REINFORCEMENT BINDING MACHINE

Abstract: A reinforcement binding machine (100,250) using a steel wire (106) comprises a means (146) for feeding said steel wire (106) into a binding station (144) for binding reinforcements (102,104), a guide means (194,196) provided with a guide path (198,200) for guiding the steel (106) wire fed into the binding station (144) along a curve encircling the reinforcements and defining the binding station (144), a means (172) for twisting the steel wire (106) looped by the guide path (198,200) and defining a slot (178), through which the steel wire (106) fed in the binding station (144) is capable of passing and a means (120,142) for rotating the twisting means (172) about the axis crossing the axis of the loop formed of the steel wire (106) such as to twist the steel wire (106), the twisting means (172) being provided with a pair of pins (184) opposed to each other through the slot (178) to be moved relatively in the axial direction of the loop and a means (186,188,190,240,242) for normally urging at least one of the pins (184) such that the end faces of the pins (184) are butted against each other in the binding station (144).

Description: BACKGROUND OF THE INVENTION Field of the Invention: This invention relates to a reinforcement binding machine for binding a plurality of reinforcements crossing each other, i.e., longitudinal and lateral reinforcements of a reinforcement cage, by a steel wire. Description of the Prior Art: One of machines for binding a plurality of reinforcements crossing each other by a steel wire at intersections of these reinforcements has been disclosed in the Japanese Patent Public Disclosure (KOKAI) No. 51265/80. According to this prior reinforcement binding machine, the steel wire is guided by a guide defining a binding station to be wound by a plurality of turns around said reinforcements so as to form a loop encircling said reinforcements. Through said loop are inserted a pair of pins from the axially opposed sides of said loop along the axis. Said pins are supported by a rotor which is rotated about an axis orthogonal to the axis of said pin and extending diametrally of said loop. Thus, said steel wire wound by a plurality of turns is twisted by said pins. The respective pins are normally spaced from each other by spring force and butted against each other at the time of binding to engage said steel wire to be twisted by centrifugal force due to the rotation of said rotor exceeding said spring force. However, said prior reinforcement binding machine has such a construction that said both pins are butted against each other by the centrifugal force against said spring force. Threrefore, said both pins are left spaced from each other even if said rotor is rotated so long as said centrifugal force does not exceed said spring force in the rotational speed. Under such a condition, said pins are not inserted into said loop so that said steel wire cannot be twisted. Further, in said prior reinforcement binding machine, when the rotational speed of said rotor is reduced due to the beginning of twisting said steel wire, said centrifugal force becomes smaller than said spring force. As a result, even if said pins are inserted into said loop, since said pins are separated from each other by said spring force to be disengaged from said steel wire, said reinforcements cannot be sufficiently bound. When the rotational speed of the rotor and thus of the pin is increased to prevent the defective binding, it is difficult to get timing of completing the twist and excessive or short twist is produced since said prior machine is constructed to complete the twist when said centrifugal force becomes smaller than said spring force. In particular, if said steel wire is excessively twisted, it is twisted off or said pins are strongly restrained by said steel wire even if the steel wire is not twisted off. Therefore, said pins cannot be disengaged from the twisted steel wire by said spring force. Further, in said prior reinforcement binding machine, since the timing of butting i.e., closing said pins against each other and the timing of disengaging (i.e., opening) said pins from each other depend on the rotational speed and rotational time of said rotor, said steel wire cannot be twisted to certain strength. Also, since said prior reinforcement binding machine is constructed to determine the relative positional relationship between said reinforcements and said reinforcement binding machine according to a feeling of an operator, the position of said reinforcements in said binding portion defined by said guide for guiding said steel wire in the form of a loop along a curve encircling said reinforcements becomes indefinite. In this case, as said twisting means is rotated at the time of binding, said guide comes into contact with said reinforcements. As a result, the binding operation becomes troublesome. Further, since said prior reinforcement binding machine is provided with a cutter for cutting off said steel wire separately from the steel wire twisting means, a cutter driving mechanism, a means for synchronizing said cutter with said steel wire twisting means or the like are needed in addition to said cutter. Further, in said prior reinforcement binding machine, since said twisting means is freely rotatable at the time of stopping its rotation, a steel wire inlet of said twisting means has to be manually aligned with a steel wire outlet of a steel wire feeding path at the time of beginning of binding. Further, the steel wire inlet of said twisting means has to be manually maintained to be aligned with said steel wire outlet of said steel wire feeding path at the time of feeding said steel wire. Further, in said prior reinforcement binding machine, since a guide path provided in said guide is a groove which opens to the inside of said guide throughout the total length of said guide, the leading end of the steel wire moves along the guide path contacting the depth surface of said guide path as said steel wire is fed while a rear portion escapes from said guide path inward of said guide and thus said steel wire cannot be transformed into a loop encircling said reinforcements though said steel wire has a certain degree of regidity. SUMMARY OF THE INVENTION An object of the present invention is to provide a reinforcement binding machine capable of twisting a steel wire accurately. Another object of the present invention is to provide a reinforcement binding machine capable of twisting the steel wire to certain strength. A further object of the present invention is to provide a reinforcement binding machine which is not necessary to provide particularly a cutter driving mechanism for cutting off the steel wire and, a means for synchronizing the cutter with a twisting means or the like. A still further object of the present invention is to provide a reinforcement binding machine which is not necessary to align manually a steel wire inlet of said twisting means with a steel wire outlet of a steel feeding path at the time of beginning of binding. A still further object of the present invention is to provide a reinforcement binding machine capable of transforming accurately said steel wire fed into a guide means into a shape along a guide path of the guide means. The reinforcement binding machine according to the present invention comprises a means for feeding a steel wire into a binding portion for binding reinforcements, a guide means provided with a guide path for guiding said steel wire fed into said binding portion along a curve encircling said reinforcements to define said binding portion, a means for twisting said steel wire looped by said guide path and defining a slot, through which said steel wire fed into said binding station is capable of passing and a means for rotating said twisting means about the axis crossing the axis of the loop formed of said steel wire such as to twist said steel wire, said twisting means being provided with a pair of pins opposed to each other through said slot and disposed relatively movably in the axial direction of said loop and a means for normally urging at least one of said pins such that respective end faces of the pins butt against each other in said binding portion. In the reinforcement binding machine according to the present invention, respective end faces of a pair of pins are normally butted against each other by the urging means and the steel wire is guided by the guide means so as to surround the butted pins and reinforcements to be bound. Therefore, according to the present invention, the steel wire can be securely twisted since the rotation of the twisting means is started. In a preferred embodiment according to the present invention, said end of at least one pin butted against the other pin is shaped to produce force for separating both pins from each other in twisting said steel wire. According to this embodiment, when the steel wire is twisted by a predetermined amount, said both pins are automatically and relatively moved to be separated from each other against the urging force due to said urging means. Thereby said pins are disengaged from said steel wire to complete the twisting of said steel wire. Thus, said steel wire is securely twisted to certain strength. Further, in the preferred embodiment according to the present invention, a feeding means,a guide means, a twisting means and a rotary means are supported in a main body having a handle portion and the reinforcement binding machine can be manually carried and operated. Further it can be used in either of factory and work site. Further, in the preferred embodiment according to the present invention, a portion of the twisting means for defining a steel wire receiving spot in the slot closely contacts the steel wire outlet of a member for defining the steel wire feeding path to serve as a cutter portion for cutting off said steel wire in cooperation with said steel wire outlet at the time of rotating said twisting means. Thus, according to this embodiment, the steel wire is cut off at the beginning of rotating the twisting means by the cooperative action of the twisting means and the member for defining the steel wire feeding path. According to preferred embodiment of the present invention, said twisting means is angularly rotated by the aligning means in non-rotation so that said slot is automatically aligned with the steel wire outlet of said steel wire feeding path to receive said steel wire in said slot. According to the preferred embodiment of the present invention, said twisting means is also automatically maintained at an orientation, in which said slot is aligned with the steel wire outlet of said steel wire feeding path, by an orientation maintaining means in feeding the steel wire. Further, according to the preferred embodiment of the present invention, the steel wire fed into a first guide of said guide means in feeding the steel wire has one end moved along a guide path of said first guide and the other portions prevented from escaping from said guide path in the proximity of the steel wire inlet of said first guide by a second guide of said guide means. As a result, said steel wire fed into said first guide is fed while being blocked form the separation from said guide path by said second guide to be transformed securely into a curved shape along said guide path by the cooperative action of said first and second guides. BRIEF DESCRIPTION OF THE DRAWINGS The other objects and features of the invention will become apparent from the following description of preferred embodiments of the invention with reference to the accompanying drawings, in which: Fig. 1 is a front view showing an embodiment of a reinforcement binding machine according to the present invention; Fig. 2 is a right side view showing the reinforcement binding machine shown in Fig. 1; Fig. 3 is an explanatory illustration showing the engaging condition of gears; Fig. 4 is a sectional view taken along the line 4-4 in Fig. 2; Fig. 5 is a sectional view taken along the line 5-5 in Fig. 1; Fig 6 is a sectional view taken along the line 6-6 in Fig. 1; Fig. 7 is a front view, partially broken away, showing a rotary shaft; Fig. 8 is a right side view showing the head in Fig. 7; Fig. 9 is a front view showing a pin; Fig. 10 is a front view showing a slider; Fig. 11 is a perspective view showing a positioning mechanism and an aligning mechanism; Fig. 12 is a sectional view taken along the line 12-12 in Fig. 6; Fig. 13 is a sectional view taken along the line 13-13 in Fig. 4; Fig. 14 is a front view showing the opened condition of a guide for defining a binding portion; Fig. 15 is a sectional view showing another embodiment of an urging means for the pin; Fig. 16 is a longitudinal secitonal view showing a further embodiment of the reinforcement binding machine according to the present invention; and Fig. 17 is a plan view showing the binding machine shown in Fig. 16. DESCRIPTION OF THE PREFERRED EMBODIMENTS A reinforcement binding machine 100 shown in Figs. 1 and 2 comprises a main body 108 for supporting various mechanisms for binding the intersection of reinforcements 102,104 with an elongated steel wire 106. In the embodiment shown, the reinforcement 102 is one of longitudinal reinforcements for a concrete pile and the reinforcement 104 is a spiral reinforcement wound around the longitudinal reinforcements. The reinforcements 102,104, however, may be other reinforcements such as reinforcements for reinforced concrete structure, for example. As shown in Figs. 1 to 6, the main body 108 is provided with a gear case 112 projecting forward from a box-like frame 110, a support wall 114 provided integrally with the gear case 112, a cover 116 disposed removably behind the frame 110 and a handle portion 118 extending downward for the frame 110. Since the reinforcement binding machine 100 is provided with the handle portion 118, said machine 100 can be carried and manually operated. Further, it can be used in either of factory and work site and any desired places. On the rear side of the frame 110 is mounted a rotary source 120 such as an electric motor, an air motor or the like. The power, i.e., turning force of the rotary source 120, as shown in Figs. 3 to 5, is transmitted to a shaft 132 through an output shaft 122 extending through a rear wall of the frame 110, a gear 124 provided on the output shaft 122, a clutch 128 having a gear 126 meshing with the gear 124 and disposed in the frame 110 and a brake 130 connected to the output shaft of the clutch 128 and disposed in the frame 110. The shaft 132 extends back and forth in the gear case 112 and is supported rotatably by the gear case 112. The turning force of the rotary source 120, as shown in Figs. 3 to 5, is also transmitted from said gear 124 to a clutch 142 having a gear 140 through a gear 134 meshing with the gear 124, a shaft 136 attached with the gear 134, and a gear 138 provided on the shaft 136 and meshed with said gear 140. In the gear case 112 is supported a steel wire feeding mechanism 146 for feeding the wire 106 to a binding station 144. The steel wire feeding mechanism 146 is provided with a pair of steel wire feeding rollers 148,150 disposed at the outside of the gear case 112. The steel wire 106 is guided to the rollers 148,150 by a protective guide 152a and a tubular guide 152b coupled with an end of the protective guide 152a and fixed to the gear case 112. As shown in Fig. 5, one roller 148 is fixed to a shaft 154 extending horizontally and rotatably through the gear case 112. The turning force transmitted to the shaft 132 is transmitted to the roller 148 through a worm 156 mounted on the shaft 132, a worm wheel 158 meshing with the worm 156 and the shaft 154 mounting said worm 154. The other roller 150, as shown in Figs. 1 and 4, is rotatably supported by a lever 162 connected pivotably to the gear case 112 by a pin 160 and normally urged toward the roller 148 by a spring 166 surrounding a slide shaft 164 supported movably back and forth by the gear case 112. Force for urging the roller 150 against the roller 148 can be varied by adjusting the position of a nut 165 screwed onto a slide shaft 164 thereon. The rollers 148,150 have synchronizing gears 168,170 meshing with each other. Thereby, both rollers 148,150 are rotated in synchronization with each other to feed the steel wire 106 which is supplied to the guide 152b into the binding station 144. Also, as shown in Figs. 4 to 6, the reinforcement binding machine 100 comprises a twisting mechanism 172 for twisting the steel wire 106 fed into the binding station 144. The twisting mechanism 172 is provided with a rotary shaft 174 rotatably extending back and forth through the clutch 142 and the frame 110. The rotary shaft 174 is coupled with the clutch 142 by a key (not shown) and rotated about the axis of the rotary shaft 174 by receiving the turning force of the rotary source 120 through the clutch 142. As shown in Fig. 7, the rotary shaft 174 has a groove 144a for receiving said key for coupling the rotary shaft 174 with the clutch 142. The rotary shaft 174 is provided with a bifurcated head 176 at an end of the side of the binding station 144. As shown in Fig. 7, the head 176 has a base 176a provided fixedly on an end of the rotary shaft 174 and a pair of branches 176b extending from the base 176a parallel to the axis of the rotary shaft 174, the base 176a and branches 176b defining a U-shaped slot 78. As shown in Figs. 7 and 8, the base 176a and branches 176b have a circular section having the identical diameter dimension. Portions of the branches 176 opposed to each other through the slot 178 are formed with holes 180 extending from the slot 178 through an outer periphery. The head 176 is formed on the outer peripheral surface with a groove 182 extending axially of the rotary shaft 174 through the holes 180. In the respective holes 180 of the head 176 are disposed pins 184 movably toward and away from each other. Each of said pins 184 (Fig. 9 shows one of them) has a conical front end 184a and a semispherical rear end 184b. The front ends 184a are disposed opposed to each other in the holes 180. As will be later described, the front end 184a may have other shapes to gradually reduce the diameter dimension toward the front end such as U-shape, V-shape, semicircular sectional shape, conical shape and semispherical shape for example so long as force for separating the pins 184 from the opponent one when twisting the steel wire 106 acts on the pins 184 through the steel wire 106. The respective pins 184 are butted against each other by an urging means including a receiving seat 186 disposed on the rotary shaft 174, a slider 188 supported on the shaft 174 movably in the axial direction of the rotary shaft 174, a compression coil spring 190 disposed between the receiving seat 186 and the slider 188 and a nut 192 screwed onto the rotary shaft 174. As shown in Fig. 10, the slider 188 is provided with a ring 188a fitted slidably on an end of the rotary shaft 174 and a pair of urging pieces 188b extending parallel to the axis of the ring 188a from the ring and received slidably in the groove 182 of the head 176. The inner end surface of the urging piece 188b is a tapered surface 188c, in which force for butting the pins 184 against each other is applied to the pins 184. The urging force of a spring 190 can be set to any value by adjusting the position of the nut 192 on the rotary shaft 174 and an interval between the receiving seat 186 and the slider 188. As the urging means for butting the pins 184 against each other, as shown in Fig. 15, for example, may be used other means such as a leaf spring 242 disposed in the groove 182 of the head 176 and fixed to the head 176 by a screw 240. As shown in Figs. 1 and 4, a pair of guides 194,196 for defining the binding station 144 are disposed on an end of the support wall 16. The respective guides 194,196 have arcuate phase opposed to each other. The respective guides 194,196 are formed on said arcuate phase with steel wire guide paths 198,200 for guiding the steel wire 106 fed into the binding station 144 through an inner portion deeper than a pin 184 in the slot 178 of the twisting mechanism 172 along a curve encircling the reinforcements 102,104. The steel wire guide paths 198,200 are grooves which open to the side of said arcuate phase, i.e., the side of the binding station 144. The guide 194 is fixed to the support wall on the rear end and formed on the rear end edge with a steel wire feeding path 202 for guiding the steel wire 106 fed into the binding portion 144 toward an inner portion deeper than the pin 184 in the slot 178 of the twisting mechanism 172. The steel wire feeding path 202 in the embodiment shown is a hole extending from the side of the rollers 148, 150 through the binding station 144, while it may be a groove which opens backward. The end face of the neighborhood of the steel wire outlet from the steel wire feeding path 202 of the guide 194 to the binding station 144 is adapted to have a curved surface with the approximately same curvature as the outer peripheral surface of the head 176 of the twisting mechanism 172. The other guide 196, as shown in Fig. 14, is supported by a support wall 116 in such a manner that the guide 194 can be angularly rotated about the pin 204 provided on one end of the guide 196 thereby other end of the guide 196 is approached and separated from the end of the guide 194. The guide 196 is normally urged by a spring 206 shown in Fig. 1 in the direction of coming the end into contact with an end of the pin 184. As shown in Figs. 1 and 2, the opposed end faces of the guides 194,196 are inclined to define a V-shaped space 208 opening forward with the opposed end surfaces when both ends come into contact with each other. Further, as shown in Figs. 1, 6 and 11, the reinforcement binding machine 100 comprises a positoning mechanism 210 for determining the relative positional relationship between the reinforcements 102,104 and the reinforcement binding machine 100 when binding. In the embodiment shown, as shown in Fig., 6, the positioning mechanism 210 is provided with rods 212 disposed symmetrically about the rotary shaft 174 and Y-shaped positioning members 214 fixed to the ends of the rods respectively. Each of the rods 212 extends parallel to the rotary shaft 174 and is supported on frame 110 to be slided back and forth by a rod guide 216 mounted on the frame 110. The positioning members 214 are positioned symmetrically about the binding station 144 and mounted on the rods 212 in such an orientation that steel wire receiving portions 214a of the positioning members 214 are aligned with each other and the binding station 144. The rear ends of the rods 212 are interconnected by a connecting piece 220 of an aligning mechanism 218 for aligning the steel wire inlet of the slot 178 with the steel wire outlet of the steel wire feeding path 202 in the stoppage of the twisting mechanism 172. The aligning mechanism 218, as shown in Fig. 11, comprises a spring 222 disposed on the end of the rod 212 to urge forward the rod 122 and a dog clutch 224 in addition to the connecting piece 220. The dog clutch 224 is provided with a flange 224a fixed to the rear end of the rotary shaft 174 and a flange 224b fixed to a portion opposed to a flange 134a of the connecting piece 130. The dog clutch 224 is a so-called torsional clutch having two saw-tooth-like teeth with inclined surfaces on the respective flanges 224a,224b which are provided with said teeth opposed to each other. The dog clutches 224 are normally coupled with each other when the rods 212 are normally urged forward by springs 222. However, the dog clutches 224 can be disengaged from each other by holding the reinforcement binding machine 100 with hands to apply the positioning member 214 to the reinforcements 102,104 to be bound while urging the reinforcement binding machine 100 against the reinforcements 102,104 to retreat the rod 212 against the force of the spring 222. Further, as shown in Figs. 6 and 12, the reinforcement binding machine 100 has an orientation maintaining mechanism 226 for maintaining an orientation of the twisting mechanism 172 at the orientation where the steel wire inlet of the slot 178 is aligned with the steel wire outlet of the steel wire feeding path 202, even if the dog clutch 224 is disengaged in the stationary state of the twisting mechanism 172. The orientation maintaining mechanism 226 is a low torque slip mechanism provided with a disk 218 fixed to the rear end of the rotary shaft 174 and stoppers 230 disposed so as to be capable of being in and out from V-­ shaped notches formed at two symmetric positions on an outer periphery of the disk. The stopper 230 in the embodiment shown is a ball disposed in a hole provided in a plate 232 fixed to the rear wall of the frame 110, said stopper 230 being pressed toward the disk 228 by a spring 234 disposed in the hole of the plate 232. The disk 228 is fixed to the rotary shaft 174 by a key so as to receive the stopper 230 in the notch when the twisting mechanism 172 has an orientation in which the steel wire is received in the slot 178, ii.e., when the slot 178 is aligned with the steel wire outlet of the steel wire feeding path 202. When the stopper 230 is pushed into the notch of the disk 228, the teeth of the dog clutch 224 mesh with each other. On the cover 116 are mounted the rotary source 120, clutches 128,142 and a switch 236 for controlling the brake 130. The switch 236 is mounted at the portion opposed to the dog clutch 224. The switch 236 applies the positioning member 214 to the reinforcements 102,104 to be bound, pushes the binding machine 100 toward the reinforcements 102,104 to retreat the rod 212 and is closed by the dog clutch 224 when the reinforcements 102,104 reach predetermined position in the binding station 144. As shown in Figs. 4 and 13, the guide 196 is provided with an auxiliary guide 238 for preventing the steel wire fed through the slot 178 of the twisting mechanism 172 into the guide 196 from getting out of the steel wire guiding path 200. As shown in Fig. 13, the auxiliary guide 238 has the orientation in which the steel wire guide path 200 opens in front of the rotational direction of the steel wire rotated by the twisting mechanism 172 in the steel wire guide paths 200,198 when the steel wire is twisted. Thus, when the steel wire in the steel wire guide path 200 is rotated about the rotary axis of the twisting mechanism 172 therewith, the steel wire gets out of the steel wire guide path 200. The auxiliary guide 238 in the embodiment shown is provided in the steel wire inlet of the guide 196, while it may be provided throughout the inside of the guide 196. In stand-by, the dog clutch 224 is engaged since the rod 212 is pushed forward by the spring 222. Thus, on the flange 224a of the dog clutch 224 acts force for turning the rotary shaft 174 in the direction opposite to the rotational direction in the twisting through the flange 224b. However, since the stopper 230 of the orientation maintaining mechanism 226 engages the recess of the disk 228, the twisting mechanism 172 is maintained at the orientation in which the slot 178 is aligned with the steel wire outlet of the steel wire feeding path 202. Thus, when binding the reinforcements, the slot 178 does not need to be aligned with the steel wire outlet of the steel wire feeding path 202 and the steel wire inlet of the steel wire guide path 200 of the guide 196. At the time of binding, the reinforcement binding machine 100 makes the direction of arranging the ends of guides 194,196 and the positioning member 214 coincide with the direction of the reinforcement 102 and is urged against the reinforcements 102,104 at the orientation in which the surface defining the V-shaped space 208 between the guides 194,196 is applied to the reinforcements 102,104. Thus, since force for separating the end of the guide 196 from the end of the guide 194 acts on the end of the guide 196, the guide 196, as shown in Fig. 14, is adapted to expand the space between the respective ends of the guides 194,196 by the reinforcements 102,104 against the spring 206 while being angularly rotated to receive the reinforcements 102,104 in the binding station 144. The reinforcements 102,104 entering the binding station 144 are received by the positioning member 214. Thus, since the position of the reinforcements 102,104 in the binding portion 144 is determined, the operation for relatively positioning the reinforcements 102,104 and the reinforcement binding machine 100 is not needed. When the reinforcements 102,104 are received in the binding station 144, the guide 196 is returned to the original condition by the spring 206. When the reinforcement binding machine 100 is further pushed, the positioning member 214 is pushed by the reinforcements 102,104 so that the rod 212 is retreated against the force of the spring 222. When the reinforcements 102,104 reach a predetermined position in the binding station 144, the switch 236 is closed by the dog clutch 224. Therefore, since the rotary source 120 and the clutch 128 are first operated, the steel wire 106 is fed through the steel wire feeding path 202 to the binding station 144 by the steel wire feeding mechanism 146. At this time, the dog clutch 224 is disengaged, while the twisting mechanism 172 is maintained by the orientation maintaining mechanism 226 at the orientation in which the slot 178 is aligned with the steel wire outlet of the steel wire feeding path 202. The end of the steel wire fed to the binding station 144 reaches the steel wire guide path 200 of the guide 196 through the inner portion deeper than the pin 184 in the slot 178. When the steel wire 106 is further fed out, the end of the steel wire advances while contacting the bottom surface of the steel wire guide path 200. The other fed portion of the steel wire, however, tends to get out of the steel wire guide path 200 due to the rigidity of the steel wire itself. However, since the auxiliary guide 238 is provided in the steel wire inlet of the guide 196, the fed-out steel wire does not get out of the steel wire guide path 200 and is bent at the auxiliary guide 238 along the steel wire guide path 200. Thus, the end of the fed steel wire advances in the steel wire guide paths 200,198, reaches again the steel wire guide path 200 of the guide 196 through the inner portion deeper than the pin 184 in the slot 178 and is wound around the reinforcements 102,104 in the form of a loop by a plurality of turns, for example, 2 to 5 turns. Thus, the pin 184 is located inside the loop formed of the fed steel wire. When the steel wire 106 is fed by a predetermined amount, the clutch 128 is disengaged, the brake 130 is operated and the feeding of the steel wire 106 is stopped. Instead, the clutch 142 is operated to rotate the twisting mechanism 172. Therefore, the steel wire fed to the binding portion 144 and wound around the reinforcements 102,104 is cut off by the cooperation of the steel wire receiving portion of the head 176 and the steel wire outlet of the steel wire feeding path 202 of the guide 194 at the time of beginning of the rotation of the rotary shaft 174 and the head 176, thereby being twisted by the rotation of the pin 184. In this way, since the steel wire receiving portion of the head 176 and the steel wire outlet of the steel wire feeding path 202 of the guide 194 are constructed to cut off the steel wire, a cutter for cutting and a mechanism for driving the cutter are dispensed with. As a result, the construction of the machine is simplified and economized. Since the steel wire is twisted while contacting the end 184a of the pin 184, the pins 184 are subjected to force for separating the pins 184 from each other by a reaction of twisting. Thus the steel wire is twisted to predetermined strength. When said force exceeds the force of the spring 190, the twisted steel wire gets out of the pin 184. Therefore, the steel wire can be twisted to certain strength at all times. The torsional strength of the steel wire may be set to any desired value by adjusting the positions of the nut 192 on the rotary shaft 174 and the receiving seat 186 to adjust the force of the spring 190. Thereafter, when the reinforcement binding machine 100 is retreated, since the rod 202 and the dog clutch 224 are advanced by the spring 222, the switch 236 is opened to stop the rotary source 120 and release the clutch 142. The bound reinforcements 102,104 can be removed from the binding station 144 by further retreating the reinforcement binding machine 100 to expand the space between the ends of the guides 194,196 by the reinforcements 102,104. When the dog clutch 224 is again engaged, force due to the force of the spring 222 applied to the contact surface of the flanges 224a,224b acts on the rotary shaft 174 in the direction opposite to the rotational direction in twisting. Thereby, the rotary shaft 174 is rotated until the stopper 230 of the orientation maintaining mechanism 226 engages the recess in the disk 228. The twisting mechanism 172 is maintained at the orientation in which the slot 178 is aligned with the steel wire outlet of the steel wire feeding path 202. Next will be described a reinforcement binding machine 250 shown in Figs. 16 and 17. Further, the same members as those of the reinforcement binding machine 100 shown in Figs. 1 to 14 will be designated by the same symbols and the description of the operation will be omitted. The reinforcement binding machine 250 also comprises a main body 252 having a handle portion 118, a steel wire feeding mechanism 254, a pair of guides 256,258 for defining the binding station 144, a twisting mechanism 260 for twisting the steel wire fed in the binding station 144, a rotary mechanism including the rotary source 120 for rotating the steel wire feeding mechanism 254 and the twisting mechanism 260, a positoning mechanism 262 for positioning the reinforcements 102,104 in the binding station 144, an aligning mechanism 264 for the twisting mechanism 260 and an auxiliary guide 268 provided on an orientation maintaining mechanism 266 and the guide 258. The main body 252, twisting mechanism 260, rotary mechanism, orientation maintaining mechanism 266 and auxiliary guide 268 are constituted from the same members as those of the corresponding mechanisms of said reinforcement binding machine 100 and operated in the same way as said mechanisms. The steel wire feeding mechanism 254 is constituted from the same members as the steel wire feeding mechanism 146 of the reinforcement binding machine 100 and operated in the same way as said mechanism 146, while it is arranged upside down, compared with the steel wire feeding mechanism 146 of the reinforcement binding machine 100 to feed the steel wire 106 slantly from below to above. A pair of guides 256,258 are supported by the support wall 114 to be rotated angularly for moving the ends to and away from each other and the ends are urged by the spring 270 to contact each other. The positioning mechanism 262 is provided with a pair of M-shaped bent positioning members 272 which are fixed to the support wall 114 by bolts and nuts in such an orientation that V-shaped reinforcement receiving portions 272a are aligned with each other and the binding station 144. The aligning mechanism 264 is provided with a connecting piece 274, a spring 276, a dog clutch 278 and a solenoid mechanism 280 for disengaging the dog clutch against the force of the spring 276. The spring 276 is arranged around a shaft 284 fixed to the connecting piece 274 and a plate 282 parallel to the connecting piece. The solenoid 280 is fixed to the plate 284. The steel wire feeding path 286 for guiding the steel wire 106 fed from the steel wire feeding mechanism 254 to the binding station 144 is formed into a feed guide 288 fixed to the support wall 114. The end face of the feed guide 288 at the side of the binding station 144 is curved to have the same radius of curvature as the head of the twisting mechanism 260 to closely contact said head and cut off the steel wire. In the reinforcement binding machine 250, the dog clutch 278 is urged forward and engaged by the spring 276 in stand-by. Since the stopper of the orientation maintaining mechanism 266 engages the recess on the disk, the twisting mechanism 260 is maintained at the orientation in which the slot of the twisting mechanism 260 is aligned with the steel wire outlet of the steel wire feeding path 286. At the time of binding, the reinforcement binding machine 250 makes the direction of arranging the ends of the guides 256,258 and the positioning member 272 coincide with the direction of the reinforcement 102 and is urged toward the reinforcements 102,104 at the orientation in which the surfaces of the guides 256,258 defining the V-shaped space 208 are applied to the reinforcements 102,104. Thus, the guides 256,258 are angularly rotated in the direction of separating the ends from each other to receive the reinforcements 102,104 in the binding station 144. Under such a condition, a switch (not shown) is manually closed, the rotary source 120 and clutch 128 are operated and the steel wire 106 is fed through the steel wire feeding path 286 to the binding station 144 by the steel wire feeding mechanism 254. The steel wire fed to the binding station 144 reaches the steel wire guide path 200 of the guide 256 through the inner portion deeper than the pin 184 in the slot 178 of the twisting mechanism 260. When the steel wire 106 is further fed out, the fed steel wire is bent along the steel wire guide path 200 at the auxiliary guide 268 while advancing in the steel wire guide paths 200,198, and wound around the reinfocements 102,104 in the form of a loop by a predetermined number of turns again through the passage from the inner portion deeper than the pin 184 in the slot of the twisting mechanism 260 to the steel wire guide path 200 of the guide 258. Thus, the pin 184 is located inside the loop formed of the fed steel wire. When a predetermined amount of the steel wire 106 is fed out, the clutch 128 is disengaged, the brake 130 is operated to stop the feeding of the steel wire 106. Instead, the dog clutch 278 is first disengaged by energizing the solenoid 280 and then the twisting mechanism 260 is rotated by operating the clutch 142. In this case, the steel wire wound around the reinforcements 102,104 is cut off by the steel wire inlet of the head of the twisting mechanism 260 and the steel wire outlet of the steel wire feeding path 286 of the feeding guide 288 at the time of beginning of the rotation of said head and the rotary shaft of the twisting mechanism 260, thereby being twisted by the rotation of the pin 184. When the steel wire is twisted, it is twisted while contacting the end of the pin 184 and the force of separating the pins 184 from each other acts on each pin 184 through a reaction in twisting. Therefore, when the steel wire is twisted to predetermined strength and said force exceeds the force of the spring 190, the twisted steel wire gets out of the pin 184. Hence, the switch is manually opened, the rotary source 120 is stopped, the solenoid 280 is deenergized and the dog clutch is again engaged. When the dog clutch 278 is again engaged, since the force in the direction opposite to the rotational direction in twisting acts on the rotary shaft 174, of the twisting mechanism 260, the rotary shaft 174 is rotated until the stopper of the orientation maintaining mechanism 266 engages the recess on the disk, and the twisting mechanism 260 is maintained at the orientation in which the recess is aligned with the steel wire outlet of the steel wire feeding path 286. Thereafter, the reinforcement binding machine 250 is retreated from the reinforcements 102,104 and can be removed from the binding slot 144 by expanding the space between the ends of the guides 256,258 with the reinforcements 102,104.

Claims: 1. A reinforcement binding machine (100,250) using a steel wire comprising: a means (146) for feeding said steel wire (106) into a binding station (144) for binding reinforcements (102,104); a guide means (194,196) provided with a guide path (198,200) for guiding said steel wire (106) fed into said binding station (144) along a curve encircling said reinforcements (102,104), and defining said binding station (144); a means (172) for twisting said steel wire (106) looped by said guide path (198,200) and defining a slot, through which said steel wire (106) fed in said binding station (104) is capable of passing; and a means (120,142) for rotating said twisting means (172) about the axis crossing the axis of the loop formed of said steel wire (106) such as to twist said steel wire (106); said twisting means (172) being provided with a pair of pins (184) opposed to each other through said slot (178) to be moved relatively in the axial direction of said loop and a means (186,188,190,240,242) for normally urging at least one of said pins (184) such that the end faces (184) of the pins are butted against each other in said binding station (144). 2. A reinforcement binding machine as claimed in claim 1, wherein said twisting means (172) is further provided with a rotor (174,176) having said slot (178) and said pins (184) are supported at a portion opposed to each other through said slot (178) of said rotor (174,176) to move to and away from each other. 3. A reinforcement binding machine as claimed in claim 2, wherein said rotor is provided with a rotary shaft (174) extending in the direction orthogonal to the moving direction of said pin (184) and a head (176) provided fixedly to the end of the rotary shaft (174) at the side of said binding station (144) and defining said slot (178). 4. A reinforcement binding machine as claimed in claim 3, wherein said urging means comprises a receiving ring (186) fixed to said rotory shaft (174), a slider (188) supported around said rotory shaft (174) movably in the direction of the rotary axis of the rotory shaft (174) and having an end contacting said pin (184) to move said pins (184) to each other and a spring (190) disposed between said slider (188) and said receiving ring (186) and urging said slider (188) in the direction along said rotary axis to move said pins (184) to each other. 5. A reinforcement binding machine as claimed in claims 3, wherein said urging means is provided with a pair of leaf springs (242) supported by said rotory shaft (174) and contacting the opposite side end face to the opposed end faces of said pins (184) to urge said pins (184) to move to each other. 6. A reinforcement binding machine as claimed in claim 1, wherein the end face (184a) of at leat one of said pins (184) butted against that of said other pin has a shape so as to produce force of separating said both pins (184) from each other in twisting said steel wire (106). 7. A reinforcement binding machine as claimed in claim 1, wherein it further comprises a main body (108,252) having a handle portion (118) and supporting said feeding means (146), said guide means (194,196), said twisting means and said rotating means (120,142), and the end face of at least one of said pins (184) butting against said other pin having a shape so as to produce force of separating both said pins (184) from each other in twisting said steel wire (106). 8. A reinforcement binding machine as claimed in claim 7, wherein it further comprises a means (210,262) for positioning said reinforcements (102,104) in said binding station (144). 9. A reinforcement binding machine as claimed in claim 8, wherein said positioning means (210,262) is provided with a pair of Y-shaped or M-shaped members (214,272) disposed symmetrically about said binding station (144). 10. A reinforcement binding machine (100,250) using a steel wire (106) comprising: a means (146) for feeding said steel wire (106) along a wire feeding path (202) extending toward a binding station (144) for binding reinforcements (102,104); a guide means (194,196) provided with a guide path (198,200) for guiding said steel wire (106) fed into said binding station (144) along a curve encircling said reinforcements (102,104) and defining said binding station (144); a means (172) for twisting said steel wire (106) looped by said guide path (198,200) and defining a slot (178) through which said steel wire (106) fed into said binding station (144) is capable of passing; and a means (120,142) for rotating said twisting means (172) about the axis crossing the axis of the loop formed of said steel wire (106) to twist said steel wire (106); a portion of said twisting means (172) for defining a spot, through which said steel wire (106) is received in said slot (178), contacting closely a wire outlet of a member for defining said wire feeding path (202) to provide a cutter portion for cutting off said steel wire (106) in cooperation with said wire outlet in rotating said twisting means (172). 11. A reinforcement binding machine (100,250) using a steel wire (106) comprising: a means (146) for feeding said steel wire (106) along a wire feeding path (202) extending toward a binding station (144) for binding inforcements (102,104); a guide means (194,196) provided with a guide path (198,200) for guiding the steel wire (106) fed into said binding station (144) along a curve encircling said reinforcements (102,104) and defining said binding station (144); a means (172) for twisting said steel wire (106) looped by said guide path (198,200) and defining a slot, through which said steel wire fed into said binding station (144) is capable of passing; and a means (120,142) for rotating said twisting means (172) about the axis corssing the axis of the loop formed of said steel wire (106) to twist said steel wire; and a means (218,264) for aligning said slot (178) with a wire outlet of a member for defining said wire feeding path (202) such as to receive said steel wire (106) in said slot (178) by angularly rotating said twisting means in non-rotation of said twisting means (172). 12. A reinforcement binding machine as claimed in claim 11, wherein said aligning means (218) is provided with a movable body (212,220) slidable in the direction of the rotary axis of said twisting means (172), a dog clutch (224) having a first tooth and a second tooth (224a224b), the axis of the dog clutch (224) coinciding with the rotary axis of said twisting means (172), said first tooth (224a) being fixed to said twisting means (172), said second tooth (224b) being fixed to said movable body (220), a spring (222) for urging said dog clutch (224) and said movable body (220) in the direction of coupling the dog clutch (224) and a positioning member (214) fixed to said movable body (212,220) and pressed against at least one of said reinforcements when binding said reinfocements (102,104) to move said movable body (212,220) in the direction of disengaging said dog clutch (224). 13. A reinforcement binding machine as claimed in claim 11, wherein said aligning means (264) is provided with a movable body (224) slidable in the direction of the rotary axis of said twisting means (172), a dog clutch (278) having a first tooth and a second tooth, the axis of the dog clutch (278) coinciding with the rotary axis of said twisting means (172), said first tooth being fixed to said twisting means (172), said second tooth being fixed to said movable body (272) and a solenoid mechanism (280) for coupling and disengaging said dog clutch (278). 14. A reinforcement binding machine as claimed in claim 11, wherein it further comprises a means (226,266) for maintaining said twisting means (172) at an orientation in which said slot is aligned with said wire outlet in non-rotation of said twisting means (172). 15. A reinforcement binding machine as claimed in claim 14, wherein said orientation maintaining means (226,266) is provided with a disk (228) fixed to said twisting means (172) coaxially with the rotary axis of the twisting means (172) and having a recess on an outer peripheral edge, a stopper (230) disposed in said recess so as to be partially in and out from the recess and a spring (234) for urging the stopper (230) toward said recess. 16. A reinforcement binding machine (100,250) using a steel wire comprising: a means (146) for feeding said steel wire (106) along a wire feeding path (202) extending toward a binding station (144) for binding reinforcements (102,104); a guide means (194,196) provided with a guide path (198,200) for guiding the steel wire (106) fed in said binding station (144) along a curve encircling said reinforcements (102,104) and defining said binding station (144); a means (172) for twisting said steel wire (106) looped by said guide path (198,200) and defining a slot (178), through which said steel wire (106) fed in said binding station (144) is capable of passing; and a means (120,142) for rotating said twisting means (172) about the axis crossing the axis of the loop formed of said steel wire (106), to twist said steel wire; said guide means (194,196) being provided with a pair of first guides (194,196) having arcuate phase and said guide path (198,200) along said phase at a side of said slot (178) to guide said steel wire (106) fed in said binding station (144) along said curve and disposed relatively movably to move the opposed phase to and away from each other with reference to the rotary axis of said twisting means (172) and a second guide (238) disposed in the neighborhood of a portion of said first guide (194,196) for receiving said steel wire (106) from at least said wire feeding path (202) end preventing said steel wire (106) fed in said guide path (198,200) from getting out of said guide path (198,200). 17. A reinforcement binding machine as claimed in claim 16, wherein said guide path (198,200) opens to said phase side of said first guide (194,196). 18. A reinforcement binding machine as claimed in claim 16, wherein said second guide (238) is provided fixedly in the proximity of the wire inlet of said first guide (194,196). 19. A reinforcement binding machine as claimed in claimi 16, wherein said second guide (238) is disposed to be capable of approaching or retreating from the proximity of the wire inlet of said first guide. 20. A reinforcement binding machine (100,250) with a steel wire (106) comprising: a means (146) for feeding said steel wire (106) along a wire feeding path (202) extending toward a binding station (144) for binding reinforcements; a guide means (194,196) provided with a guide path (198,200) for guiding said steel wire (106) fed into said binding station (144) along a curve encircling said reinforcements (102,104) and defining said binding station (144); a means (172) for twisting said steel wire (106) looped by said guide means (194,196)and defining a slot (178), through which said steel wire (106) fed into said binding station (144) is capable of passing; and a means (120,142) for rotating said twisting means (172) about the axis crossing the axis of the loop formed of said steel wire (106) to twist said steel wire; and a means (218,264) for aligning said slot (178) with a wire outlet of a member for defining said wire feeding path (202) such as to receive said steel wire (106) in said slot (178) by rotating angularly said twisting means (172) in non-rotation of said twisting means (172); said twisting means (172) being provided with a pair of pins (184) opposed to each other through said slot (178) and disposed to move relatively in the axial direction of said loop and a means (186,188,190,240,242) for normally urging at least one of said pins (184) such that the end faces of the pins are butted against to each other in said binding station (144); a portion of said twisting means (172) for defining a portion of said slot (178) to receive said steel wire (106) contacting closely a wire outlet of a member for defining said wire feeding path (202) to provide a cutter portion for cutting off said steel wire in cooperation with said wire outlet in the rotation of said twisting means (172); said guide means (194,196) being provided with a pair of first guides (194,196) having arcuate phase and said guide path (198,200) along said phase at said phase side such as to guide said steel wire (106) fed into said binding station (144) along said curve and disposed relatively movably to move the opposed phase to and away from each other with reference to the rotary axis of said twisting means (172) and a second guide (238) disposed in the neighborhood of a portion for receiving said steel wire (106) from at least said wire feeding path (202) of said first guide (194,196) and preventing said steel wire (106) fed into said guide path (198,200) from getting out of said guide path (198,200).

Inventors: MUGUMURA, HIROSHI, SAWANO, TAKAYASU, TOYODA, HIROSHI
Applicants: KABUSHIKI KAISHA TOYODA KIHAN
Application year: 1987
Main classification: E04G21
IPC codes: B21F27, B21F15, E04G21, B21F31