US3159949A - Profile edge and rabbet grinding machine - Google Patents

Description

Dec. 8, 1964 K. HEESEMANN 3,159,949

PROFILE EDGE AND RABBET GRINDING MACHINE Filed July so, 1962 6 Sheets-Sheet 1 fm/errtar: Karl Hese mann nrrvs.

Dec. 8, 1964 K. HEES EMANN 3,159,949

PROFILE EDGE AND RABBET GRINDING MACHINE Filed July so, 1962 e Sheets-Sheet 2 .[m emar? Karl Heesemcm n ggfpm Dec. 8, 1964 K. HEESEMANN 3,159,949

PROFILE EDGE AND RABBET GRINDING MACHINE Filed July 30, 1962 6 Sheets-Sheet 5 m emon' Karl He esemarm yuaj-m ATTYJ.

Dec. 8, 1964 K. HEESEMANN PROFILE EDGE AND RABBET GRINDING MACHINE Filed July 30, 1962 6 Sheets-Sheet 4 K Nu R an mw mm mm mm on R mm M mm mm mm mm mm mm mm mm vm [we/#021 Karl Heesemann Dec. 8, 1964 K. HEESEMANN 3,159,949

PROFILE EDGE AND RABBET GRINDING MACHINE Filed July 30, 1962 6 Sheets-Sheet 5 jm/emon' Karl Heesemann Ar-ryx Dec. 8, 1964 K. HEESEMANN PROFILE EDGE AND RABBET GRINDING MACHINE Filed July so, 1962 6 Sheets-Sheet 6 mm mm mm mm mm mm Wm an 5 mm m m A ee Wa d e H United States Pate 3,159,949 raornr. anon AND Planner GRZNDEJG Manama Karl Heesemann, 5 Friedenstrasse, iiehme uher. Bad @eynhausen, Germany Filed .luly Sit, i962, Ser. No. 213,386 laims priority, application Germany, Get. 28, 1961,

H 43fi93 15 Claims. (Cl. 51-138) 7 This invention relates to a bandgrinding machine for profile, edge and rabbet grinding, in which a preferably large-area workpiece is fed on a work table along an abrasive band preferably parallel to the direction of movement thereof.

In the machines of this type hitherto known the work table is mounted on the frame. of the machine so that it is adjustable in height, horizontally and at an angle to the abrasive hand. If it is desired to grind, by such machines, profiles or other shapes on chiefly large-area workpieces, such as for example upper rims, bottom rims or plates, which shapes form an acute angle to the bearing surface of the workpiece or even extend parallel thereto, the work table must be displaced to a corresponding degree. Due to the feeding elements for the.

workpiece such an adjustment is, however, only possible to a limited extent, with the result that such profiles cannot be ground on the above-mentioned machines. The conventional machines are also open to the objection that the working height changes continually owing to the necessary adjustment of the work table.

One object of the invention is to overcome these objections.

According to the invention, a hand grinding machin for profile, edge and rabbet grinding comprises a frame, a work table mounted on said frame, a conveyor mounted in said table for feeding workpieces along said table, an axle extending parallel to the path of movement of the workpieces, at least one endless circulating abrasive band, and driving, guiding and pressing-on devices for said abrasive band swingable together with said abrasiv band about said axle. Y

The abrasive band with its driving, guiding and pressing-on device may also be shiftable in vertical and/or horizontal direction.

According to a preferred embodiment the pivot axle is constituted by a carrier axle which carries the abrasive hand with its driving, guiding and pressing-on devices, and carriages are provided in which said carrier axle is mounted and which are shiftable in height and/ or laterally in relation to the frame.

The machine according to the inventionallows the abrasive band to be adjusted with its driving, guiding and pressing-on devices at an angle and possibly also in vertical and horizontal direction to such a degree that it can always be brought into the necessary position in relation to the workpiece moving on the work table serving as a workpiece guide. Thework table may be rigidly mounted on the main frame of the machine or may be additionally adjustable in height. The feeding and guiding devices for the workpiece are at the same time prefer ably so arranged that they form an aggregate with the Work table and consequently with the main frame and are not influenced by the adjustmentof the grinding aggregate. A profile, edge andrabbet grinding machine,

particularly with the above-mentioned features of the invention, enablestwo opposite edges of a workpiece to be ground in an advantageous manner'in a single passage of the workpiece.

' On the band grinding machines hitherto 'khbwh for such twosided grinding, it is only possible to grindtwo V opposite straight edges on solid wood "pieces to a-premeans Fatented Dec.v 8, 1964 ice chines then lack the adaptability to the workpiece which is necessary for such grinding work. 7

. Another object of the invention is "to improve the hitherto known profile, edge and/or rabbet grinding machine-s with endless circulating abrasivebands, on which two opposite edges of a workpiece can be ground in a single passage of the workpiece.

To achieve this object, the band grinding machine according to the invention is provided with two oppositely arranged endless circulating abrasive bands which are adjustable to the'width of the workpiece to be fed between said abrasive bands substantially parallel to the direction of movement thereof, the pressing-on device comprising pressure shoes or pieces which are arranged to press said abrasive bands against the workpiece fed in a straight line, guides being provided in which said pressure pieces are mounted, adjustable weights serving for regulating the grinding pressure and elbow levers connecting said weight with at least one of said pressure pieces. I a

By this construction both opposite abrasive bands can automatically adjust themselves to the Width of the workpiece within certain limits, so that, according to the ad- 7 justment of the slidable counterweights, a uniformly strong pressure is exerted by the pressure shoes against the abrasive bands and consequently against the work piece. As a result, the points at which the abrasive bands engage adapt themselves exactly to the shape of the workpiece and the chip removal takes place only in accordance with the' grinding pressure which has been set. The shape of the surface of the edge of the workpiece is not changed but ground out uniformly everywhere. It is thus possible to grind workpieces, the edges of which are covered with very thin veneers, for example about 0.6 mm. in thickness and even constructed as rabbets or profiles. p, i

By such an arrangement of the pressure shoes the tolerances which; occur with every workpiece are automatically taken into consideration without running the risk of the thin veneers being ground through.

Inan expedient form of construction of the'ban'd grindmg machine according to the invention, besides this automatic adjustment of the grinding pressure, these pressure shoes or pieces can be so controlled that they two abutments are arranged in the path of travel of the FIG.1; p

. FIG. 3 is a cross section through the machine taken i on line 111-411 of FIG. 1;. r

pas-sing workpiece, guides-are provided on which said abutments are shiftahle in parallel relationship in the direction of movement ofthe workpiece, and control devices couple said abutments with the pressure shoes or These abutments are preferably constructed as pieces.

contact rollers which project into the range of the end edges of the workpiece and are moved thereby.

Two preferred embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which: 5

FIG. '1 is a rear view of a band grinding machine according to the invention with abrasive b and removed; FIG. 2 is a top plan view of'the machine shown in 1 16.4 is a sideielevationof a workpiece with a tile at a'yery acute angle to the work table .as well as j of a profiled tool with the abrasiveband' located between ;the workpiece andl the' tool andshown insection;

rection.

FIG. is a section through a modified band grinding machine taken on line V-V of FIG. 6, the band grinding machine being provided with two opposite pressure shoes or pieces for endless circulating abrasive bands;

FIG. 6 'is a top plan view of the machine shown in FIG. 5;

FIG. 7 is a diagrammatic view, on a larger scale, of two contact rollers arranged side byside and mutually displaced as abutments for a controlling device, thehousing of the rollers being shown partly in section;

FIG. 7a is a section through the housing of one of the contact rollers shown in FIG. 7, with the contact roller inside elevation, and

FIG. 8 is a longitudinal s'ectionthrough a control valve for moving the pressure shoesor'pie'ces.

Referring to FIGS. 1 to 3, a Work table 2 is fixed on a stand or frame 1. A conveyor belt 3 is fitted in the work table '2 in such a manner that it can transport a workpiece 4. The conveyor belt 3 is driven by a geared motor (not shown), the speed of which is'infinitely variable. To ensure that the workpiece 4 has a good hold on the conveyor belt 3, .it is pressed against the conveyor belt by pressure rollers 5 which are provided, for example, with a suitable rubber cover and resiliently mounted in vertical direction. An abutment rail 6 on -the work table 2 forms an accurate straight guide for the workpiece 4.

An abrasive band 7 runs over a pulley 9 driven by a motor '8' and a pulley 11 which can be 'tensioned by a band tightener 10. The driving and tightening aggregates for the abrasive band 7 are mounted on; a carrier axle 12 which is rotatable about its axis in horizontal supports 13. The carrier axle 12 is turnable about its axis by means of a worm gear 15 with a band wheel 16. This worm gear 15 is self-locking so thatthe carrier axle 12 is fixed in any adjusted position. The horizontal supports 13 are adjustable in horizontal direction on guide rods 17 by meansof a spindle 18- connected with a hand wheel 19. The guide'rods 17 are arranged in a vertical carriage 20 which is guided on vertical'iguides 21 fixed-in the frame 1. The vertical carriage 20-can .be adjusted in vertical direction by a spindle 22 provided with ahand wheel 23. v v

The pressure rollers 5 are arranged ona pressure beam 24 soas to be adjustable inheight and inhor'izontal di- The pressure beam 24 =is-'fittedon horizontal arms 25 which are adjustable in height jointly or indi: vidually on two posts 26. These posts 2 6 are rigidly connected to the frame 1 'so' that the pressure elements 5, 24 and 25 form a unit with the frame 1. t

If workpieces 4 are to be ground on the machine, the vertical support 20 and the horizontal carriages 13 are so adjusted and. the carrier. axle 12 is turned about its axisthrough such an angle that the undeformed abrasive band 7 runs parallel to the surface to be ground on the workpiece 4 and about in the -middle thereof.

In FIG. 4 a difierent workpiece 27 is shown having a profile which forms a very acute angle with the work table 2. The abrasive band 7 is undeformed in the position shown and lies substantially parallel to the tangent of the profile shape. The abrasive band 7 is pressed against the profile to be ground bymeans of a profiled tool 28. The abrasive band '7 is thereby deformed to correspond to the profile shape to be ground. i

For grinding such parts the whole grinding vaggregate is therefore swung about the'carrier axle 12 and adjusted in vertical: and horizontal direction so that the abrasive hand assumes the correct position to the profile tobe 7 ground.

The modified construction shown in FIGS. 5, 6, 7, 7a.

and 8 has the same fundamental construction. A work table 32 is fixed on a mainframe 31 and aconveyor belt.

33 -is built thereinfso that it canconvey a workpiece l 34 resting on it. The conveyor belt'33 is driven by'a geared motor (not shown), the speed of which is infi easily adjustable in axial direction.

. nitely variable. To give the workpiece 34 a good hold onthe conveyor belt 33, it is pressed against the conveyor belt 33 by pressure rollers 35 which are provided, for example, with a suitable rubber cover and mounted so that they are resilient in vertical direction. An abutment rail 36 forms an accurate straight guide for the workpiece 34.

An endless abrasive band 37 (FIG. 6) runs over a pulley 33 driven by a motor (not shown) and a pulley 49 adjustable by a belt tightening device 39. The driving and tightening aggregates for the abrasive band are arranged on a carrier. axle 41. The carrier axle 41 is mounted in horizontal carriages 42 so as to be turnable about its axis by means of a worm gear 44 having a hand wheel 45. The worm gear 44' is self-locking so that the carrier axle 41 is fixed in any adjusted position.

The horizontal carriages 42 are adjustable on guide rods 46 in horizontal direction by means of a spindle 47' With a hand wheel 48 The guide rods 46 arefixed in a vertical carriage 4? which is guided on vertical guides 50 fixed in the main frame 31. The vertical carriage 49 is adjustable in vertical direction by means of a spindle 51 with a hand wheel' 52. p

The pressure rollers 35 are arranged on a pressurebeam 53 so as tobe adjustable in height and in horizontal direction.

An endless abrasive band 54 runs over two pulleys 55 and a pulley 56, the pulley 56 being driven by amotor .57. The pulleys '55 and 56 including the motor 57 are mounted in a carriage 58 which is adjustable on guides 59 in vertical direction by means of a spindlefitl; The guides 59 are fixed on a horizontal carriage 61 whichisadjustable on guides 62' inhorizontal'direction by means of a spindle 63 with a hand wheel 64. The guides 62 are mounted at one end in the main frame 31"and at the other end in an auxiliany frame 75.

Two pressure shoes or pieces 65a and 6511, which press. theabrasive bands 37 and 54 from the inner sides thereof against the workpiece 34 when grinding, are mounted by means of guide rods 66 on balls in guides 67 so-that the guide rods 66 with the pressure pieces 65aand 65b are are rigidly connected to the guide rods 66. Two set screws 69 permit the adjustment of the range of movement of the pressure pieces 65a and 65b in relation to the abrasive bands 37 and 54 Holding arms 70 are ar ranged on the guides 67 and at their free ends elbow levers 72 are mounted so that they are rotatable about pivots 71 in the vertical plane. The elbow levers 72 are connected to the cross-members 68 by means of connect ing pieces 73. They carry counterweights 74 which are adjustable in longitudinal direction and exert moments of force about the pivots 71. The gforcesresulting there from are transmitted by the guide rods 66'to the pressure pieces 65:: and 65b and there exert the grinding pressure during the grinding operation. By adjusting the counter- Weights 74 on the elbow levers 72, these forces or the grinding pressure can be adjusted within certain limits.

Two contact rollers" 76 and-77 are mounted so that they are elastically yieldable in housings 76a and 7741 by means of springs 76b and 77b andare slidable in the axial direction of the pressure beam 53 on guides 78 and 79,

respectively. In FIG. 6 the contact rollers 76 and 77 are located side by side; the working position in which the- contact rollers 76 and 77 are displaced in relation to each other is shown in FIG. 7. The contact- 'rollers'76' and 77' (FIG. '7) operate limit switches 81 and -;-arranged in the housings 76a and 77a, respectively, and

connected in series, so that they close a control circuit when both contactrollers-76 and 77 are in lowered position, that is,-.when no workpiece is pass'ingunder the, con: tact rollers 76 and 77. By the closing ofthe'circuit, coils 32a of two electromagnetic control-valves 82 (FIG. 8) coordinated one to each of the pressure pieces 65::

and 65'!) or their guide rods 66 are energized, with the Cross-members 68 result that slide valves 83 shift to the left in FIG. 8 and connect passages 84 with outer chambers 85 and diaphragnls 86. Under the action of compressed air the diaphragms 86 and push rods 87 connected therewith are moved towards the right, so that the cross-members as and the guide rods 66 lift the pressure pieces 65a and 65b oil the abrasive bands 37 and 54 with the result that the grinding operation stops immediately.

When a fresh workpiece 4 approaches, the front contact roller '77 (FIG. 7) is first raised. The contact of the limit switch 83 interrupts the circuit and springs 86 move the slide valves 83 of the two electromagnetic control valves 52 towards the right. The compressed air passages 84 are interrupted and the compressed air can escape from the outer chambers 85 through passages 29, so that the diaphragms 86 and consequently the push rods 8'? move back into their initial positions. As a resuit, the cross-members e53 we again free and the pressure pieces 65a and 6573 are pressed against the inner sides of the abrasive bands under the action of the counterweights 74, thereby pressing these bands against the workpiece.

After the passage of the workpiece, the circuit is then again closed when the workpiece has run past the rear contact roller 76.

This two-contact-roller systern' and especially its arrangement enables the lag of all switching and control elements, the rate of deed and the different lengths of feed paths necessary during the running in and out of the workpiece to be taken individually into consideration.

The control arrangement for the pressure shoes or pieces, equipped with contact rollers as abutments, enables, particularly in combination with the diaphragm control valves, the pressure pieces to be applied and removed without jerk as the workpiece runs through. By shifting the contact rollers parallel to the direction of travel of the workpiece, the moment when the pressure shoes or pieces move can be adjusted according to the rate of feed.

The movement of the pressure shoes or pieces when engaging and/ or disengaging the abrasive bands can be controlled not only in the manner described but also in other ways, for example electrically, pneumatically, mechanically or by combinations of these means.

I claim:

1. A band grinding machine for profile, edge and rabbet grinding; said machine comprising a zfirame, a stationary work-supporting table mounted on said frame for supporting the piece to be worked, and at least one grinding unit which is vertically and horizontally adjustable; said grinding unit comprising an endless abrasive band mounted for longitudinal movement, driving means for driving said band in longitudinal movement, means for guiding said band so that it is efiective Where needed, and a pressure device for forcing said band at least at one point along its length against the piece being worked; a conveyor on said table for conveying pieces to be worked along said table past said points on said band; an axle disposed parallelto the path of movement of the pieces to be worked, said grinding unit being rotatably mounted as a Whole on said axle; and means for vertically and horizontally adjusting the position of said aide with respect to said table.

2. A band grinding machine as claimed in claim 1, wherein the abrasive band is so guided that the work- 7 pieces are fed in front thereof.

3.A band grinding machine as claimed in claim 1, wherein the abrasive band is guided parallel to the feed direction of the workpieces.

4. A band grinding machine as claimed in claim 1, wherein said axle also comprises a carrier which carries the abrasive band with its driving, guiding and pressingon devices, and wherein supports are provided in which said axle is mounted and which are shiftable in height and laterally in relation to the frame. l

5. A band grinding machine as claimed in claim 4, wherein the supports are constructed as horizontal supports and guide rods serve for guiding said horizontal supports thereon and a spindle is provided for adjusting the supports on said guide rods in horizontal direction.

6. A band grinding machine as claimed in claim 5,-

7. A band grinding machine as claimed in claim 6,

wherein vertical guides are fixed in the frame and the vertical carriage is shiftable on said vertical guides.

8. A band grinding machine as claimed in claim 4, wherein a self-locking worm gear serves for adjusting and fixing the axle.

9. A band grinding machine as claimed in claim 1, wherein the conveyor comprises an endless circulating conveyor belt, and further including pressure rollers which are mounted vertically resilient on a pressure beam and serve for pressingthe workpieces onto said conveyor belt.

10. A band grinding machine as claimed in claim 9, wherein posts are connectedwith the {frame and horizontal arms are vertically shiftable on said posts and the pressure beam which carries the pressure rollers is arranged on said horizontal arms.

11'. A band grinding machine as claimed in claim 1, wherein two oppositely arranged endless circulating abrasive bands are provided which are adjustable to the width of the'workpiece to be fed between said abrasive bands substantially parallel to the direction of movement thereof, wherein the pressing-on device comprises pressure shoes or pieces which are arranged to press said abrasive bands against the workpiece fed in a straight line, wherein guides are provided in which said pressure pieces are mounted, and wherein adjustable weights serve for regulating the grinding pressure and elbow levers connect said weights with at least one of said pressure pieces.

12. A band grinding machine as claimed in claim 11,

wherein the pressure show or pieces are mounted on ball devices couple said abutments with the pressure shoes or pieces.

14. A band grinding machine as claimed in claim 13 wherein the abutments are constructed as contact rollers. 15. A band grinding machine as claimed in claim 13,

wherein a magnet-controlled compressed air valve with diaphragm is provided as each control device.

References Cited in the file of this patent UNITED STATES PATENTS 2,456,217 'Rothrock Dec. .14, 1943 2,479,506 Payton Aug. 16, 1949 2,637,951 White May'l2, 1953 4 2,934,864

'Karbowski May 3, 1960

Claims (1)

1. A BAND GRINDING MACHINE FOR PROFILE, EDGE AND RABBET GRINDING; SAID MACHINE COMPRISING A FRAME, A STATIONARY WORK-SUPPORTING TABLE MOUNTED ON SAID FRAME FOR SUPPORTING THE PIECE TO BE WORKED, AND AT LEAST ONE GRINDING UNIT WHICH IS VERTICALLY AND HORIZONTALLY ADJUSTABLE; SAID GRINDING UNIT COMPRISING AN ENDLESS ABRASIVE BAND MOUNTED FOR LONGITUDINAL MOVEMENT, DRIVING MEANS FOR DRIVING SAID BAND IN LONGITUDINAL MOVEMENT, MEANS FOR GUIDING SAID BAND SO THAT IT IS EFFECTIVE WHERE NEEDED, AND A PRESSURE DEVICE FOR FORCING SAID BAND AT LEAST AT ONE POINT ALONG ITS LENGTH AGAINST THE PIECE BEING WORKED; A CONVEYOR ON SAID TABLE FOR CONVEYING PIECES TO BE WORKED ALONG SAID TABLE PAST SAID POINTS ON SAID BAND; AN AXLE DISPOSED PARALLEL TO THE PATH OF MOVEMENT OF THE PIECES TO BE WORKED, SAID GRINDING UNIT BEING ROTATABLY MOUNTED AS A WHOLE ON SAID AXLE; AND MEANS FOR VERTICALLY AND HORIZONTALLY ADJUSTING THE POSITION OF SAID AXLE WITH RESPECT TO SAID TABLE.

Images