Shuttle 30 which rides around the rails from the lower and upper transfer assemblies, and that is lifted and dropped using the carriers around the vertical transfer assemblies, is shown in Figs. 6, 7 and 8. The shuttle includes a base with twelve wheels in four sets of three which ride around the rails in such a way that the shuttle is held in a definite position relative to the rails. As observed in Fig. 6, some wheels includes wheels 52 and 53 that are freely rotatable about parallel axes that are offset from one another to ensure that the peripheral surfaces of the wheels engage opposite parallel surfaces of the track. Another wheel 54 in each set rotates about a good axis that is perpendicular to the axes of wheels 52 and 53 to ensure that wheel 54 rides on the surface perpendicular to and between the other two surfaces. As pointed out above, each rail is usually U-shaped and has three inwardly facing contact surfaces. Two of contact surfaces 49 and 50 are parallel with one another and also the third surface 51 is perpendicular and stretches between the parallel surfaces. Wheels 52 and 53 ride on surfaces 49 and 50 as the third wheel 54 rides against surface 51. Parts of the rails are shown in Fig. 7 with the wheels in touch therewith. Each of the four sets of wheels makes contact in this way to ensure that the shuttle is safely situated.
Connected to the shuttle base is really a motor and control housing 56 along with a roll support 58 which holds a roll of film, suggested in phantom lines at 61, to be distributed. Roll support 58 contains a spindle 59 on which a film roll is mounted, the roll being held by latches 60 that are moved outwardly to interact inner surfaces of the roll after it’s loaded to the spindle. The spindle is installed on an interior shaft that is rotatable involved with the shuttle and also the motor housing, the interior shaft being attached to the shaft of the motor, not individually shown, that is within the housing. The motor in housing 56 rotates spindle 59 in a controlled speed which enables dispensing of the film in a preferred rate as a function of the speed of motion of the shuttle around the coil being wrapped and keeps tension within the departing film to ensure that it’s extended as it is being distributed.
Before finishing the outline of the shuttle, attention is asked to Fig. 9 which shows an enlarged partial view of vertical transfer assembly 28 and carrier 35, and Fig. 10 that is a sectional view of the carrier. Carrier 34 is similar to carrier 35. The carrier comprises a regularly U-shaped body having arms 64 and 65 along with a base portion 66. The arms have rails 67 and 68 each of which is U-shaped, as observed in Fig. 10, and therefore are dimensioned to be the same size and shape as rails 44 and 45 along transfer assembly 26. When carrier 35 is at the top of vertical transfer assembly 28 as shown in Fig. 1, rails 67 and 68 form continuations of rails 44 and 45 and also the carrier may then behave as a docking station to take over shuttle 30 or 31 when belt 38 provides it.
Carrier 35 includes a latch member 70 which protrudes outwardly between rails 67 and 68 and rides on the latch shaft 72. A compression spring 74 urges latch 70 toward rail 67. Latch 70 includes a beveled end along with a side recess 73. The objective of latch 70 is to engage the shuttle when it’s received within the carrier from one belt drive and hold it in position up to the carrier has arrived at the end of its vertical travel and get ready to release the shuttle to another belt drive. For this function, the shuttle has two latch pins 62, one at each end of the shuttle, to interact a latch at the end of its travel in either direction. Fig. 8 shows carrier 35 in phantom lines with latch 70 in position to interact a latch pin 62. The distal end of latch 70 is beveled to permit the latch pin to slip along its beveled surface, moving the latch aside after which engaging recess 73.
Motor and control housing 56 consists of a set motor in addition to a control module which controls the unwinding speed of the motor. The unwinding speed determines the quantity of tension on the film being distributed and, therefore, the quantity of stretching of the film as the film is wrapped around the coil. Normally, roll 61 of the film carries enough film to wrap several coils, relying on the dimensions of the coils and realizing that two rolls of film are being distributed in each wrapping operation. To ensure that the motor speed to be modified correctly for each coil, it’s desirable to determine the outer diameter of the film roll before starting a wrapping operation and also to provide this diameter information towards the motor control. This measurement can be created manually or automatically using, for instance, an optical calculating device. The information may then be provided towards the motor control either manually or automatically.