Die cutting machine with magnetic holder for accurate die positioning

Interposed between the cutting surface and the pressure head is a magnetic die holder including base and die carrying sections, the former being mounted on a telescoping member which is pivotally connected to the head for vertical movement therewith and which permits movement of the holder in a plane parallel to the cutting surface. The base and die carrying sections are connected by a spring to permit the die carrying section to be vertically displaced with respect to the base section for accurate positioning of the die relative to the cutting surface. The die carrying section is also rotatable relative to the base section to permit orientation of the die at any angle with respect to the cutting surface. The die carrying section includes an electromagnet which retains the die thereon. Also located on the die carrying section are a pair of handle grips, each having a switch mounted thereon, both of which must be simultaneously actuated in order to initiate vertical movement of the pressure head. By holding the grips, the die can be displaced and rotated relative to the base section to accurately position and orient the die, and the switches can be actuated. Thus, the die can be accurately positioned and successive die cutting cycles can be performed in a completely safe and highly productive manner without the necessity of the operator removing his hands from the grips.

The present invention relates to die cutting machines and, more 
particularly, to a die cutting machine with a magnetic holder for accurate 
die positioning. 
Die cutting machines used for cutting patterns in sheet material are well 
known in the art and have taken a variety of different forms. Basically, 
such machines consist of a cutting surface upon which the sheet material 
to be cut or otherwise impressed is placed and, mounted thereabove, a 
pressure head. The head is vertically movable, usually by hydraulical or 
electrical means, towards and away from the surface. Between the pressure 
head and the surface is interposed a die which has thereon the outline of 
the pattern to be cut. The operator of the machine manually positions the 
die with respect to the cutting material. The pressure head is then 
actuated, commonly by a foot pedal or hand actuated switch, such that the 
pressure head moves downward to force the die into the material to be cut. 
At the end of its downward movement, the pressure head automatically 
reverses direction and returns to its original position. Thereafter, the 
operator repositions the die relative to the material and repeats the 
cutting cycle. After the entire sheet of material has been cut, same is 
removed and a new piece of material is placed on the cutting surface. 
The overall productivity of the machine depends upon how quickly the 
operator can complete the successive cutting cycles. The time required to 
complete each cutting cycle depends on the amount of time required to 
position the die in the required location and thereafter to actuate the 
pressure head, as well as the time it takes for the pressure head to 
complete its stroke. Positioning and orientation of the die requires 
manual manipulation by the operator of the die, which may be heavy and/or 
bulky. In order to overcome this problem, holders upon which the dies are 
mounted, have been utilized. There are, however, certain mechanical 
requirements which must be met by such die holders. The mounting apparatus 
used to attach the die holder to the remainder of the machine must be 
easily manipulatable such that the die can be positioned as required with 
respect to the cutting surface at a variety of different locations and 
orientations. Further, while the die holder must hold the die at least a 
small distance above the surface of the material to be cut such that the 
die can be moved along the surface, it must permit movement of the die in 
a direction normal to the cutting surface during the vertical movement of 
the head. 
It is necessary that the holder retain the die at a position very close to 
the cutting surface for accurate positioning. However, when the die is 
rapidly moved parallel along the cutting surface between cuts, same must 
be far enough away from the cutting surface to prevent swells or other 
irregularities in the cutting surface, such as are inherent in leather, 
for example, from interfering with movement of the die. Moreover, the 
holder must be able to meet these requirements for a variety of dies of 
different depths, sizes, shapes and weights. 
In addition, government safety standards require that the die cutting 
machine be designed such that the operator's hands are never in the die 
area during the time when the pressure head is actuated. This rule is 
designed to prevent accidents which would occur if the operator 
inadvertently placed his hand in the path of the die movement during the 
actuation of the pressure head. One method of preventing such accidents is 
to utilize a pair of switches, each of which must be simultaneously 
depressed by a different one of the operator's hands to actuate the 
pressure head and which are located on a part of the machine which is 
remote from the die area. Since both of the operator's hands must be on 
the switches when the pressure head is actuated, they cannot be in the 
path of the die movement and thus accidents of this type are eliminated. 
With this type of system, the operator usually must first position the die 
and thereafter remove his hands therefrom and place same on the switches, 
located on another portion of the machine, before actuation of the 
pressure head can take place. While this method of operation has the 
advantage of preventing accidents, it does not promote high productivity 
because of the time required in moving the operator's hands. 
It is, therefore, a prime object of the present invention to prove a die 
cutting machine with magnetic holder for accurate die positioning which 
permits increased productivity in a completely safe manner. 
It is a second object of the present invention to provide a die cutting 
machine with magnetic holder for accurate die positioning wherein the die 
is magnetically retained by the die carrying section of the holder which 
is manipulatable such that it can be displaced from its normal vertical 
position towards the cutting surface for more accurate die positioning. 
It is a third object of the present invention to provide a die cutting 
machine with magnetic holder for accurate die positioning wherein the 
holder is mounted on a telescoping member affixed to the pressure head for 
vertical movement therewith. 
It is a fourth object of the present invention to provide a die cutting 
machine with magnetic holder for accurate die positioning wherein the 
pressure head actuating and die holder magnetic actuating switches are 
located on the die carrying portion of the holder such that the operator's 
hands can never be in the path of the die during the actuation of the 
pressure head and the operator can control successive positioning and 
cutting operations without the necessity of relocating his hands. 
It is a further object of the present invention to provide a die cutting 
machine with magnetic holder for accurate die positioning wherein the die 
carrying section of the holder is provided with a pair of handle grips for 
manipulating same to position and orient the die and upon which are 
located switches which, when simultaneously actuated, serve to initiate 
movement of the pressure head. 
It is still another object of the present invention to provide a die 
cutting machine with magnetic holder for accurage die positioning wherein 
the electromagnet actuating switch is located in proximity to the handle 
grips. 
In accordance with the present invention, the die cutting machine includes 
a support, a cutting surface mounted on the support, a pressure head 
mounted on the support above the cutting surface, and means effective when 
actuated for vertically moving the head toward and away from the surface. 
A die and means for holding the die are interposed between the head and 
the cutting surface. Means are provided for mounting the die holding means 
for movement in a plane substantially parallel to the cutting surface. The 
mounting means is connected to the pressure head for vertical movement 
therewith. The holding means comprises a base section connected to the 
mounting means and a die holding section including an electromagnet for 
retaining the die. Means are provided to permit displacement of the die 
carrying section relative to the base section towards the cutting surface 
prior to pressure head actuation to permit accurate positioning of the 
die. 
Means are provided to adjust the displacement permitting means to vary the 
relative positions of the die carrying section with the base section so as 
to accommodate dies of different sizes. The displacement permitting means 
preferably comprises a tension spring and the means are included for 
varying the tension of the spring to accommodate dies of different weight. 
First and second grip means are located in spaced relationship on the die 
carrying portion to permit the operator to manually locate, rotate and 
displace the die relative to the cutting surface. Preferably, first and 
second switch means are located on the first and second grip means, 
respectively, and must be actuated simultaneously to initiate head 
movement. Further, the electromagnetic actuating means is also preferably 
mounted on the die carrying section, in proximity to the grip members, 
such that successive die cutting cycles can be performed accurately, 
safely and without the necessity of relocation of the operator's hands. 
The mounting means comprises a telescoping structure which is pivotally 
mounted to the pressure head such that the holder can be moved in a plane 
substantially parallel to the cutting surface but far enough above same 
such that the irregularities in the surface do not interfere with the 
movement of the die. Further, the die carrying section is rotatably 
mounted to the base section such that the angular orientation of the die 
may be varied as required. Since the telescoping structure is mounted to 
the pressure head, the entire assembly is movable with the head towards 
and away from the cutting surface. 
Since the die holder is interposed between the pressure head and the 
cutting surface, a few inches above the cutting surface, the path of 
movement of the pressure head towards the cutting surface need only be a 
few inches. However, the depth of penetration of the die into the cutting 
surface must be accurately controlled. A specially designed head utilizing 
hydraulic and mechanical drive linkages is therefore preferably used in 
this connection.

As seen in FIG. 1, the die cutting machine of the present invention 
comprises a frame, generally designated A, supporting a cutting surface, 
generally designated B, upon which a sheet of material to be cut or 
otherwise impressed is situated. Also mounted on frame A is a pressure 
head, generally designated C, which, when actuated, is movable toward and 
away from cutting surface B, a limited distance. Interposed between 
pressure head C and cutting surface B is a die holder, generally 
designated D, designed to support a die, generally designated E. Die 
holder D is mounted on pressure head C for vertical movement therewith by 
mounting means, generally designated F, which is not visible in FIG. 1. 
Frame A comprises four upstanding members 10, only two of which are seen in 
FIG. 1. Members 10 support a generally horizontal table-like cutting 
surface B upon which is situated a flexible cutting pad 12. Upon cutting 
pad 12 a sheet material (not shown in FIG. 1) to be cut or otherwise 
impressed is located. Connected across the top of upstanding members 10 is 
a cross-member 14 to which pressure head C is mounted. Pressure head C 
preferably has a structure which is similar to the structure of the 
pressure head disclosed in U.S. Pat. No. 3,682,029, issued Aug. 8, 1972, 
entitled Balanced and Double Action Cutting Apparatus, which is assigned 
to the assignee herein. This head has hydraulic and mechanical linkages 
which operate together to assure that each stroke has the same bottom 
limit and thus the die has the same penetration depth for each cut. 
Pressure head C is hydraulically driven, by means of a hydraulic cylinder 
16, between a retracted position, as shown in FIG. 1, and an extended or a 
die cutting position. The pressure head moving mechanism includes a pair 
of vertical guide members 18, 20, which are connected between cross-member 
14 and pressure head C, to guide the vertical movement of pressure head C 
relative to cross-member 14. Adjacent each of the vertical guide members 
18, 20 are a pair of toggle arms 22, 24, and 26, 28, respectively. Toggle 
arms 22 and 26 are pivotally mounted to cross-member 14 by means of 
brackets 30, 32. Toggle arm 24 is pivotally mounted at one end thereof to 
toggle arm 22 and at the other end thereof to pressure head C. In a 
similar manner, toggle arm 28 is pivotally mounted to toggle arm 26 at one 
end thereof and to pressure head C at the other thereof. The junction 
between toggle arms 22 and 24 is operably connected to the junction 
between toggle arms 26 and 28 by means of a rod 34, such that each pair of 
toggle arms move simultaneously. Hydraulic cylinder 16 is provided with a 
piston rod 36 extending therefrom which is connected to the junction 
between toggle arms 22 and 24. 
When cylinder 16 is actuated, piston rod 36 is extended such that the 
toggle arms 22 and 24 become substantially vertically aligned. Because of 
connecting rod 34, both sets of toggle arms 22 and 24, and 26, 28 must 
move simultaneously. Thus, the actuation of cylinder 16 causes both sets 
of toggle arms to be substantially vertically aligned, thereby moving 
pressure head C towards cutting surface B a distance accurately defined by 
the length of the aligned toggle arms. The movement of pressure head C 
towards cutting surface B causes die holder D to force die E through the 
sheet material on cutting surface B, so as to cut or otherwise impress the 
material as required. Thereafter, cylinder 16 is automatically actuated to 
retract piston rod 36, thereby causing the toggle arm pairs to return to 
the position depicted in FIG. 1 and causing the pressure head to return to 
the retracted position. 
Die holder D comprises a base section 38 which is supported by mounting 
means F in a vertical position stationary with respect to pressure head C. 
Thus, base section 38 of die holder D is designed to move in the vertical 
direction along with pressure head C. Further, support means F, the 
structure of which is explained in detail below, permits die holder D to 
be moved in a plane parallel to cutting surface B anywhere under pressure 
head C. This latter movement is necessary in order to position die E at 
various locations along the cutting surface B. 
A die carrying section 40, of die holder D, is rotatably and linearly 
moveably mounted on base section 38. Supported on die carrying section 40 
are a pair of grip members 42, 44 each of which has mounted thereon a 
switch, shown in the drawing as a pair of depressable triggers 46, 48. As 
explained in detail below, simultaneous depression of triggers 46 and 48 
will cause actuation of the pressure head drive cylinder 16. Also situated 
on grip 44 is a switch 50 which, when normally closed, energizes an 
electromagnet situated within die carrying section 40 so as to retain die 
E to the bottom thereof. Grip members 42 and 44 can be manipulated so as 
to move die holder D in a plane substantially parallel to the cutting 
surface B and to displace and rotate die carrying section 40 with respect 
to base section 38. Thus, die E can be moved to any angular orientation 
with respect to the cutting surface. The displacement of die carrying 
section 40 with respect to base section 38 permits the operator to place 
the die E on the cutting surface to accurately position same prior to 
actuation of the pressure head C. 
Since the operator can manipulate the die and actuate the pressure head 
while holding the grip members, a number of successive cutting operations 
can be performed safely without removing the operator's hands from grips 
42, 44. After the sheet material is positioned, on the cutting surface, 
the operator grasps the grip members and manipulates die holder D such 
that it is above die E, which is placed anywhere on the sheet. The 
operator actuates button 50 so as to energize the electromagnet within die 
carrying section 40 to cause die E to adhere to the bottom of die holder 
D. Holding the grips, one in each hand, the operator positions the die E 
over the location on the sheet material at which the first cut is to be 
performed and moves the die into the desired angular orientation. This is 
achieved by moving die holder D in a plane substantially parallel to the 
cutting surface and rotating die carrying section 40 with respect to base 
section 38. The operator then presses down on the grip members to displace 
die carrying section 40 relative to base section 38 such that the die E 
rests on the material to be cut in order to accurately position same. The 
operator simultaneously depresses triggers 46 and 48 to actuate the 
pressure head drive cylinder. Actuation of the pressure head drive 
cylinder 16 causes the pressure head to move to its extended position, 
thereby forcing the die through the sheet material to an accurate depth of 
penetration defined by the extension of the toggle arms. After the head 
reaches the extended position, completing the cut, it automatically 
returns to its retracted position. As a safety measure, the pressure head 
drive cylinder 16 cannot be reactuated until the head has returned to the 
retracted position and the triggers have been released and again 
simultaneously depressed. Before the next depression of triggers 46 and 
48, the operator will manipulate grips 42 and 44 so as to reposition, 
reorient and displace the die E in position for the next successive cut in 
the sheet material. When this is completed, the triggers are again 
simultaneously depressed and a second cut is performed. Successive cuts 
are made with the die being repositioned, reoriented and displaced between 
each cut, until the entire material has been cut by successive cutting 
operations. The sheet material is then removed and a new sheet positioned 
on cutting surface B. 
The structure of mounting means F is illustrated in FIG. 2. Mounting means 
F comprises a rigid tubular member 52 supported between the end thereof by 
the lower portion of a bracket 54. The upper portion of bracket 54 has a 
bifurcated or "U" shape, with a shaft 56 extending between the extended 
arms of the "U". Rotatably mounted about shaft 56 is a tubular member 58, 
connected to a second bifurcated or "U"-shaped bracket 60, which is in 
turn bolted to the back of pressure head C. Brackets 54 and 60 permit 
tubular member 52 to be pivoted with respect to pressure head C while 
supporting tubular member 52. 
Tubular member 52 is connected to a second tubular member 62, of larger 
diameter, in telescoping fashion. Tubular member 62 is, in turn, rigidly 
connected to base section 38 of die holder D. By means of tubular members 
62 and 52, and brackets 54 and 60, die holder D is movable virtually 
anywhere below pressure head C in a plane slightly above and substantially 
parallel to cutting surface B. This is illustrated in FIG. 6. 
FIG. 6 is a schematic representation showing how the die holder D can be 
positioned and oriented to perform five separate cutting operations, along 
the length of a sheet of material 64 situated on surface B. It is to be 
noted that in each position the flat side of die E is shown as oriented to 
be substantially parallel to the front edge of sheet material 64. However, 
it should be appreciated that die carrying section 40 can be rotated 
relative to base section 38 such that any angular orientation of the die 
with respect to the cutting surface can be obtained. Viewed in this 
manner, the reason for designing die carrying section 40 of die holder D 
to be rotatably movable with respect to base section 38 of the die holder 
D can be appreciated. In FIG. 6, die holder D is shown in three positions, 
the two end positions and the middle position of the five cuts 
illustrated. From this drawing it is clear that not only do tubular 
sections 52 and 62 telescope with respect to each other, but that tubular 
member 52 is movable with respect to bracket 54. That is, tubular member 
52 can be pulled through bracket 54 in order to permit die holder D to be 
displaced a distance from bracket 54 greater than the telescoping ability 
of tubular members 52 and 62, so as to permit placement at the extreme 
ends of sheet material 64. 
FIGS. 4 and 5 show the swivel assembly of mounting means F in greater 
detail. As will be appreciated from FIG. 5, which is a rear view of the 
swivel assembly, the lower portion of bracket 54 has a bifurcated part 
with a bore therethrough. At the bottom of the bore is provided a pair of 
bolts 66 which are utilized to adjust the relative positions of the 
bifurcated parts. Tubular section 52 is situated within a ball bushing 
collar 68 which acts as a bearing to permit tubular section 52 to move 
relative to bracket 54. This permits die holder D to be linearly displaced 
with respect to bracket 54 a distance larger than the telescoping 
mechanism between tubular section 62 and tubular section 52 would permit. 
The upper part of the lower portion of bracket 54 tapers to form a neck 
70, which forms the bottom of "U"-shaped upper section of bracket 54. 
Bracket 60, which is pivotally mounted to bracket 54 by means of shaft 56, 
is rigidly mounted on pressure head C by means of bolts 72. 
FIGS. 3A and 3B show the structure of die holder D. Tubular member 62 is 
rigidly connected to base section 38 of die holder D. Base section 38 
includes a downwardly extending hollow cylindrical member 74 mounted on 
member 62. Member 74 has a plurality of longitudinally extending grooves 
76 spaced along the outer surface thereof, only one of which is shown. On 
the exterior surface of member 74 are screw threads 75. Base section 38 
also includes a second hollow cylindrical member 78, situated within 
member 74 and having screw threads 77 in meshing engagement with threads 
75 on member 74. A collar member 80, also a part of base section 38 is 
affixed to member 76 by means of screws 81, only one of which is shown. 
The upper portion of collar member 80 has a radial bore 82 within which is 
situated a spring loaded ball bearing 84 cooperating with grooves 76 on 
member 80 in detent fashion. As will now be appreciated, collar member 80, 
and member 76 fixed thereto, can be rotated as a unit with respect to 
cylindrical member 74. This relative rotation will cause member 76 to move 
in a vertical direction with respect to member 74. Since, as explained 
below, the carrying portion 40 is normally urged against the lower portion 
of member 76, the vertical displacement of member 76 relative to member 80 
will cause die carrying section 40 to be vertically displaced relative to 
member 80 and thus relative to the portion of base section 38 mounted on 
member 62. 
Spring loaded detent member 84 cooperates with grooves 76 on the outer 
surface of member 80 such that member 76 is detented into any one of a 
number of different rotational positions relative to member 80. Each 
detented position represents a different relative vertical displacement of 
die carrying section 40 relative to member 80. In this manner, the 
distance between the die carrying surface of section 40 and the cutting 
surface can be varied to accommodate dies of different sizes. 
Die carrying section 40 of die holder D is operably connected to base 
section 38 by means of a tension spring 86. Spring 86, at its upper end, 
is connected to an externally threaded screw 88 having a longitudinal 
groove 90 therein. Groove 90 is keyed to base section 38 by protrusion 91 
to prevent rotation of screw 88. An internally and externally threaded 
worm gear 92 is rotatably mounted around screw 88 and held in position by 
housing 94. Rotation of gear 92 will thus cause screw 88 to move in the 
vertical direction. Gear 92 meshes with worm 96 fixed to shaft 98 which, 
in turn, is mounted on control knob 100. Thus, the rotation of knob 100 
serves to adjust the tension of spring 86 which acts as a counterbalance 
for the weight of the die. The adjustability of the tension on spring 86 
therefore permits the apparatus to function with dies of a variety of 
different weights. 
The lower portion of spring 86 is connected to die carrying section 40 by a 
rotatable bracket 102 to provide for rotation between the sections to 
facilitate angular orientation of the die. Die carrying section 40 is 
cylindrical in shape with an opened top end to receive the spring 86 
therein. The top edge 104 of cylindrical section 40 is normally urged 
against the lower rim of member 76. When section 40 is vertically 
displaced by pushing down on hand grips 42, 44, spring 86 is extended and 
the die placed on the cutting surface. When the pressure head is actuated, 
base section 38 moves towards die carrying section 40 until rim 106 
engages edge 104. Further movement of the pressure head causes base 
portion 38 to exert a downward force on die carrying section 40 to push 
the die through the material to be cut. 
Grip member 42, 44 are mounted on a support ring 108 which, in turn, is 
affixed to the outer surface of die carrying section 40. Members 42, 44 
are spaced from the exterior surface of section 40 to permit easy access 
thereto. 
A shell 108 is provided in die carrying section 40 in order to house an 
electromagnet 110 which is held therein by means of a set screw 112. 
Electromagnet 110 is connected to an electrical source (not shown), 
through switch 50 (not shown in this drawing) by means of cables 114. The 
hollow portion of section 40 permits the cables from triggers 46 and 48, 
as well as from switch 50, to be connected through section 38 and pass 
through a grommet 16 adjacent member 62 and thereafter extend down tubular 
members 62 and 52 for connection to the remainder of the electrical 
system, described in detail below. In this manner, no cables are situated 
outside the die holder D to get in the way of the operation of the 
machine. 
It should be appreciated that the die holder D is illustrated in FIG. 3 in 
its non-extended state. However, when section 40 is displaced relative to 
section 38 by extending spring 86, there will be a distance of a few 
inches between the sections. It will therefore be appreciated that 
pressure head C need only move a distance equal to the displacement of 
section 40 relative to section 38 plus a distance equal to the thickness 
of the material to be cut. Therefore, pressure head C need only move a few 
inches and this movement can take place in a relatively short amount of 
time so as to reduce the amount of time necessary for each cutting cycle. 
FIG. 7 shows a schematic diagram of the electrical system of the die 
cutting machine of the present invention. A conventional three-pole motor 
114 is utilized to drive the compressor (not shown) which provides the 
necessary hydraulic pressure to drive pressure head cylinder 16 to move 
pressure head C between its retracted and extended positions. Motor 114 is 
connected by means of fuses 116 and 118 to one side of a transformer 120. 
The other side of transformer 120 is connected to an "off" pushbutton 
switch 122, shown in the off position, and an "on" pushbutton switch 124, 
shown in the on position, which energize a relay M. Normally open relay 
contacts 1 M are situated in parallel with switch 124 to latch the motor 
on after button 124 is depressed. A power lamp R is provided to indicate 
that the motor is energized. Fuses 126 and 128 are connected to both 
terminals of transformer 120. 
Triggers 46 and 48 are each shown to have two sets of contacts 46a, 46b and 
48a, 48b, respectively. Contacts 46a and 48a are normally closed, thereby 
energizing relay 1CR, so as to open normally closed relay contacts 1CR3. 
Contacts 1CR3 are located in series with the contacts 2CR4 and 3CR5 which 
when all are closed energize motor 114 to move the pressure head C from 
the retracted to the extended (down) direction. Relay 1CR is latched into 
the energized condition through contacts 1CR1 and normally closed contacts 
2CR1, to prevent the downward movement of head C until switches 46 and 48 
are simultaneously depressed. 
When switches 46 and 48 are simultaneously depressed, contacts 46b and 48b 
close and contacts 46a and 48a open. When this occurs, relay 3CR is 
energized, relay contacts 1CR2 being closed because relay 1CR is latched 
into the energized condition and contacts 2CR3 being normally closed. The 
energization of relay 3CR causes contacts 3CR3 and 3CR4 to close and 
contacts 3CR2 to open. The closing of contacts 3CR3 energizes relay 2CR 
which, in turn, causes contacts 2CR2 to close thereby latching relay 2CR 
in the energized condition and contacts 2CR1 to open, thereby deenergizing 
relay 1CR. Contacts 2CR3 are also opened. Relay 3CR will thus remain 
energized only as long as limit switch 1LS remains closed. Limit switch 
1LS will remain closed until the pressure head reaches its extended 
position. Thus, relays 1CR3, 2CR4, and 3CR5 are all closed and the 
pressure head will proceed downward until limit switch 1LS opens, at which 
time relay 3CR is de-energized thus opening contacts 3CR5 to stop the 
downward movement of the pressure head. Contacts 3CR4 (now opened) prevent 
reenergization of relay 3CR as the pressure head moves in the upward 
direction. Contacts 3CR3, now opened, cut off the alternate path of 
energization of relay 2CR. 
As relay 3CR is de-energized, normally closed contacts 3CR6 close. Limit 
switch 2LS, which is normally closed, and is held open by the pressure 
head until it reaches its extended position, is now closed and the motor 
114 drives the hydraulic compressor in order to move the pressure head in 
the upward position. Once pressure head C reaches the retracted position, 
limit switch 2LS is again held open and movement of the pressure head is 
terminated. 
It should be appreciated the downward movement of the pressure head cannot 
take place until relay 3CR is energized. Relay 3CR can be energized only 
if relay 1CR is energized and relay 2CR is de-energized. However, relay 
1CR cannot be energized until both of the switches 46 and 48 are released. 
Therefore, after the pressure head returns to its retracted position, a 
new cutting cycle can not be initiated until both of the triggers 46, 48 
are released and thereafter simultaneously depressed. Thus, for safety 
reasons, a new cutting cycle can not be initiated accidently. 
Electromagnet 102 is connected in series with normally closed pushbutton 50 
which connects the magnet to a DC power supply so as to energize same to 
retain die E to the under-side of die holder D. Upon depression of switch 
50, the electromagnet 102 is de-energized to permit changing of the dies. 
It should, therefore, be appreciated that the present invention is a die 
cutting machine which permits increased productivity while assuring the 
operator's safety. The increased productivity is achieved by permitting 
consecutive cutting cycles to be performed without relocation of the 
operator's hands and through the use of a "short stroke" pressure head. 
Mounting means are provided which permit the operator to position and 
orient the die holder, and thus the die, at any location on the material, 
to be cut. The same grips which permit manipulation of the die holder also 
contains the pressure head actuating triggers, which require simultaneous 
actuation to provide head movement. In addition, a pushbutton switch in 
proximity to the grips is provided to de-energize or energize the 
electromagnetic die retaining means. Since the operator must have both 
hands on the triggers for head actuation, there is no possibility of an 
accident because his hands are then out of path of movement of the 
pressure head. 
While only a single preferred embodiment of the present invention has been 
disclosed herein for purposes of illustration, it is clear that many 
modifications and variations could be made thereto. It is intended to 
cover all of these variations and modifications all within the scope of 
the present invention as defined by the annexed claims.