Abstract: A bridge assembly includes a urethane-base flexible bridge die having an inner surface and an outer surface. The bridge die is formed for use on a discrete section of a rotary die cylinder and is used with at least one rotary cutting die mounted to the rotary die cylinder. The bridge die has at least one score so that the bridge assembly may be resized by removing a portion of the bridge assembly at the score. A plurality of rubber strips are also included and are attached to the outer surface of the bridge die.

Abstract: A molded anvil blanket is formed with a projection depending at each end, the ends for abutting when wrapped about the anvil, the anvil having a transverse channel for receiving the projections. The projections mate to form a common recess enclosed by a metal angle member secured to each projection. The angle member and projections have a transverse slot for mounting the blanket end and projections on a pneumatic mechanism attached to the anvil. The mechanism includes an air cylinder secured to the anvil in a radial anvil bore. The cylinder has a shaft which extends in response to pressurized air. A spring attached to the air cylinder and to a T-bar which releasably engages the blanket common recess normally biases the projections locked into the channel in a fail safe mode. The activated air cylinder lifts the projections out of the channel so the blanket ends can be manually released from the anvil by sliding the T-bar out of engagement with the projections via the slots in the projections and angle member.

Abstract: An anvil blanket is molded urethane sheet material and formed with a plurality of interlocking fingers at mating opposing blanket ends and includes a depending projection which mates with a channel in the anvil about which the blanket is wrapped. A urethane insert having a hardness greater than the blanket material is molded embedded in the blanket to form a portion of the fingers and a portion of the projection depending from the fingers. A woven fiberglass fabric provides support for the blanket which is molded to the fabric. The insert has a durometer greater than that of the blanket to minimize the formation of surface recess defects at the projection which might otherwise occur due to the increased thickness of material at the projection. The insert may have other properties different than that of the blanket material including rebound, modulus, and cut and tear strength among others for resisting the formation of blanket surface defects. Different embodiments are disclosed.

Abstract: A cutting mat comprises a cutting mat body and a lock assembly arranged to secure the cutting mat to a rotary anvil. The lock assembly comprises male and female locking members formed at opposite ends of the cutting mat and integral therewith. There are no metal frames or other components welded or otherwise secured to the male or female locking members. The female locking member slips into an axial channel on a rotary anvil. The cutting mat is wrapped around the rotary anvil, and the male member is inserted into the axial channel in locking relationship with the female locking member. Further, the axial edges of the cutting mat are formed in mating, complimentary serpentine shape to prevent a cutting blade from slipping into the seam between adjacent cutting mat surfaces.

Abstract: The invention is a cylinder cover engageable with a channel. The cylinder cover includes a flexible blanket with two ends, the ends configured to substantially abut when the blanket is circularly wrapped. Further, the cylinder cover includes a female member attached to the first end of the blanket, the female member having a leg connected with and opposing a resilient engaging element by a base member. The resilient engaging element is configured to frictionally engage a sidewall of the channel. Attached to the second end of the blanket is a substantially rigid male member. When engaged with the channel, the blanket is substantially continually supported by a rigid substrate.

Abstract: A device for cross cutting material webs includes a cutting-cylinder pair formed of mutually cooperating cylinders having respective cylinder cores and circumferential surfaces formed by exchangeable circumferential elements, the circumferential elements being arranged removably around the respective cylinder cores of the cylinders.

Abstract: A three hole punch system is for use in an image capturing device. The three hole punch system uses elastomeric rollers that punch holes in the edge of a sheet as it passes between two rollers. If desired, the rollers can act as a transport for the sheet without punching holes in the sheet. After the holes are punched, the resultant slugs are pushed back into the holes and the sheet is retrieved by the operator.

Abstract: The present invention is related to a device for varying a cylinder's effective diameter. It includes a shell member being removably mounted on a surface of a cylinder. On the easy exchangeable shell member having a base plate an elastic material is provided allowing for a compressible surface gain.

Abstract: A cover for a rotary die is centrifugally cast with multiple layers to substantially eliminate stress when the cover is cast in an arcuate shape for use in a die cutting system. A locking mechanism attached to ends of the cover is designed to be convenient to install on and remove from a cutting cylinder.

Abstract: To improve a cutting device comprising a machine frame, a rotatably mounted anvil drum with an anvil surface, a rotatably mounted cutting tool with a cutter cooperating with the anvil surface in such a way that in successive rotary positions, respectively successive cutter sections stand in an operative position with successive anvil surface sections in order to cut a material passing through between the cutting tool and the anvil drum, such that the cutting tool has as long a service life as possible, it is proposed that the cutting tool and the anvil drum be pretensioned, that the cutting tool be supported by at least one supporting ring via successive supporting ring sections on successive supporting surface sections of the anvil drum, that the respectively operative supporting ring section act on the respectively operative supporting surface section with a bearing force corresponding approximately to the difference between pretensioning force and cutting force, and that the supporting ring be of such cons

Abstract: A high-speed shear with a knife, particularly a chisel-type knife with a knife edge, arranged on at least one of two oppositely arranged drums, wherein the knife can be accelerated to the feeding speed of the rolled strip and the drums can be adjusted relative to each other for carrying out a cut. At least one drive unit provided for the drums serves to accelerate the drums to the speed of the rolled strip to be cut and at least one of the drums may be provided with a separately controllable adjusting device. The chisel-type knife of the knife drum is mounted so as to protrude from the cutting circle towards the anvil or the surface portion of the second drum acting as an anvil and to mount the chisel-type knife of the knife drum so as to be resiliently supported against a predetermined restoring force.

Abstract: A rotary die cutter for cutting a series of irregular-shaped blanks from a continuous web. The rotary die cutter includes a male die cylinder that has a series of die cavities formed along its outer circumference. Each of the die cavities includes a surrounding cutting edge that defines the shape of the blank to be cut. The male die cylinder is pressed into engagement with either an anvil cylinder or a female die cylinder to form either crush-cutting or shear-cutting nips therebetween. The continuous web is fed into the cutting nip such that the cutting edges of the die cavities contact the web to cut the blanks from the web. A plurality of vacuum ports positioned in the die cavities along the outer circumference of the male die cylinder are connected to a source of vacuum contained in the male die cylinder to remove the die-cut blanks from the web. The die-cut blanks are vacuum-transferred to a stacking unit, while the scrap web is continuously discarded by air-conveying removal.

Abstract: Pressure working on each support mechanism or on a clearance adjusting mechanism disposed on opposite end portions of a knife rotor and a plain rotor while a sheet material being cut is measured. The clearance adjusting mechanism is actuated to adjust the contact pressure of the knife based on the measured pressure.

Abstract: A circular cylindrical bearing section for a die cutter blanket comprises two segments pivoted relative to each other at one interface therebetween and resiliently urged radially apart by spring plungers at a second interface therebetween. A blanket section is wrapped about the two segments which are resiliently urged against the overlying blanket section secured to the bearing section by a conventional channel in the bearing and mating male-female interlocking members on the blanket. An array of bearing-blanket sections on an anvil roll are axially coupled by annularly spaced mating pins and notches at opposite axially facing edges of the bearing sections. The array of bearing-blanket sections are selectively slid as a unit along the anvil roll to rapidly relocate the blanket sections to minimize local blanket wear. The interlock members of each blanket section may be misaligned axially with the respect to the interlock members of the adjacent blanket sections.

Abstract: A dual purpose rule guard for two-piece rotary cutting dies consists of a pair of confrontable allochiral guards. Each defines on its confronting surface a first portion thereof recessed inwardly therefrom and a second portion thereof projecting outwardly therefrom. The guards of the pair are interdigitable for assuming an interlocked position with respect to each other to insure the correct alignment of the cutting dies and of their rules. Additionally, each guard is so positioned relative to its cutting die that its second outwardly projecting portion projects outwardly of the confrontable edge or join line of the cutting die so that it functions as an overhang to keep the knife at the join line upwardly and away from any storage surface.

Abstract: An apparatus for cutting, including an anvil cylinder which may have a plurality of cut rubbers strips affixed around the anvil cylinder and a cut cylinder which is mounted for rotation about an eccentric axis. Two knife boxes may be mounted on the cut cylinder, each knife box having a knife and cheekwood for securing the knife to the cut cylinder. A paper tape guides the material to be cut between the cut cylinder and the anvil cylinder. When one knife box degrades, a knife sleeve on the cut cylinder can be indexed so that the other knife box takes the place of the degraded knife box. When a cut rubber strip degrades, the anvil cylinder can be indexed so that another cut rubber strip takes the place of the degraded cut rubber strap. Either of these functions can occur while the apparatus is still running. The anvil cylinder can also use a cut rubber sleeve.

Abstract: An apparatus is described for forming a web (N) that is permeable to liquids and designed to separate two environments and to allow the liquid to flow in one direction from one of said environments to the other, in which said web is caused to pass between two contra-rotating cylinders (5, 7) that are pressed against each other, one of said cylinders (7) having a surface provided with projections which cause perforations in said web (N). The cylinder (7) with the projections is turned at a peripheral speed greater than the peripheral speed of the other cylinder (5), with a consequent relative slipping action between the surfaces of the two cylinders (5, 7).

Abstract: A polyurethane layer is bonded to a sheet metal liner and secured to an anvil roller channel by depending interlocking male and female locking members at the respective blanket ends. The female locking member comprises a U-shaped channel member formed from the liner. The channel member has an extension formed of doubled over sheet material with an inclined lip for engaging the anvil channel in resilient interference fit in cooperation with a distal channel member side wall. The channel member is filled with the layer material as the layer is formed to form a solid female member and has a lateral side wall from which a locking projection extends for locking engagement with a mating recess in the male member. A wedge projection projects from a face of the male member contiguous with the outer blanket surface. The wedge projection extends from the blanket outer surface an extent smaller than the blanket layer thickness to minimize insertion load on the male member due to interference with the female member.

Abstract: A house wrap film product includes a laminated poly film with a first poly film ply and a second poly film ply and micropuncture formed in the laminated poly film to allow vapor transmission from a first side of the laminated poly film to a second side of the laminated poly film. Each of the poly plies is formed of a spiral cut film having a first ply with a first orientation and a second ply having a second orientation, the first orientation being at an angle with respect to an edge of said film and said second orientation being at an angle with respect to an edge of said film, said first ply and said second ply being laminated together cross oriented such that said first orientation extends in a different direction from said second orientation. The micropuncture provides a deformed region of said film, surrounding said hole. A method is provided for forming the house wrap product.

Abstract: A cutter assembly for severing pieces from a length of material and advanced into proximity thereto includes a driven anvil roll and a driven rotary cutter roll disposed in opposed relation with each whereby the length of material is advanced between the rolls for cutting. The cutter roll carries at least one knife blade on its periphery to cut the material against the anvil roll into predetermined lengths as it is advanced between the rolls. The at least one knife of the cutter roll is mounted at an angle with respect to the longitudinal axis of the cutter roll so as to engage the material in a shearing motion and the cutter roll is attached to the anvil roll and mounted so as to be movable away from the anvil roll against the force of resilient means as the knife contacts the anvil roll during rotation. The degree of such movement may be adjusted by the use of shims removably placed between the resilient means and the mounting point of the cutter roll.

Abstract: The present invention is an anvil cover latch assembly which includes a female latch member having a generally U-shaped frame. The frame has an upper segment, a side segment and a base segment with the base segment having an upwardly angled end section. The upper segment, side segment and base segment are configured to form a channel into which is cast an insert of elastically deformable material. The insert is disposed such that a locking edge is formed by an exposed portion of a lower surface of the upper segment. A male latch member has a substantially planar shoulder region which is designed to engage the locking edge on the female portion.

Abstract: A die cutter blanket covers an anvil roller and includes a polyurethane coating bonded to a sheet metal liner secured to an anvil roller channel by interlocking male and female locking portions secured to the blanket ends. The female locking portion comprises an end of the blanket coating depending from the blanket end and overlying a depending backing liner leg. Both are riveted to a first leg of an L-shaped member. An elastomeric element is secured to an end edge of the second leg via a tongue and groove and/or by bonding. The second leg and element are in interference compressive friction engagement with the channel. The male locking portion is interlocked to the inserted female portion. In other embodiments a separate compressible strip is secured in or formed part of the channel material to engage an end of the second leg. A further shim is in the channel or attached to the first leg and cooperates with the element to provide desired additional compressive frictional engagement with the channel.

Abstract: A trimming apparatus and method for cutting a strip of sheet material, such as wood veneer, is described including a clipping trash gate. A strip cutter including a cutter knife mounted on the trash gate for pivotal movement and a stationary cutter member cooperate to cut defective trash portions from the strip as it is conveyed past the trash gate. The trash gate opens to discharge the trash portions from the strip path through the gate. The stationary cutter member is made of soft plastic material, such as ultra high molecular weight polyethylene. The stationary cutter element is cut by the knife blade to form the cutting edge of such stationary cutter member and to simultaneously accurately align it with the knife blade cutting edge. The cutting edge of the knife blade is spaced from the stationary cutter member by a distance which is tapered along the length of the knife for progressive engagement of the knife cutting edge with the stationary cutter member to provide a scissor cutting action.

Abstract: A sewing machine has improved material cutting before stitching. The machine includes a sewing head and stitch area where stitching of strip material occurs. Strip material is fed by a timing belt along a predetermined path of travel into the stitch area. A lower cutter roll is positioned along the predetermined path of travel, and the strip material passes over the lower cutting roll. The lower cutter roll is driven by a transmission system connected to the sewing head motor. At least one circular configured, freely rotatable rotary knife engages the lower cutter roll and any strip material passing thereover is cut before stitching.

Abstract: Attachments for use with existing cylinders or shafts in printing press equipment. The attachments are used to mount a scoring blade, a perforating blade or an anvil to the cylinder or shaft. The blade or the anvil is separably mounted to the attachment and to the cylinder for easy assembly and disassembly.

Abstract: A method for cutting sheet material such as corrugated cardboard with a die cutter so as to reduce the amount of paper dust produced. The die cutter of the present invention utilizes a cutting rule having a base section and a cutting section. The cutting rule is characterized by a plurality of serrated teeth extending from the cutting section of the cutting rule. Each tooth terminates in a point and has a beveled side face. Formed between adjacent teeth is a semi-circular notch. The notches extend into the cutting section.

Abstract: A removable and replaceable cover assembly for use on an anvil roll in a rotary die cutter in combination with a die roll equipped with non-serrated cutting blades consists essentially of inner and outer tubular layers of elastomeric material of different degrees of hardness, the outer layer being substantially harder than the inner layer. Since this tubular cover must be mounted on an anvil roll by relative endwise movement, the cover is disclosed in combination with a rotary die cutter having special provision for temporary removal, recovering and remounting of the anvil roll.

Abstract: A crosscutting device for a folder assembly utilizes a pair of cooperating cylinders. A cutting groove cylinder has at least one groove strip assembly on its periphery and cooperates with a cutter cylinder having a corresponding number of cutters. Each groove strip assembly includes a cutting groove component and a pressure spring component.

Abstract: A rotary cutter is disclosed for repeatedly cutting web printed sheet material with a printed repeat portion of finite length thereon which includes a cutting cylinder adapted for rotation in a manner such that the web printed sheet material passes thereby A cutting knife extends generally along the length of the cylinder on the outer surface for periodic engagement with a backup support cylinder for cutting the sheet material when positioned therebetween. The cutting knife is generally continuous along a major portion of the length thereof and has a minor arcuate portion which is discontinuous with the major portion so as to cut the sheet material whereby the sheet material on one side of the cutting line is provided with a straight cut portion having an arcuate projection extending therefrom and the sheet material on the other side of the cutting line is provided with a void portion corresponding in configuration and dimension to the arcuate projection.

Abstract: An anvil cylinder is severed along an axial direction of a shaft into a plurality of ring-shaped sections, and elastic bodies are fixedly secured to parts of outer circumferential surfaces of the severed anvil cylinder sections over the entire length of the cylinder. In addition, the respective anvil cylinder sections are adapted to be individually engaged with or disengaged from a knife with the aid of a rotary object. By adjusting the positions of the anvil cylinder sections, slitting slots can be formed by machining only at the portions where slitting slots are necessitated.

Abstract: A crosscutting device for a folder assembly utilizes a pair of cooperating cylinders. A cutting groove cylinder has at least one groove strip assembly on its periphery and cooperates with a cutter cylinder having a corresponding number of cutters. Each groove strip assembly includes a cutting groove component and a pressure spring component.

Abstract: A method and system for forming an artwork on a sheet material and punching holes therethrough while the sheet material is disposed on a working surface so that the holes are punched in precise registration with the artwork. The method comprises the steps of providing for each hole to be punched a corresponding socket in the working surface, and securing the sheet material on the working surface so as completely to overlap all of the sockets whereupon the artwork is formed on the sheet material in precise registration with a predetermined origin of the working surface. Associated with each of the sockets is a punch and block combination disposed on opposite surfaces of the sheet material, the block being formed of a softer material than the punch and having an operating surface larger than a cutting surface of the punch.

Abstract: An apparatus for cutting and splicing sheets of wood veneer includes two pairs of dies is in opposed cooperating relationship with spacing between the pairs of dies sufficient to receive at least two sheets of wood veneer in an overlapping relation therebetween. In each pair of dies, one die in opposed cooperating relationship with the other die, and one die in each pair is transversely moveable, serving as a holding die, and the other die in each pair is stationary in relation thereto and serves as a cutting die. Means are also provided to move the dies so that upon movement of the dies the overlapping sheets of material are cut and spliced in one operation.

Abstract: A rotary die cutter includes a rotatable anvil cylinder; and a knife cylinder made rotatable in a face-to-face relation to and in synchronism with the anvil cylinder and having knives fixed on the cutter circumference thereof for subjecting a sheet running at the central portions of the two cylinders to a predetermined cutting treatment by clamping the same together with the anvil cylinder. A thin film having a tape adhered thereto is attached removably to the outer circumference of the anvil cylinder in registration with the corresponding edges of the knife cylinder.

Abstract: An attachment for use with existing cylinders in printing press equipment. The existing cylinder is machined to have an an annular groove around the center portion thereof. The attachment is mounted in the groove such that a scorer/perforator blade extends beyond the surface of the cylinder.

Abstract: A fiber bundle cutting device is disclosed which includes an elastic roller; a cutting roller having a plurality of thin plate-like cutter blades extending radially therefrom, the cutter roller being disposed in parallel relation with the elastic roller in such a manner that the cutter blades can be slightly pressed against a surface of the elastic roller; a plurality of push-out members each movably mounted between a respective pair of the cutter blades and disposed adjacent to one another; and ring members respectively holding the opposite ends of each of the push-out members to maintain the push-out members in a generally cylindrical configuration; the ring members and the push-out members held by the ring members being movable to an eccentric position relative to the cutter roller so as to progressively move from the proximal to the distal edge of the cutting blades during the operation of the cutting device to discharge the cut pieces of a fiber bundle.

Abstract: Locking means for a cutting die blanket including male and female locking elements that may be quickly engaged with minimal effort. A series of shoulders, located in the female section, are provided to engage a ledge on the male section. The locking means is closed by forcing the male section into the female section through a series of steps wherein the ledge and shoulders cooperate to effect engagement.

Abstract: A replaceable cover for the cylindrical anvil of a rotary die cutter includes a blanket body of elastically deformable material, a sheet metal liner for the blanket body, and a latch assembly for securing the ends of the cover together in a lengthwise slot in the face of the anvil roll. This cover is particularly designed for use with a prior art anvil roll wherein the slot in the face of the roll has opposed parallel sides which extend at right angles to the bottom of the slot, and each of which is provided with a groove along its lower edge that forms an extension of the slot bottom. The latch assembly includes a channel member having one side secured to one end of the blanket liner so that the open side of the channel faces the other end of the blanket body for interlocking cooperation with a latch member integrally formed on the other end of the blanket body.

Abstract: A web scoring and/or perforating apparatus for signature folding machines or the like including first and second rollers. Each roller has a scoring or perforating blade portion and a resilient roller portion. The rollers are mounted, preferably, on existing, rotatably driven nip roller shafts, upstream of web folding stages in web handling systems. The blade portion of one roller is arranged to interact with the resilient portion of the other roller. Arc lengths of the scoring or perforating roller blade portions and the resilient roller portions are substantially equal to each other and to the fold line of a signature. The rollers, between which the web is advanced, are positioned and oriented to score or perforate portions of the web in alternating directions which correspond to the direction of folding of each layer of the web.

Abstract: A rotary, die cutting anvil system having a rotatable head with a cover mounted on the peripheral surface thereof. The cover includes inner and outer laminated layers. The outer layer is made of a generally tough resilient composition that is softer than the hard inner layer to which it is bonded. The inner layer has holes for receiving pins. The cover is mounted on the head by forcing the pins into the holes. The resilience and shape of the hard inner layer maintains the cover on the anvil until it is pryed off. The pins may be fixed to the anvil head or be fixed on rings or sleeves slidably mounted in grooves on the periphery of the anvil head to permit linear or oscillatory freewheeling.

Abstract: An apparatus is disclosed which applies hot melt tape to substrates such as cartons or boxes which are fed through the apparatus in a timed, spaced manner. The requirement of applying the tape to each spaced carton is met by integrating the feeding and cutting of the tape to the timing of the carton or box feeding machine. The tape is applied to a predetermined location with a desired cut length determined by the configuration of the apparatus. The apparatus can be mounted on existing machines such as folder gluers or mounted on dedicated machines.

Abstract: An apparatus for removing scrap around the die cut blanks in a web comprising a pair of rolls through which the web is passed, one roll carrying flexible pointed fingers arranged substantially parallel thereto for impaling the scrap pieces and the other roll carrying resilient material opposed said flexible pointed fingers to contact the scrap pieces so they may be impaled by the pointed fingers. Scrap pieces are impinged on the pointed fingers as the scrap pieces pass between the fingers and resilient material before the nip of the rolls and are pushed outwardly from the surface of the roll by the flexible point finger for removal by a comb, brush or vacuum means.

Abstract: There is provided an apparatus for applying constant pressure to a plurality of anvil rollers for crush-scoring used in combination with crush-scoring cylinders having protrusions extending from the surface thereof. Each anvil roller is supported in a substantially frictionless manner and the constant pressure is supplied by a flexible diaphragm acting on a plunger which can move substantially without friction in a pneumatic cylinder.

Abstract: There is provided an apparatus for applying constant pressure to a plurality of anvil rollers for crush-scoring used in combination with crush-scoring cylinders having protrusions extending from the surface thereof. Each anvil roller is supported in a substantially frictionless manner and the constant pressure is supplied by a flexible diaphragm acting on a plunger which can move substantially without friction in a pneumatic cylinder.

Abstract: A rotary die cutting cover for use on a die cutting cylinder, in which the cylinder has a cylindrical external surface and a recess slot extending the length of the cylindrical surface, the cover being formed of a mat of resilient, flexible material having integral increased thickness end portions which are received in the cylinder recess slot and in which one mat end portion has a bottom surface having a narrow slot therein extending the width of the mat, the narrow slot allowing the mat end portion to compress as it is inserted into the cylinder recess slot.

Abstract: A cutter of the present invention comprises a punching member having a punching edge and a receiving member for receiving the punching force of the punching member, the receiving member having a sandwich structure comprising two plate materials and an elastic body held therebetween. Therefore, the receiving member is capable of elastically holding the punching edge during punching.

Abstract: There is disclosed a scoring cutter for scoring printed circuit boards to a uniform thickness. The scoring cutter has top and bottom circular blades set to a gap and rotatable in opposite directions to each other. Resilient wheels, four in number, having diameters slightly larger than the blades, are mounted for rotation with respect to the blades, one on each side of each blade. A circuit board is fed between the blades, and the resilient wheels position the circuit board in the gap between the blades.

Abstract: A replaceable cover for the cylindrical anvil of a rotary die cutter includes a blanket body of elastically deformable material, a sheet metal liner for the blanket body, and a latch assembly for securing the ends of the cover together in a slot in the face of the anvil roll. This latch assembly includes a channel bar having one side welded to one end of the blanket liner so that the open side of the channel faces the other end of the assembly for interlocking cooperation with a latch member integrally formed on the blanket body. The interior of the channel is filled with the material of the blanket body, and special provision is also made to provide a metal-reinforced supporting surface for the circumferentially interfitting parts of the latch assembly.

Abstract: Apparatus for cutting and dividing a continuous stream of printed products, in which the paper sheet is folded by means of a longitudinal folding system and is then sheared to the format length, and in which the continuous stream of printed products is divided into two transport paths.

Abstract: Parallel spaced rotary arbors support a plurality of axially spaced circular slitter knives, and a series of spacer rings precisely locate the slitter knives on each arbor. Each spacer ring includes a rigid carrier ring having three circumferentially spaced undercut cavities which confine corresponding floating gage blocks each having a precision axial width slightly greater than the axial width of the carrier ring. The carrier rings on each arbor are rotatably aligned by a keyway and include a pair of flat ring sections each having circumferentially spaced tapered holes which mate with corresponding chamfered surfaces on the gage blocks. The ring sections are secured together by screws or spot welds, and the wider spacer rings have corresponding core rings confined between the ring sections.