forced in between the pistons 86, the pistons move outwardly and expand the arcuate friction elements or brakeshoes 74 into frictional contact with the surface of the drive member or brake drum 100. The available rotational driving force of the drive member or drum 100 is then transmitted through the brakeshoe or frictional elements 74, to the fluid, and the cylinder 84 fixed to the clutch support plate 64 which then becomes the driven member. Obviously, the degree of force applied to the column of fluid determines the degree of frictional contact and hence the amount of slippage between the drum and the frictional elements 74.

As shown by the arrow in FIG. 1, the drive member or drum 100 rotates counterclockwise and hence the driven member or clutch plate 64 will be driven in the same direction upon actuating the friction clutch mechanism 70.

One side of the clutch support plate 64 is extended and has integrally formed therewith or fixed thereto a pair of spaced axially aligned bearing housings 64a situated between the drum 100 and the workpiece W on the worktable 14 adjacent the abrading tool 12.

In the housings 640 are fixed axially aligned annular bearings 102 in which is pivotally mounted a pressure bar support or pivot shaft 104 with axially spaced adjusting holes in a central portion thereof. The pivot shaft 104 has an enlarged head at one end and extends, longitudinally, substantially on a horizontal axis, through, between, and beyond the spaced bearing housings 64a. A thrust collar 105 is fixed by a pin to the opposite end portion of the shaft and prevents excessive axial movement of the pivot shaft relative to the bearing housings 64a.

An elongated pressure bar 106 is slideably mounted on and adjustably fixed to the pivot shaft by a removable adjusting pin 107 extending through aligned holes in the bar and one of the adjusting holes in the intermediate portion of the support shaft 104 between the bearing housings 64a and the bar extends longitudinally therefrom above and beyond the worktable 14. The space between the bearing housing 64a is much wider than the bar 106 therefore, by removing the pin 107 the bar can be shifted axially on the shaft 104 relative to the clutch support plate 64 and hence toward and away from the cutting tool 12. Upon reinserting the pin 107 into the desired adjusting hole, the bar is again fixed to the pivot shaft 104. Also, the pivotable connection between the clutch support plate 64 and the pressure bar 106 allows the bar 106 to be pivoted about the axis of the shaft 104, in a vertical plane, relative to the clutch support plate 64, worktable 14, and the machine 10.

Further, the pressure bar 106 can be freely pivoted and partially rotated about the central or vertical axis of the shaft 36 which in addition to all of the above mentioned movements allows a great variety of sizes and shapes of workpieces to be worked upon. The pressure bar 106 may be of any suitable length, cross-sectional shape, solid or hollow, and made of any suitable material which can withstand the force to be applied to the workpiece W.

Remote control means 110 is provided for actuating the clutch mechanism 70 and is preferably situated on the opposite free end portion of the pressure bar 106. However, it could be situated on the base portion 32a or on the floor in the vicinity of the operator. The remote control means 110 is actuated by the machine operator who normally takes a position between the workpiece and the remote control means 110. It comprises a conventional master cylinder 112 fixed, as by bolting, to the inside surface of the bar 106. The cylinder 112 has a cylinder bore 114 in which is slidably mounted a piston 116. The piston 116 is biased against a stop ring at one end of the cylinder bore 114 by a spring 118 situated between a piston seal against the piston and an end cap 120 at the opposite end of the bore 114. A chamber or reservoir 122 containing a reservoir of hydraulic fluid is situated above the bore and connected to the bore 114 by an aperture 124. A vented cap 126 is provided for filling and closing off the reservoir.

A male fitting 128 is screwed into a threaded aperture in the end cap 120 and onto which is threaded a female end fitting of a conduit 130. The conduit 130 passes internally of the pressure bar 106 and out through an aperture in the wall thereof, below which the conduit 130 is connected to the flexible conduit 94 by a coupling 132.

Displacing means, such as a piston rod or actuating shaft 134 is provided for moving the master cylinder piston 116. The piston or actuating shaft extends from the master cylinder piston 116 to a fork-type link portion 136 at its opposite end that is connected by a link pin to the short lever arm ofa hand lever or remote control 138 pivotally mounted about a pivot pin 139 fixed to the top side ofthe pressure bar 106.

It can be seen that when the long lever arm of the lever 138 in front of the pressure bar is pivoted clockwise either by the operators hand or by leaning his body against it the lever 138 causes the piston rod or actuating shaft 134 and piston 116 to move to the right forcing a column of fluid to actuate the friction clutch means by spreading the pistons 86 and hence moving the friction elements 74 into frictional engagement with the drive member or drum 100.

By varying the amount of force he applies to the lever the operator can control the amount of slippage between the friction elements 74 and the drum 100. Hence, he can drive the driven member 64, the pressure bar, and feed a workpiece engaged thereby into the cutting tool at varying suitable rates.

it is obvious that the actuating shaft 134 of the displacing means for moving the master cylinder piston 116 could be a flexible shaft slideable within a fixed casing and which together are known as a Bowden cable. One end of the flexible shaft could be attached to the remote control or the short arm of the lever 138 and extend to the master cylinder piston 116 of the master cylinder fixed in another position, such as, on the base portion 32a. Also the remote control could be a foot lever on the floor or in a position easily accessible to the operator.

Alternatively, the displacing means for moving the master cylinder piston 116 may comprise remotely controlled power assist means 140 shown in FIG. 4 for actuating the friction clutch mechanism. The remotely controlled power assist means 140 may be mounted with the master cylinder 112 on the base 32. It comprises a normally open manually held electrical pushbutton or switch PB fixedly mounted on the remote free end portion of the pressure bar 106 and connected to power lines L1 and L2 within a flexible electrical conduit passing through the pressure bar 106 and out an aperture therein to a power source and to a solenoid S1 of a conventional three-way solenoid operated directional control valve V1 mounted at some convenient place on the base 32.

Slidably mounted in the valve V1 is a spool 144 including pistons separated by chambers 146 and 148. A spring 150 normally biases the spool to the right. A solenoid core is attached to the spool and both are pulled to the left upon closing PB which energizes the coil of the solenoid S1.

A conduit 152 leading from a conventional source of compressed air which is available in most shops and foundries is connected by a conventional means such as a quick disconnect and connect coupling not shown to a conventional adjustable pressure-regulating valve 158 connected to a pressure inlet port in the chamber 146 by a conduit 160.

Within the chamber 148 is an exhaust port 162 and a pressure outlet port with a conduit 164 leading therefrom connected to a pneumatic power assist cylinder 166. Slidably mounted in the cylinder 166 is a power assist piston 168. A piston rod or actuating shaft extends between the piston 168 and the master cylinder piston 116. A spring 172 about the actuating rod 170 urges and normally maintains the power assist piston 168 to the left as shown. Air can exhaust from and enter into the right-hand side of the cylinder 166 through a vent 174.

OPERATION To operate the work feed device 30 the machine operator merely actuates a switch SW on the base 32 closing a circuit and starting drive motor 42 which drives the gear reducer 50, shaft 36 and the drum 100. The machine operator if necessary, pulls pin 107 then preadjusts the pressure bar 106 on the shaft 104 a distance away from the cutting tool which will accommodate the workpiece W being worked and reinserts the pin 107 into the nearest adjusting hole in the shaft 104. A workpiece is then placed on the worktable by either the operator, or a workloading device such as a hoist, should it be too heavy. The operator positions himself to the right side of worktable 14. He then grasps the pressure bar 106 adjacent the remote control lever 138; pivots the bar about the central axis of the drive shaft 36, into engagement with the workpiece W and, if needed, about the axis of shaft 104 to center it relative to the workpiece. Movement of pressure bar 106 moves the workpiece into light engagement with the cutting tool 12 whereupon the operator now either moves the lever 138 toward the pressure bar 106 with his hand or by leaning his body against it. Moving the lever 138 actuates the friction clutch mechanism 70 and expands the friction elements 74 into engagement with the drive member or drum 100 whereby the desired amount of available high torque rotary power is transmitted to the driven member or clutch support 64 and to the pressure bar which forces the workpiece W into the cutting tool 12. Upon finishing the workpiece the operator releases the lever 138, pivots the pressure bar 106 away from the cutting tool and the workpiece, and removes the workpiece. He then loads another workpiece to be worked and repeats the process. By varying the amount of force he exerts against the lever, the operator can vary the amount of slippage between the drive and driven members and hence the feed rate from between zero and the maximum feed rate without slippage built into the work feed device 30.

The approximate maximum rate at which workpiece can be fed into the cutting tool 12 is determined by taking into consideration the rate of rotation of drive shaft 36, and the radial distance R between the central axis of the shaft 36 to the center of the cutting tool 12 or the workpiece W. For a theoretical example, assume that distance R is 2 feet and the shaft 36 rotates at l revolution per minute. A complete revolution (360) of a 2 foot arm equal to the distance R would describe a circle having a circumference and a feed rate of approximately 12.5 ft. per minute or 2.5 inches per second. If the material of the workpiece being removed is assumed to have a surface area of approximately 1 sq.in., then a volume of 2.5 cubic inches of material is removed per second. [f the material has, as cast iron does, a specific gravity of 7.2 grams/cubic centimeter than 294.966 grams (453.6 gram/lb.) 0.65 lbs. per/sec. 39 lbs/min. 2,340 lbs/hr. of material is removed.

The maximum amount of theoretical force produced by a 1 HP motor disregarding the frictional losses due to the large speed reduction of 1,750 to 1 would be approximately 2,640 lbs. at the feed rate of 12.5 ft./min. Reducing this by twothirds to compensate for frictional losses still provides ample maximum available force of approximately 880 lbs. However, selecting a motor of more or less HP would produce, proportionately, a higher or lower torque and work feed force. For example it HP 220 lbs., V2 HP 440 lbs., and 1% HP 1,320 lbs.

It is to be understood that many modifications of the embodiments of the invention disclosed hereinabove may be made within the scope of the appended claims without departing from the spirit of the invention.

Iclaim:

1. A work feed device for assisting a machine operator to force a workpiece into a cutting tool of a machine tool comprising:

a base having an upwardly extending upper portion and adapted to be rigidly fixed to a support with the upper portion positioned adjacent one side of the cutting tool;

a drive shaft extending upwardly from and supported by the upper portion for relative rotation about a central axis of the shaft;

a driven member, supported on the upper portion and about an upper end portion of the shaft for pivotable movement about the central axis, relative to the upper portion;

an elongated pressure bar of predetermined length and thickness having an end portion connected to the driven member and adapted to be pivoted about the central axis, extend longitudinally adjacent the cutting tool and in front of the machine operator to an opposite end of the bar beyond an opposite side of the cutting tool, and to be held and manipulated by the machine operator;

a rotatable drive member fixed to the upper end of the shaft and adapted to be coupled to and drive the driven member;

drive means for rotating the shaft and the drive member at high torque about the central axis relative to the housing;

clutch means, between the drive member and driven member, for coupling the drive and driven members together to transmit available power to the driven member;

means, including a remote control actuatable by the machine operator, for actuating the clutch means to engage and couple the drive member to the driven member and together therewith pivot the pressure bar toward the cutting tool;

whereby a workpiece placed between the pressure bar and the cutting tool is forced into the cutting tool.

2. A work feed device according to claim 1 further comprismeans for pivotally connecting the end portion of the pressure bar to the driven member so that the pressure bar is pivotable in a vertical plane relative to the driven member and the cutting tool.

3. A work feed device according to claim 1 further comprismg: I

means for pivotally and slideably connecting the end portion of the pressure bar to the driven member so that the pressure bar is pivotable in a vertical plane relative to the driven member and the cutting tool, and moveable relative to the driven member toward and away from the cutting tool.

4. A work feed device according to claim 3 wherein the means for pivotally and slideably connecting the pressure bar to the driven member comprises:

a pivot shaft, mounted in and extending between a pair of spaced bearing housings on the driven member and having a portion in between the spaced bearing housings connected to the end of the pressure bar, the spacing between the bearing housings being greater than the thickness of the pressure bar which is moveable between the bearing housings.

5. A work feed device according to claim 1 wherein the clutch means comprises:

friction means mounted on, moveable with, and moveable relative to the driven member for engaging the drive member and transmitting the available power to the driven member.

6. A work feed device according to claim 5 wherein the friction means comprises:

a pair of opposed, adjustable, and expandable arcuatc friction elements; and wherein the rotatable drive member comprises:

a drum extending around the friction elements.

7. A work feed device according to claim 5 wherein the drive means comprises:

a motor fixed relative to the base; and

a speed reducer fixed relative to the base and the motor and having an input shaft coupled to and rotatably driven by the m0- tor, and an output shaft, rotatable at a speed between 0.5 and 1.5

revolutions per minute, coupled to the drive shaft.

8. A work feed device according to claim 5 wherein the means for actuating the clutch means comprises:

a fluid cylinder fixed to the driven member and having an inlet port;

at least one piston slideably mounted in the cylinder adjacent one side of the inlet port and operatively connected to move the friction means into engagement with the drive member;

means for urging the friction means out of engagement with the drive means;

a master cylinder, including an outlet port, fixedly mounted on the work feed device in a suitable place remote from the fluid cylinder;

a master cylinder piston slideably mounted in the master cylinder adjacent the outlet port;

means for biasing the master cylinder piston to an inopera tive position away from the outlet port;

a conduit extending between the inlet and the outlet ports in the cylinders;

a fluid medium in the master cylinder filling the conduit, and extending between the pistons in the cylinders; and, displacing means, operable upon actuating the remote control, for moving the master cylinder piston toward the outlet port whereby the pistons together with the fluid extending between the pistons are displaced and force the friction means into engagement with the drive member.

9. A work feed device according to claim 8 wherein the displacing means comprises:

an actuating shaft extending between the master cylinder piston and the remote control; and wherein the remote control comprises:

a lever pivotally mounted on the pressure bar and having,

a short lever arm operatively connected to an opposite end of the actuating shaft, and

a long lever arm by which the machine operator can, with little effort, displace the actuating shaft and the master cylinder piston various amounts and thereby control and vary the amount of frictional contact between the friction means and the drive member, the pressure against the workpiece, and the rate the workpiece is fed into the cutting tool.

10. A work feed device according to claim 8 wherein the displacing means comprises:

a power assist cylinder, having an inlet port at one end of the cylinder, fixed adjacent and relative to the master cylinder a power assist piston slideably mounted in the power assist cylinder,

an actuating shaft extending between the power assist piston and the master cylinder piston;

means, including a directional control valve having an exhaust port, a pressure inlet port connected to a source of fluid under pressure, and a pressure outlet port connected to the power assist cylinder, for allowing the fluid under pressure to pass through the control valve, in one position, into the power assist cylinder and, in another position, to exhaust from the power assist cylinder;

an adjustable pressure-regulating valve having an outlet port connected to the pressure inlet port of the directional control valve, and an inlet port adapted to be connected to a source of fluid under pressure; and wherein the remote control comprises:

means on the pressure bar for actuating and shifting the directional control valve whereby fluid under pressure is passed into the power assist cylinder and the power assist piston which together with the actuating shaft move the master cylinder piston toward the outlet port and the friction means into engagement with the drive member.

UNITED STATES PATENT QFFICE QE'HFCATE or 3,629,977 Dated December 28, 1971 Patent No.

Inventor(s) Robert L. HOldGh It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 12, delete reference to "No. 2,477,559".

Signed and sealed this 31st day of October 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents ORM PO-105O (10-69) uscoMM-oc 00376-P69 U.S GOVERNMENT PRINTING OFFICE: 1889 0-366-334,

Patent Citations
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US1422749 *Dec 30, 1920Jul 11, 1922Dameron AdolphusWork holder
US1477151 *Jan 3, 1922Dec 11, 1923Pizzino AntoninoRest plate and fulcrum for grinding machines
US2686994 *Oct 10, 1952Aug 24, 1954Peninsular Grinding Wheel CoWork feed device for grinding machines
US3369328 *Feb 8, 1965Feb 20, 1968Minnesota Mining & MfgAbrading machinery
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4914872 *Nov 3, 1988Apr 10, 1990United Technologies CorporationApparatus and method for selectively contouring an airfoil root
Classifications
U.S. Classification451/231, 451/406, 83/401, 83/733, 451/11
International ClassificationB24B47/04
Cooperative ClassificationB24B47/04
European ClassificationB24B47/04