Method of and apparatus for continuous bakery product wrapping

An apparatus for continuous bakery products includes a carriage having opposed sealing jaws. Upper and lower webs of wrapping material extend between the jaws of the carriage along a bakery product path. Bakery products to be wrapped are advanced along the bakery product path between the webs of wrapping material and between the initially open jaws of the carriage. The jaws of the carriage are then closed to form transverse seals at the trailing edge of a leading package of bakery products and at the leading edge of a trailing package of bakery products. The carriage is advanced along the bakery product path during the sealing operation so that sealing of the bakery product packages is carried out on a continuous basis. The apparatus for continuous wrapping of bakery products further includes an infeed conveyor having guides for crowding the bakery products into a packaging configuration, a discharge conveyor, apparatus for sealing the lateral edges of the bakery product packages, and apparatus for evacuating air from the bakery product packages.

TECHNICAL FIELD 
This invention relates generally to the wrapping of bakery products in an 
automated bakery, and more particularly to a method of and apparatus for 
continuously wrapping bakery products characterized by uninterrupted 
movement of the bakery products through a bakery product path wherein the 
bakery products are received between upper and lower layers of wrapping 
material, the wrapping material is sealed in a transverse direction 
between groups of bakery products, excess air is removed from the thus 
formed product packages, lateral seals are formed to close the product 
packages, and an optional center seal is effected in the product package. 
BACKGROUND OF THE INVENTION 
As is well known in the baking industry, bakery products such as hamburger 
buns, rolls, and similar bakery products are almost universally packaged 
in polyethylene wrapping material to protect the bakery products against 
staleness, contamination, and tampering. 
In an automated commercial bakery, bakery products are baked and aligned 
into columns for movement through a slicing machine. The sliced products 
are then gathered into groups of 6 or 12, depending upon the desired 
package size, and wrapped in polyethylene wrapping material. Heretofore, 
various devices, such as those described in U.S. Pat. No. 3,355,857 and 
U.S. Pat. No. 3,760,553 have been provided for wrapping bakery products 
with polyethylene wrapping materials. 
One of the drawbacks to the typical prior art design for apparatus of this 
type involves the fact that polyethylene has a relatively high melting 
point, thereby requiring the application of heat for a relatively long 
period of time to melt the polyethylene sufficiently to effect a seal 
between the various sheets of the material comprising the bakery product 
package. For this reason, the prior art wrapping apparatus have required 
that the products being packaged remain in a stationary position during 
the sealing operation. Such requirement is detrimental in that it results 
in intermittent movement of the bakery product during the sealing 
operation, thereby slowing the packaging process. Thus, the overall 
process of slicing the bakery products, assembling the bakery products 
into groups for packaging, and packaging the bakery products is slowed 
down by the fact that the transverse sealing step has heretofore been 
stationary. 
An additional drawback to typical prior art design for apparatus of this 
type involves the fact that the completed bakery product package contains 
excess air allowing shifting and separating of the bakery products upon 
leaving the product line of the commercial bakery. 
SUMMARY OF THE INVENTION 
The present invention overcomes the foregoing and other problems long since 
associated with the prior art by providing an apparatus for wrapping the 
bakery products and sealing the polyethylene wrapping material on a 
continuous basis. In accordance with the broader aspects of the invention, 
a sealing mechanism is characterized by upper and lower jaws which are 
initially separated sufficiently to allow the bakery product group to be 
packaged to pass therethrough. Through the open jaws are passed upper and 
lower lengths of polyethylene wrapping material between which bakery 
product groups are fed under the action of the infeed conveyor. 
After a bakery product group has passed through the open jaws, the jaws are 
closed to effect dual transverse seals, one comprising the seal for the 
trailing edge of a leading package of bakery products and the second 
comprising the seal for the leading edge of a trailing package of bakery 
products. The jaws are mounted on a carriage which travels on ways to 
allow the jaws to move with bakery product package along the bakery 
product path during the sealing process, such that the movement of the 
bakery product package is continuous during the sealing process. After 
transverse sealing has been completed, a cutting band disposed between the 
two jaws is activated to separate the leading package from the trailing 
package, after which the jaws are opened and retracted. Thus, the 
requirement that the bakery product package remain stationary during the 
sealing process is omitted, increasing the rate of packaging, and thereby 
alleviating the slowdown in slicing and grouping the bakery products for 
packaging. 
After the transverse seals have been effected, the bakery product packages 
continue movement along the bakery product path for sealing of the lateral 
edges of the packages. The lateral edges of the product package pass 
through two opposed pairs of upper and lower wheels as hot air is directed 
between wheels to melt the polyethylene wrapping material, thereby 
effecting the lateral seals as the bakery product package continues 
uninterrupted movement along the bakery product path. Vacuum vents are 
inserted into the product package and activated to remove excess air in 
the package simultaneously with the completion of the lateral seals. Thus, 
the packaging material fits snugly around the bakery products to reduce 
damage thereto as a result of shifting of the bakery products once the 
product package leaves the product line of the bakery. 
An optional longitudinal center seal may be accomplished by activating 
centrally disposed upper and lower wheels to engage and move the 
polyethylene wrapping material in the center of the product package as hot 
air is directed between the wheels, melting the polyethylene material to 
effect the longitudinal center seal. The longitudinal center seal is 
effected simultaneously with the lateral seals of the product package and 
removal of the excess air within the product package, as the bakery 
product package continues uninterrupted movement along the bakery product 
path. Thus, the bakery products are wrapped at a faster rate in a package 
providing improved support to prevent shifting of the bakery products 
after the package leaves the product line of the bakery. Other advantages 
deriving from the use of the invention will readily suggest themselves to 
those skilled in the art.

DETAILED DESCRIPTION 
Referring now to the Drawings, and particularly to FIG. 1 thereof, there is 
shown an apparatus for continuous bakery product wrapping 30 incorporating 
the preferred embodiment of the present invention. The apparatus 30 
defines a bakery product path illustrated in part by the arrows 32 and 34 
and comprising an infeed conveyor 36, a bakery product wrapping conveyor 
38, and a discharge conveyor 40. 
In the operation of the apparatus 30, bakery products such as hamburger 
buns B are received on the apparatus 30 on the infeed conveyor 36 and are 
directed thereby into a throat defined by an upper web of wrapping 
material WU and a lower web of wrapping material WL. The webs of wrapping 
material WU and WL extend through a carriage 44 which includes apparatus 
for partially melting the webs of wrapping material WU and WL to form 
transverse seals at the trailing edge of a leading bakery product package 
and at the leading edge of a trailing bakery product package, and to 
thereafter sever the webs of wrapping material WU and WL to form discrete 
bakery product packages. 
The bakery products are initially directed into the apparatus 30 with the 
sealing and severing mechanism of the carriage 44 in an open condition and 
with the carriage 44 positioned at the extreme left end (FIG. 1) of its 
path of travel. After the bakery products have been received between the 
webs of wrapping material WU and WL and have passed through the carriage 
44, the sealing and severing mechanism thereof is closed and the carriage 
44 is caused to move rightwardly (FIG. 1) as the transverse seals at the 
trailing edge and at the leading edge of adjacent packages of bakery 
products are formed. When the seals have been formed, and with the 
carriage 44 continuing its rightward movement (FIG. 1), the severing 
mechanism of the carriage 44 is actuated to separate the adjacent 
packages. 
The sealing and severing mechanism of the carriage is then opened and the 
carriage is returned to the position illustrated in full lines in FIG. 1. 
The partially completed and severed packages of bakery products continue 
to travel rightwardly (FIG. 1) along the bakery product path under the 
action of the product wrapping conveyor 38 and the discharge conveyor 40. 
Referring simultaneously to FIGS. 1 and 2, the apparatus for continuous 
bakery product wrapping 30 includes a frame 50 which may be of any 
conventional construction. Preferably, however, the component parts of the 
frame 50 are formed from a material such as stainless steel since the 
apparatus 30 is intended for use in conjunction with food products. Thus, 
the frame 50 is preferably comprised of stainless steel components of 
various conventional cross-sectional configurations which are joined 
together by conventional techniques. 
The apparatus 30 further comprises a drive mechanism 52 which supplies 
operating power to all of the component parts thereof. The drive mechanism 
52 includes a motor 54 mounted on the frame 50. The motor 54 preferably 
comprises a constant speed electric motor. However, other conventional 
motor types such as hydraulic motors, pneumatic motors, etc. may be 
utilized in the operation of the apparatus 30, if desired. 
The motor 54 has an output 56 which drives a speed reducer 58 mounted on 
the frame 50. The speed reducer 58 has output shafts 60 extending from the 
opposite sides thereof. Drive sprockets 62 are mounted on the output 
shafts 60 of the speed reducer 58. 
Roller chains 64 direct operating power from the drive sprockets 62 to the 
various operating instrumentalities of the apparatus 30. Thus, the roller 
chains 64 drive driven sprockets 66 which in turn actuate drive shafts 68. 
In the preferred embodiment of the invention, a single motor 54 is 
utilized to actuate the speed reducer 58 which in turn operates through 
the drive sprockets 62, the roller chains 64, the driven sprockets 66 and 
the drive shafts 68 to operate all of the component parts of the apparatus 
30. 
Referring again particularly to FIG. 1, the carriage 44 of the apparatus 
for continuous bakery product wrapping 30 is supported for movement 
between a left-hand limit (FIG. 1) wherein the carriage 44 is illustrated 
in full lines and a right-hand limit (FIG. 1) wherein the carriage 44 is 
illustrated in broken lines. The carriage 44 is supported for movement 
between its limit of travel on stainless steel ways 70 which are in turn 
supported on the frame 50 of the apparatus 30. Antifriction bearing 
members 72 support the carriage 44 for movement along the ways 70. 
The positioning mechanism for the carriage 44 is further illustrated in 
FIG. 2. A roller chain 64' rotates a drive shaft 68' in the forward 
direction, thereby rotating a sprocket 66' in the forward direction. The 
drive shaft 68' also actuates a gear box 73 having an output shaft 74 
which rotates in the reverse direction. The gear box 73 thereby causes a 
sprocket 75 to rotate in the reverse direction. 
A clutch 76 selectively connects the sprocket 66' to a drive shaft 77, 
thereby causing the drive shaft 77 to rotate in the forward direction. A 
clutch 78 selectively connects the sprocket 75 to the shaft 77, thereby 
causing the shaft 77 to rotate in the reverse direction. A brake 79 is 
selectively operable to lock carriage 44 in the position shown in full 
lines in FIG. 1. 
The shaft 77 drives a pair of sprockets 80 which in turn drive a pair of 
timing belts 82. As is best shown in FIG. 1, the timing belts 82 are 
connected to the carriage 44. Thus, the mechanism illustrated in FIG. 2 is 
selectively operable to lock the carriage in the position shown in full 
lines in FIG. 1, to advance the carriage 44 in the forward direction, 
i.e., rightwardly in FIG. 1 until the carriage 44 reaches the limit of its 
travel as illustrated in broken lines in FIG. 1, or to move the carriage 
in the reverse direction, i.e., leftwardly in FIG. 1 until the carriage 
arrives back at its starting position as illustrated in full lines in FIG. 
1. 
The bakery product wrapping conveyor 38 comprises a web of fabric extending 
laterally across the entire width of the apparatus 30. The conveyor 38 
comprises a conveyor course defined by rollers 86 mounted on the frame 50 
of the apparatus 30 and rollers 88 mounted on the carriage 44. The bakery 
product path of the apparatus 30 as partially defined by the arrows 32 and 
34 includes a gap 90 on the carriage 44 which is provided to allow the 
sealing and severing mechanism of the carriage 44 to engage the webs of 
product wrapping material WU and WL. Because the rollers 88 defining part 
of the course of the conveyor 38 are mounted on the carriage 44, the gap 
90 is always positioned in accordance with the positioning of the carriage 
44. 
The carriage 44 of the apparatus for continuous bakery product wrapping 30 
and the sealing and severing mechanism thereof are shown in greater detail 
in FIG. 3A wherein the sealing and severing mechanism is shown in the open 
condition and in FIG. 3B wherein the sealing and severing mechanism is 
shown in the closed condition. The sealing and severing mechanism of the 
carriage 44 includes an upper portion 92 positioned directly above the gap 
90 of the course of the bakery product wrapping conveyor 38. The upper 
portion 92 of the sealing and severing mechanism includes a forward 
elongate heated bar 94 adapted to form a transverse seal at the trailing 
edge of a leading package of bakery products and a rearward elongate 
heated bar 96 adapted to form a transverse seal at the leading edge of a 
trailing package of bakery products positioned immediately adjacent to and 
behind the leading bakery product package. The bars 94 and 96 are 
preferably heated by conventional means, such as electric resistance 
heating elements mounted within the bars 94 and 96. The upper portion 92 
of the sealing and severing mechanism of the carriage 44 further includes 
an apparatus 98 for selectively raising and lowering the heated bars 94 
and 96. 
The sealing and severing mechanism of the carriage 44 also includes a lower 
portion 102 mounted within the gap 90 of the course of the bakery product 
wrapping conveyor 38. The lower portion 102 of the sealing and severing 
mechanism includes elongate rubber members 104 and 106 positioned in 
alignment with and directly beneath the elongate heated bars 94 and 96 of 
the upper portion 92, respectively. The elongate heated bars 94 and 96 and 
the corresponding elongate rubber members 104 and 106 form defined jaws 
which effect sealing of the trailing edge of a leading package of bakery 
products and the leading edge of a trailing package of bakery products, 
respectively. 
As will be appreciated by those skilled in the art, the webs of wrapping 
material WU and WL typically comprise lengths of plastic sheeting 
material. For example, polyethylene is typically employed in the bakery 
industry for the wrapping of bakery products. The temperature at which the 
elongate heated bars 94 and 96 is maintained, and the pressure applied 
between the jaws comprising the elongate heated bars 94 and 96 and the 
corresponding elongate rubber members 104 and 106 are selected in 
accordance with the material comprising the webs of bakery product 
wrapping material WU and WL so as to effect a seal therebetween. 
The lower portion 102 of the sealing and severing apparatus of the carriage 
44 includes a subcarriage 110 having the elongate rubber members 104 and 
106 mounted thereon. Pneumatic cylinders 112 are adapted to raise and 
lower the subcarriage 110 thereby moving the elongate rubber members 104 
and 106 between extreme limits of travel as illustrated in full lines and 
in broken lines in FIG. 3A. The subcarriage 110 includes guide members 114 
which cooperate with guide rollers 116 mounted on the carriage 44 to 
regulate the upward and downward movement of the subcarriage 110 under the 
action of the pneumatic cylinders 112. 
In the operation of the apparatus for continuous bakery product wrapping 
30, the elongate heated bars 94 and 96 are positioned either in the raised 
position illustrated in FIG. 3A or in the lowered position illustrated in 
FIG. 3B by the apparatus 98. The pneumatic cylinders 112 are used to raise 
the elongate rubber members 104 and 106 from the lower position 
illustrated in solid lines in FIG. 3A to a maximum upper position 
illustrated by the broken lines in FIG. 3A so as to apply the appropriate 
pressure between the jaws which effect sealing between the webs of 
wrapping material WU and WL. Thus, the elongate rubber members 104 and 106 
are not normally raised to the full limit of travel as illustrated by the 
dashed lines in FIG. 3A, but rather engage the elongate heated bars 94 and 
96 at the location illustrated in FIG. 3B under the application of a 
predetermined force by the pneumatic cylinders 112 so that the jaws 
comprising the elongate heated bar 94 and the elongate rubber member 104, 
and the elongate heated bar 96 and the elongate rubber member 106, 
respectively, are engaged at the appropriate pressure to effect sealing 
between the webs of wrapping material WU and WL. 
The subcarriage 110 has pneumatic cylinders 120 mounted thereon. An 
elongate heated severing blade 122 is mounted on a support 124 which is 
moved upwardly or downwardly under the action of the pneumatic cylinders 
120. The elongate heated severing blade 122 is heated to a higher 
temperature than the operating temperatures of the elongate heated bars 94 
and 96. Thus, upon engagement with the material comprising the webs of 
wrapping material WU and WL, the elongate heated severing blade 122 heats 
the material sufficiently to melt the material and thereby severe the webs 
WU and WL, thereby separating the leading package of bakery products from 
the trailing of package of bakery products. 
In the operation of the apparatus for continuous bakery product wrapping 
30, bakery products move through the carriage 44 under the action of the 
infeed conveyor 36 and the bakery product wrapping conveyor 38 while the 
component parts of the carriage 44 are in the open condition illustrated 
in FIG. 3A. Thereafter, the apparatus 98 of the upper portion 92 of the 
sealing and severing apparatus of the carriage 44 and the pneumatic 
cylinders 112 of the lower portion 102 of the sealing and severing 
mechanism are actuated to move the component parts of the sealing and 
severing mechanism to the closed condition as illustrated in FIG. 3B. 
Due to the heating of the elongate heated bars 94 and 96, the bars 94 and 
96 cooperate with the elongate rubber members 104 and 106 to define 
sealing jaws which effect transverse seals between the webs of bakery 
product wrapping material WU and WL at the trailing edge of the leading 
package of bakery products and at the leading edge of the trailing package 
of bakery products, respectively. During the process of forming seals at 
the trailing edge of the leading package of bakery products and at the 
leading edge of the trailing package of bakery products, the carriage 44 
and therefore the jaws comprising the elongate heated bar 94 and the 
rubber member 104, and the jaws comprising the elongate heated bar 96 and 
the rubber member 106, respectively, move with the moving webs WU and WL 
along the path defined by the ways 70. Thus, the sealing operation takes 
place on a continuous basis with the bakery products being wrapped while 
moving continuously along the product path as defined by the arrows 32 and 
34 without the necessity of stopping the movement of the bakery products 
to effect sealing of the bakery product packages. 
The carriage 44 continues to move along the bakery product path after seals 
have been effected by the operation of the elongate heated bars 94 and 96 
in cooperation with the elongate rubber members 104 and 106, respectively. 
The pneumatic cylinders 120 are next actuated to raise the elongate heated 
severing blade 122 into engagement with the portion of the webs WU and WL 
extending between the previously formed seals at the trailing edge of the 
leading package of bakery products and at the leading edge of the trailing 
package of bakery products, thereby severing the webs WU and WL and 
separating the adjacent packages of bakery products. The carriage 44 is 
then returned to the position shown in full lines in FIG. 1 while 
separated packages continue to move along the bakery product path under 
the action of the wrapping conveyor 38 and the discharge conveyor 40. 
The apparatus 98 for raising and lowering the elongate heated bars 94 and 
96 of the upper portion 92 of the heating and severing mechanism of the 
carriage 44 is further illustrated in FIGS. 4A and 4B. The carriage 44 
includes upwardly extending members 130 positioned at the opposite sides 
of the course of the product wrapping conveyor 38 and having identical 
racks 132 mounted thereon. A pair of identical pinions 134 are rotatably 
supported at the opposite ends of a bar 136 and are mounted in meshing 
engagement with the racks 132. The pinions 134 are supported by shafts 138 
which are mounted in bushings 140 mounted in the bar 136. 
Each shaft 138 extends outwardly from one side of the bar 136 and has a 
sprocket 142 mounted thereon. A timing belt 144 extends around each 
sprocket 142, around a drive sprocket 146 and around an idler sprocket 
148. A pair of pneumatic actuators 150 are mounted on a post 152 extending 
upwardly from the bar 136. Pneumatic actuators 150 are selectively 
actuated to effect rotation of identical sprockets 146 mounted on the 
opposite sides of the post 152 and supported by a drive shaft 154. Thus, 
upon actuation thereof, the pneumatic actuators 150 effect rotation of the 
sprockets 146 which operate through the timing belts 144 and the sprockets 
142 to effect equal and opposite rotation of the pinions 134. Since the 
pinions 134 are mounted in mesh with the racks 132, actuation of the 
pneumatic actuators 150 thus controls the vertical positioning of the 
elongate heated bars 94 and 96 of the upper portion 92 of the sealing and 
severing mechanism of the carriage 44. 
Referring now to FIGS. 5, 6 and 7, the infeed end of the apparatus for 
continuous bakery product wrapping 30 is illustrated in greater detail. 
The upper and lower webs of bakery product wrapping material WU and WL, 
respectively, are supplied from upper and lower rolls RU and RL, 
respectively. Spare or backup rolls of bakery product wrapping material 
are mounted adjacent to the rolls RU and RL so as to facilitate rapid 
changeover from a spent roll to a fresh roll, thereby eliminating 
downtime. The web of bakery product wrapping WU extends from the roll RU 
along a course defined by a series of rollers 160. The course of the web 
WU extends over a drive roller 162 mounted on the frame 50 of the 
apparatus 30 and ultimately driven by the motor 54. A pinch roller 164 is 
mounted on a bar 166 which is selectively pivoted about an axis 167 by a 
pneumatic cylinder 168. Thus, upon actuation of the pneumatic cylinder 
168, the pinch roller 164 engages the drive roller 162 with the web WU 
trapped therebetween, thereby advancing the web WU along the course 
defined by the idler rollers 160. 
Likewise, the web of bakery product wrapping material WL extends from the 
roll RL along a course defined by a series of idler rollers 170. The 
course of the web WL includes a drive roller 172 mounted on the frame 50 
of the apparatus 30 normally driven by the drive motor 54. A pinch roller 
174 is mounted on the bar 166 and is selectively engaged with the drive 
roller 172 under the action of the pneumatic cylinder 168. Thus, upon 
actuation of the pneumatic cylinder the pinch roller 174 is engaged with 
the drive roller 172 with the web WL trapped therebetween, whereupon the 
drive roller 172 operates to advance the web WL from the roll RL along the 
course defined by the idler rollers 170. 
The bakery products are received on the infeed conveyor 36 which comprises 
part of the bakery product path of the apparatus 30 from a discharge 
conveyor of a bakery product slicer. The bakery products are typically 
received on the infeed conveyor 36 in an expanded condition, that is, the 
bakery products are comprised of a series of longitudinally extending rows 
with spacing provided between adjacent rows. As will be appreciated by 
those skilled in the art, bakery products are typically not packaged in 
such expanded condition, but rather are crowded together as much as 
possible without damaging the bakery products in order to effect efficient 
packaging thereof. 
Referring specifically to FIGS. 6 and 7, the infeed conveyor 36 includes a 
belt 180 which extends under a pair of guides 182 which function to gather 
or crowd bakery products received on the infeed conveyor 36 into a spacing 
arrangement appropriate for packaging. Each of the guides 182 includes a 
belt 184 mounted for movement around a course defined by a drive roller 
186 and a plurality of idler rollers 188. The drive rollers 186 and 
therefore the belts 184 are driven by drive shafts 190 which are in turn 
ultimately driven by the motor 54. 
The guides 182 are selectively positionable by a lead screw 192. The lead 
screw 192 is insertedly engaged with members 194 mounted on the guides 
182, thereby selectively pivoting the guides 182 about the axes of the 
drive shafts 190. The lead screw 192 is actuated by a hand wheel 196. The 
limits of pivotal movement of the guides 182 are illustrated in full lines 
and in broken lines, respectively, in FIG. 6. 
The discharge end of the apparatus for continuous bakery product wrapping 
is illustrated in FIGS. 8, 9, 10, 11, 12 and 13. Referring particularly to 
FIGS. 8, 10 and 11, an upper lateral sealing roller 200 and a cooperating 
lower lateral sealing roller 202 are provided on each side of the course 
of the discharge conveyor 40. Referring particularly to FIGS. 10 and 11, 
the rollers 200 and 202 comprise spaced apart flanges 204 defining a gap 
206 therebetween. As specially in FIG. 10, discharge nozzles 208 extend 
into the gaps 206. The nozzles 208 each extend from a source of heated air 
210. In the operation of the lateral sealing mechanism at each side of the 
course of the discharge conveyor 40, the nozzles 208 direct heated air 
into engagement with the bakery product wrapping material extending above 
and below the bakery products being wrapped and previously sealed at the 
leading and trailing edges thereof. The heated air discharged from the 
nozzles 208 melts the bakery product wrapping material sufficiently so 
that the cooperating flanges 204 of the rollers 202 can form a seal 
between the two webs of bakery product wrapping material, thereby sealing 
the lateral edges of the bakery product packages. 
As is best shown in FIGS. 8 and 9, the apparatus for continuous bakery 
product wrapping 30 includes a blower 212 which functions to form a 
partial vacuum in a pair of vacuum tubes 214. The length of bakery product 
wrapping material situated on top of the bakery products being wrapped is 
guided between a plate 216 (FIG. 9) and a plate 217. Likewise, the length 
of bakery product wrapping material situated beneath the bakery products 
being wrapped is guided between a plate 218 and a plate 219. The vacuum 
tubes 214 establish a partial vacuum between the plates 217 and 219, 
thereby withdrawing air from the package of bakery products just prior to 
the forming of the lateral seals of the package by the rollers 200 and 
202. The apparatus shown in FIGS. 8 and 9 is not intended to "vacuum pack" 
the bakery products within the packaging formed by the apparatus 30. 
Rather, the apparatus of FIGS. 8 and 9 forms a reduced pressure condition 
within the package formed by the apparatus 30, thereby causing the bakery 
product wrapping material which surrounds the bakery products to hug the 
bakery products tightly and prevent movement thereof during shipping. This 
assures that the bakery products will be received by the ultimate customer 
in an as near perfect condition as possible. 
As is best shown in FIGS. 12 and 13, the rollers 200 and 202 which form the 
lateral seals of the bakery product packages formed by the apparatus 30 
are mounted on guides 220. A lead screw 222 extends adjacent and parallel 
to the guide 220 and is actuated by hand wheel 224. The opposite ends of 
the lead screw 222 have right-hand and left-hand threads, respectively. 
Members 226 are mounted in threaded engagement with the lead screw 222 and 
are connected to the support structure for the rollers 200 and 202. Thus, 
upon actuation of the hand wheel 224, the rollers 200 and 202 can be 
positioned appropriately for the size of the bakery product package being 
sealed thereby. 
The discharge conveyor 40 of the apparatus 30 comprising a plurality of 
spaced apart belts 228. The belts 228 travel around a course including a 
lower portion which extends through guides 230. The positioning of the 
guides 230 is controlled by a pantograph linkage 232 which is actuated by 
the lead screw 222 under the operation of the hand wheel 224. 
The pantograph linkage 232 comprises equal and opposite halves situated on 
opposite sides of the centerline of the discharge conveyor 40. The inboard 
end 234 of each half of the pantograph linkage 232 is fixed, while the 
outboard end thereof 236 is secured to the member 226 which is threadedly 
engaged with the lead screw 222. Thus, upon actuation of the lead screw 
222, the outboard ends of the pantographic mechanism 232 are moved either 
inwardly or outwardly depending on the size of the bakery package being 
conveyed. This in turn locates the belts 228 comprising the discharge 
conveyor 40 in accordance with package size. The limits of travel of the 
pantograph linkage 232 and therefore the limits of the positioning of the 
belts 228 comprising the discharge conveyor 40 are illustrated on the 
left-hand side and the right-hand side of FIGS. 12 and 13. 
FIGS. 14, 15, 16 and 17 illustrate a mechanism which can be selectively 
utilized in conjunction with the apparatus for continuous bakery product 
wrapping 30 to form a longitudinally extending center seal for the bakery 
product packages thus formed. By way of example, in the case of a bakery 
product package enclosing twelve hamburger buns, it may be desirable to 
form a center seal so that six of the hamburger buns remain sealed during 
usage of the buns comprising the first half of the package to be opened. 
The mechanism for forming a center seal in a bakery product package 
includes a lower sealing apparatus 240 shown in FIGS. 14 and 15 and an 
upper sealing apparatus 242 shown in FIGS. 16 and 17. The lower sealing 
apparatus 240 comprises a roller 244 comprising a pair of spaced apart 
flanges 246 defining a groove 248 therebetween. A nozzle 250 extends from 
a source of heated air 252 into the groove 248 extending between the 
flanges 246 of the roller 244. 
Upon actuation of a pneumatic cylinder 254, the roller 244 engages the 
length of bakery product wrapping material extending beneath the wrapped 
bakery products. Heated air from the source 252 is directed through the 
nozzle 250 and functions to partially melt the bakery product wrapping 
material. The partially melted bakery product wrapping material is forced 
upwardly by operation of the roller 244. 
Referring to FIGS. 16 and 17, the upper sealing mechanism 242 includes a 
roller 264 positioned for selective engagement with the length of bakery 
product wrapping material extending above the wrapped bakery products. The 
roller 264 comprises a pair of spaced apart flanges 266 defining a groove 
268 therebetween. A nozzle 270 extends into the groove 268 and functions 
to direct heated air into the groove from a source 272. The heated air 
functions to sufficiently soften the bakery product wrapping material so 
that the roller 264 can effect a seal with the corresponding lengths of 
bakery product wrapping material extending beneath the bakery products. 
The roller 264 is selectively positioned in engagement with the length of 
bakery product wrapping material extending above the wrapped bakery 
products by a cylinder 274. The roller 244 of the mechanism 240 is 
preferably positioned directly beneath and in alignment with the roller 
264 of the mechanism 242. Likewise, the cylinders 254 and 274 are 
preferably actuated in tandem. Thus, upon actuation of the cylinders 274 
and 254, the upper and lower lengths of bakery product wrapping material 
are pinched between the rollers 264 and 244, so that upon the application 
of heated air discharged through the nozzles 270 and 250, the bakery 
product wrapping material is softened and a seal is formed therebetween. 
Referring now to FIG. 18, the apparatus for continuous bakery product 
wrapping 30 includes a pneumatic circuit 280. Compressed air is received 
into the pneumatic circuit 280 through an inlet port 282 and is directed 
through a manifold 284 to a line 286 extending to two-position three-way 
valve 288 adapted for solenoid actuation and spring return. From the valve 
288 the compressed air is directed through a line 290 and hence to the 
sources of heated air 210 which supply heated air to the lateral sealing 
rollers 200 and 202 illustrated in FIGS. 10 and 11 and to the sources of 
compressed air 252 and 272 which supply heated air to the center sealing 
rollers 244 and 264 illustrated in FIGS. 14, 15, 16 and 17. The air 
entering the sources of heated air which serve the sealing apparatus is 
directed through a filter 292 so that the bakery product packages formed 
by the lateral sealing mechanisms and the center sealing mechanisms is not 
contaminated. 
Compressed air from the manifold 284 is also directed through a line 296 to 
a valve 298. The valve 298 comprises a two-position four-way valve adapted 
for solenoid actuation and spring return. The valve 298 functions to 
direct compressed air to the pneumatic cylinders 120 on the subcarriage 
110 which effect positioning of the elongate heated severing blade 122. 
In a like manner, compressed air for actuating the pneumatic cylinders 254 
and 274 of the center sealing mechanism shown in FIGS. 14, 15, 16, and 17 
is directed to the cylinders 254 and 274 from the line 296 through a 
two-position four-way valve 300 adapted for solenoid actuation and 
solenoid return. Compressed air for actuating the pneumatic cylinder 112 
which controls the positioning of the subcarriage 110 on the carriage 44 
is directed to the pneumatic cylinder 112 through a two-position four-way 
valve 302 adapted for solenoid actuation and solenoid return. A 
two-position four-way valve 304 adapted for solenoid actuation and spring 
return directs compressed air from the line 296 to the pneumatic actuators 
150 which control the positioning of the elongate heated bars 94 and 96. A 
two-position four-way valve 304 controls the flow of compressed air from a 
manifold 284 through a line 306 to the cylinders 168 which control the 
positioning of the pinch rollers that in turn regulate the advance of the 
webs of bakery product wrapping material WU and WL. 
Referring now to FIGS. 19A, 19B and 20, there is shown a pantographic 
linkage 310 which may be used to control the positioning of bakery product 
guides which in turn control the positioning of bakery products entering a 
bakery product slicing machine. The pantographic linkage 310 includes a 
plurality of block 314 each having a guide receiving aperture 316 formed 
therein. The bakery product guides 312 are selectively positioned in the 
aperture 316, it being understood that in some instances all of the 
apertures 316 receive a bakery product guide, whereas in other instances, 
a bakery product guide 312 is positioned in alternative apertures 316, 
depending on product size. 
The pantographic linkage 310 comprises equal and opposite halves extending 
in opposite directions from a fixed center block 318. The blocks 314 are 
slidably supported and the positioning thereof is controlled by the 
pantographic linkage 310. The linkage 310 further comprises an outboard 
block 320 which is threaded engaged with a lead screw 322. The lead screw 
is drivingly connected to a sprocket which is driven by a chain 326. Thus, 
upon the application of a suitable input to the chain 326, the outboard 
block 320 and therefore the blocks 314 are selectively positioned relative 
to the fixed block 318. The limits of travel of the pantographic linkage 
310 are illustrated in FIGS. 19A and 19B, respectively. 
Although preferred embodiments of the invention have been illustrated in 
the accompanying Drawings and described in the foregoing Detailed 
Description, it will be understood that the invention is not limited to 
the embodiments disclosed but is capable of numerous rearrangements and 
modifications of parts and elements without departing from the spirit of 
the invention.