Platen press

A method and an apparatus for varying the dwell parameters for a platen press are disclosed. The method involves creating an impression force between first and second platens using a driven biasing member where movement of the member is controlled by a tensioner. The apparatus includes a driven biasing member that is linked to at least one of the first and second platens that form the press and a tensioner linked to the biasing member. The bias and tensioner permit the dwell time to be extended and allows the impression force between the platens to be variably applied.

TECHNICAL FIELD

This invention relates to platen presses used in foil stamping, embossing, die cutting, and for other purposes. More specifically, this invention relates to improving the flexibility of the platen press implementing a tensioner in conjunction with a driven biasing member.

BACKGROUND

Platen presses perform foil stamping, embossing, or die cutting by compressing a target material between two platens. The target material is placed between the platens while they are separated. Then, a driving force is applied to at least one of the platens to force the platens together. Most implementations of platen presses require that the force between the contacted platens be relatively great. Pressure approaching 2000 pounds per square inch of image is often applied when foil stamping.

To provide such compression forces repeatedly and quickly, a driving mechanism, which is often a crank, is used to drive an arm that moves one of the platens back and forth due to the movement of the driving mechanism. The faster the driving mechanism moves, the greater the frequency of the compressions. A loading mechanism is usually employed to remove the previously stamped material from between the platens and then place new target material therebetween during each compression cycle while the platens are separated.

A glider is typically provided in the arm so that the movable platen and the arm are not rigidly connected. The glider is able to slide along the arm as needed during the impression cycle. In use, the driving mechanism causes the arm to move the platen. In platen presses that use a crank as a driving mechanism, when the crank is at a 0° or initial position, the arm holds the platens in an open position. As the crank rotates toward a 180° position or half a revolution, it pulls the platens together and creates pressure between them.

Springs are used with the glider to provide a longer dwell by allowing the platens to establish contact sooner. One end of the springs is connected to the arm and the other end connects to the glider. When the platens first come into contact, the glider is forced to slide in the direction opposing the biasing force provided by the springs due to the continued movement of the connecting arm. Until rotation of the crank approaches 180° and the arm reaches its maximum distance of travel, the compression force is provided primarily by the springs. This force is only about 1000 pounds which produces pressure well short of the 1 ton per square inch of image pressure that is often necessary.

As the crank continues to turn toward the 180° position, the springs compress and the force remains in the 1000 pound range. Finally, the crank reaches a 180° position or a half revolution and the compression force approaches the tensile strength of the arm connected to the crank due to the springs becoming fully compressed. This force approaches 45 tons for medium sized platen presses. However, the 45 tons of force is only an impulse and is not sustained. As soon as the force has peaked, the crank continues to turn, and the compression force falls back to the compression force provided by the springs until the platens separate.

Platen presses that employ springs to extend the dwell suffer from a lack of flexibility. To alter the impression force so that the springs do not contribute to extend the dwell, the springs must either be removed (and the platen's position adjusted) and replaced with spacer bushings that lock the glider in place or the springs must be locked in place. If the contribution by the springs needs to be altered but not entirely eliminated, the springs must be replaced with springs of a different force.

Furthermore, if a rigid non-extended dwell system is desired and the springs are not removed, the springs must be locked in their extended position by a mechanical blocking device such as a spacer bushing that fits between the springs and locks the glider in place. Inserting the spacer bushing effectively blocks out the springs, and this block out requires that the platen's position be adjusted so the platens do not contact as soon. The platens then must contact closer to the 180° position of the crank because the distance from the glider to the end of the rigid arm remains constant throughout the dwell.

In addition to using a spacer to effectively eliminate the springs' contribution, it is sometimes desirable to alter the duration of the extended dwell without eliminating the dwell extension altogether. Such a configuration requires various size spacer bushings be inserted depending upon the desired duration. The platens must then be repositioned so they contact at the proper time in the crank's cycle.

If an extended dwell is desired and the press is in the non-extended dwell rigid mode where the springs are blocked out, the mechanical blocking device must be removed to free the glider. Because the glider's position does not change when the blocking device is removed, the transition from non-extended dwell to an extended dwell is referred to as positive action. The distance from the glider's connection to the platen to the rigid arm's connection to the crank is not altered by removing the blocking device. Therefore, the platens' position must be adjusted by the operator so that they will contact sooner.

Using the bushing spacers is cumbersome and inefficient because several steps are necessary to replace the spacers to provide the desired dwell duration. These steps typically involve removing a rod that extends from the glider through the end of the arm and provides a track for the bushing as the glider slides. The rod is held in place by screws and must be freed before removal, and once the rod is removed, the bushing can be removed as well. The desired bushing is inserted and the rod is replaced unless the bushing inserted placed the system in the rigid mode. Additionally, each time the duration of the dwell needs to be altered by changing the bushings, such as converting the system from a fully extended dwell to the rigid non-extended dwell, the platens' relative positions must be altered so that contact is established at the appropriate time in the crank's cycle.

SUMMARY

The present invention is directed to a platen press that provides a compression force by utilizing a bias member and provides adjustment of the dwell using a tensioner linked to the bias member. The bias is provided as a source for the impression force during the extended periods of contact. Using the bias permits the dwell to be extended and pressure to be applied during the initial and ending portions of the extended dwell.

One possible embodiment of the present invention is a platen press device that includes first and second platens that form the press. A driven biasing member is included to exert a biasing force. An arm that moves at least one of the platens is also included. The arm may move in opposition to the biasing force exerted by the driven biasing member once the first and second platens establish contact. The motion of the arm in opposition to the biasing force during contact creates an impression force between the first and second platens. The duration of the dwell and the initial bias force is controlled by a tensioner linked to the driven biasing member.

An alternative embodiment of the present invention is a method for operating the platen press device that has the first and second platens and the driven biasing member. The method involves establishing contact between the first and second platens. The method also involves creating an impression force between the first and second platens by transferring the bias force provided by the driven biasing member. The bias force may be transferred to the platens by moving an arm linked to the platens in opposition to the bias force once the platens have established contact. The bias force is varied by operation of a tensioner linked to the driven bias member.

DETAILED DESCRIPTION

Various embodiments of the present invention will be described in detail with reference to the drawings, wherein like reference numerals represent like parts and assemblies throughout the several views. Reference to various embodiments does not limit the scope of the invention, which is limited only by the scope of the claims attached hereto.

Exemplary embodiments of the present invention permit compression force between the platens of the press to be applied for more than an instant period of time and then be repetitively applied. Generating a compression force that is applied over a period of time when the platens are in contact for a given press size, allows the press to stamp materials normally reserved for a larger press capable of a higher maximum compression impulse.

Some embodiments of the present invention employ a rotational-type of driving mechanism, such as a crank, attached to an arm that is linked to the movable platen through at least an energy storage device such as a spring or hydraulic cylinder. The energy storage device permits embodiments of the present invention to achieve the extended dwell time while applying an impression force throughout the extended dwell. A tensioner is provided to adjust the duration of the dwell and automatically position the platens, using a negative action approach, when configuring the system to operate from a fully extended dwell mode to a non-extended rigid dwell mode.

Other driving mechanisms and platen configurations are possible. In some embodiments, for example, both platens might move. Yet other embodiments have a variety of different drive mechanisms and structures for driving the platens.

The embodiments described illustrate a platen press having driven bias members that employ spring or fluid biases. Some examples of a fluid bias include hydraulics as well as pneumatics. Other types of driven systems may be available as well including electromechanical systems that employ devices such as solenoids that form a part of the driven biasing member in place of the springs, hydraulics, or pneumatic system.

Though embodiments illustrated and described herein show a bias furnished by a pair of springs abutting an arm and a glider, where the glider slides on the arm and is connected to one of the platens, it should be noted that many variations of connecting these components are possible. One skilled in the art will quickly see that placement of the springs can be altered, and the glider can even be eliminated. Also, alternatives embodying the present invention may use a driven biasing member that employs hydraulics or other structures such as pneumatics for providing a fluid bias that permits creation of the impression force. Such other structures are also readily apparent to one with skill in the art.

FIGS. 1 and 2illustrate one example of a platen press100embodying the present invention. The platen press includes a press base102that provides structural support for the device. A drive mechanism106, arms112and134, and driven biasing members including gliders114,142and springs146and148that provide the energy necessary to generate the impression force during the extended dwell periods in this particular embodiment. A first platen108is attached to the press base102in a stationary position. Alternatively, the first platen may be movable. A second platen110is attached to a movable platen arm104. The movable platen arms104and140are propelled by a connection to the gliders114and142, respectively.

The driving mechanism106is attached to a motor (not shown). For many applications, a 3-phase electrical motor will be utilized. In one embodiment, the electrical motor drives a shaft that links both the crank forming the driving mechanism106and a flywheel (not shown). The flywheel helps maintain the speed of the motor throughout the impression cycle and prevents the platens from becoming locked together as the impression force peaks. Although a crank is illustrated, many other driving mechanisms can be used to drive the arm112. Some examples of driving mechanisms include cams, toggles, cranks, and linear actuators such as hydraulic cylinders. One skilled in the art will recognize that many other driving mechanisms not specifically mentioned are possible as well.

The arms112and134transfer the kinetic energy of the driving mechanism to the movable platen110. The arm112is linked to the driving mechanism106by joint122, and the arm134is linked to another driving mechanism in the same fashion. As the driving mechanism106rotates, the arm112maintains a substantially horizontal alignment due to its connection to the platen arm104, and provides a back and forth motion in the generally horizontal direction. Arm134is linked to platen arm140and is moved in the same manner.

This back and forth motion swings the movable platen110in the direction of the platen108. As the driving mechanism106rotates from an initial or 0° position which is approximately a 3 o'clock position inFIG. 1, to a half revolution or 180° position, which is approximately a 9 o'clock position, the movable platen110establishes contact with the platen108. As the driving mechanism106continues to turn toward the 180° position, the impression force increases to maximum. As the driving mechanism106moves past the 180° position, the arm112moves in the opposite direction and the impression force dissipates until the platens108and110separate. This process repeats as the driving mechanism continues to turn.

Although operation of the drive mechanism is described as reaching the maximum impression force (and range of movement for the arm112) as the driving mechanism106reaches a 180° position, other configurations are possible. For example, the maximum impression force might be reached at a different angle of rotation for the driving mechanism106. The maximum travel for the arm112might also be reached at different angles of rotation.

The platen arms104and140move with respect to the press base102so that the platens108and110may be contacted and separated as the driving mechanism106rotates. The platen arms104and140are shown to have a hinged connection120to the press base102. However, many alternatives exist. For example, the platen arm could slide on rails (not shown) and move in a linear fashion rather than rotate.

The pressure provided between the two platens108and110as they establish contact is provided from the rigid arms112and through the driven biasing members which include the springs146,148,164,166in this exemplary embodiment. Also, in the embodiment shown, the gliders114and142are provided as part of the driven biasing members to complete the transfer of force from the springs146,148,164, and166to the platen arm104and movable platen110. The gliders114and142slidably engage the arms112and134to allow the arms to continue to move once the platens108and110engage. The structure of the sliding engagement between the gliders114,142and the arms112,134is discussed herein with reference to FIG.4. The gliders range of movements are controlled by their abutment against the arm112and dwell spacers riding on guide shafts, which are shown in greater detail in FIG.4.

The duration of the dwell and the appropriate positioning of the platens can be efficiently controlled by operation of a tensioner linked to the gliders114and142. In the embodiment shown, a tensioner is provided for each arm112and134. The tensioners include studs116and160that are affixed to the glider. Typically, the stud116rests in a hole in the glider114and is held in place by a pin118. The stud extends through a gap between the glider114and the end of the arm112and passes through a cylindrical hole in the end of the arm112.

The stud's end extends beyond the back outer edge of the arm112and provides threads upon which nut130is tightened. Similarly for the other arm, stud160extends through a hole in the back of the arm134and provides threads upon which another nut is tightened. Operation of the stud, pin, threads and nut are described in greater detail below with reference to FIG.4.

The gliders114and142are connected to the platen arms104and140through bearing journals126, a backshaft124, and backshaft receptacles138seen inFIG. 2. Amore detailed view of the bearing journal126, the associated backshaft124, and the backshaft receptacles138can be seen inFIG. 3, and a description of additional backshaft features is also provided herein with reference to FIG.3.

As mentioned, many alternative configurations for the driven biasing member exist and eliminate the need for the springs and/or glider. Pneumatics could be employed to provide a fluid type driven biasing member. In that case, compressible containers filled with pressurized gas could be directly connected to the second platen110as well as the arms112and134to provide the fluid bias between the two. Once the platens108and110engage, the arms112and134continue to move thereby compressing the containers. In this configuration, no glider is necessary and no dwell spacers are needed. The pressurized gas opposes the motion of the arms112and134and an impression force is developed between the platens108and110as a result. The tensioner including a pin, stud, and nut would be disposed alongside the pneumatic container to permit adjustment of the dwell's duration.

Alternatively, the arms112and134could be rigidly connected to the second platen110and the driven bias members could be used to connect the first platen108to the press base102. As in the previous example, if a compressible container is used in place of the cylinders and glider, once the platens108and110engage the arms112and134continue to move thereby compressing the container. The pressurized gas again opposes the motion of the arms112and134and an impression force between the platens108and110results. The tensioner links the base102and the first platen108and permits adjustment of the dwell's duration.

Many other configurations are possible as well, and these include using any number of driven bias member combinations. For example, a fluid-driven bias member may be linked to one platen108and the press base102, and a second fluid-driven bias member may be linked to the other platen110and the arm112. One or both of the fluid-driven bias members may be replaced by another type of driven bias member. In each of these configurations, the driving mechanism is linked either directly or indirectly to at least one of the platens108and110, and the one or more driven bias members are also linked either directly or indirectly to at least one of the platens. For one or each of the biasing members, a tensioner is provided to control the dwell's duration.

In operation, the exemplary platen press shown inFIGS. 1 and 2functions as follows. The driving mechanism106continuously turns at a nearly constant angular velocity. The rigid arms112and134move back and forth in a generally horizontal direction. The horizontal movement of the rigid arms112and134are essentially sinusoidal with respect to time. As the rigid arm112approaches the 180° position, the platens108and110establish contact. The driving mechanism106continues to turn, forcing the rigid arms112and134to continue moving to the left, in opposition to the force from the springs146,148,164, and166. Because the platens108and110are already in contact, an impression force develops between them.

The springs146,148,164, and166are initially at a baseline pressure which is the amount of pressure present when the platens108and110are separated and the springs are extended forcing the front of the glider114to abut the rigid arm112. This baseline pressure may be varied depending upon the impression force characteristics desired by choosing springs with various spring constants or by adjusting the nut130to further compress the springs. However, adjusting the nut also varies the duration of the dwell, as will be discussed below with reference to FIG.4.

As the driving mechanism continues to turn, the impression force begins to exceed the baseline pressure initially applied by the springs. Once the baseline pressure is less than the impression force, the gliders114and142slide relative to the arms112and134as the arms continue to move horizontally toward the driving mechanism106in opposition to the biasing force of the springs146,148,164, and166.

The rigid arms112and134are manufactured to have a tensile strength that exceeds the peak impression force that must be created for proper foil embossing. Once the platens108and110have established contact, the rigid arms112and134begin to experience tensile force which increases as motion of the arms112and134continues. The impression force increases as the arms112and134continue to move in opposition to the force from the springs146,148,164, and166.

FIG. 3illustrates a breakout view taken along line3—3ofFIG. 2for an embodiment where the backshaft124has an offset bearing journal126that links the gliders114and142to the platen arms104and140, respectively. The bearing journal126extends into the mounting hole provided in the gliders114and142. As can be seen inFIG. 3, the center point127of the bearing journal126does not align with the center point125of the backshaft124but is offset instead. The backshaft's ends are housed by the backshaft receptacles138that form a part of the platen arms104and140. The backshaft124is fixed within the platen arm104so that impression force is not lost due to backshaft rotation during operation. However, the backshaft124may be freed so that it can rotate relative to the platen arm backshaft receptacles138when an adjustment must be made to the platen arm's position.

The backshaft method of adjusting the platens does not account for the displacement of the glider114. Therefore, the back shaft should be rotated only to the point where the dwell spacers (discussed with reference toFIG. 4) just contact the arm112at the moment of peak impression force. This prevents the tensile force on the arms112and134from becoming too great.

As shown inFIG. 3, the backshaft receptacle138may form two pieces that surround the backshaft124and are held tightly to the backshaft124by screws that clamp the two pieces of the receptacle138firmly against the backshaft124. Alternatively, screws may pass through the receptacle138and into holes in the backshaft124to fix the backshaft's position relative to the receptacle138. Rather than providing a clamping receptacle, a cast or solid block having a bore sized to receive the backshaft124may be used. The backshaft's ends may be configured to match stops provided in the bore so that that the backshaft124can be fixed in an appropriate position for a given impression cycle by rotating the backshaft against the provided stops. The location of the stops are predetermined by methods known in the art to provide the correct platen positioning.

The platen arm's position for a given position of the rigid arm112can be varied by rotating the bearing journal126once the backshaft124is freed. If the backshaft124is freed, the bearing journal126may be rotated about its center point127. This rotation causes the backshaft to also rotate about the center point127of the bearing journal126rather than the center point125of the backshaft124.

Because the backshaft124rotates within the platen arm's receptacles and around the centerline of the bearing journal126, the receptacle138is forced to move tangentially to the direction of the backshaft's rotation. The platen arms104and140connected to the backshaft124through the receptacles138are either moved closer to the other platen108or farther away, depending upon the direction the backshaft124is rotated. Once the platen arm104is properly repositioned, the backshaft124is again fixed in position relative to the platen arm's receptacles138.

Adjusting the position of the platen arms104and140by rotating the backshaft124is useful in varying the duration of the impression but the dwell spacers (discussed below with reference toFIG. 4) must be resized to account for the resulting dwell duration. The closer the platen arm104is moved to the other platen108, the sooner contact is established and the longer contact is maintained causing more movement of the glider114through the cycle and requiring shorter dwell spacers.

Adjusting the tensioner also varies the dwell and automatically sets the platens to the appropriate position to account for the glider's maximum range of movement associated with the new dwell duration. Adjusting the tensioner rather than the backshaft permits the dwell's duration to be altered without requiring alteration of the dwell spacer's lengths.

FIG. 4illustrates the incorporation of the glider114, the springs146,148, and the tensioner (stud116, pin118, threads128, and nut130in this embodiment) into the rigid arm112. The glider142, springs164,166and other tensioner are incorporated into the rigid arm134in the same manner. The glider114slidably engages the rigid arm112. As shown, this engagement may require the rigid arm to be slotted so that the glider114fits within the slots and may slide in either linear direction relative to the arm112, but is restricted in the other two dimensions. An alternative embodiment for the glider114provides the glider with slots which the rigid arm112fits into. The glider114provides the link between the arm112and the platen arm104.

The range of movement of the glider114is controlled by the glider's abutment against the arm112in one direction and by dwell spacers150and152in the other direction. The dwell spacers150and152reside on guide shafts132and144that extend through holes in the end of the rigid arm112, and through holes in the dwell spacers150and152. The guide shafts132and144are affixed to the rigid arm112with screws. The guide shafts132and144extend through the dwell spacers150and152but terminate before reaching the glider114. A space between the end of the guide shafts132and144must be equal to or greater than the space between the dwell spacers150and152and the rigid arm112to prevent the guide shafts132and144from contacting the glider114during the impression cycle.

The tensioner including the shaft116, pin118, threads128and nut130provide the flexibility for adjusting the dwell's duration. The stud116extends into the glider114. A pin118running perpendicular to the stud's longitudinal axis passes through the glider114and the stud116to affix the stud to the glider114. The stud116extends through a hole in the arm112and beyond the back edge of the arm112. Threads128on the stud116accept a nut130. The nut's position on the stud116controls the dwell's duration as well as the preload on the springs146and148.

An alternative embodiment for the tensioner utilizes a bolt in place of the stud116. The bolt's head abuts the rigid arm in place of the nut130. The glider114has a threaded hole that receives the threads of the bolt. Turning the head of the bolt in one direction pulls the glider toward the back of the rigid arm112and decreases the dwell time and eliminates any dwell extension by making the system rigid when the dwell spacers150and152abut the rigid arm112. Turning the head in the other direction allows the springs146and148to extend and permits the glider114to slide towards the crank106and the front of the rigid arm112.

This embodiment utilizing a bolt causes the glider114to be susceptible to thread wear in addition to the bolt. Glider thread wear could cause eventual failure of the tensioner requiring glider114replacement. Therefore, the stud tensioner is preferred since thread wear and resulting tensioner failure only require replacement of the stud116and nut130and not the generally more expensive glider114.

In the illustrated embodiment, to alter the duration of the dwell and the preload on the springs146and148, the only adjustment necessary is a turn of the nut130. The stud116is fixed by pin118and cannot rotate in response to rotation of nut130. Thus, rotation of the nut130in one direction pulls the glider114towards the nut130, thereby compressing the springs146and148and reducing the distance from the dwell spacers150and152to the back portion of the rigid arm112. The glider is directly connected to the platen arm104and the platen arm104and platen110move in response to the turn of the nut130as well. Thus, an additional platen adjustment is not necessary because the adjustment of the tensioner alters the springs preload and the platens position simultaneously.

If a non-extended dwell cycle is desired, the nut130is tightened on the threads128until the dwell spacers150and152rest against the back portion of the rigid arm112. The driven bias member is effectively removed from operation during the cycle and the press behaves in a rigid manner. The platen arm104becomes rigidly connected to the rigid arm112. The dwell spacers150and152must be capable of transferring the impression force without crushing when the press is operated in the rigid mode.

When the platens are set in motion for a non-extended rigid mode dwell by movement of the driving mechanism106, they establish contact later in the cycle and separate earlier in the cycle than if the dwell had been extended. The impression force becomes virtually an impulse due to the rigidity of the connection between the arms112and134and the platen arms104and140, respectively. The platen press operates as if the platen arm104is directly connected to the rigid arm112.

If an extended dwell is desired, the nut130is turned in the opposite direction allowing the springs146and148to extend until the glider114has moved to abut the front portion of the rigid arm112. Turning the nut130to slide the glider114forward in response to the spring bias is a negative action because sliding the glider114forward effectively shortens the distance between connections122and126. Because setting the system to the extended dwell mode involves negative action as opposed to the previously mentioned positive action for systems without tensioners, no adjustment is required to the platens' positioning because the platens will automatically establish contact sooner in the extended dwell mode. They engage sooner because the negative action adjustment pulls them closer together as the glider114moves forward in response to turning the nut130and this effect occurs without further adjustment by the operator.

When the platens are set in motion for the extended dwell, they establish contact sooner and separate later than if a non-extended dwell had been used. Once contact is made between the platens and the pressure between them exceeds the baseline amount established by the springs' preload, the glider114slides along the rigid arm112as the arm112continues to move. This movement of the arm112relative to the glider114causes the springs146and148to compress and force is transferred from the springs, through the glider114and connection126into the platen110. The transfer of force results in an impression force between the platens110and108because platen108has a fixed position.

The driving mechanism106continues to rotate at approximately a constant angular velocity and the arm112continues to move, thereby moving the cylinder116. The motion of the arm112causes the glider114to continue to move in opposition to the increasing resistance from the spring bias since the platens108and110are engaged and the glider114can no longer move with the arm112. The rigid arm112experiences tension as a result because the arm's movement is opposed by the spring bias. An impression force between the platens108and110develops and increases as the arm112continues to move toward the driving mechanism106because the resistance force of the springs is transferred.

The transfer of force passes from the springs146and148through the glider114. The glider114transfers the force into the bearing journal126which transfers the force to the backshaft124. The backshaft124transfers the force to the receptacle138, which transfers the force into the platen arm104and finally into the platen110engaged against platen108.

As the glider114slides to compress the springs146and148, the shaft extends further beyond the back end of the rigid arm112. The nut130disengages the rigid arm112when the glider112first begins to slide and remains disengaged throughout the impression cycle until the glider114returns to its rest position where it abuts the front portion of rigid arm112.

As the cycle continues after the glider114first begins to move, eventually the impression force peaks as the dwell spacers abut both the glider114and the rigid arm112causing the system to become momentarily rigid. Then, the force begins to lessen as the rigid arm begins to move in the opposite direction. The glider slides along the rigid arm112as the arm112moves away from the driving mechanism106because pressure is being applied to the glider114by the spring bias.

During motion of the arm112relative to the glider114, the impression force is maintained because the spring bias is continually provided as the springs146and148extend. The springs146and148bias the glider114toward the driving mechanism106as the rigid arm112moves. Finally, the rigid arm112has moved far enough in the direction away from the driving mechanism106to cause the glider114to reach the stop provided in the rigid arm112. At that point, the platens108and110separate as the rigid arm112continues to move in the direction away from the driving mechanism106.

The parameters used in configuring the press for a specific job are determined by the amount and type of foil that will be used, the type of media that will be printed upon, and whether embossing will be done. In a typical configuration, two springs per rigid arm are used and each spring has a maximum force of about 1200 pounds. During the impression cycle, a typical glider114, dwell spacer, and tensioner configuration results in a 0.25 inch lateral movement of the glider114relative to the arm112. At a typical operating speed of 3000 impression cycles per hour, this displacement occurs within61milliseconds.

The impression force provided by the springs146and148and then the rigid arm112at the impulse point is distributed throughout the area of the image being pressed, so the resulting image pressure is dependent upon the image's dimensions. In a typical configuration, the dimensions of the platens108and110themselves are about fourteen inches of width and about twenty two inches of length resulting in an area of approximately 308 square inches.