Abstract: Fabric made up of a series of knitted collars, sleeve bands, bottom bands, plackets, or the like, intended for use on knitted sport shirts, blouses, and the like, and held together by a separator thread with a relatively high melting point is separated by means of gradually heating the fabric to near the melting point of the separator thread and then to the melting point while holding the fabric under tension.

Abstract: A monolithic piezoelectric element comprising a sintered body comprising a plurality of ceramic layers which is provided with a first electrode group which includes a plurality of electrodes electrically connected with each other and located between alternate pairs of adjacent layers, and a second electrode group which includes a plurality of electrodes interposed between the electrodes of the first electrode group and electrically connected with each other. The two groups of electrodes are electrically isolated from each other. The respective electrodes of the first and second electrode groups are electrically connected with each other through through-holes formed in the sintered body.

Abstract: The present invention provides an apparatus and method of utilization of the same of tooling for a robot or the like for installing rocker arm assemblies to the cylinder banks of an engine. A preferred embodiment of the present invention includes jaws to grip the rocker arm assembly, a bolt runner to torque the rocker arm bolt and means to angularly float the jaws, allowing the rocker arm assembly to align itself with the engine cylinder bank push rod and valve spring.

Abstract: A riveting apparatus includes a body pivotable about a horizontal axis and having first and second arms extending therefrom. Riveting structure is provided on the arms for cooperating to install and fasten rivets through a workpiece positioned between the riveting structure. The body may be rotated between a substantially horizontal to a substantially vertical position to accommodate riveting a workpiece having varying contours. The apparatus allows riveting operations to be performed at any point on the workpiece while permitting the operator to position himself immediately adjacent the point of riveting to assure proper alignment of the workpiece and proper riveting thereof.

Abstract: The tensile loading of a ceramic-metal joint, made by shrink-fit locking a cylindrical ceramic component into a flange of ferrous material in the axial direction of the ceramic component can be improved by undersizing the diameter D of the bore of the flange by 13-27 .mu.m making it, at room temperature, this much smaller than the diameter d of that part of the ceramic component to be attached to the flange by shrink-fit locking, by preparing the cylindrical surface of the said part of the ceramic component with a surface roughness Ra of 0.05-0.2 .mu.m and the surface of the bore in the flange with a roughness Ra of 0.4-0.8 .rho.m, and by heating the flange, before fitting it to the ceramic part, to a temperature such that, after fitting together the ceramic component and the flange, the resultant stresses produced on cooling the assembly to room temperature are below the yield strength R.sub.po.

Abstract: This invention relates to a method of forming hollow, box-section, frame members which include localized reinforcement. The frame members are produced by fitting a sleeve about a tube, deforming the tube and sleeve to avoid the occurrence of frictional drag in a final die, and then expanding the tube and sleeve in a final die to form the hollow, box-section, frame member. The expansion is achieved by application of an internal pressure within the tube.

Abstract: Electronic components are deposited in conveyor buckets in a desired sequence to define repetitive groups of components. These components are delivered to an insertion head for insertion into a circuit board. When a component is not properly inserted, the system stops and a replacement part is delivered by a replacement mechanism to an empty bucket on the conveyor. This empty bucket follows the buckets which held the group of components for the board being loaded.

Abstract: A tensioner having screw threads tightened by rotation of a hob drive (15) is used for applying clamping pressure to a hob (10) in a working position in a hobbing machine. The tensioner extends through the hob between the end supports (11 and 12) of the hobbing machine and has threads arranged so that a wrench system can hold part of the tensioner against rotation while the hob drive tightens the threads to a predetermined clamping torque. The tensioner can be a single draw rod (20) extending from driving end support (11), through hob (10), and into threaded engagement with idler end support (12); and the tensioner can include a hob mounting arbor (45) having threaded ends into which a pair of opposed tensioner rods (20 and 46) are threaded.

Abstract: A tool magazine, especially for milling and drilling machines, comprising a linear tool support having at least one row of tool holders, the tool support being mounted on the free ends of two swivel arms. Each swivel arm is disposed laterally of the work table and is mounted on a shaft for rotation therewith, the shaft being located in the work table. For protecting the tools inserted in the various tool holders and the tool tapers thereof, a cover is provided which contains a row of protective caps adapted to the shape of the tool tapers. The cover with the protective caps can be moved by means of a pivot lever mechanism from a position closely encompassing the tool tapers to a position permitting free access to the tool tapers. Any deposits of flushing liquid, dust particles and cuttings on the taper surfaces are effectively prevented when covered by the protective caps.

Abstract: A numerically controlled automatic tool changing machining center is provided with a rotary driven spindle concentric within which is a spindle bar that may be reciprocated out from or into the spindle by a hydraulic cylinder. Located at the forward end of the spindle bar is a tool receiving socket which is operative to releasably engage the shank of a single toolholder or multiple spindle toolhead transferred to the spindle bar from the machine tool storage magazine by a tool transfer arm. When a large, single toolholder is engaged by the spindle bar, the spindle bar is retracted into the spindle to urge the large single toolholder against the nose of the spindle.

Abstract: A method of applying a pre-tensioned, metal containment shroud to a rotor of a permanent magnet machine where pressure is applied to the inside of the shroud to stretch it so that the rotor may be inserted. This pressurization can also be used to size the shroud if the yield strength of the containment shroud is exceeded during the stretching process. The containment cylinder is proportioned such that on the removal of the pressure, the cylinder will have the required tension to clamp the permanent magnets to the rotor.

Abstract: A method of manufacturing a magnetic rotor core member for a rotating-field dynamomoelectric machine, particularly a small alternator, including the steps of: hot forging a segment of steel bar stock into a core blank approximating the external configuration desired for the rotor core member but with the pole piece fingers shorter than required for the finished pole pieces; de-burring the core blank; coining the core blank into closer conformation to the desired core member configuration; gradually cooling the core blank; rough machining only two opposed surfaces of the hub and base to assure a controlled uniform volume for subsequent processing; cold punching a shaft aperture through the hub of the core blank and simultaneously ironing the pole piece fingers into close conformity with the required finished dimensions, in particular lengthening the fingers; and, finally, cold-compressing the core blank to finished form as a rotor core member in a single cold compression step.

Abstract: A method of manufacturing a thin film magnetic head is disclosed. This method is characterized such that a protection film is formed on a substrate; only corresponding portions of the protection film to bonding pads are ground in a groove-like configuration before cutting out the thin film magnetic heads therefrom so that the bonding pads are exposed; and the substrate is cut to a predetermined size per thin film magnetic head. With this arrangement, it is feasible to prevent an upper magnetic layer from being damaged during the grinding operation.

Abstract: A magnetic head assembly of a disk drive device has an upper magnetic head fastened to a case side and a lower magnetic head mounted on a gimbal plate of a carriage side. The upper case assembly includes a plurality of leaf hinge springs extending to the vicinity of the upper magnetic head, which is bonded to a supporting plate, and wire leads from the magnetic head are soldered to the leaf hinge spring ends as lead terminals. The other ends of the leaf hinge springs extend to the rear side of the case and serve both as a pivotable hinge mounting of the case to the carriage and as lead terminals to an external read/write controller.

Abstract: A coil is wound either with insulated wire or space wound with uninsulated wire and subsequently coated with a solder resist or insulating material. If insulated wire is used, the insulation is removed from the wire either during or after winding at predetermined locations to match the location of connection pads in a conductive pattern on a substrate. The coil is appropriately aligned and laid down on the substrate and an attachment technique is used to form an electrical connection between the exposed areas of wire and connection pads on the substrate. Alternatively, uninsulated wire may be used, which is space wound and coated with a solder resist or insulating material. The uninsulated wire may either be masked prior to coating or the insulating material may be removed following coating to form exposed connection locations on the coil corresponding to the location of the connection pads on the substrate.

Abstract: A template guide tracking device useful for rapidly performing work functions such as joining together workpieces on a riveting machine. The template device has a tracking guide provided by a continuous groove having work stations provided at multiple intersection points located between adjacent segments of the groove. The groove may have a depth less than the template thickness with work stations being provided by openings extending through the template, or alternatively the groove may extend entirely through the template and have the work stations each provided by an enlarged opening or laterally located notch at the intersection point between adjacent segments of the groove.

Abstract: Device or tool for mounting BNC connectors on the wall of a chassis or housing includes a handle on a shaft for rotating a driver element which is configured to mate with and engage a BNC connector to be mounted. By using different driver elements, male BNC connectors or other similar electronic (R.F.) connectors can be mounted on a housing or chassis without damaging internal components.

Abstract: In a production system for performing predetermined processes on products which each have a memory incorporated therein, information necessary for those processes is sequentially written by an external computer in the memory incorporated in each product, and such information is read out from the memory and used by the production system to carry out the respective processes on the products in a low cost and efficient way.

Abstract: Pressures applied to a component for pickup and placement thereof are each selectable, according to introduction of gas under pressure into a piston and cylinder configuration defined by a tool, such as a vacuum spindle, telescopically supported in a tool holder. An actuator with closed loop velocity and displacement control moves the tool holder to and fro along a longitudinal axis according to a known programmable controller. Thus, compression of the gas and relative displacement between the tool and holder allows controlled pick and place pressures to be varied and monitored programmably. The pressurized gas also acts to prevent dirt contamination of the bearing surface between the tool and holder and consequent impairment of telescoping and rotational movements therebetween.

Abstract: A scissor-like utensil for cutting and serving slices of cake and similar goods has a pair of planar blades and a pair of handles by means of which the blades can be manipulated. The handles are formed with longitudinal slots and overlain so that a connector can be fitted through the adjacent slots to join the handles. The connector defines a pivot connection which permits the blades to be moved between closed and open orientations suitable respectively for cutting and gripping a serving and for releasing the serving. In the closed orientation, forward edges of the blades are proximate and substantially parallel, defining essentially a V-shaped structure corresponding to the shape of the serving to be cut, and a predetermined angle is formed between the blades which essentially determines the size of the serving.

Abstract: In one exemplar embodiment, a knife for de-veining, peeling and butterflying shrimp is disclosed having a handle and an elongated arcuate knife blade secured to the handle and extending forwardly thereof, the knife blade having an intermediate toothed blade portion disposed adjacent the handle and an arcuate blade portion extending forwardly of the intermediate toothed blade portion, the arcuate blade portion having a curvature approximating the body curvature of a de-headed shrimp. The arcuate blade portion has an upper convex cutting edge disposed thereon and a lower concave cutting edge adjacent the tip of the blade. The intermediate toothed blade portion has a plurality of spaced teeth aligned in a ramp configuration from front to rear adjacent the handle. When used, the knife tip is thrust through the body of a de-headed shrimp to slice the shrimp body along its longitudinal length to a depth traversed by the upper and lower cutting edges.

Abstract: A cutting instrument, such as a thread nipper, is provided with a safety breakaway finger loop. In use should the cutting instrument inadvertently be engaged and pulled into a textile machine, for example, the finger loop engaging the hand of the user will automatically breakaway from the body of the cutting instrument.

Abstract: A transmission device adopted for a working tool such as a weed cutter having an engine, a rotary blade, and a gear case for supporting the rotary blade. The transmission device comprises an operation pipe for connecting the engine with the gear case, a transmission shaft disposed inside the operation pipe to transmit the torque of the engine to the rotary blade, and a bearing pipe interposed between the operation pipe and the transmission shaft. The inner surface of the bearing pipe contacts with the outer surface of the transmission shaft to support the transmission shaft rotatably. A plurality of grooves are formed circumferentially on the inner surface of the bearing pipe with predetermined intervals to reduce the contacting area thereof with respect to the transmission shaft. The transmission device further comprises a vibration isolator which is fixed to an end of the operation pipe and removably engaged with a clutch housing of the engine.

Abstract: Disclosed herein is an improved pencil sharpener specifically designed to sharpen the end of a carpenter's pencil. As is well known, a carpenter's pencil has a substantially rectangular cross-section and as such can not be sharpened in a conventional pencil sharpener since conventional pencil sharpeners are designed to be used to sharpen pencils of circular cross-section. The inventive pencil sharpener is able to sharpen a carpenter's pencil by virtue of four cutter heads each of which having a cross-section subtending only a portion of the circumference of a circle and interconnected through gearing so that opposed cutter heads engage the pencil surface while the other cutter heads are spaced away from the pencil surfaces. As the first mentioned cutter heads move away from the pencil surface, the latter mentioned cutter heads rotate into position engaging the pencil surface so that a carpenter's pencil with a rectangular cross-section may be sharpened.

Abstract: A unique and novel goniometer is set forth to orient a sample in an X-ray beam, for example, to better than 0.001.degree. without introducing translation. This structure is infinitely adjustable and stable.

Abstract: A stylus is briefly placed on the surface coating of photographs for forming an artificial marking symbol on the coating. The stylus oscillates in the ultrasonic frequency range. Part of the oscillation energy of the stylus is converted into frictional heat producing a marking symbol in the coating in the form of a high contrast annular bead. The apparatus comprises a stylus, a mechanical lowering device, an electroacoustic transducer for producing the ultrasonic oscillations of the stylus, and a frequency generator, an amplifier and a voltage/current converter connected in series with the electroacoustic transducer. The transducer is supplied with a signal from the frequency generator, which signal is kept constant by a control circuit provided on the generator.

Abstract: The invention concerns a measuring transducer, of the type comprising a rigid support case, a rule in the form of a thin steel tape, pretensioned and suspended at its ends in the support case and having etched thereon the graticule of a measuring scale, as well as a rule reading head mounted in the case slidable along the tape. According to the invention, at least one tensioning bar is fixed to the case at a single point and is freely expansible in respect thereof for the remaining part, through the effect of temperature, the ends of the thin tape of the rule being anchored to the ends of said bar.

Abstract: Method and apparatus for automotive wheel alignment in which a telescope is mounted with its axis precisely parallel with the end plane defined by the automotive wheel hub. A calibrated target is placed and centered directly in front of the telescope on its optical axis. This procedure is repeated for the wheel on the other side of the vehicle. The vehicle is then moved a distance, for example 50 feet, from the targets which are left in place. The telescope is again placed on the wheel hubs and the targets sighted. If both targets remain on the optical axis the wheels are in perfect alignment. If they are not, the calibrations on the target indicate the direction and extent of misalignment.

Abstract: A leveling instrument is provided with a flexible length of tubing extruded with a pair of thin-walled, balloon-like diaphragms at opposite ends thereof. The tubing contains a flow passage filled with liquid in communication with atmospheric pressure acting upon the liquid through the diaphragms. The liquid provides a leveling medium for the instruments for establishing the level of one location with respect to another location. A method of manufacturing the leveling instrument is also disclosed.

Abstract: An attachment for a hair dryer performs the function of providing a lower velocity diffused air flow with apparatus to separate and lift the hair and allow the entire hair strand, from root to end, to be dried at the same time. The attachment includes a base member shaped to expand and turn a column of air from a conventional blow dryer by, for instance, 45 degrees. A face plate holds a diffuser pad in position. Extending from the face plate away from the base are a plurality of hair lifters, each of which lift a small amount of hair, so as to permit the entire hair, from root to end, to receive air and be dried at the same time. The face plate includes a plurality of holes therethrough to permit air flow and each hair lifter includes a post extending upward from the edge of the hole and an extension from the top of the post into the area above the corresponding hole. This structure allows the face plate to be fabricated by injection molding.

Abstract: A lightweight athletic shoe includes a midsole of compressible material having portions of differing hardness which limit overpronation and effectively absorb shock while conforming to the shape of the foot. The midsole includes a central portion of relatively soft material, a lower peripheral portion of intermediate hardness extending around the central portion in the heel region and forward along each side to the toe region, and a raised upper peripheral portion of relatively hard material located above the lower peripheral portion and extending forward to the ball region of the midsole. The central portion conforms to the contour of the foot so that the force is uniformly distributed, while the peripheral portions cradle the sides of the foot so as to limit overpronation and oversupination.

Abstract: In a ski boot having a toe- and heel-piece and an anklet consisting of an anklet front part and an anklet rear part it is proposed that the toe- and heel-piece is soft to deformation in the instep region in the direction of variation of the clear instep width, that the anklet front part is displaceable perpendicularly of a transverse axis on lateral articulation points on the side parts of the toe- and heel-piece, in the direction of variable action of the anklet front part along the instep line on the deformation-soft instep region of the toe- and heel-piece, and that tension means serving for the adjustment of the anklet front part on the articulation points act upon the anklet front part.

Abstract: A pipeline trenching plough is towed along the seabed by a tow wire (20) connected to a ship or tractor. The course of the plough is changed or maintained by oppositely-acting forces imposed on the wire (20) and on the body (10) of the plough by a hydraulic ram (24). The offset angle between the wire (20) and the lengthwise direction (30) of the plough is monitored by a potentiometer (33, 35). The wire (20) is connected to the plough at a real hitch point (22) vertically above the center of resistance (23) of soil forces on the ploughshare (12) and landside (14). Under normal equilibrium conditions the forces from the ram are zero. The forces required to change the course are small and independent of the offset angle. Ram force can counteract a side-sloping seabed. In modifications, the wire (20) is connected to a virtual hitch point formed by an adjustable linkage; or by a carriage adjustable along a transverse beam.

Abstract: A removable identification collar for baby bottles. The collar has a planar portion having a wall defining a hole therethrough. The collar is placed over the neck of a bottle with the neck passing through the hole and the collar is maintained on the bottle by a standard nipple cap. The collar has a flange connected to the planar portion whereby a portion thereof is adapted to receive a gummed label. A raised ridge conforming closely to the periphery of a gummed label is provided to prevent infants from readily removing the label.

Abstract: A logic control linear drive magnetic motor is used to reciprocate approximately 180.degree. the flat panels which make a display board. Each panel of the display board is connected to a pulley which is in a plane perpendicular to the longitudinal dimension of the vane. A continuous drive cord is connected to each end of a shuttle cylinder of the motor and is wrapped around the pulley drum. Movement of the shuttle cylinder moves the drive cord which controls the rotation of the vanes.

Abstract: A stationary display member is mounted on a display apparatus and provided with a plurality of slots which communicate between front and rear faces of the stationary display member and which are disposed in parallel to and equally spaced a given interval from each other. A movable display member is mounted on the rear face of the stationary display member and comprised of a plurality of segments successively disposed on one another in a partially overlapped relation. Each segment has a width more than twice the slot interval such that about a half portion thereof is covered by the adjacent segment. The uncovered remaining segment portions are slidably inserted into the respective ones of the slots. A linear motor drives the movable display member to project the uncovered segment portions from the slots to change display.

Abstract: Apparatus for the cyclic rearrangement of a pile of rectangular or square sheets, especially a pile of photographic prints, is provided. The apparatus has a first and a second frame part which may be moved relative to one another and parallel to the main plane of the pile, and a picture changer which, on movement of the frame parts backwards and forwards, removes an individual sheet at one end of the pile and adds it to the other end of the pile. The picture changer includes a first and a second separating member which, resiliently biased towards each other, define a through-gap which for the entry of the sheet being separated has a spacing greater than the thickness of one sheet and less than the thickness of two sheets, which spacing is, during the outward movement of the frame parts, maintained or reduced to the thickness of the sheet being separated, as appropriate.

Abstract: An illuminated sign assembly has a cabinet of somewhat resilient sheet material with a self-hinging sign frame on at least one side which snap fits into the cabinet without use of a conventional hinge. An assembly may be provided for security and tensioning the vinyl sheet of a sign face into the frame. The snap action is provided by interaction between a channel defined by a system of resilient flanges formed by a portion of the cabinet to which the frame is hinged, and an abutment on a rearwardly extending flange on a hinged side of the frame.

Abstract: An ambidextrous release for gun magazines for semi automatic pistols such as Colt, government Model "Colt", and other semi automatic pistols. The new release is built into conventional gun magazine release structures and it only requires a catch lock release lever which is positioned externally of the gun butt or grip on the right side thereof as one holds the pistol operatively.

Abstract: A so called machine or automatic gun having a cone shaped device mounted about the gun muzzle, a washer like or ring member slidably affixed to the gun stock, a muzzle blast deflector device and a ball joint swivel device. The muzzle blast causes the muzzle to be deflected about the inner circular confines of the cone. In this manner, a somewhat circular bullet dispersion pattern is obtained. The size of the circular dispersion pattern may be adjusted by forward/rearward movement of the ring member to control the motion of the muzzle during the burst firing.

Abstract: The invention concerns a procedure for undermining underwater terrain (S) thus creating an upward rising current (Tj) able to lift items lying on the terrain (S) or half-buried in it, in order to collect them in a recovery net. The invention also covers devices to be used for harrowing and cleaning shell-fish beds or for dredge-fishing shell-fish.

Abstract: The multi-layer structure enables the accomplishment of very light-in-weight and squashing-resistant tubular elements, in particular fishing rods, as it consists of a plurality of layers made of very thin carbon fibers (1) having a high or very high modulus of elasticity, disposed parallel to and alongside each other and impregnated with a matrix resin, said layers being alternated by further layers of very thin aramide fibers (2) disposed parallel to and alongside each other and impregnated with a matrix resin. Carbon fibers and aramide fibers are inclined with respect to each other.

Abstract: A commonly available five gallon pail is used as the base structure for a fishing accessory container. A compartmented insert is sized to fit in the pail and is supported by a rim which overlies the rim of the pail. A lid, which may be a domed lid hinged to the insert, provides a cover for the insert. This arrangement provides space in the pail below the insert, compartments within the insert, and space above the insert, all of which may be used to convey various accouterments for a fishing expedition.

Abstract: A plastic crab trap that is molded in one operation, including a cover member, and side walls that are adequately reinforced for rigidity, taper upwardly and have slots through which water can flow. The cover is molded in place in what will be the top opening, but reversed from its operating portion, and is connected in the opening through sprues which feed plastic from the input opening for plastic material after molding the cover. After molding, the cover is cut loose from the main part of the crab trap, and upon rotating the cover 180.degree. provided hinge and latch members between the cover and the main body of the crab trap are properly positioned without further operations. Additionally, a specific bait box holder is provided adjacent to the cover so that when the cover is closed, the bait box will be held in place, and can be easily removed for service once the cover is opened.

Abstract: A fly or insect catcher having the appearance of a common fly swatter with a handle and head, which catcher has a sheet of adhesive material disposed on the head and a hingeably attached cover arranged to cover the head when not in use. A quantity of insecticide may be disposed in the cover to aid in killing the insects caught on the adhesive when the cover is closed.

Abstract: The seed pellets have a core which contains grains of seed, organic substrate, loess, organic fertilizer, fungicides and, possibly, pesticides, and a wetting agent which promotes surface wettability. At least one bitter substance may also be present and made to cover the core in the form of a coat, or be distributed within the core. The core is furthermore provided, with a semipermeable coat, which consists of at least one starch and/or latex. The loess acts as a binding agent which serves to intimately bind the various constituents of the core to each other, and to act as a water storing agent in addition to the organic substrate. The semipermeable coat also contributes to the improvement and control of water conservation. Thus the pellets may be made to include sensitive seeds too which require much water for germination and/or may be sown in relatively dry regions and, furthermore, are resistant to breakage and abrasion.

Abstract: An eccentric grinder includes a motor-driven shaft, an eccentric drive connected to the shaft to impart to a grinding disc one mode of grinding motion and a rolling drive including friction or toothed crowns on the grinding disc and the housing cooperating with each other to impart to the grinding disc another mode of grinding motion. The grinder is provided with a ring carrying two toothed crowns at the opposite edges thereof and releasably insertable into a recess formed in a ring-shaped element fixed to the housing of the grinder so that one mode of grinding can be easily changed to the other mode of grinding.

Abstract: A method is provided for sharpening a serrated cutting edge having spaced points separated by indentations. The method involves loosely supporting a plurality of rods of abrasive material and then applying the cutting edge tranversely across the rods so that the rods are forced into positions whereat they are spaced in correspondence with the indentations. The rods are locked in the resultant positions whereafter the cutting edge is wiped along the rods with the rods being positioned in the indentations. The apparatus for practicing the aforesaid methods involves a plurality of elongated rods supported on a resilient pad and clamped into position by the use of clamping devices which are adjustable to release the rods for positioning and to hold the rods in position once they are moved into the appropriate positions.

Abstract: The disclosure relates to a machine for aligning and attaching partly-worked lens blanks to a block so that the remainder of the blank can be machined. The machine comprises a vee-shaped holder for supporting the block with it axis vertical above a moveable table on which the lens blank is supported. The moveable table is freely moveable in any direction in a horizontal plane and the machine includes means for bringing the block and partly-worked lens into contact and achieving alignment of the axes of the block and lens blank by permitting the lens blank to move in any direction in a horizontal plane. A film of liquid adhesive is provided between the surface of the lens blank and the block which acts both as a lubricant and as a bonding agent when correct alignment has been achieved.

Abstract: An apparatus for sanding and collecting sanded particles. The particle collecting sander includes a base member having a negative pressure chamber contained within. The base is secured to a cover member which is provided with a multiplicity of grooves extending across the outer surface of the cover member. A plurality of ports are provided in the grooves to create a fluid connection between the grooves and the negative pressure chamber. A pourous abrasive material overlays the cover member. In operation a series of negative pressure zones are created across the surface of the pourous abrasive material.