Abstract: There is provided a punching unit capable of punching holes in high-performance by increasing a punching force and by rotating a punch. A guide hole that guides the punch in the vertical direction is formed to have a narrow upper part, a wider lower part and inclined surfaces between them. An actuation pin engages with a cam and the punch moves up and down to punch a hole when a cam member reciprocates. The actuation pin abuts with the inclined surface of the guide hole at the punching position, so that the punch is rotated and a cam inclined angle is reduced by an inclined angle of the guide hole, allowing a large punching force.

Abstract: A chain tensioner has a plunger (14) slidably fitted in a bottomed cylinder (12) formed in a housing (11), and configured to resiliently urge the plunger (14) by a return spring (13) in the direction along which the plunger (14) is projected out from the cylinder (12), wherein the chain tensioner is configured to attach an engagement clip (19) to the opening of the cylinder (12), and to provide an engagement portion engageable with the engagement clip (19) to the end of the plunger (14) on the projection side thereof, so as to allow the engagement clip (19) and the engagement portion to engage with and disengage from each other corresponding to the position of rotation of the plunger (14).

Abstract: A chain tensioner (1) having a plunger (12) slidably assembled in a cylinder portion (13) together with a return spring (11), the chain tensioner (1) further has a stopper plate (22) having a through-hole (22a) formed therein, through which the plunger (12) is inserted; and a biasing member (24) disabling movement of the plunger (12), by applying a biasing force to the end of the stopper plate (22) so as to incline the stopper plate (22), the chain tensioner is configured to apply a hydraulic pressure of a hydraulic oil of an engine to the stopper plate (22), so as to reduce the inclination of the stopper plate (22) against the biasing force applied by the biasing member (24), to thereby allow movement of the plunger (12).

Abstract: A paper cutting device, for cutting multiple sheets of paper stacked in layers on a table, comprises a paper retainer (2) descending from an upper side along a guide and a cutter (3) diagonally ascending from the lower side. A receiving part (18) is mounted on the lower surface of a paper retaining frame (20). The receiving part (18) is formed by joining a base plate (36) with a large elastic modulus such as a metal to a resin receiving plate (37). A slip prevention structure is installed on the junction surfaces of the base plate (36) and the receiving plate (37) to suppress the extension/retraction of the receiving part of the paper retainer so as to prevent wrinkles from occurring in the paper near a blade receiving surface when the paper is cut off.

Abstract: A bush is pressed into a link plate in a turning link rank that turns relatively with a pin. The bush is molded into a seamless cylindrical shape by cold-forging and is coated with a metal carbide layer formed by cementation of chrome, vanadium and other metals and having Vickers hardness of 1300 Hv or more similarly to the pin. Afterwards, the bush is treated by a quenching, tempering or isothermal transformation process. Thereby, wear resistance of the pins and the link plates of a silent (link) chain is improved, productivity is improved and associated costs are reduced.

Abstract: A greasing through hole is perforated through one outer link plate, and greasing device is attached to the through hole. Degreasing through-holes are perforated through an outer link plate or an inner link plate on the side distant from the outer link plate with a bearing section A between the link plates, and degreasing device 22 is attached to those through-holes. Lubricant injected from the greasing device is supplied to the bearing section A through a gap c between the sealing device and the outer link plate, and used lubricant within the bearing section A is discharged out of the degreasing device through another gap c.

Abstract: There is provided a punching unit having a structure permitting to reduce a force required for punching, permitting to lessen parts and permitting to punch holes through a member to be perforated at arbitrary positions thereof. The punching unit has a holder that holds one or plurality of sets of punches and dies. The holder is movable in an array direction in which a plurality of holes to be perforated through the member is arrayed. An eccentric cam is disposed above the holder in parallel with the array direction. The punches within the holder are driven toward the dies by rotating the eccentric cam regardless of moving positions of the holder. Thus, the punching unit can perforate a number of holes greater than the number of punches held within the holder by sequentially moving the holder and by rotating the eccentric cam.

Abstract: Large impacts act on a spoke wheel and spokes fastened by nipples tend to be loosened when a racing off-road motorcycle and the like repeatedly jumps and lands. A hub is connected with a rim by using deformed spokes each having a deformed portion. The deformed spoke is fastened while being elastically deformed so that the deformed portion extends by the nipple. As compared to a straight spoke, the deformed spoke has low longitudinal elastic modulus and substantially the same stiffness with a spoke having an equal diameter.

Abstract: The invention provides a rotary-type punching unit that solves a problem of a prior art rotary-type punching unit that its punching torque is highly peaked in beginning and ending punching, thus disabling to punch a heavy paper or the like and degrading the quality level of punch holes. A blade surface of a punch of the invention is formed as an inclined surface inclined with respect to the outer peripheral surface of a punch shaft or of a die shaft such that a leading edge thereof is higher than a trailing edge with an inclination angle within a range of 5° to 15° (preferably 10°). A die surface of the die is formed into a surface of a circular arc centering on a rotational axis of the shafts. Thereby, the peaks of the punching torque are reduced and the quality level of the punch hole is kept high.

Abstract: A seal chain in which a sealing member having a shape of a “plus” in section is steadily twisted (turned) and deformed into a shape of an “X” and whose abrasion resistance and flexing torque are improved. The sealing member is formed such that inner diametric side end faces of third and fourth lip portions extending in a transverse direction from a center base portion extend in a direction orthogonal to a radial direction and outer diametric side end faces thereof are formed as tapered faces such that width of the lip portion is widened from an edge face toward the base portion. A diagonal distance of the center base portion is within a range of 0.8 to 1.0 of a clearance between inner and outer link plates.

Abstract: There is provided a punching unit capable of punching holes in high-performance by increasing a punching force and by rotating a punch while keeping the same basic structure with that of a prior art unit. A guide hole that guides the punch in the vertical direction is formed to have a narrow upper part, a wider narrow part and inclined surfaces between them. An actuation pin engages with a cam and the punch moves up and down to punch a hole when a cam member reciprocates. The actuation pin abuts with the inclined surface of the guide hole at the punching position, so that the punch is rotated and a cam inclined angle is reduced by an inclined angle of the guide hole, allowing a large punching force.

Abstract: A method prevents a cylindrical body from buckling in externally curling edges of both side portions by pressing curling dies in an axial direction after molding the cylindrical body having a drop portion whose outer diameter is small and two side portions whose outer diameter is large by enlarging a cylindrical material made of aluminum alloy by electromagnetic molding. In curling the edges of the side portions, a buckling preventing die restrains an outer periphery of the drop portion of the cylindrical body. Because the buckling preventing die receives the axial compression force of the curling dies, it can prevent the cylindrical body from buckling and deforming. The buckling preventing die is what a split die disposed on the side of an outer periphery of the cylindrical material in the electromagnetic molding is used as.

Abstract: A bush is pressed into a link plate in a turning link rank that turns relatively with a pin. The bush is molded into a seamless cylindrical shape by cold-forging and is coated with a metal carbide layer formed by cementation of chrome, vanadium and others and having Vickers hardness of 1300 Hv or more similarly to the pin. After that, the bush is treated by a quenching, tempering or isothermal transformation process. Thereby, wear resistance of the pins and the link plates of a silent (link) chain is improved, productivity is improved and the cost is cut.

Abstract: There is provided a punching unit that is readily adjusted, is capable of always punching high quality holes through sheets and is steadily capable of discharging punch chips. A punch shaft and a die shaft are disposed vertically in parallel between side plates and these very punch shaft and the die shaft compose structural members (reinforcing members) of the punching unit. The die shaft has a die shaft body formed into a hollow cylinder and is provided with dies that correspond to the punches of the punch shaft at an outer peripheral surface thereof while fitting into die holes penetrating to the hollow section. A chip discharging screw plate fixed to the right side plate is disposed in the hollow section of the die shaft. Punch chips are transported along slopes of the chip discharging screw plate and discharged out of an opening when the die shaft rotates.

Abstract: A highly durable and compact chain disconnecting and connecting tool that may be used for a chain at a sprocket part for winding the chain and that can receive an operational load at two places is provided. A first block has an engaged pressure actuating member coupling member. A second block is coupled with the first block turnably by the coupling member and has a cutout on one side and a through hole on another side of the block. The tool is attached to the chain from an opening while positioned engagement with an edge projection of a tap bolt that is screwed with the first block and with the cutout or the through hole.

Abstract: A chain pin manufacturing method that requires only one heat treatment step of forming a boundary part composed of (V, Cr) 8C7 by Cr and C in a base material at first through a cementation process in a VCl atmosphere by using Cr-rich steel as the pin base material and of forming a surface layer composed of V8C7. A Cr content in the boundary part decreases gradually toward the base material and the surface layer and the boundary part is not clearly divided. The inventive manufacturing method is simple and enables to manufacture the pin having high abrasion resistance and suitably used in a severe environment like a timing chain.

Abstract: A chain tensioner has a plunger (14) slidably fitted in a bottomed cylinder (12) formed in a housing (11), and configured to resiliently urge the plunger (14) by a return spring (13) in the direction along which the plunger (14) is projected out from the cylinder (12), wherein the chain tensioner is configured to attach an engagement clip (19) to the opening of the cylinder (12), and to provide an engagement portion engageable with the engagement clip (19) to the end of the plunger (14) on the projection side thereof, so as to allow the engagement clip (19) and the engagement portion to engage with and disengage from each other corresponding to the position of rotation of the plunger (14).

Abstract: There is provided a double-face driving silent chain wherein the size of each inner link plate of an exterior driving link train to a back face thereof is set to be equal to or greater than the size of each link plate of an interior driving link train. Thereby, inner side planes of the back face of the inner link plate abut against the both side planes of an interior driving sprocket and guide and prevent the silent chain from engaging with the sprocket in twist. All the link plates, other than the inner link plates of the exterior driving link train, have the same shape when seen from the side and the outermost link plate of the interior driving link train is thin as compared to the other link plates.

Abstract: There is provided a highly durable and compact chain disconnecting and connecting tool that may be used for a chain at a sprocket part for winding the chain and that can receive an operational load at two places. A first block has a pressure actuating member screwed therewith and a coupling member fixed thereto. A second block is coupled with the first block turnably by the coupling member and has a closed-end hole on one side and a through hole on another side of the block. The tool is attached to the chain from an opening while positioned and engaging an edge projection of a tap bolt that is screwed with the first block with the closed-end hole or the through hole.

Abstract: To provide a pin tip attachment structure that can engage a container with a bottom, such as a can or bottle, and convey the container without scratching it, a small diameter portion having a predetermined length is formed at a front end portion of a pin. A bushing is fitted in a lower end portion of a cylindrical hole of a pin tip having the cylindrical hole opened at a lower end side, and the bushing is vertically movably inserted onto the small diameter portion of the pin. A stopper portion for retaining the bushing is provided at a front end of the small diameter portion. A spring receiver portion is provided below the small diameter portion, and a coil spring is provided in a compressible manner between the spring receiver portion and the bushing or the lower end of the pin tip.