Patent GB-728174-A (GB)
Title: Improvements in or relating to wrapping machines
Inventor: KOTTMANN ARTHUR ALBERT
IPC: B65B25/18
Filed: 1953-01-21
Abstract: 728,174. Wrapping machines. AMERICAN MACHINE & FOUNDRY CO. Jan. 21, 1953, No. 1737/53. Class 94 (1). Articles, e.g. loaves, are wrapped in a machine comprising a lower loaf feed runway and an upper discharge runway, a web feeding and draping means including a drape member intermediate the runways and having its rear end in vertical alignment with the feed runway, a wrapping mechanism including an elevator movable past the rear end of the drape member from a position in alignment with the feed runway to a position in alignment with the discharge runway, means for raising and lowering the elevator, and means for shifting the elevator rearwardly during its movement past the drape member so that tension is maintained on the wrapper web whilst the loaf &c. is being wrapped. The loaf or wrapping machine may be connected in tandem with a slicing machine and the sliced loaves to be wrapped are transferred one at a time from a conveyor G by a shuttle mechanism H to a feed conveyer A. The latter is intermittently driven so that a loaf is pushed by the conveyer onto an elevator. B during each movement of the conveyer. In passing from the conveyer to the elevator the loaf engages the leading edge of a web of wrapping material suspended from a drape table C over which the web is fed from, a rack K. The web is clamped between the article and elevator and a pull is exerted-on the web which operates a tension controlled feed mechanism L. The elevator then moves from an inclined to a horizontal position in alignment with a discharge runway and during this movement is moved slightly rearwardly to maintain tension in the web which now surrounds the loaf. The web is then cut, and the loaf moved from the elevator by an endless pusher conveyer M and through a folding and heating section D and a cooling section E. During this movement the cut end of the web passes underneath the loaf. The bottom of the cooling section is formed with an endless belt N and the sides with two endless belts P which grip and travel with the loaves so that lapping portions of the wrapper are caused to set. The elevator, which is reciprocated with a pause at the upper and and lower limits of its movement, and the conveyers M, N and P, which are continuously driven, are driven by an electric motor through chains and sprockets. Main driving mechanism (Figs. 1, 5, 6). The electric motor 2 is supported on a frame 31, Fig. 5, pivotally mounted about a pin 32 ; by increasing the tension in a driving belt 34 by a handwheel 18 a pair of pulleys 35, between which the belt sits, are moved apart, and the belt engages the pulleys with a smaller radius, and the belt speed is thereby reduced. A chain 5 is driven via a pulley 33 and gearing within a housing 40, and passes over sprockets 41, 42 and 43 thereby driving shafts 3 and 4. A wheel 44 on shaft 4 has arms with pins or rollers 45, Fig. 6, which engage radial slots 46 in a Geneva gear 47. A gear 48 secured to the Geneva gear engages a gear 49 to drive the conveyer A. The conveyer may be stopped independently of the wrapping mechanism by means of a clutch mechanism comprising a ratchet 55 on the sprocket 42, and a pawl 58 on an arm 57 secured to the shaft 4 which engages either of two teeth 56 on the ratchet. A cam 60 with a pair of arms 62 with inclined faces is pivoted about pins 61, and the arms can straddle the shaft 4 to hold the pawl out of engagement with the ratchet. The cam is disengaged from the pawl by a bar 66 with a tapered end 66a which is slid between a roller 65 on the cam and the gear housing wall. The feed conveyer A (Figs. 10, 14), comprises a pair of chains 27, carried between transversely spaced pairs of bars 69, 70, which travel parallel to a bed plate 25. Transverse bars 71 secured to the chains include flights 26. Guide rails 72 are supported by spaced nuts 76 on a transverse threaded shaft 77, and by similar nuts on a similar shaft arranged above the rails (not shown). Each shaft has a right and left hand screw thread engaging the spaced nuts, and the shafts are rotated by a handwheel 24 to adjust the rails laterally towards and away from the conveyer centre to correspond with the article or loaf size. Chain tightening sprockets 30 are carried on arms 83 pivoted to a shaft 82, and are secured by nuts and bolts in the desired position. Shuttle mechanism. The conveyer G is of the endless flight, pusher type with flights 89 pushing loaves over a bed 88 and delivering them one at a time to a shuttle plate 92 which is horizontally reciprocated towards and away from the bed. The plate 92 is adjustably secured to bars 97 sliding in guides 98, and is driven by levers 99 attached at their lower ends to a transverse shaft 100 and at their upper ends to the bars 97. One lever 99 has an arm with a roller engaging a groove in a cam 104 secured to and driven by a shaft 6, and the plate is thereby reciprocated in timed relation with the movements of the flights 26 on the conveyer A and the flights 89 on conveyer G. Elevator mechanism (Figs. 16, 20, 23). The loaves are fed to a platform 105 on the elevator B from the conveyer A, and the elevator moves from an inclined position to a horizontal position in alignment with the discharge runway. The platform is supported on arms 106 connected by pivots 107 to rocker arms 14. attached to a rock shaft 108. During the upward movement of the elevator the arms 14 are rocked rearwardly and tension is maintained on the wrapper web. Springs 109 urge the elevator forwardly. A lever 113 is mounted about a pivot 112 and is connected to two diverging links 114 connected at their upper ends to a transverse rod 115 which connects the arms 106. A cam 116 fixed to the shaft 3 has a groove which engages a roller 117 on lever 113 and the elevator is thereby oscillated with pauses at the upper and lower positions. The elevator retracting mechanism includes a lever 120 mounted about a bracket 119 and carrying a roller .121 held against a cam 122 on the shaft 3 by a spring 123, and a further roller 124 engages an arm 125 attached to the rock shaft 108. An adjustable abutment is provided between the roller 124 and arm 125 ; the connection between the links 114 and the rod 115 is also adjustable. The wrapper web, which hangs from the drape table, is drawn between the bottom of the article or loaf and the platform as the loaf is pushed thereon, and a follower 136 on the platform is pushed rearwardly by the loaf. The follower includes a guide bar 137 extending through a guide 138, which bar is held in the rearward position by a friction shoe 140. The guide 138 may support a part 144 to which is adjustably secured a hold-down plate 146. Tuckers (Figs. 16, 18, 20). Detachable tucker plates 148 engage with the opposite edge portions of the wrapper web to fold them over the ends of the loaf during movement of the loaf onto the elevator. They are swung laterally onto the loaf ends, and are bolted to parts 149 secured to the ends of arms 150 swingingly mounted on pivots 151 mounted on slides 152 supported on a transverse rod 153. The slides have integral arms 154 sliding on a transverse rod 115 to prevent their rocking about the rod 153. The slides have vertical slots 156 through which extend vertical plates 157 rigidly attached to side rails 158 supporting the side members of the discharge runway. The side rails can be moved laterally to accommodate loaves of varying width, and this movement causes the slides 152 and the tucker plates to move laterally correspondingly. The arms 150 extend rearwardly and carry rollers 159 that bear against a transverse bar 160 attached to rocker arms 161 connected by pivots 162 to the elevator arms 106. A lever 163 on one arm 161 carries a roller 164 engaging with a cam 165 on the shaft 3 to spread the tucker plates to receive an article. Springs between the slides 152 and arms 150 swing the plates towards each other and urge the rollers 159 against the bar 160. Limit stops are provided for the inward swinging of the tucker plates and for the pivotal movement of the bar 160. Each roller 159 can be adjusted on its arm 150 relative to the bar 160. An article retainer 180 (Figs. 16, 18, 20, 23) extends through a slot in a shear bar 178 and is centrally positioned beneath the elevator platform 105. The retainer comprises arms 181 with retaining fingers 182 which are positioned in front of a loaf &c. during upward elevator movement. The rear end of the retainer has aligned trunnions which slide in slots in brackets 185, and a rear arm 186 is pivotally connected to an arm 190 pivoted on a rock shaft 187 which is rocked by a lever 192. The latter is pivoted at 194 on a link 193 pivoted on the transverse rod 115, and the lever 192 carries rollers 195, 197. A segment cam 196 engages roller 195 when the elevator is in line with the feed conveyer, and the fingers 182 are moved in front of the loaf which has been pushed onto the elevator. In this position the fingers are received in recesses in the transverse bars 71 and thereby avoid engagement with the adjacent flight 26. When the elevator reaches its upper position a trip plate 198, Fig. 16, on the machine frame engages roller 197 to bring the retainer entirely beneath the elevator platform. The retraction movement of the retainer is positive whereas its movement into the retaining position is yield able. Spring detent members yieldably hold the retainer in its extreme positions. A locking bar 208 carried by the guide bar 137 of the clamping follower engages a projection on the arm 190 to lock the retainer in its retracted position during the elevator downward movement and until the clamping follower is moved rearwardly. Web cut-off mechanism (Figs. 5, 18, 27). In its upper position the elevator is urged forwardly by the springs 109, and idler rollers 176 are urged against a paper feed roller 215. During the elevator upward movement the wrap