US3782044A - Wide abrasive belt type lumber planing machine - Google Patents

Wide abrasive belt type lumber planing machine Download PDF

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Publication number
US3782044A
US3782044A US00249175A US3782044DA US3782044A US 3782044 A US3782044 A US 3782044A US 00249175 A US00249175 A US 00249175A US 3782044D A US3782044D A US 3782044DA US 3782044 A US3782044 A US 3782044A
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United States
Prior art keywords
machine
shoe
conveyor belt
pressure
pressure shoe
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Expired - Lifetime
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US00249175A
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English (en)
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P Olin
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Timesavers Inc
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Timesavers Inc
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B21/00—Machines or devices using grinding or polishing belts; Accessories therefor
    • B24B21/04—Machines or devices using grinding or polishing belts; Accessories therefor for grinding plane surfaces
    • B24B21/12—Machines or devices using grinding or polishing belts; Accessories therefor for grinding plane surfaces involving a contact wheel or roller pressing the belt against the work

Definitions

  • ABSTRACT A wide abrasive belt lumber planing machine in which the planing action is performed by a contact drumsupported abrasive belt as the workpiece is moved through the machine, with its top surface in contact with the belt.
  • An in-feed pressure shoe and an outfeed pressure shoe press down on the workpiece just as it enters and leaves the abrasion zone, and to preclude the generation of abnormally high friction'loads due to variations in thickness of the workpiece, the force with which the in-feed shoe is pressed down is produced by a pressure-regulated air cylinder.
  • the abrasive head of machines of this type comprises an endless coarse grit abrasive belt trained around two vertically spaced apart rollers that have their axes parallel and horizontal.
  • the lower one of these rollers is the contact drum, the axis of which is fixed with respect to the frame of the machine during operation of the machine.
  • the contact drum is driven by a motor mounted on the machine frame to thus impart orbital motion to the abrasive belt normally in the direction opposite to the movement of the workpiece through the machine.
  • the upper roller is an idlermounted for bodily up and down motion and biased upwardly when the machine is in operation to maintain tension on the abrasive belt.
  • Workpieces are carried under the abrading head by the top stretch of a horizontally oriented endless conveyor belt that is driven by a motor separate from the one that drives the contact drum.
  • the top'stretch of the endless belt is solidly supported by frame-carried structure which includes freely rotating rollers and a flat, horizontal platen by which the top working stretch of the conveyor belt is firmly supported directly beneath the contact drum.
  • the workpiece As a workpiece is carried through the machine by the conveyor belt, and just before it comes in contact with the abrading head, and again just after passing out from under the head, the workpiece should be firmly pressed down against the conveyor belt, so that its upper surface travels as nearly as possible in a horizontal plane spaced above the lowermost surface of the contact drum-supported abrasive belt a distance determined by the amount of stock to be planed off. Without such firm downward pressure on the workpiece directly upstream and downstream of its contact with the drumsupported abrasive belt, there would be no assurance of achieving accurate planing of the workpiece. It is, therefore, essential to the success of the operation to hold the workpieces firmly down on the conveyor belt.
  • the means for thus pressing the workpiece down against the conveyor belt comprises a pair of pressure shoes which extend transversely across the conveyor belt and project inwardly towards and under opposite sides of the contact drum to slidingly engage the workpiece in zones closely adjacent to, but at opposite sides of, the zone of abrasion.
  • a pair of pressure shoes which extend transversely across the conveyor belt and project inwardly towards and under opposite sides of the contact drum to slidingly engage the workpiece in zones closely adjacent to, but at opposite sides of, the zone of abrasion.
  • Both the pressure shoes and the freely rotatable rollers have a degree of bodily up and down motion and are biased downwardly so that they exert a yielding downward force on the workpiece.
  • the biasing force upon both the in-feed pressure shoe as well as the outfeed pressure shoe and all of the rollers has been exerted
  • the present invention is based upon a recognition that, in prior wide abrasive belt planing machines, the use of springs to impart downward bias to the in-feed pressure shoe which engages the workpiece as it enters the abrasion zone, has been responsible for requiring the drive motor for the conveyor belt to be considerably larger and more powerful (and, therefore, more expensive) than it really needed to be.
  • the heretofore unappreciated relationship between the power of the motor driving the conveyor belt and the character of the in-feed pressure shoe biasing means arises from the fact that the workpieces generally rough lumber have a substantial variation in thickness from point to point along their length.
  • FIG. 1 is a view in side elevation ofa wide belt sanding machine embodying the principles of this invention
  • FIG. 2 is a vertical sectional view through the contact drum and the pressure shoes of the machine, showing the relationships of those parts to one another and illustrating the principles of this invention more or less diagrammatically.
  • FIG. 3 is an enlarged view generally similar to FIG. 1, but with portions of the machine housing broken away to illustrate details of construction;
  • FIG. 4 is an end view of the in-feed pressure shoe and its associated structure, said view being taken on the plane of the line 4-4 in FIG. 5;
  • FIG. 5 is a view in elevation of the structure shown in FIG. 4, taken from the right-hand side of FIG. 4, but with portions broken away to illustrate details of construction.
  • the numeral 5 designates generally the abrading head of a wide abrasive belt lumber planing machine, which head comprises, in general, a wide endless abrasive belt 6 trained around a lower contact drum 7 and an upper tension roll 8.
  • the contact drum is journalled on the frame 9 of the machine for rotation on a fixed axis and is driven in the customary manner by a powerful motor (not shown).
  • the tension roll 8 is mounted in a known manner for limited bodily up and down motion and is biased upwardly to maintain tension on the abrasive belt.
  • a conveyor which is designated generally by the numeral 12 and which comprises a supple endless belt 13 trained around horizontally spaced apart rollers 15 and 16 with a straight upper working stretch 17 extending between those rollers.
  • the roller 15 is driven by an electric motor connected therewith through an appropriate transmission system, as more or less diagrammatically illustrated in FIG. 1 at 19. In this manner, orbital motion is imparted to the conveyor belt in the direction to move its upper stretch from right to left, as viewed in the drawings.
  • the upper stretch of the conveyor belt is supported by idler rollers 20 and a flat smooth surfaced platen 21, located directly beneath the contact drum.
  • the distance between the bottom of the contact drum-supported abrasive belt and the top surface of the platen thus determines the amount of stock that is removed from a workpiece fed through the machine, and since the machine must be capable of handling a wide range of workpiece thicknesses, that distance must be adjustable.
  • the entire conveyor is mounted on the machine frame in a known manner for bodily up and down adjustment.
  • the workpiece be held in firm engagement with the platensupported conveyor belt directly adjacent to the zone of abrading action, and especially just as it enters that zone.
  • the necessary downward force for this purpose is applied to the workpiece by an in-feed pressure shoe 24 and an out-feed pressure shoe 25.
  • the downward force which these pressure shoes exert on the workpiece must be applied as close as possible to the zone of engagement between the abrasive belt and the workpiece and, for this reason, the pressure shoes are shaped to have toe portions 26 that project inwardly under the contact drum, as best seen in FIG. 2. Essentially, only these toe portions of the shoes engage the workpiece.
  • the pressure shoes 24 and 25 extend across the full width of the conveyor belt and are mounted on cross shafts 27 and 27 which have their ends received in coaxial bores in vertical mounting brackets 28 that are rigidly fixed to the main frame of the machine, only one of these brackets being shown in the drawings.
  • the pressure shoes are preferably castings and have flat parallel end walls 29. Between these end walls the cross sectional shape of the shoes is essentially uniform and defined by a concave front surface 30 and a convex back surface 31 which is stepped, as at 32, to define the heel of the shoe. Forwardly of this heel the bottom surface 33 of the shoe slopes downwardly to join the botto n st rface34 of the toe of the shoe.
  • the end walls 29 of the shoes have coaxial bores to receive the cross shafts 27 and 27 whereby each shoe is rockably supported by its respective cross shaft.
  • the cross shaft 27 and the bore in the end walls 29 of this shoe are coaxial; but in the case of the in-feed shoe 24 which must be bodily vertically adjustable, the connection between each of its end walls 29 and the cross shaft 27 includes an eccentric 35 keyed to the shaft and journalled in the end wall of the shoe.
  • the eccentrics at the opposite ends of the shoe are, of course, coaxial and being keyed to the cross shaft it follows that by rotation of the shaft the axis about which the shoe rocks can be raised and lowered between limits determined by the throw of the eccentrics.
  • Another collar 38 on the extreme end of the shaft into which the cap screw 36 is threaded provides for securing the shaft in a selected position of rotary adjustment.
  • the collar is keyed to the supporting bracket 28, as at 39, and is releasably clamped to the shaft.
  • the in-feed pressure shoe 24 must be capable of up and down motion. While the prior art use of springs to force the in-feed shoe down onto the workpiece did not preclude such up and down motion, it often resulted in the exceptionally severe friction loads referred to hereinbefore, which sometimes were so great that they stalled the conveyor drive motor. To prevent this from happening, a higher horsepower motor was used. This, of course, entailed a significant increase in the cost of the machine, not only because the motor was more expensive, but also because the transmission system had to be capable of handling the increased loads.
  • an air pressure cylinder 41 is mounted at each end of the in-feed shoe by being secured to a bracket 42 that is welded to the inner face of the adjacent frame'carried mounting bracket 28.
  • These air cylinders are preferably of the conventional diaphragm type, having a plunger 43 connected to and projecting from one side of a diaphragm 44 to be forced outwardly of the cylinder by air pressure manifested at the opposite side of the diaphragm.
  • the outer end of the plunger 43 bears against an upwardly projecting arm 45 on the pressure shoe 24, and to accommodate arcuate motion of this arm, the plunger applies its thrust to the arm through a swivel connection 46.
  • An adjustable stop 48 limits downward rocking movement of the toe portion of the pressure shoe. This stop consists simply of the head of a bolt that passes freely through a hole in the bracket 42 and is threaded into the upper portion of the shoe. Lock nuts on the bolt secure it against loss of adjustment.
  • each of these rolls is freely rotatably mounted on a cross shaft 52, the ends of which are secured to and connect a pair of arms 53 that are located beyond the ends of the rolls.
  • These arms are pivotally mounted on the cross shafts that rockably mount the pressure shoes and project beyond the back sides of the shoes.
  • extensions 54 into which bolts 55 are threaded to project upwardly therefrom and have their headed ends pass through holes in horizontal ledges 56 that are welded to the mounting brackets 28 and to the adjacent brackets 42.
  • Compression springs 57 encircling the bolts 55 are confined between the underside of the ledges 56 and nuts 58 threaded onto the bolts, to yieldingly maintain the idler rolls at a predetermined level tangent to the plane containing the underside of the toe portions of the pressure shoes when no workpiece is present.
  • a wide abrasive belt lumber planing machine having a frame, a contact drum rotatably mounted in the frame, a conveyor belt that has a horizontally extending Working stretch which is solidly supported by frame carried means including a platen beneath the contact drum, and by which workpieces are carried under the drum to be abraded by an orbitally moving abrasive belt trained around it, and power drive means for the conveyor belt, said machine also having a pressure shoe near the contact drum, a portion of which engages workpieces to confine them tightly against the conveyor belt directly before they are engaged by the abrasive belt, said machine being characterized by:
  • A. means mounting the pressure shoe on the machine frame for rocking movement about a horizontal axis transverse to the direction workpieces are carried through the machine by said conveyor belt, whereby the workpiece engaging portion of the shoe can move arcuately up and down;
  • means including a pressure regulating valve for supplying compressed air to said pneumatic forceapplying means in such manner that the force produced thereby remains substantially constant.
  • a wide abrasive belt lumber planing machine having a frame, a contact drum rotatably mounted in the frame, a conveyor belt that has a horizontally extending working stretch which is solidly supported by frame carried means including a platen beneath the contact drum, and by which workpieces are carried under the drum to be abraded by an orbitally moving abrasive belt trained around it, and power drive means for the conveyor belt,
  • said machine also having a pressure shoe near the contact drum, a portion of which engages workpieces to confine them tightly against the conveyor belt directly before they are engaged by the abrasive belt,
  • said machine being characterized by: A. means mounting the pressure shoe on the machine frame for rocking movement about a horizontal axis transverse to the direction workpieces are carried through the machine by the conveyor belt, with the work engaging portion thereof spaced from said horizontal axis and located closely adjacent to the lowermost portion of the contact drum to move arcuately up and down and hold a workpiece down on the conveyor belt; and B. pneumatic biasing means acting on the pressure shoe in a direction to urge its workpiece engaging portion downward towards the conveyor belt with a yielding force that remains constant irrespective of the distance between said portion of the shoe and the conveyor belt, said pneumatic biasing means comprising v 7' V I. an air cylinder mounted on a fixed part of the machine at an elevation above that of said horizontal axis with the axis of the cylinder substantially horizontal, the air cylinder having a plunger which is projected axially from the cylinder by air pressure therein,
  • biasing means reacting between each of said pair of arms and the machine frame to yieldingly force the hold-down roll downward.
  • the machine of claim 1 further characterized by: lost motion connection means connected between said rigid arm and a part fixed with respect to the frame of the machine for defining a limit of downward motion of the workpiece engaging portion of the pressure shoe.
  • said means for rockably mounting the pressure shoe including an eccentric, rotation of which provides for up and down adjustment of the axis about which the pressure shoe rocks.
  • said means for rockably mounting the pressure shoe comprises a cross shaft supported at its opposite ends from fixed parts of the machine, and having the shoe rotatably mounted thereon with its workpiece engaging portion spaced horizontally in one direction from the cross shaft; and further characterized by:
  • E. motion limiting means connected between the machine frame and the said arms for maintaining said roll at not less than a predetermined distance above the platen.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
US00249175A 1972-05-01 1972-05-01 Wide abrasive belt type lumber planing machine Expired - Lifetime US3782044A (en)

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US24917572A 1972-05-01 1972-05-01

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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3832808A (en) * 1973-07-09 1974-09-03 Timesavers Inc Abrasive belt-type lumber planing machine
US4038784A (en) * 1976-05-07 1977-08-02 Acrometal Products, Inc. Method and apparatus for cross grain abrading to produce a rough-sawn effect
US4151705A (en) * 1977-10-13 1979-05-01 Kimwood Corporation Combination ram biased board hold-down and exhaust infeed
US4322919A (en) * 1980-06-27 1982-04-06 Acrometal Products, Inc. Self-centering feed mechanism for an abrasive grinding machine
US4356670A (en) * 1979-12-17 1982-11-02 Minnesota Mining & Manufacturing Company Apparatus and method for in-line planing of lumber using angled abrasive head
FR2534839A1 (fr) * 1982-10-20 1984-04-27 Elan Machine automatique a ebavurer des pieces de petites dimensions
EP0684107A3 (en) * 1994-05-24 1996-04-10 Timesavers Inc Automatic run limit lock for press block of a finishing machine.
US6769958B1 (en) 2002-08-21 2004-08-03 Howard W. Grivna Material removal monitor
US20040235391A1 (en) * 2002-08-21 2004-11-25 Grivna Howard W. Material removal monitor
WO2018147847A1 (en) * 2017-02-08 2018-08-16 Sterling Lumber Company, Llc Crane mat and method of manufacture
US10577753B2 (en) 2015-08-03 2020-03-03 Sterling Site Access Solutions, Llc Crane mat and method of manufacture

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5388487A (en) * 1977-01-14 1978-08-03 Hitachi Seiko Ltd Error correcting system of nc machine

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US554758A (en) * 1896-02-18 Machine for cleaning and polishing moldings
US2791070A (en) * 1956-03-23 1957-05-07 Engelberg Huller Co Inc Abrading machine
US3208187A (en) * 1963-12-10 1965-09-28 Ernst Paul Apparatus for working on plate-shaped workpieces in conjunction with a machining tool
US3271909A (en) * 1964-03-13 1966-09-13 Carborundum Co Grinding apparatus
DE1921566A1 (de) * 1969-04-28 1970-12-03 Walter Tilleke Druckbalken fuer Schleifmaschinen

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US554758A (en) * 1896-02-18 Machine for cleaning and polishing moldings
US2791070A (en) * 1956-03-23 1957-05-07 Engelberg Huller Co Inc Abrading machine
US3208187A (en) * 1963-12-10 1965-09-28 Ernst Paul Apparatus for working on plate-shaped workpieces in conjunction with a machining tool
US3271909A (en) * 1964-03-13 1966-09-13 Carborundum Co Grinding apparatus
DE1921566A1 (de) * 1969-04-28 1970-12-03 Walter Tilleke Druckbalken fuer Schleifmaschinen

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3832808A (en) * 1973-07-09 1974-09-03 Timesavers Inc Abrasive belt-type lumber planing machine
US4038784A (en) * 1976-05-07 1977-08-02 Acrometal Products, Inc. Method and apparatus for cross grain abrading to produce a rough-sawn effect
US4151705A (en) * 1977-10-13 1979-05-01 Kimwood Corporation Combination ram biased board hold-down and exhaust infeed
US4356670A (en) * 1979-12-17 1982-11-02 Minnesota Mining & Manufacturing Company Apparatus and method for in-line planing of lumber using angled abrasive head
US4322919A (en) * 1980-06-27 1982-04-06 Acrometal Products, Inc. Self-centering feed mechanism for an abrasive grinding machine
EP0108009A1 (fr) * 1982-10-20 1984-05-09 Société ELAN Société à Responsabilité Limitée dite: Machine automatique à ébavurer des pièces de petites dimensions
FR2534839A1 (fr) * 1982-10-20 1984-04-27 Elan Machine automatique a ebavurer des pieces de petites dimensions
EP0684107A3 (en) * 1994-05-24 1996-04-10 Timesavers Inc Automatic run limit lock for press block of a finishing machine.
US6102781A (en) * 1994-05-24 2000-08-15 Timesavers, Inc. Automatically securable travel limiting stops for pressure shoes used in an abrasive finishing machine
US6769958B1 (en) 2002-08-21 2004-08-03 Howard W. Grivna Material removal monitor
US20040235391A1 (en) * 2002-08-21 2004-11-25 Grivna Howard W. Material removal monitor
US6913512B2 (en) 2002-08-21 2005-07-05 Howard W. Grivna Material removal monitor
US10577753B2 (en) 2015-08-03 2020-03-03 Sterling Site Access Solutions, Llc Crane mat and method of manufacture
WO2018147847A1 (en) * 2017-02-08 2018-08-16 Sterling Lumber Company, Llc Crane mat and method of manufacture

Also Published As

Publication number Publication date
JPS4930997A (ref) 1974-03-19
AU4659272A (en) 1974-04-04
CA953918A (en) 1974-09-03
JPS5226635B2 (ref) 1977-07-15

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