[ 0025 ] fig4 shows , schematically , the preferred embodiment of the present invention , a modular twist - wrap apparatus 100 together with a conventional continuous flow - wrap packaging line 50 ( only a portion of which is shown ). the conventional line , being well known , will not be described or illustrated in any detail , and by itself , it does not form part of the present invention ( although the combination of the conventional packaging line with the modular apparatus claimed herein , is within the scope of the invention ). [ 0026 ] fig1 illustrates the well - known form of candy bar wrapping 20 obtained with the conventional type of continuous flow - wrapping packaging process . in the conventional process , the products 12 being wrapped are placed on a continuous film of known composition , which is usually preprinted with artwork , logos , product name , etc . the side edges of the film are brought together and welded or glued to produce a seam 14 , thus forming a tubular shape 16 containing the articles 12 being packaged , as illustrated in fig2 . in the conventional processing , the tubular shape is then divided into portions each containing one product , and the ends of each portion are welded or glued shut , thus producing the form shown in fig1 . these conventional processing steps , like the apparatus used to perform them , are well known in the art and will not be described in greater detail . when the modular twist - wrap apparatus 100 of the preferred embodiment is attached to and used with the standard continuous flow - wrap line 50 , the operation of the latter is modified in certain respects . first , since it is desired to form a twist - wrap rather than a flat seam at each end of the package , the placement of adhesive on the film must be adjusted accordingly ( the twists that are formed at the ends of the package may be secured in any fashion that proves effective , including the use of either heat - seal or a cold adhesive ). second , the cut - and - seal 55 ( the component of the standard continuous flow - wrap line that cuts the tubular shape 16 shown in fig2 into individual portions and then seals the ends ), is set only to perform the cutting , and does not seal the ends of the individual packages . third , the registration and the encoder signals used in the control of the standard line are supplied to the modular twist - wrap apparatus . according to the preferred embodiment , these are the only control signals that need to be supplied to the modular twist - wrap apparatus from the standard line . the modular twist - wrap apparatus 100 receives the tubular products , in their individual “ product wraps ” 24 ( i . e ., a segment cut from tube 16 and containing the product 22 to be packaged in a single package ), from the upper arbor 57 of the cut - and - seal 55 . three drums 110 , 130 and 150 are provided in the twist - wrap apparatus , and perform the following operations on the products . the first drum 110 is a transfer - and - rotate drum ( see also fig5 and 9 ), which receives the product 24 from the cut - and - seal 55 into a product gripper 112 ( fig5 ). while the product 24 is transported to the second drum 130 by rotation of the transfer - and - rotate drum 110 , the product gripper 112 itself is rotated to re - orient the product by 90 ° ( see fig8 and 9 ). as a result , the product 24 is delivered to the second drum 130 in an orientation with the open ends of the product &# 39 ; s “ wrap ” extending in a line parallel to the axis of rotation of the second drum ( this is indicated schematically in fig4 where product 24 is viewed from the side while in the cut - and - seal , is rotating on the first drum 110 , and is seen end - on while on drum 130 ). the second drum 130 is where the actual twist - wrap formation is performed . for this purpose , the product 24 , held by a product gripper 112 ( like those on the transfer - and - rotate drum 110 ), is gripped at each end by twist grippers 132 ( see fig6 ), which are timed to close on the “ tube ” once the product is securely received by the product gripper 112 on the twist - wrap drum 130 . the twist grippers 132 are then rotated about their own axis ( parallel to the axis of drum 130 ) through an angle of 720 ° while the twist - wrap drum 130 is itself rotating . the force applied in this fashion twists the ends of the “ tube ” into the desired twist - wrap shape , and the adhesive seals the package . the twist grippers 132 are then opened , and the product 30 (“ 30 ” rather than “ 24 ” because it is now twist - wrapped ) is transferred to the third drum 150 , the discharge drum . the discharge drum 150 has the function of receiving the packaged product 30 from the twist - wrap drum 130 , delivering the product to the desired discharge point , and discharging it in an orderly fashion . as shown in fig5 the transfer - and - rotate drum 110 has twelve product grippers 112 provided on its circumference . the product gripper 112 comprises a base portion , or head , 114 whose upper surface contains vacuum tooling ; that surface is shown as rectangular , but could be given any shape found advantageous in handling the particular product in question . one or more ports 116 ( only one is shown ) are provided in the upper surface of the head 114 of the product gripper 112 to permit the application of suction from the interior of the drum , to hold the product and the wrap securely against the product gripper 112 . in the preferred embodiment , the product gripper 112 has three linear rods or fingers 118 , two along one side and one on the opposing side of the head 114 . these rods 118 are each movable between a closed position , in which they approach each other and thus grip and secure the product , in cooperation with the vacuum suction , and an open position , in which they are moved outward from each other and away from the product . additional views of such product gripper 112 ′ and 112 ″ in place on one of the drums , are provided in fig1 and 12 . these versions of the product gripper 112 ′ and 112 ″ differ in a number of details , such as the shape of fingers or rods 118 ′ and 118 ″, from the design shown in fig5 . the lateral or circumferential surface of the transfer - and - rotate drum 110 , on which the twelve product grippers 112 are mounted , is actually made up of twelve flat surfaces 120 of equal size , each carrying one of the product grippers 112 . each product gripper 112 is mounted such that it can be rotated on the flat surface 120 on which it is mounted , the rotation being about an axis passing through the product gripper 112 and through the axis of the transfer - and - rotate drum 110 itself . as an empty product gripper 112 on the transfer - and - rotate drum 110 passes the upper arbor 55 of the cut - and - seal 50 ( see fig7 and 8 ), the vacuum suction is actuated in that product gripper 112 , while that holding the product 24 on the cut - and - seal upper arbor 55 is deactivated . this releases the product 24 from the cut - and - seal 50 , and transfers it to the product gripper 112 on the transfer - and - rotate drum 110 . the rods 118 on the product gripper 112 move to their closed position , holding and orienting the product 24 on the product gripper 112 . as the drum 110 rotates about its axis to advance the product 24 toward the twist - wrap drum 130 , the product gripper 112 itself is caused to rotate so as to reorient the product 24 ( see fig8 - 10 ). in the preferred embodiment , the product gripper 112 is rotated through 90 °, so that the open ends of the product “ tube ” 24 lie along a line parallel to the drum axis . this rotation of the product gripper is performed while the drum 110 has rotated through 240 °. the product 24 is now in the proper place and orientation to be transferred to the twist - wrap drum 130 . the transfer to the twist - wrap drum 130 is performed by the rods 118 of the product gripper 112 being moved to their open position , and then the vacuum suction being deactivated , to release the product 24 onto an identical product gripper 112 on the twist - wrap drum 130 . at the same time , vacuum suction is applied to the product 24 by the product gripper 112 that is receiving the product onto the twist - wrap drum 130 , and the rods 118 of the receiving product gripper 112 are closed to secure the product 24 , completing the transfer . ( the remainder of the description of the operation of the twist - wrap drum 130 will be provided in the following section .) as the transfer - and - rotate drum 110 continues to rotate through the next 120 °, the product gripper 112 , now empty , is rotated back into its original orientation , so that it is ready to receive a product upon reaching the cut - and - seal 50 again . the opening and closing of the rods 118 on the product grippers 112 is controlled by a face cam arrangement , while the rotation of the product grippers 112 to reorient the product is achieved by means of a barrel cam arrangement . since these techniques are well understood in the art , they need not be described in detail . the twist - wrap drum 130 , as is seen most clearly in fig6 actually includes a center drum 134 disposed between an inner drum 136 and an outer drum 138 , all three of which are driven to rotate at the same speed . the center drum 134 has on its lateral or circumferential surface twelve product grippers 112 , which are identical to those of the transfer - and - rotate drum 110 but which cannot rotate about their own axes . as a result , the product remains in the same orientation all the time it is on the twist - wrap drum 130 . the inner and outer drums 136 and 138 each carry twelve twist grippers 132 , one adjacent to each of the product grippers 112 on the center drum 134 . each twist gripper 132 has a pair of jaws 140 , which can open and close , and are supported for rotation about the twist gripper &# 39 ; s own axis ( which is parallel to the axis of the twist - wrap drum 130 ). it will be noted that the housings 142 and 144 of the twist grippers 132 are not all the same , some containing one twist gripper 132 , and some containing two each . moreover , posts 146 extend across the center drum 134 and connect these larger housings 144 . the purpose of these double housings 144 and the posts 146 is to supply the drive force from the inner drum 136 to the outer drum 138 , using techniques well - known in the art . in the preferred embodiment , the twist grippers 132 do not rotate at all times , but only the amount and at the times necessary to achieve the desired twist - wraps . for this purpose , they are driven by geneva wheel mechanisms 180 shown in detail in fig1 and 14a - 14 j . one such mechanism is provided for each of the 24 twist grippers 132 , and is located at one end of the associated twist gripper 132 . in addition , the inner and outer drums 136 and 138 each have a respective disc 182 ( see fig1 a ) on which is mounted a radial gear rack 184 , together with two pins , an acceleration pin 186 and a deceleration pin 188 , which are respectively at the beginning and the end of the radial gear rack 184 . these two discs 182 are stationary during rotation of the twist - wrap drum 130 . each geneva wheel mechanism 180 is provided with a mounting 170 that carries the geneva wheel mechanism 180 smoothly on the surface of the drum 136 or 138 . mounted coaxially with the disc 182 is a rotatable arm 190 for each of the twist grippers 132 , at the radially - outer end of which is a small gear wheel 192 , which in operation rides along and in engagement with the radial gear rack 184 . a cam path 194 is secured to the gear wheel 192 , and is caused to rotate as the gear wheel 192 moves along the radial gear rack 184 . these cam paths each have portions that are to engage the acceleration and deceleration pins 186 and 188 , respectively . during rotation of the twist - wrap drum 130 , each of the cam paths 194 in turn come into engagement with the acceleration pin 186 , and the associated gear wheel 192 then engages and rides along the gear rack 184 to drive the twist gripper 132 , rotating the latter through 720 °, thus twisting the end of the product “ wrap ” and forming the twist - wrap . the formation of the twist - wrap is assisted by an arcuate plate 196 ( shown in fig1 and 13 ), which helps hold the product in place against the product gripper 112 as the twist grippers 132 twist . in operation , when the product gripper 112 on the twist - wrap drum 130 has secured the product 24 from the transfer - and - rotate drum 110 , the twist grippers 132 adjacent to that product gripper 112 are moved to the closed position , gripping the ends of the product “ wrap ”. after the twist - wrap has been formed , the twist grippers 132 open , and the twist - wrapped product 30 is ready to be transferred to the discharge drum 150 . the opening and closing of the twist grippers 132 is achieved by a barrel cam . the timing of this is controlled by the indexing of the geneva wheel 180 itself , thus guaranteeing that the twist grippers 132 will engage and securely grip the product “ wrap ” before the twisting begins . again , the further - details of these cam arrangements are within the ordinary level of knowledge of those in the art , and need not be described further . the discharge drum 150 is provided with twelve product grippers 112 identical to those of the other two drums 110 and 130 ( but , unlike those of the transfer - and - rotate drum 110 , not themselves mounted for rotation ). the transfer of the product 30 from the twist - wrap drum 130 to the discharge drum 150 is achieved in the same manner as that from the transfer - and - rotate drum 110 to the twist - wrap drum 130 , and therefore will not be described in detail . the present invention has been described by reference to the preferred embodiment thereof , including enough detail to enable those of ordinary skill to make and practice the invention , and including what the inventors currently consider to be their best mode ( if any ) of practicing the invention . nonetheless , many modifications and variations will now be apparent to those skilled in the art , and the scope of the present invention is therefore not to be limited by the details of the foregoing description , but only by the terms of the following claims .