Sprocket Chain Patents (Class 59/5)
  • Patent number: 6105356
    Abstract: A drive chain has a plurality of links (1) each comprising a pair of opposed cranked link plates (2). Each link plate (2) has two connection apertures (7) and is connected to an adjacent link plate (2) by a pin (6) passing through overlapping connection apertures. An aperture (7) at one end of each link plate is fitted with a sleeve (11) in which said pin (6) is releasably engaged by means of a key connection. The sleeve (11) is connected to said link plate (2) by means of an interference fit with the respective connection aperture (7).
    Type: Grant
    Filed: March 8, 1999
    Date of Patent: August 22, 2000
    Assignee: Renold PLC
    Inventors: Bryan William Capstick, Edward Joseph Brownhill, Michael Charles Christmas
  • Patent number: 5966921
    Abstract: In order to provide a timing mark at a specific place on part of a timing chain in a manner in which the quality of the timing chain is maintained, a timing chain 4, made endless by outer plates 1 and inner plates 2 being connected by means of connecting pins 3 is provided with a timing mark 1' at a specific part on one side of an outer plate 1. The timing mark 1' is placed on the outer plate 1 between the connecting pins 3 and is in the shape of a web extending from an inner edge of the outer plate 1 to an outer edge thereof. The timing mark 1' is provided by baking a coating on the outer plate 1 after the timing chain has been assembled.
    Type: Grant
    Filed: June 19, 1998
    Date of Patent: October 19, 1999
    Assignee: Tsubakimoto Chain Co.
    Inventors: Kazuhiko Shimaya, Arimasa Kaga
  • Patent number: 5950416
    Abstract: A tentering chain is assembled of inner links and outer links or link plates interconnected by journal pins passing through the outer link plates and through the inner links so that the latter are positioned between the outer link plates. The inner links have plates which are provided with integral bearing bushings that are interconnected at a junction (J) formed by pressing four bearing bushings together with a transition fit after a bearing roller has been placed on each of two of the four bushings to form the inner links. The inner link plates form with their bearing bushings two chain link sections (1, 2) that are easily interconnected at the junction (J) and also easily disconnected again at the junction. Both sections are made by casting or drop forging.
    Type: Grant
    Filed: February 6, 1998
    Date of Patent: September 14, 1999
    Assignee: Lindauer Dornier Gesellschaft mbH
    Inventors: Horst Kerner, Hans-Juergen Maierhofer, Werner Bosch
  • Patent number: 5943855
    Abstract: A chain includes a plurality of link assemblies connected with each other. One of the adjacent link assemblies has a first pair of plates disposed apart in the direction perpendicular to the longitudinal direction of the chain and a pair of hollow cylindrical bushes press-fitted to the first pair of plates. The other of the adjacent link assemblies has a second pair of plates disposed apart in the direction perpendicular to the longitudinal direction of the chain so as to locate at the outside of the first pair of plates and a pin penetrated through the bush and press-fitted to the second pair of plates. A moisture absorption member which retains lubricant oil between the bush and the pin is placed between facing surfaces of the first and second plates. The moisture absorption member has a large deformation amount and a small restoration amount.
    Type: Grant
    Filed: June 10, 1998
    Date of Patent: August 31, 1999
    Assignees: Tsubakimoto Chain Co., U.S. Tsubaki, Inc.
    Inventors: Masaru Morimoto, Leon N. Ducharme
  • Patent number: 5941059
    Abstract: A silent chain, as well as a rocker pin and a plate of the silent chain, are provided which are capable of enhancing the transmission efficiency, and improving the fatigue strength of the plate to thereby prolong the service life of the silent chain. Rocker pins are inserted into the pin holes of each plate of a plurality of plates of a silent chain. The rocker pins are located closer to outer ends of the plate and are formed with generally flat plate abutting surfaces. The plate abutting surfaces are received by generally flat pin seating surfaces of the pin holes, respectively, to surely prevent rotation of the rocker pins relative to the pin holes. Further, in addition to the generally flat pin seating surfaces, generally flat and short continuous surfaces are formed centrally up and down of each pin hole. Thus, stress concentration on the plate is diminished and the fatigue strength of the plate is improved.
    Type: Grant
    Filed: October 21, 1997
    Date of Patent: August 24, 1999
    Assignee: Tsubakimoto Chain Co.
    Inventors: Makoto Kanehira, Masao Maruyama, Hitoshi Ohara, Masahiro Sato, Nobuyuki Fujimoto, Takayuki Funamoto
  • Patent number: 5865021
    Abstract: The present invention relates to the case hardening, tempering and coating of a medium carbon alloy chain pin. A medium carbon alloy chain pin is provided and is case hardened to a selected radial depth. The case hardened chain pin is quenched and then tempered to introduce a gradient from the surface of the chain pin inwardly in carbon content and hardness. The chain pin is then coated with an electroless nickel and fluorinated carbon co-deposition to increase surface hardness.
    Type: Grant
    Filed: August 25, 1997
    Date of Patent: February 2, 1999
    Assignee: AMSTED Industries Incorporated
    Inventors: Robert T. Duerigen, Andrew J. Binford
  • Patent number: 5857318
    Abstract: A transmitting chain is provided which can lower surface pressure between a bushing and a pin, which can well maintain a lubricating state, and which is high in durability so as to be capable of withstanding high load. A groove or a depression, into which lubricating oil, supplied from outside of the chain, is moved, is formed in at least one of a group including an inner peripheral surface of a bushing and an outer peripheral surface of a pin. A difference, space, or clearance, located between an inside diameter of the bushing and an outside diameter of the pin, of portions of the chain not including the groove or depression, is set in a range of from about 0.05 to 0.6% of the outside diameter of the pin.
    Type: Grant
    Filed: February 24, 1998
    Date of Patent: January 12, 1999
    Assignee: Tsubakimoto Chain Co.
    Inventors: Nobuhiro Odai, Junichi Uchimaru
  • Patent number: 5809767
    Abstract: A chain with a seal body has a swelling seal body arranged between respective inner and outer plates provided on either side on a connecting pin. Any one of a water absorbent, an oil absorbent, and both a water and oil absorbent is contained in the base material resin of the seal body so that a swelling property is imparted to the seal body. When any one of water and oil is present around the chain, any one of the water and oil, respectively, penetrates into the clearance between the seal body and the plate to swell the seal body in the clearance part. Thus, the primary purpose of the chain with a seal body is to block a clearance between the inner and outer plates and the seal body in the chain by utilizing any one of the water absorbent, the oil absorbent, and the water and oil absorbent contained in the seal body.
    Type: Grant
    Filed: September 4, 1997
    Date of Patent: September 22, 1998
    Assignee: Tsubakimoto Chain Co.
    Inventor: Koji Tanaka
  • Patent number: 5806297
    Abstract: A resin chain is provided which includes a reinforcing plate and a resin portion having a contact surface therebetween such that it is difficult to separate the reinforcing plate from the resin portion at the contact surface. The resin chain includes outer plates with pins fitted therein and inner plates with bushings fitted therein. The outer plates and the inner plates are connected to each other in an alternate manner. A first reinforcing plate is a constituent of each outer plate. The first reinforcing plate has a pair of cylindrical front and rear boss portions with pins fitted therein and a flange portion which rises radially from the outer peripheries of the boss portions to connect the paired front and rear boss portions to each other. A second reinforcing plate is a constituent of each inner plate.
    Type: Grant
    Filed: November 20, 1997
    Date of Patent: September 15, 1998
    Assignee: Tsubakimoto Chain Co.
    Inventor: Koji Tanaka
  • Patent number: 5787700
    Abstract: A sealed chain is provided that traps lubricant and dust electrostatically. The chain includes an inner plate which is penetrated by a bushing and an outer plate which is penetrated by a pin. The inner and outer plates are connected alternatingly. Between the inner plate and the outer plate, a seal which is coaxial with the bushing and the pin, is provided in contact with the inner and outer plates. The contact area between the seal and the inner plate is smaller than the contact area between the seal and the outer plate. An annular dust hole, which is around the end of the bushing for sliding on the pin is formed on the inner part of the surface of the seal facing the inner plate. When chain bends due to, for example, winding by a sprocket, the seal slides on the inner plate thus, generating electrostatic charge. The end of the bushing 12, which slides on the pin, is encircled by the dust hole, which entraps lubricant electrostatically on sliding surfaces and dust formed by the wear of sliding surfaces.
    Type: Grant
    Filed: May 30, 1997
    Date of Patent: August 4, 1998
    Assignee: Tsubakimoto Chain Co.
    Inventor: Koji Tanaka
  • Patent number: 5758484
    Abstract: A silent chain for power transmission applications wherein the chain is in sliding contact with a chain guide or tensioner. The chain is constructed of some link plates having a higher back than other link plates. In operation, the higher backed links slide against the chain guide or tensioner while the lower backed links do not contact the chain guide or tensioner. Because not all of the links slide against the chain guide, the friction between the chain and chain guide is reduced.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: June 2, 1998
    Assignee: Borg-Warner Automotive, Inc.
    Inventors: Timothy J. Ledvina, Philip J. Mott
  • Patent number: 5667442
    Abstract: A chain link 1 assembly body includes a pre-molded resin sleeve having a uniformly cylindrical inner periphery and a partially convexly contoured outer periphery, a bushing conformed to the shape of the sleeve and inner links each having a bushing press-fitted hole for fitting around the ends of the bushing. The method includes the step of providing an engineering plastic resin sleeve and a bushing. The sleeve is pre-molded to have a uniformly cylindrical inner periphery and an outer periphery having a convex contour for a central portion of the sleeve and uniformly cylindrical contours for the opposed ends of the sleeve. The bushing is originally uniformly cylindrical prior to its ends being press-fitted into bushing press-fitted holes of inner links.
    Type: Grant
    Filed: June 28, 1995
    Date of Patent: September 16, 1997
    Assignee: Tsubakimoto Chain Co.
    Inventor: Koji Tanaka
  • Patent number: 5465568
    Abstract: A chain structure for bicycles is composed of a series of inner chain plates, outer chain plates, rollers, and pins. Each inner plate has three arcuate peripheries at respective ends and slanting surfaces along one side of the arcuate peripheries. Each outer plate has also three arcuate peripheries at respective ends and slanting surfaces along one side of the arcuate peripheries. The slanting surfaces of the inner chain plates and outer chain plates are adapted to facilitate engagement of sprocket teeth with the chain plate.
    Type: Grant
    Filed: January 17, 1995
    Date of Patent: November 14, 1995
    Assignee: Yaban Chain Industrial Co., Ltd.
    Inventor: Wen-Bin Wang
  • Patent number: 5461852
    Abstract: A chain comprising links and pins formed from fiber reinforced thermoplastic resin is disclosed. Each link has bores, and each pin has a body for insertion through the bores of adjoining links to connect the links pivotally. The body has two diametrically opposite rows of grooves formed in its peripheral surface, has a front end from which an annular shell projects coaxially and an axial protrusion extends through the shell coaxially, and has a rear end formed with a flange. The shell has a radially outwardly projecting shoulder formed around its mid-portion, has a frustoconical front end portion, and has radially extending slits which makes the shell radially compressible. The link which has a bore positioned at the inlet for the insertion of the pin, has bosses which are engageable with the flange for holding the pin against rotation to maintain the rows of grooves at right angles with respect to a longitudinal direction of the links.
    Type: Grant
    Filed: May 3, 1994
    Date of Patent: October 31, 1995
    Assignee: Hitachi Metals, Ltd.
    Inventor: Hiromitsu Nagamatsu
  • Patent number: 5437148
    Abstract: A chain including a plurality of pairs of inner and outer link plates interconnected by pivot pins extending through aligned apertures in the inner and outer link plates. A roller surrounds each pivot pin between the inner link plates. The roller is integral with the pivot pin. An aperture of each of the outer link plates is formed with an inwardly extending tubular protrusion. This protrusion is received within an aperture of an adjoining inner link plate. The roller is rotatable relative to the link plates.
    Type: Grant
    Filed: March 15, 1994
    Date of Patent: August 1, 1995
    Inventor: Stefan Karp
  • Patent number: 5400585
    Abstract: A chain structure is provided which includes a base plate having a pair of integral cylinders extending from one side. A connecting plate has a pair of elliptically contoured apertures at respective ends adapted to receive the corresponding cylinders. Each of the cylinders has an annular groove formed in a top portion with tapered surfaces. Each of the apertures has a pair of tapered walls at respective sides adapted to matingly engage with the tapered side walls of the connecting plate when the connecting plate is inserted into the base plate and the apertures are aligned in the annular grooves.
    Type: Grant
    Filed: May 19, 1994
    Date of Patent: March 28, 1995
    Assignee: Yaban Chain Ind'l Co., Ltd.
    Inventor: Wen B. Wang
  • Patent number: 5345753
    Abstract: In a silent chain, guide link plates are installed in a row along the sides of the link plates. The guide link plates are provided with central openings having rounded corners. The width of the inner beam portion of the central opening is limited by the inner edge of the central opening and the inner edge of the guide link. The width of the outer beam portion of the central opening is limited by the outer edge of the opening and the outer edge of the guide link plate. The width of the inner beam portion is equal to or less than the width of the outer beam portion. Alternatively, the guide link plates are provided with slits extending from the inner edge, and the inner edges of said slits are curved.
    Type: Grant
    Filed: July 28, 1993
    Date of Patent: September 13, 1994
    Assignee: Borg-Warner Automotive, K.K.
    Inventors: Tomonori Okuda, Tetsuji Kotera, Kouji Morishige
  • Patent number: 5299416
    Abstract: A link for connecting a chain. The link has a first outer chain plate, a first pin, a second pin, and a second outer chain plate. The first outer chain plate has two circular holes. The pin has, at a first end, an enlarged flat head and, at a second end, a dome head near which a groove extends so as to form a neck. The second outer chain plate has a circular hole and a hole consisting of a relatively small semicircular hole overlapping partially with a relatively large semicircular hole. In a plant, the first pin is (a) inserted through a hole of the first outer chain plate, holes of two inner chain plates, and the circular hole of the second outer chain plate and (b) riveted at both heads to thereby combine these elements conventionally. The second pin is inserted through the other hole of the first outer chain plate and the enlarged flat head thereof is secured to the first outer chain plate.
    Type: Grant
    Filed: January 12, 1993
    Date of Patent: April 5, 1994
    Inventor: Chia-Long Wu
  • Patent number: 5291730
    Abstract: A knuckle connector is used to connect spacedly end knuckles of a chain strand to form a chain loop. The knuckle connector includes a pair of link units, each of which has a link pin and an oval-shaped link plate formed with a circular through-hole on one end and a retaining hole on an opposite end. The link pin has a head secured in the through hole and a tail end formed with a peripheral channel. The link pin of one of the link units extends through a pin hole formed in a corresponding one of the end knuckles such that the peripheral channel initially extends into a large insert part of the retaining hole in the link plate of a remaining one of the link units. The peripheral channel of the link pin of one of the link units engages the link plate of the remaining one of the link units in a diameter-reduced retaining part of the retaining hole when the end knuckles are pulled apart.
    Type: Grant
    Filed: April 8, 1993
    Date of Patent: March 8, 1994
    Assignee: KMC Chain Industrial Co., Ltd.
    Inventor: Nick Wu
  • Patent number: 5199197
    Abstract: A sidebar is provided for an offset sidebar trenching chain. The sidebar has an inner edge which slides along a boom of a trenching machine, when the trenching chain is in use. The sidebar is induction hardened through a portion thereof extending from the inner edge, for increased resistance to wear due to friction.
    Type: Grant
    Filed: June 11, 1990
    Date of Patent: April 6, 1993
    Assignee: Rexnord Corporation
    Inventor: John H. Thuerman
  • Patent number: 5140806
    Abstract: A roller chain for bicycles comprises a plurality of outer links each having a pair of outer plates each having two pin holes, two pins extending through the pin holes and connecting the outer plates of each of the outer links with one another, a plurality of inner links arranged alternately with the outer links and each having a pair of inner plates each provided with a bearing collar defining an inner hole and carrying a roller. The inner holes have a cross-section which is elongated in a longitudinal direction. At least one of the pin holes in the outer plates and the inner holes in the bearing collars are offset so that a roller pitch of the inner and outer links in a stretched state of the chain is adjusted substantially to the same value.
    Type: Grant
    Filed: June 18, 1990
    Date of Patent: August 25, 1992
    Inventor: Bernhard Rohloff
  • Patent number: 5107672
    Abstract: A rigid drive assembly is constructed of two interconnected, flexible chain elements.
    Type: Grant
    Filed: May 10, 1991
    Date of Patent: April 28, 1992
    Assignee: The Will-Burt Company
    Inventor: Harry E. Featherstone
  • Patent number: 5092118
    Abstract: A chain link having a pair of spaced sidebars provided with a set of aligned bores and a round pin positioned within so as to extend through the aligned bores utilizes sidebars and a pin which cooperate in a manner which positively secures the pin in position within the bores and which accommodates a removal of the pin from the bores in a manner which prevents damage to the link components. The pin has a head on one end and an annular rib on its other end, and the sidewall of one of the aligned bores possesses a diameter which tapers in size from one end of the bore to the other end thereof and is adapted to flex outwardly to accommodate the passage of the annular rib therethrough.
    Type: Grant
    Filed: January 9, 1991
    Date of Patent: March 3, 1992
    Assignee: Jeffrey Chain Corporation
    Inventor: Paul J. VanDeMark
  • Patent number: 5056306
    Abstract: In a process for producing a metal plate in such a way that it can be joined up to form a chain, use is made of a casting or forging tool, which forms a base part and a sole part of the plate, a specific sole part from several sole parts being associated with the base plate. The tool comprises at least one part forming the base part of the plate and another part forming the sole part of the plate. The resulting plate has reception rings on one plate side and an equal number of ring notches on the other plate side and side guides on the plate underside and at least one engagement gap.
    Type: Grant
    Filed: November 6, 1989
    Date of Patent: October 15, 1991
    Inventor: Hans-Rudolf Zepf
  • Patent number: 4941315
    Abstract: A sidebar is provided for a trenching chain. The sidebar has an inner edge which slides along a boom of a trenching machine, when the trenching chain is in use. The sidebar is induction hardened through a portion thereof extending from the inner edge, for increased resistance to wear due to friction.
    Type: Grant
    Filed: February 13, 1989
    Date of Patent: July 17, 1990
    Assignee: Rexnord Corporation
    Inventor: John H. Thuerman
  • Patent number: 4926529
    Abstract: A tenter frame is illustrated wherein a chain is fabricated by press fitting a pin receiving bushing constructed of Vespel and the like into a steel bushing and then boring a pin receiving opening therein and utilizing wear strips constructed of Vespel in a dovetail configuration opposite the tenter chain providing a lubrication free tenter wherein the chain may be tensioned without excessive stretching.
    Type: Grant
    Filed: September 15, 1988
    Date of Patent: May 22, 1990
    Assignee: Marshall and Williams Company
    Inventors: Christopher E. Hosmer, John F. Whaley
  • Patent number: 4893464
    Abstract: An offset sidebar chain for use in a machine including pairs of offset sidebars having heights perpendicular to the direction of chain travel, when the chain is in use, at least one pair of offset sidebars of the chain having an extended height, and each including a first portion having opposite ends, a forward end adapted to be connected by a chain pin to a preceding pair of sidebars, and a rearward end adapted to be connected by another chain pin to a trailing pair of sidebars and the pair of extended height sidebars including an extended height portion having structure for supporting a tool.
    Type: Grant
    Filed: December 2, 1988
    Date of Patent: January 16, 1990
    Assignee: Rexnord Corporation
    Inventor: John H. Thuerman
  • Patent number: 4878345
    Abstract: The present invention discloses an improved chain assembly and a method for making the same. In general, the method of making a chain assembly in accordance with the present invention, comprises forming a plurality of links having a preselected shape and placement of apertures therein. A plurality of wire blanks are formed having an outer diameter to permit insertion into the apertures of the links. Such link is retained in a fixed position and a wire blank is inserted into each aperture of the link. On one end of each wire blank, a head is formed having a diameter larger than the aperture into which the wire blank is inserted. A mating link is placed into engagement with each link containing wire blanks with the end of each blank inserted in one aperture of the mating link in a manner to form a chain assembly. On the other end of each wire blank, a head is formed to complete interlocking of the links and blanks in forming the chain assembly.
    Type: Grant
    Filed: September 15, 1987
    Date of Patent: November 7, 1989
    Inventor: Stephen K. Bechtold
  • Patent number: 4757681
    Abstract: This invention relates to a chain link plate which is constructed by a high tensile strength fiber which is wound around between two pivot points and which is fixed to each other by adhesive material. The link plate is improved in strength and decreased in weight.
    Type: Grant
    Filed: June 18, 1987
    Date of Patent: July 19, 1988
    Assignee: Tsubakimoto Chain Co.
    Inventors: Kazumasa Matsuno, Takashi Tsujimoto, Takerou Nakagawa, Yasumasa Tubakimoto, Makoto Kanehira
  • Patent number: 4750325
    Abstract: A chain link having a pair of curved extremities and being generally in the shape of an elongated loop. The loop defines two sides which converge towards the middle of the link where the two sides are rigidly jointed together, as by a weld, thereby forming a pair of interior spaces progressively narrowing towards the middle. Such link is adapted for use in alternation with pin links in a chain designed to remove waste material in a livestock enclosure. A method of making the link is further disclosed.
    Type: Grant
    Filed: April 9, 1987
    Date of Patent: June 14, 1988
    Inventor: Fernand Messier
  • Patent number: 4747261
    Abstract: A load transmitting chain (1) comprises a series of links each formed by a number of link plates (2) arranged side by side and meshing with the link plates of the adjacent link to which they are pivotally connected by link pins (4). The chain is intended for use in transmitting force from a hydraulic cylinder having a piston rod, for example in a fork-lift truck. To avoid damage to the piston rod by contact of the links (2), which are of steel, with it, the chain is provided with a row of additional protective link plates (5) which are sandwiched between the link plates (2) and have projecting portions (11). The protective link plates (5) are made of plastics material and the projecting portions (11) act as buffers so that they come into contact with the piston rod without causing damage and prevent direct contact between the steel link plates (2) and the piston rod.
    Type: Grant
    Filed: September 10, 1986
    Date of Patent: May 31, 1988
    Assignee: Rexnord Kette GmbH & Co KG
    Inventor: Ludger Frenker-Hackfort
  • Patent number: 4724669
    Abstract: A conveyor or chain having a tubular filament-wound cylindrical element used as the pins interconnecting the link plates and/or as rollers or bushings in the chain assembly. The element is formed from a length of tubular material which is wound on a mandrel having an outside diameter equal to the inside diameter of the tubular element. The filament of the winding is a long aramid fiber which is integrated in the tubular material by an adhesive agent.
    Type: Grant
    Filed: April 30, 1986
    Date of Patent: February 16, 1988
    Assignee: Tsubakimoto Chain Co.
    Inventors: Makoto Kanehira, Takashi Koizumi, Takerou Nakagawa, Kazumasa Matsuno, Yasumasa Tsubakimoto, Fumio Ochiai, Takashi Tsujimoto
  • Patent number: 4594846
    Abstract: A track joint is provided with a controlled running clearance by means of a controlled interstice producing membrane placed between the opposing axial thrust surfaces of the joint. The membrane is of a substance which sacrifically self-destructs upon the initial pivotal movements of the joint. The purpose of the membrane is to relieve the joint of compressive loads which become locked in the joint during its assembly and can cause galling of the thrust surfaces and injury to track seals in the joint.
    Type: Grant
    Filed: May 16, 1985
    Date of Patent: June 17, 1986
    Assignee: Caterpillar Tractor Co.
    Inventors: Richard E. Livesay, Charles E. Grawey
  • Patent number: 4572588
    Abstract: Connecting elements for crawler track vehicle chains constructed pursuant to the dually-hinged pin principle, wherein the connector is arranged interiorly of the chain members. The connectors consists of two clamps each having arms which can be inserted offset into each other, and which are fastenable by means of screw connection to the link pins of adjacent chain link members, each clamp encompassing respectively one link pin and form-fittingly fixed thereto, the link pin having a cross-section in at least the region of the connectors deviating from a circular cross-section, and wherein the clamps lockingly interengage in each other.
    Type: Grant
    Filed: February 27, 1984
    Date of Patent: February 25, 1986
    Assignee: Diehl GmbH & Co.
    Inventors: Hagen-Heinz Wiesner, Heinz E. Mattern
  • Patent number: 4543818
    Abstract: This seal check apparatus is mounted on a track press and checks the airtightness of a track joint immediately after the completion of assembly of a track chain using the track press. The apparatus comprises a base assembly mounted on the track press; a vacuum head which is engageable with and disengageable from the track joint on the track press; a member provided with freedom of displacement on the base assembly and supporting the vacuum head with freedom of displacement; a first actuating member provided on the base assembly and displacing the vacuum head supporting member; a second actuating member provided on the vacuum head supporting member and displacing the vacuum head; a gas system for sucking gases from the vacuum head when the latter engages the track joint; and a control member for controlling the operations of both actuating members and the gas system.
    Type: Grant
    Filed: February 18, 1983
    Date of Patent: October 1, 1985
    Assignee: Maruma Jyusharyo Kabushiki Kaisha
    Inventors: Yasumitsu Moriki, Tadashi Sato, Kazuyoshi Yamamoto, Izumi Takahashi