Method and apparatus for transferring relatively flat objects

An apparatus for transferring a relatively flat object from a work station along a transfer path includes an upper tooling within the work station for locating the object in a ready position by causing an upper surface of the object to adhere to the tooling. The object is thus unsupported along its lower surface. A manifold forming at least one orifice is located adjacent to and directed toward the ready position, and is connected to a source of pressurized gas. A valve initiates and discontinues flow of pressurized gas through the orifice. A control system controls the valve to direct a stream of pressurized gas through the orifice as or before an object is located in the ready position, thereby causing the transfer of the object in free flight from the work station.

BACKGROUND OF THE INVENTION 
The present invention relates to a method and apparatus for the transfer of 
relatively flat objects from a first work station and, more particularly, 
to the means by which the object to be transferred is propelled from the 
work station. The present invention is especially adapted for use within 
equipment for the manufacture of shells used to close the ends of metal 
cans. 
One common way of packaging liquids, foods and other products, particularly 
beer, soft drinks, juices and the like, is within cans typically formed 
from aluminum or steel. In such cans, the can body is either manufactured 
to include both the can side walls and an attached bottom end, or the 
bottom end is formed separately and subsequently joined to the side walls. 
The upper end, which includes the means by which the can is later opened, 
is manufactured separately and attached to the can body after the can has 
been filled. The can ends, often referred to within the art as shells, are 
generally manufactured within ram presses. While various particular 
methods of shell formation are known and available, it is often necessary 
as a part of these methods to transfer the shells from a first to a 
succeeding work station. In any case, it is also necessary to transfer the 
shells from a work station out of the press. In view of the large 
quantities of cans and shells that are manufactured, it is desirable to be 
able to form quantities of the shells very rapidly. This necessitates a 
transfer system that is both quick and reliable. 
Various types of transfer systems for shells are known. In one approach, 
the shell is partially formed within the first tooling station and then 
positioned for transfer. A device is actuated to strike the shell with an 
edgewise blow that propels the shell outwardly from the tooling. The shell 
moves lateral-y along a transfer path either out of the press for further 
processing, or to a second station within the press for additional 
operations. 
An example of this type of transfer system may be seen in U.S. Pat. No. 
4,561,280. There, a driver extends an actuator to provide the blow for 
moving the shell along the transfer path. Ideally, the shell moves in free 
flight without contacting the restraining structure defining the path 
until the shell is captured at the second station. This system has been 
found to work well. However, it is not unusual for shell forming presses 
to be operated at speeds in excess of 24,000 strokes per hour. Such rapid 
and repetitive action takes a significant toll on mechanical devices. 
Thus, while the driver described above is specifically designed for speed 
and reliability, failures of the mechanical drivers would not be totally 
unexpected. Moreover, it would not be unusual for the driver mechanism to 
develop an unwanted sticking effect, whereby extension or retraction of 
the shell driving actuator could be slightly delayed. 
Particularly where a shell is being transferred into a second work station 
within the same press, speed and consistency in transfer times is of great 
importance. Thus, it is not only necessary that the shell drivers continue 
to function, but that they continue to operate with optimum performance. 
Otherwise, shells could be delayed in being discharged from the press work 
station. While it might be possible to provide detectors for determining 
the occasional late arrival of shells at a second station, there is no 
practical way of delaying operations in the stations since such operations 
are under the control of the press drive. With the press running at speeds 
of several hundred strokes per minute, the timing of individual strokes 
cannot be altered. Thus, a late arriving shell could be subjected to 
forming or other work steps prior to proper positioning within the 
tooling. At best, this result in a deformed workpiece, but could also 
cause disruption of the manufacturing process requiring restarting of the 
press, removal of lodged workpieces, or even repair to damage to the press 
tooling itself 
It can be seen, therefore, that any improvement in the transfer mechanism 
for moving shells from a press tooling and directing them into a transfer 
path is advantageous. Such improvements that increase either the speed or 
reliability of the transfer process will be reflected in a smaller number 
of defective shells and greater reliability of the press operation as a 
whole. 
SUMMARY OF THE INVENTION 
In meeting the foregoing needs, the present invention provides an apparatus 
for transferring a relatively flat object from a work station along a 
transfer path. Means located within the work station locates the object in 
a ready position by causing an upper surface of the object to adhere to 
the locating means, whereby the object is unsupported along a lower 
surface thereof. An orifice defining means is located adjacent to the 
ready position for defining an orifice directed toward the ready position. 
Supply means connected to the orifice defining means connects the orifice 
defining means to a source of pressurized gas. Valve means disposed within 
the supply means initiates and discontinues flow of pressurized gas 
through the orifice defining means. A control means controls the valve 
means such that the object is transferred in free flight from the work 
station. 
In accordance with the invention, the orifice defining means may define a 
plurality of orifices, each directed toward the ready position at an 
angular relationship with respect to the other orifices. A manifold means 
interconnects the orifices. The supply means is in turn connected to the 
manifold means. The control means controls the valve means to direct a 
stream of pressurized gas through the orifices toward said ready position 
at least when an object is located in the ready position to cause he 
transfer of the object. 
The orifice defining means may define the orifices so as to form the 
streams of pressurized gas along mutually converging paths toward the 
ready position. These mutually converging paths should converge near the 
center of an object supported in the ready position. 
Preferred embodiments of the invention include two or three orifices, 
although a greater number may be used. 
According to another embodiment of the invention, the orifice defining 
means located adjacent to the ready position defines at least one orifice 
directed toward the ready position. The control means which controls the 
valve means to direct a stream of pressurized gas through the orifice 
operates such that the stream is initiated prior to location of an object 
in the ready position. As a result, transfer of the object in free flight 
from the work station is caused as the object is located into the ready 
position. 
The object locating means may include a lower surface, with the lower 
surface defining therein a vacuum opening. A source of vacuum connected to 
the vacuum opening causes the object to adhere to the lower surface. 
The object locating means may be a portion of a vertically-acting, 
reciprocating tooling set for working upon the object, the lower surface 
being defined on an upper tooling of the set. The ready position may be 
defined at an upper portion of a stroke of the tooling set. 
The tooling set may include a blank punch disposed as the outermost portion 
of the tooling set, the blank punch being constructed to punch a blank 
from a sheet of stock material. The object locating means is defined on a 
portion of the tooling set disposed radially inward of the blank punch. 
The blank punch is raised to its uppermost stroke position subsequent to 
location of the object locating means at the ready position, whereby the 
blank punch shields the object from the stream of pressurized gas until 
the blank punch is raised past the ready position. 
According to another embodiment, the invention is incorporated within a 
reciprocating ram press having a vertically-operating tooling set within 
each of a plurality of work stations for separating blanks from a sheet of 
stock material and for forming the blanks into relatively flat objects, 
and means for transferring each object from its corresponding work station 
along a transfer path. 
Each of the tooling sets has an upper tooling including means for locating 
an object in a ready position by causing an upper surface of the object to 
adhere to the upper tooling, whereby the object is unsupported along a 
lower surface thereof. Orifice defining means is located adjacent to the 
ready position at each of the work stations for defining at least one 
orifice directed toward the ready position. A supply means is connected to 
each of the orifice defining means for connecting all of the orifice 
defining means to a source of pressurized gas. 
A single valve means is disposed within the supply means but remote from 
the work stations for initiating and discontinuing flow of pressurized gas 
through all of the orifice defining means. Control means controls the 
valve means to direct streams of pressurized gas through the orifices at 
least when the objects are located in the ready position, thereby causing 
the simultaneous transfer of the objects in free flight from the work 
stations along the transfer paths. 
The supply means may include a manifold connected to the source of 
pressurized gas and a plurality of supply lines, one of the supply lines 
being connected between the manifold and each of the orifice defining 
means. 
Accordingly, it is an object of the present invention to provide apparatus 
and a method for transferring a relatively flat object from a work station 
along a transfer path; to provide such apparatus and method that is 
particularly adapted for use within a reciprocating ram press; to provide 
such apparatus and method that is particularly adapted to transfer shells 
used for closing metal cans; to provide such apparatus and method that is 
usable with shells of varying materials and weights; to provide such 
apparatus and method that is usable to transfer shells either from a first 
partial forming station to a second, succeeding forming station, or from a 
forming station out of the press; to provide such apparatus and method 
that can increase the speed with which transfers of such shells are made; 
to provide such apparatus and method that can increase the reliability 
with which transfers of such shells are made; to provide such apparatus 
and method that can increase the output of shells from the press; and to 
provide such apparatus and method that can decrease the number of shells 
damaged as a result of improper transfer. 
Other objects and advantages of the invention will be apparent from the 
following description, the accompanying drawings, and the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings, a typical ram press used in the 
manufacturing of shells for can ends is shown generally in FIGS. 1 and 2. 
The press includes a drive motor 10 coupled to a flywheel 12 on the press 
crankshaft 14 which reciprocates the ram 16 along gibs 18 that are mounted 
to posts 20 extending upwards from the press bed 22. Upper tooling is 
fixed at 24 to the bottom of ram 16, and cooperating lower tooling is 
fixed at 26 to the top of bed 22. The relatively thin metal stock 28 from 
which the shells are formed is fed incrementally from a roll 29 into the 
front of the press. 
The present invention is not dependent upon any specific method of shell 
formation, so long as the shells are at least partially formed with the 
ram press and transferred from the forming tooling. Thus, any one of a 
variety of methods may be used. In one preferred method, a two-step 
process requiring two separate toolings for each shell to be formed is 
used. At the first tooling, a blank is punched from the sheet of stock 
material. Into the blank is formed a substantially flat central panel and 
an upwardly extending chuckwall about the edge of the panel to produce a 
partially formed shell. The partially formed shell is then transferred to 
a second tooling within the same press, where the shell is captured and 
located. At this tooling, a countersink is formed into the shell at the 
base of the chuckwall by moving the panel upward relative to the chuckwall 
to produce a completed shell. Portions of this method and the necessary 
apparatus are described in detail below; further details may be found in 
commonly-assigned U.S. Pat. No. 4,561,280 of Bachmann et al, issued Dec. 
31, 1985, which is hereby incorporated by reference. 
However, it is not necessary that the two-step method disclosed in the 
above-referenced patent be used. For example, a method in which the 
forming that occurs within the press takes place at only a single station 
would also be appropriate, as is shown in either U.S. Pat. No. 4,382,737 
of Jensen et al, or U.S. Pat. No. 3,537,291 of Hawkins. With such a 
method, finishing of the shells is performed following their ejection from 
the press. 
For the preferred shell-making method and apparatus, the press tooling for 
each of the first stations 30 (or first stage of the method) is shown 
generally in FIG. 3. The upper tooling 32 is connected for operation by 
the press ram, while the lower tooling 34 is fixedly mounted to the press 
frame. 
Lower tooling 34 includes die cut edge 36, over which the metal stock 
enters the tooling at a level generally indicated by line 38. Die cut edge 
36, along with die form ring 40 are solidly supported by block member 41 
which is in turn supported by base member 43. Additionally, lower tooling 
34 includes draw ring 42, positioned between die form ring 40 and die cut 
edge 36. A center pressure pad 44 is located concentrically within form 
ring 40. Draw ring 42 is supported by springs 45 (only one shown) mounted 
in base member 43. Springs 45 are shown in FIG. 3 in a compressed 
condition, caused by pressure exerted upon draw ring 42 when the tooling 
is closed. The center pressure pad 44 is supported by spring 47 mounted 
within pressure pad 44 and base member 43 central to the first station 
tooling. Spring 47 is also shown in a compressed condition from force 
exerted by the upper tooling 32. 
When the tooling is open, draw ring 42 and center pressure pad 44 are 
retained in the lower tooling 34 by flanges 49 and 51 integrally machined 
on the respective tooling portions with draw ring 42 bottoming against die 
cut edge 36 and center pressure pad 44 against form ring 40. In such case, 
the uppermost surface of draw ring 42 is at a position some distance below 
the lowest point of shear on the die cut edge 36, while the uppermost 
surface of the center pressure pad 44 is some distance above draw ring 42 
and below lowest point of shear on die cut edge 36. 
Upper tooling 32 is provided with blank punch 46 which is positioned to 
cooperate with draw ring 42 for compression of spring 45 as the tooling is 
closed. A knockout and positioner 48 is located above die form ring 40, 
and punch center 50 is provided with an appropriate configuration to 
produce the partially completed shell, as well as to clamp a blank in 
cooperation with center pressure pad 44. Blank punch 46, knockout and 
positioner 48, and punch center 50 are all closed simultaneously upon 
lower tooling 34 as the press ram is lowered. 
The operation of the first station tooling 30 to produce the blank from the 
stock and partially form a shell is shown in detail in FIGS. 4-7. In FIG. 
4, the tooling is shown already partially closed. The stock 28 initially 
entered the tooling along a line indicated at 38, and as the press ram is 
lowered, a flat blank 58 is produced by shearing the stock material 
between die cut edge 36 and blank punch 46. 
As the press ram continues downward, the blank punch 46, knockout and 
positioner 48, and punch center 50 all continue to move simultaneously. At 
the point illustrated in FIG. 5, the blank 58 is still pinched between 
blank punch 46 and draw ring 42, and between punch center 50 and center 
pressure pad 44, beginning the formation of the shell over die form ring 
40. As the blank 58 is formed over form ring 40, it is pulled from between 
blank punch 46 and draw ring 42. 
Referring now to FIG. 6, the press ram continues to move downward as the 
punch center 50 begins to form the panel of shell 58 (heretofore referred 
to as blank 58). The shell material is no longer held between the bank 
punch 46 and the draw ring 42, but is still contained between punch center 
50 and center pad 44, and the draw ring 42 no longer controls the 
formation of the shell. The clearance between the inside diameter of the 
blank punch 46 and the outside diameter of the die form ring 40 is 
selected to provide an appropriate amount of drag or resistance on the 
shell 58 to insure proper formation. The upward-extending chuckwall 54 of 
the completed shell begins to be formed. 
In FIG. 7, the tooling is shown in its closed position with the press ram 
bottomed against appropriate stop blocks. The first portion of the shell 
formation operation is completed, with a shell 58 being formed having a 
flat panel 60 terminating at a relatively large radius area 62. The large 
radius area 62 forms the junction region of chuckwall 54 with the panel 
60, and will later form the shell countersink and panel form radius. A 
much tighter radius will later be provided for the shell countersink. 
The shell is further provided with a lip 64 extending generally outwardly 
and upwardly from the chuckwall 54, but having general downward curvature. 
Lip 64 is provided with two distinct curvatures, with the portion adjacent 
chuckwall 54 having only slight relative curvature and thus providing the 
upward extension of lip 64. The outermost portion is provided with a 
relatively sharp downward curvature by die center form ring 40, and the 
lowermost portion of the outer edge of lip 64 is formed to at least even 
with, if not above, the point where lip 64 connects with the shell 
chuckwall 54. 
It will be noted that upon closure of the tooling, knockout and positioner 
48 does not contact shell 58. Once the forming operation has been 
completed, the press ram is raised to open the tooling. As the tooling is 
opened, shell 58 is held within blank punch 46 by the tight fit of shell 
58 therein caused during its formation and is carried upward by upper 
tooling 32. For reasons that will be described in detail below, once the 
lowermost portion of shell 58 has cleared the stock level indicated in 
FIG. 4 at 38, knockout and positioner 48 halts its upward movement, while 
blank punch 46 and punch center 50 continue to rise with the press ram 
toward the uppermost portion of the press stroke shown in FIG. 8. When the 
upward movement of knockout and positioner 48 is stopped, shell 58 will 
contact knockout and positioner 48 which knocks out, or pushes, shell 58 
from within the still-moving blank punch 46. 
The shell 58 is then held in position on knockout and positioner 48, as 
shown in FIG. 8, through application of a vacuum to shell 58. A vacuum 
passage 66 connects with a conventional shop vacuum supply to provide the 
vacuum to the surface of punch center 50. This vacuum then causes the 
shell 58 to adhere to the surface of knockout and positioner 48. 
Upon completion of the first operation upon the shell, it is moved by the 
transfer means of the present invention, to be described in detail below, 
either out of the press or to a corresponding one of a plurality of second 
stations for completion of the formation process. 
At the second station tooling (not shown), the partially completed shell is 
captured and located within the tooling. The complete transfer and 
repositioning operation occurs between successive strokes of the press, so 
that as the press ram is next lowered, the tooling of the second station 
acts to work the partially completed shell into a finished shell. In 
carrying out this operation, the tooling clamps the chuckwall of the 
shell, whereafter a raised central panel is formed into the shell to 
define a countersink at the base of the chuckwall. Further, the lip is 
given additional downward curl to properly configure the lip for later 
seaming to the upper end of a can body. The details regarding this 
operation, which are not necessary to understand the present invention may 
be found by reference to the above incorporated U.S. Pat. No. 4,561,280. 
Returning now to FIG. 8, once the shell which has been formed within the 
first station tooling is positioned, the shell 58 is ready to be 
transferred either to a subsequent tooling station or out of the press. 
The mechanism through which shell transfer occurs is the impinging of at 
least one directed blast of preferably compressed air, but alternatively 
any appropriate pressurized gas, against the chuckwall 54. The blast is 
sufficient to propel the shell from the tooling in the direction indicated 
by arrow 68. 
The air stream is caused to emerge from manifold 70 which includes air 
passages therethrough which define at least one nozzle or orifice opening 
from manifold 70. The air stream is initiated by an air valve 71, 
connected to a remote source of compressed air. Manifold 70 is secured to 
the stripper plate 74, positioned near the location for partially 
completed shells which are supported for transfer. 
Also in FIG. 8, a transfer mechanism is shown for moving a partially 
completed shell from a first station tooling into a transfer path for 
delivery to a second tooling station where formation is completed. Only 
upper tooling 32 is shown, it being understood that the cooperating lower 
tooling is disposed beneath stripper plate 74 with tooling 32 lowered by 
the press ram through an opening (not shown) in the stripper plate. 
Manifold 70 is positioned adjacent tooling 32, so that the manifold will 
be in position to direct at least one stream of air against a shell 58 
positioned on the lower, working surface of tooling 32. 
Referring also to FIG. 9, the shell 58 will be propelled in substantially 
free flight into the entrance to a transfer path 82 leading to a second 
tooling station 84. There, the shell is captured and located within 
appropriate capturing mechanism 86 prior to being operated upon by the 
second station tooling. Details of the capturing mechanism 86 may be seen 
by reference to U.S. Pat. No. 4,561,280, which has been incorporated 
hereinto by reference. 
Transfer path 82 is partially enclosed, and is defined by a pair of side 
walls 88 mounted to stripper plate 74. A pair of cross members 90 and 92 
are connected between walls 88, and a pair of polished rails 94 are 
connected to the underside of each member 90 and 92 to define a top for 
the transfer path. Because the shell is propelled to travel substantially 
in free flight along the path, walls 88, plate 74 and rails 94 are 
provided only to occasionally guide a shell and to prevent shells from 
inadvertently leaving the transfer path. Normally, a shell does not travel 
in contact with these surfaces. 
A typical length for transfer path 82 from the first station tooling to the 
second station tooling is in the order of, but not limited to, 
approximately 10-30 inches (25 to 75 cm). 
It is preferred that the compressed air or other pressurized gas be 
supplied to air driver mechanism 71 be supplied at a pressure of 
approximately 60-85 psi (4.2 to 6.0 kg/cm.sup.2). However, it has also 
been found that pressures within the range of approximately 25-95 psi 
(1.7-6.7 kg/cm.sup.2) are usable. 
It has been found that for particular shapes of shells, and particularly 
for shells of greater thicknesses heavier materials such as steel, it is 
advantageous for manifold 70 to define more than one orifice. The multiple 
orifices form multiple streams of compressed air which are directed 
against the shell. 
One embodiment for a multiple orifice manifold is shown in FIG. 10. 
Manifold 70 includes an inlet port 122 into which is located a fitting 124 
connected to air supply line 126. From inlet port 122 the internal 
passageway of manifold 70 branches into three air paths 128, 130 and 132. 
Each terminates in an orifice or nozzle 134, 136 and 138, respectively. 
The orifices 134, 136 and 138 are arranged in a converging relationship, 
directed toward the shell mounted to the bottom surface of the first 
station tooling 32. The orifices define a convergence point which is near 
the center of the mounted shell. While it is not critical that the 
convergence point be at the center of the shell, the air streams emerging 
from the orifices should not converge prior to reaching the shell, and 
should preferably not converge until the shell has been moved by the air 
streams at least some distance. For the example illustrated in FIG. 10, 
the orifices 134 and 138 are arranged at 15.degree. angles with respect to 
center orifice 136. 
Manifold 70 is preferably formed from steel, and in such case may be made 
in three pieces as shown in FIG. 10 for ease of machining. However, it 
will be recognized that manifold 70 may be formed in other manners, for 
example, by molding the manifold from plastic. 
A second embodiment for the manifold may be seen by reference to FIG. 11. 
In this case, manifold 140 provides only two orifices 142 and 144 directed 
towards a shell carried on the bottom of a tooling 146. The arrangement of 
the orifices is such that they define lines of convergence which meet at 
about the center of the supported shell. In the particular embodiment 
shown, the relative angle between the orifices is 10.degree.. 
After a shell has been transferred from the first tooling station, and 
captured and worked into its final form at second station 84 (FIG. 9), the 
shell must be removed from the second station and out of the press. 
Accordingly, a manifold 140 is mounted adjacent tooling station 84, 
connected to the compressed air supply via valve 148. Thus, as the second 
station tooling is raised to lift the completed shell to a ready position, 
air is directed from the orifices of manifold 140 to propel the shell from 
the tooling station and out of the press. 
Further details regarding the detailed structure of the second station 
tooling may be seen by reference to the incorporated U.S. Pat. No. 
4,561,280. 
In the case of manifold 140, only two orifices are needed since transfer 
times out of the second station are less critical than from the first 
station. This is due to the fact that a shell transferred from the first 
station must be positioned within the second station tooling prior to the 
next press stroke, whereas a shell transferred from the second station 
need only clear the press prior to the next stroke. 
While embodiments have been specifically disclosed having two and three 
orifices within a single manifold, it will be recognized that four or more 
orifices could be useful in some applications. Further, other angular 
relationships between the orifices could be used, so long as the orifices 
are arranged to reliably propel the shell along the desired transfer path. 
The orifices for manifolds 120 and 140 have a preferred dimension of 0.120 
inches (0.305 cm), but it has been found that adequate transfer can be 
obtained with an orifice size ranging from 0.060-0.140 inches (0.150-0.350 
cm). The manifold orifice is preferably circular, but may be of other 
shapes. 
The duration for which air valve 71 is energized to direct air through 
manifold 70 is dependant upon the distance over which the shell is to be 
transferred, as well as the size of the shell. Thus, this duration may 
vary over a relatively wide range. However, for several working 
embodiments of the apparatus disclosed herein, duration times vary between 
approximately 0.040 and 0.140 seconds. 
Details regarding valve 71 and control of the valve will be described in 
detail below. 
It has been found to be helpful to use, as part of the transfer apparatus, 
an air assist mechanism along the transfer path. The assist mechanism may 
be seen by reference to FIG. 9. An air valve 96 which may be similar in 
construction to air valve 71 directs air to the assist mechanism from a 
reduced source of compressed air or other pressurized gas, preferably a 
source of 25 to 50 p.s.i. (1.7 to 3.5 kg/cm.sup.2). Valve 96 is in turn 
connected to a conduit 104 extending downwardly along the exterior of one 
side wall 88. Conduit 104 curves around the end of wall 88 to the entrance 
to transfer path 82, where conduit 104 terminates in an open end. At the 
open end, a nozzle 106 is formed consisting preferably of simply a 
flattened portion of conduit for focusing the air emerging from the 
conduit. Nozzle 106 is positioned adjacent the inner surface of wall 88 
and against base plate 74, and is directed down path 82 in the direction 
of shell movement. 
Valve 96 is actuated to permit air flow through conduit 104 just after a 
shell has entered into the transfer path 82, and air flow is continued 
until the shell has completed its movement along the path to the second 
tooling station. It has been found that the air supplied in such a manner 
provides a pushing force behind the shell as the shell effectively rides 
the air stream, as well as some turning motion to the shell as a result of 
the application of air at one side of the transfer path. Further, it is 
believed that the air stream provides a cushion upon which the shell is at 
least partially supported. These effects have been found to be beneficial 
in facilitating shell movement along path 82 for transfer. Specifically, 
shell speed is increased, and the direction of the moving shell is more 
closely regulated to decrease contact with the structure defining the 
transfer path. 
The transfer mechanism as shown in FIGS. 8 and 9, particularly the air 
driver mechanism, is specifically adapted to carry out the transfer of a 
shell from a first station tooling to a second station tooling within the 
same press. Of course, the present invention is not limited solely for 
such a transfer, but rather can be used for any shell transfer, or for 
transfers of other relatively flat objects moving in edgewise fashion. In 
a shell press having a two-stage tooling arrangement, such as that shown 
in FIG. 9, it is anticipated that a similar air assist mechanism may be 
used in conjunction with the shell transfer mechanism moving shells from 
the second station tooling station out of the press. 
The electrical control means for controlling operation of the press for the 
manufacture of shells is shown schematically in FIG. 12. Power is supplied 
to main drive motor 110 through lines L1, L2 and L3 for driving the press 
ram to open and close the tooling of the first and second stations. A 
series of operator controls 112, which may be mounted on one or more 
conveniently located control panels, enable the press operator to control 
stopping, starting and speed of the press, as well as to control and 
monitor various other press functions. 
A number of press functions are controlled by a programmable rotary 
position switch 114 that provides a variety of separate switching 
functions, each of which may be adjusted to open and close switching 
contacts at predetermined angular positions of the press crank. Rotary 
switch 114 is mounted for operation to the press frame, and is coupled to 
the rotary press ram drive through a drive chain or the like, and hence is 
coupled indirectly to motor 110 as indicated in FIG. 12. The switch is 
connected to the ram drive so that the switch position designated 
0.degree. coincides with the uppermost position of the press ram stroke. 
The electrically operated functions of the press are directed by a 
microprocessor 116 which interfaces with operator controls 112 and rotary 
position switch 114. The microprocessor 116 is programmed to control 
various press functions in proper timing and sequence. 
As has been described, each partially completed and completed shell formed 
by the press is transferred from a press tooling station by directing a 
stream of air against the shell through manifold 70 or manifold 140. Each 
manifold 70 or 140, as well as each air assist nozzle 106 is in turn 
controlled by a corresponding air valve 71, 96 or 148, the valves being 
electrically connected for control purposes to rotary position switch 114 
as shown in FIG. 12. The valves are actuated at the appropriate points in 
each press stroke by rotary position switch 114. In this way, the shells 
are transferred only when the press toolings are in correct position for 
transfer. 
A press such as that described herein can be provided with multiple tooling 
sets to produce a plurality of shells with each stroke. A plurality of 
first station toolings and a corresponding number of second station 
toolings and transfer apparatus can be arranged on the press bed so that 
each stroke produces one shell for each tooling set. An example of such a 
press which produces four shells per stroke is shown in FIG. 13. 
Sheet stock 150 is fed into the press beneath stripper plate 152 supporting 
the transfer apparatus. Four first stations 154 are provided for severing 
a blank from the stock 150 and partially forming the shell. Each of first 
stations 154 includes a corresponding three-orifice manifold 70. (A 
manifold having one, two, four or more orifices could also be used, 
depending upon the length of transfer.) Following completion of the 
operation at each first station, air flow through the corresponding 
manifold is initiated to transfer the shell along the transfer path as 
indicated by arrows 156 to a corresponding second station 158. 
At each second station 158, a capturing mechanism 160 operates to 
accurately position the shell within the lower tooling of the second 
station. During the next stroke of the press following that which 
partially formed the shells at the first stations, the tooling at each 
second station 158 closes, thereby completing formation of each shell. 
Following opening of the tooling, a corresponding two-orifice manifold 140 
is actuated to transfer the completed shells from each of the second 
stations 158, as indicated by arrows 162. (Here also, a manifold having 
one or three or more orifices could also be used, depending upon the 
length of transfer.) 
Because the toolings at each of first stations 154 and second stations 160 
are identical, and because the transfer paths are also identical, air flow 
through all manifolds 70 is initiated simultaneously and air flow through 
all manifolds 140 is initiated simultaneously. As a result, it is possible 
to use a single valve 71 for all manifolds 70 and a single valve 148 for 
all manifolds 140. Such an arrangement is illustrated in FIG. 13, and is 
advantageous in that the number of valves is reduced over individual 
valves for each manifold. Further, the system complexity is reduced since 
only air lines need extend into the press tooling area; the electrical 
wiring necessary for control may be kept clear of this area. Servicing of 
the valves is also facilitated, since the valves may be mounted in any 
convenient location. 
While not shown in FIG. 13, a single valve may also be used to initiate air 
flow through any air assist mechanisms which may be installed as part of 
the press toolings. 
An appropriate and preferred valve for use in controlling air flow through 
multiple manifolds is commercially available from Ross Operating Valve Co. 
of Troy, Michigan under part no. W6076B4321. An appropriate mounting base 
from the same source is sold under part no. W409B91. Such valve is a 
four-way valve, having one inlet port, two outlet ports and two exhaust 
ports. Of course, many other commercially available valves are appropriate 
for use with the present invention. 
In the particular embodiments disclosed herein, including that shown in 
FIG. 13, rotary position switch 114 causes valve 71 to be energized 
whenever switch 114 reaches an appropriate rotational position with 
respect to selected actuation times. For example, in one working 
embodiment of the invention, valve 71 may be actuated whenever rotary 
switch 114 reaches the position of 277.degree.. It should be noted that 
this position for rotary switch 114 will occur when the press ram has 
completed most of its upward stroke and the shell has been properly 
positioned. Each shell will then be struck with a blast of air from 
manifold 70 and will be transferred away from its respective tooling 
station. 
In an alternative embodiment, valve 71 may be actuated whenever rotary 
switch 114 reaches the position of 220.degree.. This initiates air flow 
prior to arrival of the shell in the proper ready position for transfer. 
However, particularly in the case of steel or other relatively heavy 
shells, advance of the air initiation insures that adequate air flow is 
present when the shell in fact reaches the ready position. This has been 
found to improve transfer reliability. By comparing FIG. 7, it can be seen 
that as the tooling is raised, blank punch 46 will shield the shell from 
air flow until blank punch 46 is lifted above the level of the supported 
shell. At such time, however, the shell will have been properly 
positioned. (At the second station, no such shielding occurs.) 
Valve 71 is controlled to discontinue the air stream emerging from manifold 
70 at a crank position of 0.degree.. 
While the forms of apparatus herein described constitute preferred 
embodiments of this invention, it is to be understood that the invention 
is not limited to these precise forms of apparatus, and that changes may 
be made therein without departing from the scope of the invention which is 
defined in the appended claims.