US 3830122 A
In an automatically controlled cutting machine for cutting thick layups of sheet material, apparatus is provided to dispense a liquid fluid onto the tool for cooling, lubricating or other ancillary functions. The apparatus includes a presser foot which rides on top of the sheet material during a cutting operation and the presser foot permits liquid to flow to the reciprocating blade whenever the blade is cutting through the sheet material. A liquid absorbing material in the presser foot insures that the cutting portion of the blade receives the liquid.
Description (OCR text may contain errors)
United States Patent Pearl Aug. 20, 1974 APPARATUS FOR DISPENSING A LIQUID 1,958,912 5 1934 Clark 83/169 x 3,029,510 4/1962 Marden, .lr. 83/169 x ONTO A TOOL  Inventor: David R. Pearl, West Hartford,
 Assignee: Gerber Garment Techology, lnc.,
East Hartford, Conn.
 Filed: Mar. 26, 1973  Appl. No.: 344,895
 US. Cl 83/169, 83/925 CC  Int. Cl. 826d 1/10, B26d 7/08, A4lh 43/00  Field of Search 83/169, 925 CC; 30/1233  References Cited UNITED STATES PATENTS 1,172,058 2/1916 Scheyer 83/925 CC 1,375,989 4/1921 Williams 1,435,125 11/1922 Meyer 30/1233 Primary ExaminerJ. M. Meister Attorney, Agent, or FirmMcCormick, Paulding & Huber 5 7 ABSTRACT In an automatically controlled cutting machine for cutting thick layups of sheet material, apparatus is provided to dispense a liquid fluid onto the tool for cooling, lubricating or other ancillary functions. The apparatus includes a presser foot which rides on top of the sheet material during a cutting operation and the presser foot permits liquid to flow to the reciprocating blade whenever the blade is cutting through the sheet material. A liquid absorbing material in the presser foot insures that the cutting portion of the blade receives the liquid.
9 Claims, 5 Drawing Figures PATENIED AUG 2 01974 SHEET 2 BF 2 TOOL BACKGROUND OF THE INvENTIoN The present invention relates to automatically controlled cutting machines in which a cutting tool is moved at a high speed relative to sheet material in a cutting or similar operation. More particularly, the invention relates to apparatus which dispenses a cooling, lubricating or other liquid onto the tool during the operation.
With the advent of numerically controlled cutting tools of the type disclosed in US. Pat. No. 3,495,492 entitled Apparatus For Working on Sheet Material and having the same assignee as this invention, it has been possible to increase the rate at which areciprocating cutting tool is translated along a cutting path through a multi-ply layup formed from woven fabrics, plastics, vinyl and other limp sheet materials. For clean and efficient cutting the increased translational rates frequently require higher reciprocation rates to generate the necessary relative movement between the cutting edge of the blade and the sheet material. With certain materials such as vinyl and other products, the higher reciprocation rates produce enough heat to cause fusin g of adjacent plies of the material. In addition to damaging the material, such fusing may make separation of pattern pieces diff cult duringlater stages of a manufacturing program where the pieces are, for example, sewn or. otherwise assembled with other pattern pieces.
In the past, reciprocating cutting blades suspended in cantilever fashion I have been both lubricated and cooled by delivering a liquid to a guide block in which a reciprocating blade is slidably supported. Usually,
} however, the blade is not drawn entirely into the guide block during each reciprocation stroke and, consequently, the lower end of the blade which does-a substantial portion of the cutting does not receive its share of the liquid. Heating of this critical portion of the blade contributes to the fusion problem and can result in weakening of the blade with eventual failure.
Increasing the flow of liquid so that it can flow by gravity to the lower portion of the blade does not pres.- ent a realistic solution to the problem. The reciprocation rates are generally too high to allow liquid to ever reach the lower portion during a single reciprocation cycle and excess liquid is wiped off the blade as it plunges into the material on the down stroke. Furthermore, the excess liquid may mark or otherwise soil the sheet material.
It is, accordingly, a general object of the present invention to disclose apparatus for dispensing liquid onto the entire cutting portion of the blade which moves in contact with a multi-ply layup of sheet material.
SUMMARY OF THE INVENTION The present invention resides in an apparatus for dispensing cooling, lubricating or'other liquid onto a cut-.
the blade and so that the blade can be moved in and out I ting'operation.
of cutting engagement with the sheet material at any desired location. I
The apparatus comprises a material holddown foot which is suspended from the support carriage for movement relative to the carriage in a direction perpendicular to the sheet material and adjacent the tool. The foot has'a presser plate defining a lower pressing surface which rests against the sheet material during a cutting operation and prevents thematerial from lifting. A source of liquid carried on the support carriage is connected by means of a liquid conduit means to the cutting tool. Flowcontrol means actuated by the holddown foot opens and closes the liquid conduit means during the cutting operation while the pressing surface of the holddown foot rests against the sheet material. A liquid absorbing material is mounted on the foot and contacts all portions of the tool in the vicinity of the foot during the cutting operation.
Through this apparatus, all or most portions of the tool receive a cooling or lubricating liquid and the absorbing material prevents excess quantities of the liquid from being deposited on the sheet material being cut.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an automatically concutting tool guide block and dispensing apparatus in detail during a cutting operation.
FIG. 4 is a fragmentary view of the pinch viewed from the right in FIG. 3.
FIG. 5 is an enlarged fragmentary view of thecutting tool and dispensing apparatus with the tool elevated above the sheet material before or after a cutting operation.
valve as DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view of a numerically controlled cutting. machine, generally designated 10, in v which the present invention may be utilized. The cutting machine 10 works upon a stack or layup 12 of sheet material to cut out a plurality of pattern pieces 14 in response to' digitized information 'on'a program tape 16. The tape 16 is read by a numerical controller 18 which converts the information into motor commands that are transmitted to the cutting table 20 of the machine 10. The table includes a frame 22 containing a penetrable bed 24 having a support surface on which the sheet material "is spread to form the layup 12. The bed 24 may be constructed of blocks of foamed plastic or bristled mats that can be easily penetrated by a cut ting tool which plunges through the layup from above. A vacuum holddown system,'such as that disclosed in US. Pat. 3,495,492 referenced above, may be utilized to hold the layup in position on the table FIGS. 1 and 2 illustrate the manner in which a cutting tool, taking the form of a reciprocating knife blade 30,
is translated through the layup l2 duringa cutting,
operation. The blade 30 is suspended in cantilever fashion at its upper end from a support carriage 32 which during a cutrotates under the-influence of a controlled drive motor (not shown) about an axis coincident with the .leading, cutting edge of the blade. The rotatable support carriage 32 is in turn supported above the bed 24 by an X- carriage 34 translatable over the bed in the illustrated X-direction and an Y-carriage translatable on the X- carriage and relative to the bed in the illustrated Y- direction. Motor commands from the controller 18 are transmitted through the cable 38 to motors (not shown)'which drive the X and Y-carriages. The X- carriage 34 has pinions (not shown) which engage the racks 40 at each side of the table to accurately position the carriage in the longitudinal or X-direction. A lead screw 42 extending transversely of the tableand carried by the X-carriage engages the Y-carriage 36to accurately position the carriage in the lateral or Y- direction. A guide bar 44 extending parallel to the lead screw provides a track in conjunction of the portion of the X-carriage bridging the table for accurately moving the carriage 36 in the Y-direction.
As shown most clearly in FIG. 2, the rotatable supportcarriage 32 is mounted on an elevating platform 48 at the projecting end of the X-carriage 36. The platform 48 is adjusted vertically between upper and lower limits on a track 50 through a motor (not shown) regulated by the controller 18. The platform 48 is illustrated at its lower limit in FIG. 2 and in this position, the reciprocating blade at the lower end of its stroke pierces through the layup l2 and into the penetrable bed 24. When the platform 48 is at the upper limit of the track 50, the blade is supported above and entirely disengaged from the layup as. shown in FIG. 5.
Mounted on a pedestal 52 at the upper portion of the rotatable carriage 32 is a motor 54 which is connected to the reciprocating blade 30 by means of drive pulleys 56 and 58 and drive belt '60. The pulley 58 is mounted on the end of a crankshaft 62 which reciprocates the blade 30 when the motor 54 is operating.
Suspended from a lower pedestal 66 of the rotatable support carriage 32 is a guide block 70 in which the blade 30 reciprocates. It will be readily understood that the supporting and driving mechanism for the blade 30,
including the motor 54 and the guide block 70, translates up and down relative to the bed 24 with the support carriage 32 and elevating platform 48, and the mechanism and rotates relative to the platform with the support carriage. With such movements, the blade 30 may plunge through the layup 12 at any point on-the bed 24 and can be rotated into a tangent position 'at each point along a contoured cutting path as the carriages 34 and 36 translate the blade through the layup. In this fashion, a plurality of pattern pieces can becut from different regions of the cutting-table 20 in response to the information programmed on the tape 16.
Turning more specifically to the present invention illustrated in FIGS. 2 and 3, a source of liquid in the form of a bottle 72 is mounted on the upper side of the rotatable support carriage 32. A flexible liquid conduit in the form of a plastic tube 74 leads from the bottle 72 to a fitting 76 on the blade guide block 70. In FIG. 3 the dotted lines illustrate the fluid path formed by the flexible tubing 74 between the bottle and the block.
Within the block a drilled channel 78 leads to a port 5 80 adjacent the upper end of the guide slot for the blade 30 and another port 82 adjacent the lower end of the guide slot. An adjustable metering valve 84 iscon layup 12. Water alone or mixed with a slight amount of detergent, oil or silicone lubricant may be used for the lubricating and cooling functions.
In accordance with the present invention, the dispensing of liquid from the bottle 72 onto the blade 30 is controlled by a material holddown or presser foot which cooperates with the reciprocating blade 30 to hold the sheet material down and in place, particularly during the upstroke of the blade. In this regard a pinch valve 92 actuated by the foot 90 is fastened to the block 70 to open the tube 74 whenever the cutting blade 30 and block70 are lowered by the platform 48 into a cutting position as illustrated in FIGS. 2 and 3. Conversely, the valve 92 squeezes or clamps the tube closed whenever the blade is elevated out of contact with the layup as illustrated in FIG. 5. v
The presser foot 90 in FIG. 3 is comprised generally of a pressure plate 94 fixedly secured by a screw 96 to the lower end of a depending support rod 98. The plate 94 has central cutout accommodating and circumscribing the blade 30. The support rod 98 slides vertically within the guide block 70 in a direction parallel with the reciprocation'of blade 30. The rod bears an elongated slot 100 at its midsection which is intercepted by a pair of dowels 102 fixed to the block. The slot 100 and dowels102 allow 'the lower pressing surface of the pressure plate 94 to' rest on thetop ply of the layup 12 under the weight of the foot 90 but pre- 112, and a biasing spring 114 which urges the lever v againstthe tube 74. The upper end ofjthe lever 110 is biased toward the support rod 98 under a light force applied to the lever by the spring 114.
When the support rod 98 projects through the upper end of the block 70 because the presser foot is resting on the layup 12 as illustrated in FIG.:3, the lever 110 is held away from the tube 74 so that liquid may readily pass through the tube into the channels 78 leading to the'reciprocating blade 30. When the blade 30 and the block 70 have been lifted above the layup by the platform 48, the presser foot 90 fans to. its lowest limit in the block as illustrated in FIG, 5 and the lever 110 is permitted to pivot about the axis of hinge 112' and over the angledcamming surface 116 at the upper end of the 1 support rod 98. The force supplied'to the lever 110 by the spring 114 is adequate to crush or clamp thetube 74 in a closed condition which prevents lubricating or cooling liquid from passing to the blade from the bottle 72. When the block 70 is again lowered and the blade 30 is plunged through the layup to start another cut, the foot 90 contacts the layup and .camming surface 116 pushes lever 110 away from the clamping position so that liquid again passes to the blade. The flow of liquid is, accordingly, regulated by the presser foot and is delivered to the blade on demand.
As shown in FIG. 3 a central recess 120 is defined in the presser plate 94 and a liquid absorbing material 122 such as felt, polyurethane foam or other sponge material fills the recess. A latch 124 pivoted at one end on a screw l26'holds the absorbing material in the recess and allows the material to be replaced from time to time.
The liquid absorbing material 122 performs several functions. It captures excess liquid which flows from the bottle 72 through the channel 78 and down the sides of the blade so that the underlying sheet material in the layup 12 will not be soiled by the liquid. In addition, the material 122 contacts and surrounds the blade 30 in the vicinity of the cutout 95 in the plate 94 and wipes the liquid onto the lower end of the blade as the blade reciprocates to ensure proper cooling and lubrication of the blade, particularly along the lower portion of the blade which is heated by friction between the blade and the sheet material of the layup.
The operation of the liquid dispensing apparatus is relatively simple. While the elevating platform 48 is in its uppermost position, the cutting blade 30 is translated over the layup 12 to a point where the cutting operation is to begin. On command from the controller 18, the platform 48 is adjusted downward to its lowest position and the blade 30 which may already be reciprocating pierces through the layup and into the penetrable bed 24. At the same time, the presser foot 90 makes contact with the upper ply of the layup and slides in the block 70 from the position shown in FIG. 5 to the position shown in FIG. 3. The pinch valve 92 opens the passageway in the tube 74 when the lever 110 is pivoted about the axis of hinge 112 by the support rod 98. At that point liquid begins to flow from the bottle 72 through the tube 74 and block 70 and down the blade 30 to the absorbing material 122 where it is captured. Lubrication and cooling achieved by the liquid dispensing apparatus is achieved at the important portions of the blade and without contaminating the sheet material with excess liquid.
While the present invention has been defined in a preferred embodiment, it will be understood that numerous modifications and substitutions can be had without departing from the spirit of the invention. For example, the pinch valve 92 can be replaced by a more conventional valve located in a nonflexible fluid conduit between the bottle 72 and the block 70. The particular operating linkage connecting the presser foot 90 with an actuating member of the valve need not necessarily take theform of the support rod 98 and lever 110. The valve can be actuated electrically, pneumatically, magnetically or otherwise by the foot. The operation of the dispensing apparatus utilizes the movement of the support carriage relative to the sheet material to actuate the valve 92; however, if the material is brought into engagement with the cutting tool suspended from a stationary support, the associated relative movement would also serve the actuating function. I-Ience, relative movement of the parts effects the same results in an equivalent manner regardless of which parts are movable or fixed. The absorbing material 122 carried in the pressure plate 94 may include bristle-type brushes which rub against the blade and transfer liquid to the blade as it reciprocates. Sponge material mounted on rollers may be positioned in the plate to make rolling contact with the flat sides of the blade. It should also be understood that although the invention has been disclosed in conjunction with a cutting machine having a reciprocating blade, it may also be applied to cutting machines having rotary blades. Accordingly, the present invention has been described in a preferred embodiment by way of illustration rather than limitation.
sheet material and is operationally disassociated from the material, and a second position in which the tool is closer to the sheet material to permit the tool and the sheet material to be operationally engaged with one another in a work operation; a material holddown foot suspended from the support carriage with the tool for movement relative to the carriage and the tool in the perpendicular direction and adjacent the tool, the foot having a pressing surface which rests against the sheet material when the tool and sheet material are operationally engaged during a work operation; a source of liquid; liquid conduit means connected to the source and leading from the source to the tool; flow control means actuated by the holddown foot for opening the liquid conduit means during a work operation when the pressing surface of the holddown foot rests against the sheet material; and a liquid absorbing material mounted on the foot and contacting a portion of the tool in the vicinity of the foot during a work operation.
2. Apparatus for dispensing liquid onto a tool as defined in claim 1 wherein the flow control means comprises a valve in the fluid conduit means between the source and the tool, the valve having an actuating member displaced by the holddown foot to open the valve when the pressing surface is rested on the sheet material by the support carriage.
3. Apparatus for dispensing a liquid as defined in claim 2 wherein: the holddown foot includes a support rod depending from the support carriage and slidable relative to the support carriage in the direction perpendicular to the sheet material, and a pressure plate hearing the pressing surface connected to the depending end of the support rod; and the valve actuating member is mounted for movement by the support rod.
4. Apparatus for dispensing a liquid as defined in claim 3 further including resilient means connected with the carriage and the actuating member for biasing the member toward a position closing the valve.
5. Apparatus for applying a liquid to a cutting tool which advances relative to sheet material along a cutting path, the tool being suspended from a tool support above a surface on which the sheet material rests in a spread condition, comprising: a tool platform holding the tool and mounted on the tool support for movement of the tool toward and away from the surface on which the material rests and between a cutting position and a non-operating position; a holddown foot slidably suspended from the tool platform for movement relative to the tool perpendicular to the surface on which the material rests and including a pressure plate defining a cutout accommodating the tool during a cutting operation; a liquid absorbing material positioned in the pressure plate at the cutting operation; a liquid supply source; and means actuated by the slidably suspended holddown foot when the platform moves the tool and foot into the cutting position for supplying liquid from the source to the liquid absorbing material in the foot during the cutting operation.
6. Apparatus for applying liquid as defined in claim wherein the liquid absorbing material circumscribes the cutting tool at the cutout in the holddown foot.
'7. Apparatus for applying liquid as defined in claim 5 further including a metering valve in the means for supplying toregulate the flow of liquid from the source.
to open the supply means when the pressure plate rests,
8 on the sheet material.
9. Apparatus for dispensing a liquid onto a tool which works upon sheet material and is mounted on a support carriage controllably movable relative to the sheet material in directions both parallel to and perpendicular to the material comprising: a material holddown foot suspended from the support carriage for movement relative to the carriage in the perpendicular direction and adjacent the tool, the foot having a pressing surface which rests against the sheet material during a work operation; a source of liquid; liquid conduit means connected to the source and leading from the source to the tool; and flow control means including a pinch valve actuated by the holddown foot for opening the liquid conduit means during a work operation when the pressing surface of the holddown foot rests against the sheet material, the pinch valve having a flexible tube in the conduit means and a pivotally mounted clamp member adjacent the tube for pinching the flexible tube closed.