US 3916662 A
Apparatus for straightening and cutting bar stock to form substantially straight reinforcing bars of selected length, and for stacking selected numbers of the cut reinforcing bars for ready removal from the apparatus.
Description (OCR text may contain errors)
Kite @tates mold 1 Nov. 4, 1975 1 APPARATUS'FOR SGHTENING AND CUTTING REKNFORCING BAR 1 1 Referemes Cited 75 Inventor: William T. Arnold, Welland, UNITED STATES PATENTS Canada 1,911,150 5/1933 Hallden 83/293 1,954,525 4/1934 Hallden 72/129 [731 Asslgnee: W l and Metal P Y 2,350,975 6/1944 Rodder 83/293 Limited, Welland, Canada 3,757,552 9/1973 Ritter 7. 72/12  Filed: Aug. 6, 1973 Primary Examzner-Lowell A. Larson 1 1 pp 86,185 Assistant Examiner-Robert M. Rogers Attorney, Agent, or FirmRogers, Bereskin & Parr  Foreign Application Priority Data ABSTRACT Nov. 14, 1972 Canada 156430 Apparatus for straightening and cutting bar stock to 52 Us. CL 72 72 8 2 3 form substantially straight reinforcing bars of selected Int 2 length, and for stacking selected numbers of the cut  Field at 29 132 17 reinforcing bars for ready removal from the apparatus.
9 Claims, 15 Drawing Figures US. Patent N0v.4,1975 Sheet10f9 3,916,662
US. Patent Nov. 4, 1975 Sheet 2 of9 3,916,662
i t Nov. 4, 1975 Sheet 3 0f 9 US. Patent Nov. 4, 1975 Sheet 4 of9 3,916,662
US. atei NOV. 4, 1975 Sheet5of9 391,2
US. atent Nov. 4, 1975 Sheet 6 of9 3,916,662
Sheet 7 of 9 atent Nov. 4, 1975 Sheet 8 of 9 "US, Patent Nov. 4, 1975 Sheet 9 of9 3,916,662
APPARATUS FOR STRAIGHTENING AND CUTTING REINFORCING BAR This invention relates to apparatus for straightening and cutting bar stock to form substantially straight reinforcing bars of selected length, and for stacking selected numbers of the cut reinforcing bars for ready removal from the apparatus.
Smaller sections of reinforcing bars are supplied from steel rolling mills in coils for ease of storage. Subsequently, each coil must be straightened and cut into lengths suitable for use in building structures. The coils are formed while the reinforcing bar is hot and consequently when the coils cool, each coil tends to remain in the cooled position due to a stress memory caused by cooling. If an attempt is made to straighten the coil this memory must be destroyed uniformly over the length of the reinforcing bar. If the memory is retained anywhere over the length of the bar then the bar will not be straight.
One of the more common straightening methods includes passing the bar through a rotating tube which effectively hammers bends in the reinforcing bar to straighten the bar. Although this method has proved to be reasonably acceptable for some reinforcing bars, the method nevertheless suffers from the disadvantages that the memory is not destroyed completely and that the tube creates a twist in the reinforcing bar. In extreme cases these disadvantages combine to create a spiral effect in the reinforcing bar.
It is an object of the present invention to provide apparatus for receiving coiled reinforcing bar and for straightening the reinforcing bar before cutting the straightened reinforcing bar into selected lengths and numbers of lengths.
The invention will be better understood with reference to the drawings, in which:
FIG. 1 is a perspective view of a straightening and cutting stations of the apparatus according to the invention;
FIG. 2 is a perspective view ofa coil storage creel and is a continuation of the right hand end of FIG. 1;
FIG. 3.is a perspective view of a handling station which receives lengths of reinforcing bar from the cutting station and which is a continuation of the left hand end of FIG. 1;
FIG. 4 is a rear view of the straightening and cutting stations showing a drive to the stations;
FIG. 5 is a sectional end view on line 5-5 of FIG. 4;
FIG. 6 is a partially diagrammatic top view ofa length measuring mechanism associated with the cutting station;
FIG. 7 is a perspective view of part of the measuring mechanism;
FIG. 8 is a sectional end view on line 8-8 of FIG. 1; FIG. 9 is a sectional front view on line 9-9 of FIG.
FIG. 10 is a sectional front view on line l0l0 of FIG. 8;
FIG. 11 is a front view on line 11-11 of FIG. 8;
FIG. 12 is a perspective view of an indexing mechanism associated with the handling station and positioned adjacent the cutting station;
FIG. 13 is a view similar to FIG. 12 illustrating the operation of the indexing mechanism;
FIG. 14 is a sectional end view on line l4l4 of FIG. 13; and
FIG. 15 is a view similar to FIG. 2 and illustrates the storage creel in position for receiving a further coil of reinforcing bar.
The extent of the apparatus is seen with reference to FIGS. 1, 2 and 3 which together show the apparatus in perspective. Structural parts of the apparatus will be described with reference to their function, and then the operation of the apparatus will be described. To this end reference is'made initially to FIG. 1 to describe some of the more important features of the invention. Reinforcing bar 20 is driven through a straightening station 22 which both straightens the bar and feeds it towards a cutting station 24. Before entering the cutting station 24 the bar drives a slave wheel 26 forming part ofa length measuring mechanism 28 for operating synchronized cutters 30, 32 to cut the bar into selected lengths and to cut selected numbers of reinforcing bars.
The straightening station 22 is coupled by a chain 34 to a primary transmission 36 having an output shaft 38. As seen in FIG. 2, the output shaft 38 is coupled to a secondary transmission 40 to drive a creel 42 carrying coiled reinforcing bar 20. As will be described, reinforcing bar 20 is driven off the creel at a speed which matches the requirements of the straightening station 22.
Full details of the creel 42 will be described subsequently with reference to FIGS. 2 and 15. At this point it is sufficient to state that the creel is continuously adjustable vertically so that the reinforcing bar 20 is drawn off the creel at a substantially constant level as the height of coil on the creel is reduced. Such an arrangement ensures that as the coil leaves the creel, the bend in the bar caused by the cooling memory remains in a plane containing the centre of curvature of the bend. This ensures that the memory acts horizontally and not at an angle to the horizontal. The importance of this relationship will become apparent after further description of the straightening station 22.
A furtherimportant consideration is that the creel be positioned to the front and side of the straightening station 22 to limit the stresses applied to the coil as it passes between the creel 42 and the station 22. If this relationship is not correct, there is a possibility that the bar will be stressed beyond the elastic limit at locations along the bar causing kinks in the bar prior to straightening.
Returning to the cutting station 24 shown in FIG. 1, reinforcing bar 20 which has been cut into lengths is fed from the cutting station 24 into a handling station 44 which changes the end-to-end arrangement of the bars leaving the cutting station into side-by-side relationship. This station includes an indexing mechanism 46 for receiving cut reinforcing bars and for grouping the bars into bundles in the handling station 44.
Having introduced the main elements generally, the apparatus will now be described starting at the creel 42 (FIG. 2) and ending in the handling station 44.
As seen in FIG. 2, the creel 42 carries coils of reinforcing bar which are progressively removed from the creel for straightening. As is common in the art, the coils are substantially all of the same diameter so that the creel 42 is driven at a speed which is linked in a constant ratio relative to the drive within the straightening station.
As seen in FIG. 1, the reinforcing bar 20 is received from the creel 42 by the straightening station 22. This station includes a primary straightener S4 and a secondary straightener 56. The primary straightener 54 is pivotally attached to the secondary straightener 56 for movement about a vertical axis defined by pivots 58 (one of which is shown). Primary straightener 54 includes a platform 60 on which a pair of rollers 62 are rotatably mounted in fixed relation thereto. Rollers 62 rotate about respective vertical axes for combining with three rollers 64 which are located relative to the platform 60 by an adjusting mechanism 66. As can be seen from the drawing, rollers 64 are mounted on slider assemblies which are linked to a pivoted arm 68. The arm 68 is biased towards the rollers 62 by an adjusting screw 70 so that the location of the rollers 64 relative to the rollers 62 can be adjusted about the pivot point of arm 68. Also, adjustment screw 72 is provided for rotating the primary straightener 54 about the pivots 58. These adjustments are used to locate the primary straightener so that the bar runs smoothly into the first of the grooved rollers 62, 64 to locate the bar before being bent successively about the other rollers 62, 64. The first bend is about the second of rollers 64 and is against the memory. The number of rollers 62, 64 can be increased if preferred.
Turning now to the secondary straightener 56, first or lower rollers 74 are independently mounted for rotation about respective horizontal axes in sliders 76, some of which are omitted for clarity. The sliders 76 are attached to a heavy upright structural element 78 and are located vertically by a screw and lock nut arrangement 80 which passes through a rib 82 attached to the element 78. This mounting arrangement of the lower rollers 74 is to permit aligning the rollers with a common tangent at the points of contact with the bar 20. Once alignment is completed these rollers would not be adjusted further. The reasons for this alignment requirement will become evident when describing the preparation of the apparatus for use.
Rollers 74 are relatively close together at the right hand or entry end of the straightening station 22 and, progressing towards the left of the station, the rollers are gradually separated further and further until the rollers at the exit end are spaced relatively far apart. A similar spacing is provided for second or upper rollers 84 with each one of the rollers 84 being positioned substantially midway between a corresponding pair of lower rollers.
Upper rollers 84 are mounted on movable parts of sliders 86 coupled to the element 78 for adjustment to permit aligning these rollers with a common tangent at the points of contact with the bar 20. However, each of the slider movable parts is coupled by an adjusting screw 88 to a heavy bar 90 which is in turn attached by adjusting screws 92 to lugs 94 on the upper edge of the structural element 78. The adjusting screws 88 allow the rollers 84 to be aligned as will be described, and the adjusting screws 92 permit the bar 90 to be tilted so that rollers adjacent the entry end of the station 56 are brought into more positive engagement with the bar 20 than are upper rollers 84 adjacent the exit end of the straighteners 56. Consequently, the bar 20 is deformed initially as it enters the secondary straightener 56 and the length measuring mechanism 28. The bar then passes sequentially through a pair of driven guide wheels 96; through a guide 98 which locates the rod horizontally; and then between the rotary cutters 30, 32 which are operable by the length measuring mechanism 28 to cut the bar before the bar passes through a second pair of driven guide wheels 100. Before describing the measuring mechanism 28 it will be convenient to describe FIGS. 4 and 5 which illustrate drive mechanisms used to drive various parts of the apparatus already described.
As seen in FIG. 4, an electric motor 102 drives a belt 104 in a horizontal plane to transmit torque through a right angle reduction gear box 106 which in turn is coupled at its output side to V-belts 108. As seen in FIG. 8, there are three of these belts. However, it will be appreciated that the number of belts depends upon the power transmitted and this number can vary. Returning to FIG. 4, the belts 108 pass around a wheel 110 associated with a clutch mechanism 111 and mounted on a shaft 112. A chain wheel 114 is coupled to wheel 110 for movement therewith and connected by a chain 116 to a further chain wheel 118 mounted on a layshaft 120. Further chain wheels on the layshaft 120 drive respective chains 122, 124 which in turn drive respective chain wheels 126, 128 attached to respective shafts 130, 132. The shaft 130 is effectively a further layshaft to which two further chain wheels are attached for driving respective chains 34 and 134. As previously described, the chain 34 is coupled to the primary transmission 36 (FIG. 1) for driving creel 42 (FIG. 2).
The chain 134 follows a tortuous path about four lower sprockets 136 coupled to four corresponding lower rollers 74 (FIG. 1) and around three upper sprockets 138 coupled to respective upper rollers 84 (FIG. 1). The chain 134 also passes about a sprocket 140 forming part of a chain tensioner 142.
As a result of the path followed by the chain 134, the upper rollers 84 coupled to sprockets 138 rotate in an opposite direction to the lower rollers 74 coupled to sprockets 136. Consequently, these rollers combine to drive the bar 20 through the straightening station 22 and on to the cutting station 24. Before completing the description of FIG. 4, it will be convenient at this point to refer to FIG. 5 which is a section on line 5-5 of FIG. 4 and showing one of the upper sprockets 138.
As seen in FIG. 5, upper sprocket 138 is mounted on a shaft 144 which also passes through one of the upper rollers 84. Roller 84 defines a peripheral depression 146 for locating the reinforcing bar 20 as it passes through the straightening station. Consequently, the depression 146 together with the corresponding depressions in the other rollers 84 and lower rollers 74 cause the bar to remain in a vertical plane thereby tending to straighten any variations from a vertical plane which may still exist after the bar has passed through the primary straightener 54.
The shaft 144 is welded to a pair of square slider plates 148, 150 spaced one at either side of a vertically extending slot 152 in the structural element 78. The plates 148, 150 are located horizontally between respective pairs of vertical ribs 154, 156 welded to the element 78 (Only one rib of each pair of ribs is shown in FIG. 5). As a result of the structure shown in FIG. 5,
the shaft 144 together with plates 148, 150 can move vertically between the pairs of ribs 154, 156. This vertical movement is controlled by the corresponding adjusting screw 88 and also by the position of the bar 90 which is coupled to adjusting screw 92 (FIG. 1).
The arrangement shown in FIG. 5 is also typical of the lower sliders 76 which support lower rollers 74. However, it will be evident from a comparison of FIGS. 2 and S that for each of the lower rollers 74, the screw and lock nut 80 take the place of the adjusting screw 88 associated with a corresponding upper roller.
Returning now to FIG. 4, the chain 124 which was previously described as driving chain wheel 128, also drives a chain 158 which passes about a sprocket 160 on the shaft 132. The chain 158 passes about idler sprockets 162, 164 and then about drive sprockets 166, 168 which respectively drive the guide wheels 100 (FIG. 1); and then about a sprocket 170. The sprocket 170 and shaft 132 respectively drive the guide wheels 96 (FIG. 1).
The drive system shown in FIG. 4 distributes power from the motor 102 to drive three upper rollers 84 (FIG. 1); four lower rollers 74 (FIG. 1); transmission 36 (FIG. 1), which drives creel 42 (FIG. 2); the clutch mechanism 11 1 (which will be described drives the cutters 30, 32); and the pairs of guide wheels 96, 100.
The clutch mechanism 111 is linked to the length measuring mechanism 28 (FIG. 1) and signals from the mechanism 28 are relayed by electrical conductors 172 to an electro-hydraulic control 174 mounted on the rear of the structural element 78. Control 174 is connected to a pump 176 which is driven by a motor 178 for supplying a substantially constant pressure of hydraulic fluid drawn from a reservoir 180. An outlet pipe 182 from the pump 176 is connected to an inlet 184 on the control 174 for supplying pressure to control outlet pipes 186, 188 which are respectively connected to hydraulic actuators 190, 192. The other piping shown is for returning hydraulic fluid to a return pipe 194 on the reservoir 180. For clarity of drawing, portions of the piping have been omitted. The operation of this part of the structure will be described after further structural aspects ofthe apparatus have been described.
The length measuring mechanism 28 will now be described. As seen in FIG. 1, the slave wheel 26 drives a shaft 196 through chains 198, 200. Shaft 196 is then coupled by a further chain 202 to a chain wheel 204 on a shaft 206. This shaft and chain wheel are shown in FIG. 6 where it will also be seen that a pair of engagement mechanisms in the form of electro-magnetic clutches 208, 210 are also mounted on the shaft 206.
Clutches 208, 210 are adapted to drive respective pinions 212, 214 which are in meshing engagement with respective slave racks 216, 218. The arrangement of these racks can be better seen in FIG. 7.
Rack 218 is slidably located on a support 220 and is attached at one end to a chain 222 which passes over a sprocket 224 and then under a sprocket 226 before terminating at an anchor 228. The rack 216 is similarly mounted and similar parts of associated structure are given primed numerals to identify them with reference to parts already described.
The respective sprockets 226, 226 form parts of recoupled to respective levers 230, 230. Consequently, when either one of the clutches 208, 210 is disengaged, the corresponding counterweight assembly returns the rack to the right of FIG. 7. When however, the clutch is engaged, the rack will be caused to move in the opposite direction and towards the cutting station 24 whereby energy is stored as the associated counterweight assembly is raised.
The length measuring mechanism 28 is arranged so that when a rack is being moved towards the cutting station 24, the rack moves at about 12.5 percent of the speed of the bar 20. However, it will be evident that with suitable gearing this speed reduction can be different.
Returning to FIG. 6, the mechanism 28 also includes a pair of length-setting racks 236, 238 coupled by respective pinions 240, 242 to shafts 244, 246. These shafts are connected to control handles 248, 250 which are associated with respective length indicators 252, 254. The arrangement is such that when one of the control handles 248, 250 is rotated, the length indicated at 252 or 254 is changed and the corresponding one of the racks 236, 238 is moved accordingly.
A fifth rack 256 is also provided and this rack is coupled through a pinion 258 to a reversible motor 260. The motor includes a slipping clutch and can be driven in either direction continuously as will be described. A plate 262 on the fifth rack 256 is provided for engaging a stop 264 on the end of rack 236 to prevent continuous movement to the right and also to engage a similar stop 256 on the end of rack 238 to prevent continuous movement to the left. In the position shown, the rack 256 is being biased to the right so that the plate 262 is in engagement with the stop 264 on the end of rack 236. The operation of this part of the mechanism 28 will now be described for better understanding of the remainder of the apparatus.
In the position shown in FIG. 6, the operator has selected two lengths of reinforcing bar. On the indicator 252, the operator has indicated that he wants lengths of 12 feet 6 inches. In FIG. 6, the mechanism 28 is in position for cutting these lengths. Combined counter and control 268 is used to indicate how many of a particular length of reinforcing bar is required. As shown, the operator requires 15 lengths, each of which is 12 feet 6 inches long. While these lengths are being cut, the operator has selected a further 20 lengths of 30 feet long. At the instant shown in FIG. 6, the slave rack 216 has moved to the left driven from the slave wheel 26 (FIG. 1). The leading end of rack 216 has reached one of two microswitches 270, 272 and the other slave rack 218 has moved to the right under the influence of the corresponding counterweight assembly (FIG. 7) until it can move no further. This rack is in the rest position. Because the plate 262 on rack 256 is located against stop 264 on rack 236, the reinforcing bar 20 (FIG. 1) has moved through a length of 12 feet 6 inches since it was last cut. Micro-switch 270 signals to the combined counter and control 268 that the cutting station should be activated to cut off a further length. This signal spective counterweight assemblies 229, 229' and are rotatably coupled to distal ends of pivotally mounted levers 230, 230'. Counterweights 232, and 232 are also connected to the levers 230, 230. to bias the respective racks 218, 216 towards the right of FIG. 7. Rapid return movement of the counterweights under gravity is prevented by the use of dashpots 234, 234' passes through conductors 172 to the electro hydraulic control 174 (FIG. 4). For the moment it will be assumed that this signal causes the cutting station to sever the bar and at the same time the control 268 deenergizes the clutch 208 and energizes the clutch 210. The rack 216 then begins to move to the right (as drawn) under the influence of the corresponding counterbalance assembly and the rack 218 begins to move towards micro-switch 272. It will now be appreciated that when the rack 218 meets the micro-switch 272 a further 12 feet 6 inches of bar will have passed through the cutting station and the cutter will again be activated to sever the bar 20. The cycle is repeated until the combined counter and control 268 has satisfied the demand for 15 lengths of bar each of which is 12 feet 6 inches long. At this point the reversible motor 260 is reversed to drive the rack 256 towards the left of FIG. 6 and into the chain-dotted position. This movement takes place relatively rapidly to ensure that by the time one of the racks 216, 218 has again met the corresponding microswitch 270, 272 the plate 262 is in engagement against the stop 266 on rack 238. Because rack 238 corresponds in position to a length of 30 feet as shown on indicator 254, the apparatus will then continue to cut the reinforcing bar until lengths of 30 feet have been completed. In the event that further bars are required the operator can reset the dials showing 15 lengths each of 12 feet 6 inches while the 30 feet lengths are being cut provided that the reset length is less than 30 feet long. This is because the racks 216, 218 can only drive up to plate 262 which is at 30 feet.
Reference is now made to FIG. 8 which shows a cross section through the clutch mechanism 111. The V-belts 108 drive the wheel 110 which is mounted for rotation on shaft 112 (FIG. 4). The cutter 30 is fixedly mounted on the shaft 112 which is also rotatably mounted within a housing 276 attached to the rear of structural element 78. A spur gear 278 is fixed to the shaft 112 and is in mesh with a similar spur gear 280 on a shaft 282 which is also rotatably mounted in the housing 276 and which carries the cutter 32. Drive from the wheel 110 to the cutters 30, 32 is transmitted through an expanding clutch 284 attached to an element 286 which is fixed on the shaft 112. A clutch actuator 288 is also coupled to the element 286 for causing the clutch 284 to engage the wheel 110 so that the shaft 112 and hence the cutters 30, 32 will be driven as will be described.
Referring to FIGS. 8 and 11, a tensioning mechanism 296 is shown attached to an inner end of shaft 282. Tensioning mechanism 296 functions as a brake to help stop cutters 30, 32 when clutch 284 is disengaged from wheel 110. Tensioning mechanism 296 also enables clutch actuator 288 to operate or engage clutch 284 as will be described more fully below.
Tensioning mechanism 296 is associated with actuator 192 (also seen in FIG. 4) which operates a brake band 320 about a disc 322. Disc 322 is fixed to shaft 282, so that when actuator 192 is energized, the brake band locks the disc 322 to stop or prevent rotation of shafts 282, 112. A ratchet arrangement 324 may be used, so that actuator 192 can be de-energized once the disc has been stopped. Disc 322 and thus cutters 30, 32 then can rotate only in one direction; when actuator 192 is de-energized and clutch 284 is engaged with wheel 110.
Referring now to FIGS. 8 and 9 clutch actuator 288 is shown having a plate 292 rotatably mounted on ele ment 286. Plate 292 has a peg 294 projecting through element 286 into engagement with expanding clutch 284. Plate 292 also has four peripheral steps 298, 300, 302, and 304 each of which includes a respective buffer 299, 301, 303 and 305 on its face. A lever 306 is pivoted at 308 and attached at one end to the actuator 190 (see also FIG. 4). At the other end of the lever, a peg 310 is provided for engaging the buffered steps on the plate 292, when the actuator 1980 is in a withdrawn position. Upon energizing the actuator 190 to move into an expanded position, the lever 306 rocks and the peg 310 moves out of engagement with the step 298. This operation takes place only when the length measuring mechanism 28 signals to the electro hydraulic control 174 (FIG. 4) that the cutters 30, 32 are to be activated for cutting the bar 20.
A spiral spring 290 is anchored at its inner end to element 286 and at its outer end to plate 292. When cutters 30, 32 are held at rest by tensioning mechanism 296, peg 310 engages one of the buffered steps on plate 292 and spring 290 is held in tension between element 286 and plate 292. It will be appreciated that tensioning mechanism 296 maintains the tension in spring 290, because this tension would be lost if tensioning mechanism 296 were to allow shaft 282 to rotate freely. It is the tension in spring 290 that provides the motive force to enable clutch actuator 288 to engage clutch 284.
Clutch 284 is engaged when actuator 190 moves or rocks lever 306. The plate 292 then tends to rotate under the influence of the spring thereby moving the peg 294 to operate the clutch 284.
As seen in FIG. 10, the clutch is located within a cylindrical recess 312 in the wheel 110. The clutch assembly 111 includes a pair of brake shoes 314, 316 arranged so that when the peg 294 moves to the right as drawn in FIG. 10, the shoe 316 is moved outwards at its lower end at the same time a curved lever 318 moves about a pivot 312 to apply a similar movement to the upper end of shoe 314. Consequently, both shoes are moved into engagement with the cylindrical surface of the recess 312 thereby locking the element 286 (on which the brake shoes are assembled) to the wheel 110. Consequently, the shaft 112 then moves with the wheel to drive the cutters 30, 32 synchronously for cutting the bar 20.
Returning to FIG. 9, as soon as the actuator 190 has allowed the step 298 to escape to the left as drawn, the actuator is reversed so that the peg 310 returns to its original position as shown in FIG. 9 for engaging the buffer 305 of the next step 304. When this engagement takes place, peg 294 returns to the position shown in FIG. 10 so that brake shoes 314, 316 are again disengaged from wheel 110. However, the inertia of the parts driven by the engagement of the clutch causes the shaft 112 to continue turning. At this point actuator 192 activates tensioning mechanism 296 to help stop the rotation of shafts 282, 112 (and cutters 30, 32). The continued turning of shaft 112 also causes spring 290 to be tensioned, which tension also helps to stop rotation of cutters 30, 32. When tensioning mechanism 296 finally stops cutters 30, 32, spring 290 is therefore tensioned and ready to repeat the cutting cycle, by energizing actuator 190 to allow plate 292 to rotate. It will be appreciated that the braking or stopping action of tensioning mechanism 296 holds spur gears 278, 280 in constant load transmitting engagement, so that there is zero backlash in these gears during rotation of cutters 30, 32.
The plate 292 has four steps so that with each actuation of the clutch the cutters rotate through In FIG. 1 each cutter is shown with two blades 319 so that the bar will be cut only when the cutters rotate through degrees. This arrangement permits the measuring mechanism 28 to be short because larger lengths of bar can be cut by setting the mechanism to half the length and cutting will take place only after the plate 292 rotates through two 90 steps. Alternatively for small lengths the cutter can each have four blades for cutting after each 90 rotation of plate 292.
After the bar has been cut to length, it passes into the indexing mechanism 46 and then into the handling station 44. The purpose of the indexing mechanism 46 is to ensure that as each bar is received from the cutting station 24, the bar is first located in a horizontal position and separated from the following bar before being allowed to fall under gravity into the housing station 44. It will be appreciated that the bars travel from the cutting station in substantially end-to-end relationship and that each bar must be handled individually in order to avoid impact and possible entanglement between successive bars.
Reference is now made to FIGS. 3 and 12 with particular reference to FIG. 12. A cut reinforcing bar has entered the indexing mechanism 46 and a succeeding bar 20" is following the bar 20' into the mechanism 46. The bar 20 extends from an outer end of a converging guide 326 and into the mechanism 46. Guide 326 is open at its rear and attached at its upper surface to a backing plate 328 forming a fixed part of the framework of the handling station 44. The plate 328 supports a bearing housing 330 carrying a shaft which is also rotatably mounted at its opposite end in a bearing 334 (FIG. 3). The shaft carries an indexing head 335 which can be rotated incrementally by an actuator 336 operated through a linkage 338. Shaft 332 has a tubular cross-section beyond the indexing head 335 to rigidify the shaft and four fins 340 are attached to the tubular portion of the shaft for combining with a generally cylindrical cover 342 to define three elongated chambers 344, one of which contains the reinforcing bar 20.
Actuator 336 is energized by the control 174 (FIG. 4) to move a cranked lever 346 about a pivot 348 so that a link 350 which is pivotally attached to the lever 346 will move towards the indexing head 335. Link 350 has a roller 352 attached to it for movement within a track defined by respective outer and inner guides 354, 356. Upon activating the actuator 336, the link 350 begins to move towards the head 335 below the inner guide 356 and the roller 352 engages one of four arms on the head 335 to thereby rotate the head 335 through about 90. This position is shown in FIG. 13 in which the roller 352 has completed its contact with the arm of the head 335 and the lever 346 is prevented from further rotating movement by engagement at its distal end with one of the arms on the head 335. A spring 358 which is attached to the lever 346 and to the link 350 has been energized as the angle between the link 350 and the lever 346 changes. Consequently, the roller is then made to move upwardly by the spring so that upon returning the actuator 336 to its original position, the roller 352 moves above the inner guide 356 thereby ensuring that the roller does not engage the indexing head 335 as the roller returns to its original position.
When the roller 352 reaches the original position shown in FIG. 12, the spring 358 is de-energized and the link falls under gravity into its original position ready for the next cycle.
The indexing head 335 is located against return rotation by a ratchet 360 shown in FIG. 14, and also in ghost outline in FIG. 13. The ratchet consists of a fixed arm 362 to which is pivotally connected a secondary arm 364 biased by a spring 366 to move into engagement with the indexing head 335. After each movement of the indexing head, the secondary arm 364 locates an arm on the indexing head to prevent reverse rotation.
Returning to FIG. 12, in the position shown, the reinforcing bar 20' has reached a point at which the actuator 336 is to be energized. This rod must be indexed through before the next bar 20 reaches the indexing head 335. Upon energizing the actuator, the bar 20 is carried around the shaft 332 until it occupies chamber 344 which is open at its lower end between a corresponding fin 340 and the cover 342 to allow the bar 20 to fall into the handling station 44.
As seen in FIG. 3, the bar 20 falls towards previously cut bars which are held in place by arms 368 attached to a common shaft 370 which can be rotated by an actuator 372 operating through a link 374 to move the arms 368 downwardly thereby releasing the rods to fall into supports 376.
Because the indexing mechanism 46 must be actuated before the bar 20 has reached its final position, a gate 378 which is pivotally mounted on a shaft 380 can be operated by an actuator 382 to push the bar 20 until its trailing end is in alignment with other bars supported by arms 368. The gate 378 is energized as soon as the bar 20 has left the guide 326 and is operated simultaneously with the actuator 336 by the control 174.
Actuator 372 is also operated by the control 174 but only after the desired number of bars 20' have been cut and supported by the arms 368. The entire bundle of bars is then released to fall into the support 376 from which they are removed for storage.
Reference is now made to FIGS. 2 and 15 to describe the creel 42 which as described is driven from output shaft 38. This shaft is coupled to the secondary transmission 40 by a pair of spur gears 384, 386 (FIG. 15). The gear 384 is coupled directly to the shaft 38 and is rotatably mounted in a housing 388 attached to a base plate 390. The housing 388 is shaped to combine with a cover 392 on the transmission 40 to locate the transmission 40 and to enclose the meshed gears when the creel is in an operational position (FIG. 2).
The transmission40 is attached to a shaft 394 which is pivotally mountedin a pair of bearing supports 396, 398 attached to the base plate 390. A pair of cranks 400 (one of which is seen) are also attached to the shaft 394. These cranks are coupled to a pair of ganged double-acting hydraulic actuators 402 which are operable to cause rotation of shaft 394 for moving the creel between the operational position shown in FIG. 2 and a re-loading position shown in FIG. 15. The hydraulic system (not shown) associated with actuators 402 is such that the oil in the system is used to limit sudden movements of the creel caused by the transfer of weight as the creel is tilted. For instance, as the creel moves from the position shown in FIG. 2 towards the FIG. 15 position, a point will be reached at which the creel will tend to accelerate due to the weight transfer outwards beyond shaft 394. Consequently, oil will be forced from the actuator and the system will control the rate of flow of this oil to effectively dampen the acceleration. A similar arrangement is provided within the system for use when the creel returns to the FIG. 2 position.
The secondary transmission 40 drives a circular base plate 404 which rotates on a suitable lower bearing.
Three separate heavy uprights 408, 410, 412 are welded to the plate 404 and define respective cylindrical outer surfaces which have their centres of curvature on the axis of rotation of the creel. These outer surfaces taper inwardly adjacent their upper extremities and terminate at a generally circular top plate 414 which in plan is concentric with base plate 404. The tapered portions of the outer surfaces provide a lead for engaging coils of reinforcing bar 20.
The upright 412 is spaced slightly from the other two uprights 408, 410 to define narrow slots 416 (one of which is seen). A wider slot 418 is defined between uprights 408, 410 for reasons which will be described. The slot 418 is further defined by a notch 420 in the top plate 414.
The creel 42 also includes an adjustable annular platform 422 which is a sliding fit about the uprights 408, 410 and 412. The platform includes three inwardly extending arms 424, 426 and 428 which extend horizontally through the respective wider slot 418 and a pair of narrower slots 416, and then turn upwardly to meet on the axis of rotation of the creel. A hydraulic actuator 429 is fixed to the base plate 404 and supports an upper bearing 430 attached to the underside of the inner extremities of these arms. Consequently, the base plate 404, uprights 408, 410, 412 and top plate 414 form a rotatable spool 421 which carries and drives an adjustable platform 422 and the adjustment is made by energizing a hydraulic actuator from a control source (not shown) and coupled to an input connection 432 (FIG. 15).
In use the actuator 429 can be adjusted as required while the spool is rotating to feed the reinforcing bar at a constant level to the straightening station 22 (FIG. 1). Once all of the bar has been removed from the creel, the creel is stopped and the platform 422 lowered to the bottom of spool 421. Next the hydraulic actuators 402 are energized to tip the spool towards the reload portion shown in FIG. 15. Because the slot 418 is wider than slots 416, the spool finds a preferred position in which the slot 418 is uppermost. This allows a loader having a single arm to feed a new supply of coiled reinforcing bar on to the spool and to withdraw the arm by lowering it into slot 418 to disengage the bar before withdrawing the arm. The actuators 402 are then energized to move the creel into the FIG. 2 position ready to again feed the straightening station.
Having completed the description of the mechanical aspects of the invention, the operation of the apparatus will now be described. Before commencing to use the apparatus, all of the rollers are aligned in groups using suitable straight edges and the like. For instance the rollers 74 would be set to be tangential to the straight edge. Next the adjusting screws 70 and 72 are used to set the primary straightener according to experience with the material to be straightened and then the bar 90 of the secondary straightener is lowered at the entrance end of the secondary straightener. The position of bar 90 is also based on experience and to some extent trial and error. It should be noted that the bar 90 is positioned so that at the exit end of straightener 56, the rollers 84 have only slight contact with the reinforcing bar 20.
In practice it may be necessary to run some of the bar through the apparatus before final adjustments can be made to ensure that the desired degree of straightness is achieved.
Referring now to Flg. 2, the creel 42 is loaded with coils of reinforcing bar 20 and is positioned to feed the bar horizontally through a relatively small curvature to the primary straightener 54 and then to the secondary straightener 56. The powered drive to the secondary straightener is used to feed the bar between some of the rollers 74, 84 and then on until the end of the bar has passed between guide wheels 100. If preferred, a manual control can be used to sever a short length of the bar because the end of the bar will normally be difficult to straighten. This will also set the apparatus ready for cutting the bar into lengths,
The primary straightener operates in the plane of the materials memory to destroy the memory without kinking or otherwise setting the bar in other than a straight position. However, it has been found that the memory may deviate slightly from a single plane and consequently the secondary straightener is used to further work the bar and destroy the memory.
The arrangement of the upper and lower rollers is such that initially the bar is deformed alternately downwardly and then upwardly a little less each time it meets new rollers until such time as there is little or no deflection between the last of the upper and lower rollers adjacent the slave wheel 26.
When the apparatus is started, the bar is fed past the cutter and, as previously described, the length measuring mechanism 28 is used to energize the clutch mechanism 111 for cutting the bar into selected numbers of a particular length.
After each bar is cut and it enters the indexing mechanism 46, the actuator 336 (FIG. 12) is energized to index the bar 20 out of the position which the next bar 20" will occupy. After the selected number of these bars have been received on the arms 368 (FIG. 3) the actuator 372 is energized to lower the bundle of bars to storage or support area 376.
Although the electro-hydraulic control 174 has not been described in detail, it will be appreciated that it can be of any form suitable for providing the described sequence necessary to produce straight bars in selected lengths. In the foregoing description, all actuators are hydraulic and are operated by electrical input to the control 174. Hydraulic pressure is available from the pump 176 (FIG. 4) as previously described.
It will be evident that the straightening station can take any orientation provided that the straighteners work on the bar relative to the bars memory in the manner described. For instance, the bar could be fed from a horizontal spool in the creel in which case the primary straightener would operate in a vertical plane and the secondary straightener would then operate in a horizontal plane.
The primary straightener combines with the creel arrangement to remove the major part of the memory. Although the secondary straightener has been included, in come instances if sufficient rollers were added to the primary straightener it may be sufficient to straighten reinforcing bar. In such an arrangement the feed from the creel becomes more critical. This is because the primary straightener works in a single plane and if the plane containing the memory does not coincide with this plane there will be a component of the memory remaining which will cause a curvature in the finished bar.
What I claim is:
1. Apparatus for straightening and cutting curved bar stock to form substantially straight reinforcing bars of selected lengths, the apparatus comprising:
a straightening station comprising: a primary straightener for receiving the curved bar stock; and a secondary straightener fixedly positioned to receive the bar stock from the primary straightener;
the primary straightener comprising: rollers engageable against opposite sides of the bar stock in the plane containing the curved bar stock, and the primary straightener being pivotally coupled to the secondary straightener for angular adjustment of the primary straightener about an axis which is per pendicular to said plane;
the secondary straightener comprising first and second rollers engageable against opposite sides of the bar in a plane which is substantially perpendicular to said first-mentioned plane, the first rollers being aligned with a common tangent to these rollers and the second rollers being aligned with a common tangent to these second rollers, the first and second rollers being spaced from one another so that there is a respective one of the second rollers positioned intermediate each adjacent pair of first rollers, and so that the spaces between succeeding respective first and second rollers increase in length from an entrance end of the secondary straightener adjacent the primary straightener towards an exit end of the secondary straightener, the first and second rollers at the entrance end being positioned for more positive engagement with the bar stock than are the corresponding first and second rollers at the exit end;
an adjustable measuring mechanism operable by straightened bar stock passing through the straightening station to measure selected lengths of the bar stock and to provide signals when the said lengths have been measured;
a cutting station operable to cut the bar stock as the straightened bar stock passes through the cutting station from the straightener to form individual reinforcing bars;
control means responsive to said signals to operate the cutting station so that the bar stock is cut into individual reinforcing bars of said selected lengths; and
drive means for contact with the bar stock to drive the bar stock through the apparatus.
2. Apparatus for straightening and cutting curved bar stock to form substantially straight reinforcing bars of selected lengths, the apparatus comprising:
a straightening station for receiving bar stock and straightening the bar stock;
an adjustable measuring mechanism operable by straightening station to measure selected lengths of the bar stock and to provide signals when the said lengths have been measured;
drive means for contact with the bar stock to drive the bar stock through the apparatus;
a cutting station operable to cut the bar stock as the straightened bar stock passes through the cutting station from the straightener to form individual reinforcing bars, the cutting station comprising: a pair of rotatably mounted cutters coupled one to the other for contemporaneous movement to cut the bar stock; a clutch; a clutch actuator operable to engage the clutch for connecting the cutters to the drive means; a tensioning mechanism to limit backlash of one cutter relative to the other cutter; control means responsive to said signals to operate the clutch actuator so that the bar stock is cut into individual reinforcing bars of said selected lengths.
3. Apparatus as claimed in claim 1 in which the cutting station comprises:
a pair of rotatably mounted cutters coupled one to the other for contemporaneous movement to cut the bar stock; a clutch; a clutch actuator operable to engage the clutch for connecting the cutters to the drive means; a tensioning mechanism to limit backlash of one cutter relative to the other cutter;
control means responsive to said signals to operate the clutch actuator so that the bar stock is cut into individual reinforcing bars of said selected lengths.
4. Apparatus as claimed in claim 1 in which the measuring mechanism comprises:
a slave drive sensitive to bar stock movement; first and second engagement mechanisms selectively connectible to the slave drive; first and second racks slidably mounted for linear movement and operably coupled to the respective engagement mechanisms; first and second switch means responsive to engagement by respective leading ends of the first and second racks to provide first and second signals; means mounting the switch means for movement towards or away from the racks for selectively varying the length of bar stock to be cut; means biasing the racks to move away from the switch means, whereby in use the racks are driven alternately to engage the respective switch means and to return to a rest position under the influence of the bias means, each rack upon engagement with a corresponding switch means causing a corresponding said signal and also causing the corresponding said engagement means to disengage and simultaneously cause the other said engagement means to engage for driving the other rack.
5. Apparatus as claimed in claim 1 in which said plane is horizontal and in which the apparatus further comprises:
a handling station for receiving cut reinforcing bars from the cutting station and for converting the endto-end arrangement of the reinforcing bars into side-by-side relationship, the handling station including an indexing mechanism comprising: means defining elongated chambers disposed about an axis parallel to a path followed by the reinforcing bars in leaving the cutting station; means operable to rotate said chamber means about said axis in incremental steps, said rotation means being coupled to the control means for operation when a major part of a reinforcing bar has entered one of the chambers so that another chamber is brought into alignment to receive the succeeding reinforcing bar, the first reinforcing bar then being free to fall from said one of the chambers for side-by-side grouping with previously handled reinforcing bars.
6. Apparatus as claimed in claim 2 in which the apparatus further comprises:
a handling station for receiving cut reinforcing bars from the cutting station and for converting the endto-end arrangement of the reinforcing bars into side-by-side relationship, the handling station including an indexing mechanism comprising: means defining elongated chambers disposed about an axis parallel to a path followed by the reinforcing bars in leaving the cutting station; means operable to rotate said chamber means about said axis in incremental steps said rotation means being coupled to the control means for operation when a major part of a reinforcing bar has entered one of the chambers so that another chamber is brought into alignment to receive the succeeding reinforcing bar, the first reinforcing bar then being free to fall from said one of the chambers for side-by-side grouping with previously handled reinforcing bars. 7. Apparatus as claimed in claim 1 and further comprising: a creel adapted to support a supply of said bar stock, the bar stock being coiled; and means coupling the creel to the drive means whereby the creel is driven to feed the bar stock to the straightening station.
8. Apparatus as claimed in claim 7 in which the creel comprises: a generally cylindrical spool adapted to extend through the coiled bar stock; and a platform movable axially of the spool to adjust the position of the bar stock on the spool; and actuator means coupled to the platform for adjusting the axial position of the platform on the spool.
9. Apparatus as claimed in claim 8 in which said plane is horizontal and the spool rotates about a vertical axis, the creel further comprising: means pivotally mounting the spool for rotating the spool between an operational position in which the axis of the spool is vertical and a reload position in which the axis of the spool is generally horizontal; and further actuator means coupled to the spool for moving the spool between said operational and reload positions.