Abstract
A compact, portable in-line heat press machine that holds the upper heated platen horizontal and laterally aligned with the lower platen is provided. The lower frame has front and rear pivot joints on each side of such frame to accommodate linkage arms pivotally attached to it and the upper frames which has similar pivot joints. As such the upper heated platen is lifted up and straight back with respect to the lower platen assembly which completely clears the lower platen for unobstructed loading/unloading of lower platen while keeping the upper platen assembly in a horizontal position. When the upper platen is moved into the lower position, a locking mechanism affixes the upper and lower platen assemblies so that the platen actuators can cause a linear movement between them thus causing a pressing action.
Claims
1. A heat press for textile substrates, the heat press comprising: a frame; a lower platen assembly supported on the frame and including a lower platen; an upper platen assembly supported on the frame and including an upper platen; wherein the upper platen assembly is supported on the frame for movement in a first mode relative to the lower platen assembly to and between a closed position wherein the upper platen is in registration with the lower platen to clamp the substrate therebetween, and an open position wherein the upper platen is displaced vertically and rearwardly away from the lower platen while maintaining lateral alignment.
2. The heat press of claim 1, wherein the upper and lower platens are supported on the frame such that the upper and lower platens remain parallel to one another and laterally aligned in the closed and open positions, and during the entire movement between the closed and open positions.
3. The heat press of claim 1, wherein the frame comprises: a base; a pair of first linkages, each configured as four-bar linkages coupling the base and the upper platen assembly; and a pair of second linkages, each configured as three-bar linkages coupled with the pair of first linkages and the upper platen assembly.
4. The heat press of claim 3, wherein: The upper platen assembly comprises a pair of guide slots; the pair of second linkages are engaged with the guide slots for movement therealong; and the guide slots are configured such that upper platen assembly is locked against movement when the upper platen and the lower platen engage a substrate in closed position.
5. The heat press of claim 4, wherein at least one of the upper platen or the lower platen is supported on the respective upper platen assembly or lower platen assembly for movement in a second mode, wherein the movement in the second mode is independent of the first mode and is in a direction such that the upper and lower platens are moved toward one another when the heat press is in the closed position.
6. The heat press of claim 5, wherein the movement in the second mode is linear.
7. The heat press of claim 5, further comprising: at least one actuator operatively coupled with at least one of the upper or lower platens; the at least one actuator configured to evenly press the upper platen and the lower platen against one another via the second movement mode.
8. The heat press of claim 7, further comprising: at least one biasing member operable to bias one of the upper or lower platens in a direction away from the other of the upper or lower platens.
9. The heat press of claim 7, wherein: the at least one actuator comprises four actuators positioned at symmetric locations proximate peripheral edges of the upper or lower platens; and the four actuators are operable to control forces applied between the upper and lower platens independently of one another.
10. The heat press of claim 1, further comprising at least one actuator operatively coupled with the frame and operable to move the first platen assembly to and between the open and closed positions.
11. The heat press of claim 1, wherein the lower platen is supported on the frame for at least one of: a third movement mode in directions aligned with a fore-aft axis of the press; or a fourth movement mode in directions substantially perpendicular to the fore-aft axis of the press.
12. The heat press of claim 1, further comprising at least one of: at least one perimeter sensor configured to detect the presence of an object within a pressing area associated with the upper and lower platens; at least one interference sensor configured to detect interference of the moving upper or lower platens before the heat press reaches the closed position; at least one parallelism sensor configured to determine a parallel condition between the upper and lower platens, and a control system configured to actuate movement of the heat press responsive to signals from the at least one parallelism sensor; or at least one gesture sensor configured to detect a gesture of an operator, and a control system configured to control operation of the heat press in response to signals from the at least one gesture sensor.
13. A method of heat pressing a substrate, comprising: moving an upper platen from a closed position in close proximity to a lower platen, to an open position spaced apart from the lower platen while maintaining the upper platen in a horizontal orientation; wherein moving the upper platen comprises moving the upper platen in directions vertically upward and backward relative to the lower platen while maintaining lateral alignment of the upper platen with the lower platen.
14. The method of claim 13, further comprising: placing a substrate on the lower platen; and moving the upper platen relative to the lower platen from the open position to the closed position; wherein moving the upper platen relative to the lower platen comprises moving the upper platen in directions vertically downward and forward relative to the lower platen while maintaining lateral alignment of the upper platen with the lower platen.
15. The method of claim 13, further comprising automatically moving the upper platen relative to the lower platen from the open position to the closed position when the heat press is not being used for heat pressing a substrate.
16. The method of any one of claim 13, further comprising: least detecting the presence of an undesired object withing a pressing area with at prohibiting movement of the upper platen relative to the lower platen from the open position to the closed position in response to a detected presence of an undesired object.
17. The method of claim 13, further comprising: locking the upper platen and the lower platen in the closed position.
18. The method of claim 14, further comprising: detecting with a sensor a gesture made by an operator and associated with an intended command for operating the heat press; and actuating movement of the upper platen in response to the detected gesture.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] The accompanying drawings, which are incorporated in and constitute a part of this Specification, illustrate exemplary embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the principles of the invention.
[0048] FIG. 1 is a perspective view of an exemplary machine for heat pressing substrates in accordance with the principles of the present disclosure.
[0049] FIG. 2A is a side view of the machine of FIG. 1, with the upper heated platen assembly in a fully open position.
[0050] FIG. 2B is a side view of the machine of FIG. 1, with the upper heated platen assembly in a fully closed position.
[0051] FIG. 3A is a section view illustrating the locking mechanism during pressing of a thin substrate.
[0052] FIG. 3B is a section view illustrating the locking mechanism during pressing of a thick substrate.
[0053] FIG. 4A is a partial detail of the upper platen assembly illustrating a force actuator assembly.
[0054] FIG. 4B is a partial detail view similar to FIG. 4A, showing additional structure of the machine.
[0055] FIG. 5A is an enlarged perspective view of the machine of FIG. 1, illustrating a perimeter obstruction scanner system.
[0056] FIG. 5B is an enlarged detail view of the perimeter obstruction scanner assembly of FIG. 5A.
[0057] FIG. 6 is a top perspective view of the machine of FIG. 1 with structure removed to illustrate detail of the primary movement assembly.
[0058] FIG. 7 is a detail of the machine of FIG. 1, illustrating a motion/level sensing and adjusting system.
[0059] FIG. 8 is a bottom perspective view of the machine of FIG. 1, illustrating non-contact process start sensors.
[0060] FIG. 9 is a perspective view of another exemplary machine for heat pressing substrates in accordance with the principles of the present disclosure, wherein the machine includes four force actuators.
[0061] FIG. 10 is a perspective view of another exemplary machine for heat pressing substrates in accordance with the principles of the present disclosure, wherein the machine includes four compressed air bags as force actuators.
DETAILED DESCRIPTION
[0062] FIG. 1 depicts an exemplary machine 1 for heat pressing substrates in accordance with the principles of the present disclosure. The machine 1 includes a lower platen support frame 2, a lower platen 3 which can be easily interchanged for different size platens, an upper heated platen assembly 4 which contains the heated platen 5, front primary lift arms 6 and rear primary lift arms 7 as the major components.
[0063] FIG. 2A is a side view of the machine 1 in the fully open position. The front primary lift arms 6 and rear primary lift arms 7 are each attached to the lower platen support frame 2 through the use of front lower pivot joints 8 and rear lower pivot joints 9. This allows each arm to freely pivot around each pivot joint causing the arms to rotate in a circular manner. The front primary lift arms 6 have holes at either end which align with the front lower pivot joint 8; the same hole pattern is also on the rear primary lift arms 7. The opposite end of each front and rear primary lift arms has pivot holes which align with front upper pivot joints 10 and rear upper pivot joints 11 that are within the upper heated platen side frame 12. The straight distance between the upper and lower pivot holes in the front primary lift arms 6 and rear primary lift arms 7 are substantially the same values (i.e., withing typical manufacturing tolerances) such that the lower platen support frame 2, upper heated platen side frame 12, front primary lift arm 6 and rear primary lift arm 7 form a four bar parallel motion mechanism that acts through the four pivot points. The lower platen support frame 2 and upper heated platen assembly 4 have substantially the same four bar parallel motion mechanism on each side of the machine 1 which lifts the upper heated platen assembly 4 substantially upwardly and rearwardly with respect to the lower platen 3, while keeping the upper heated platen assembly 4 perfectly horizontal and parallel with the lower platen 3.
[0064] FIG. 2B is a side view of the machine 1 in its fully closed position.
[0065] FIG. 3A is a section view showing the locking mechanism 13 which holds or locks the position of the upper heated platen assembly 4 with respect to the lower platen 3. The locking mechanism 13 is a second three bar linkage with four pivot points 14, 15, 16, 17 which it acts about. The entire locking mechanism 13 is guided through two substantially identical guide slots 18a & b which are cut into the lock link guide plates 21. Pivot points 16 & 17 are guide pins which protrude through each of the front guide slot 18a and rear guide slot 18b. These guide slots 18a, 18b are horizontally spaced at substantially the same distance as the front upper pivot joint 10 and rear upper pivot joint 11. This arrangement allows the locking mechanism to freely travel along the length of the two guide slots 18a, 18b without restriction or binding. Pivot joints 16 and pivot joints 17 are tied together through connecting link 23. Each of the front primary lift arms 6 have a third pivot hole some distance past the pivot holes attached to the front upper pivot joint 10. This third pivot hole is connected to the front lock links 22a through pivot joint 14. Each of the rear primary lift arms 7 also have a third pivot hole some distance past the pivot holes attached to the rear upper pivot joint 11. This third pivot hole is also connected to the rear lock links 22b through pivot joint 15. Pivot joint 16 protrudes through guide slot 18a which guides the path of pivot joint 16 through the entire movement of the upper heated platen assembly 4. Likewise, pivot joint 17 protrudes through guide slot 18b which guides the path of pivot joint 17 through the entire movement of the upper heated platen assembly 4. The combination of front lock links 22a, rear lock links 22b, connecting link 23, and pivot joints 10, 11, 16, 17 all work in unison to create the locking mechanism 13. There are two components to each guide slot; a horizontal slot 19 and a slot incline 20. Pivot joints 16 & 17 travel along each respective guide slot 18a, 18b. The position of each guide joint 16 & 17 with respect to the horizontal slot 19 or slot incline 20 portion of each guide slot 18a, 18b dictate whether the primary movement is in a lock state or travel (unlocked) state. When each of the pivot joints 16 & 17 are traveling along the horizontal slot 19 of each guide slot 18a, 18b, the upper heated platen assembly is travelling from its open position to its closed position and vice-versa. When pivot points 16 & 17 are travelling up the slot incline 20 portion of each guide slot 18 a & b the heated platen 5 is substantially vertically above the lower platen 3 and within close proximity to touching the lower platen 3. At any point the pivot joints 16 & 17 are travelling on the slot incline 20, a vertical downward force applied to the heated platen 5 to make contact with the lower platen 3 or a substrate place on the lower platen 3 will cause an equal and opposite force to be placed on pivot joints 16 & 17 to the slot incline 20. This equal and opposite force acting on pivot joints 16 & 17 will cause the locking mechanism 13 to lock the upper heated platen assembly 4 in place and restrict any vertical or horizontal movement. The reason this action occurs is that the equal and opposite force is acting on pivot joints 16 & 17 at a point where the resultant force on slot incline 20 is substantially at right angles to slot incline 20. Thus, the entire locking mechanism restricts any further movement.
[0066] FIG. 3B shows the locking mechanism functional and working on thicker substrates as pivot joints 16 & 17 are still substantially perpendicular to slot incline 20 even though they are further down slot incline 20 when compared to their position in FIG. 3A. At any point that the substrate is contacted by the heated platen 5, regardless of substrate thickness, the locking mechanism 13 can hold the upper heated platen assembly 4 stationary so that a pressing action can occur. Thus, the locking mechanism 13 allows for any thickness of substrate to be placed on the lower platen 3 and a clamping action will occur automatically, without any adjustments or settings being made by the machine operator.
[0067] FIG. 4A depicts a detail of the force actuator assembly 24 of the upper platen assembly 4. In the embodiment shown, there are two force actuators 25 which act upon the heated platen 5 to push it vertically down onto the lower platen 3. These force actuators 25 can be electric, pneumatic or hydraulic actuators which create proportional linear force based on the input power supplied. In the preferred design electric actuators similar to Commex Inc. part #CX.LAT7 could be used. These actuators are electrically driven with internal DC motors, integral gearbox and a trapezoidal lead screw as the linear output member. The screw end is attached to a press block 26 which acts as a torque arm to keep the lead screw from rotating and to insulate the lead screw and force actuator from any heat produced by the heated platen 5. The bottom of the press block 26 can be made slightly spherical or have a raised boss from its bottom surface to provide point contact on the top of the heated platen 5. Should one side of the heated platen 5 come in contact with the subject substrate slightly before the other, the point contact will allow the heated platen 5 to adjust its level to accommodate such situation. These force actuators 25 are current controlled devices where the amount of current supplied to them at a given DC voltage will produce a precise and repeatable adjustable force output. Thus, the machine 1 control system can produce the desired output force onto the substrate by controlling the current given to each force actuator 25.
[0068] In FIG. 4B of the exemplary embodiment, the force actuators 25 push on the top of the heated platen 5 and rely on a lift spring system 27 in order to lift the heated platen 5 when the force actuators 25 are retracted at the end of the press cycle. Each lift spring system 27 has a lift screw 28 which is attached to the heated platen 5 and retains the top of the lift spring 29. The lift spring system 27 and force actuators 25 are all mounted on the force actuator bracket 30 which is a structural member of the upper heated platen assembly 4. Alternatively, the force actuators 25 could be mechanically attached to the heated platen 5, which would push on and pull on the heated platen 5 and negate the need for a lift spring system 27. As the force actuators 25 forcefully push down onto the substrate supported by the lower platen 3, the resultant forces are transmitted through the upper heated platen assembly 4 frame to the pivot joints 14 & 15, through the front lock link 22a and rear lock links 22b, through the pivot joints 16 & 17 onto the slot incline 20 of the lock link guide plates 21 where the resultant force is then transmitted through the pivot points 10 & 11 through the front primary lift arm 6 and rear primary lift arm 7 to the front lower pivot joint 8 and rear lower pivot joint 9 which are integral to the lower platen support frame 2 that supports the lower platen 3. Thus, the forces in the machine 1 are in equilibrium and the press functions as expected.
[0069] In another embodiment, force actuators could alternatively be located within the lower platen support frame 2 and directly below the lower platen 3 so as to push vertically upward on the lower platen 3. In this configuration, the lower platen would have a linear guide system which would allow it to move freely in a vertical path. Once the upper heated platen assembly 4 has been lowered to the preferred pressing position and has been locked in place by the locking mechanism 13, the lower force actuators can lift the lower platen 3 with substrate for pressing.
[0070] FIG. 5A shows a perspective view of a perimeter obstruction scanner system 31 and its placement behind the rear edge of the lower platen 3. This system uses one or more non-contact distance sensors to sense the area just over the lower platen 3 and subject substrate at all times that the heated platen 5 is not in contact with a substrate. The invisible pulsed beam 32 is emitted from the perimeter obstruction scanner system 31 through a scanning slot 33 in the front of the scanner housing 34. The system uses a scanning motor 35 to continuously rotate the sensor so as to make the invisible pulsed beam 32 traverse the complete area under the heated platen 5. This invisible pulsed beam 32 scanned just above the substrate on the lower platen 3 so that it can detect any foreign object or person’s hand before the heated platen 5 makes contact with the subject substrate. If there is any object in the path of the invisible pulsed beam 32, the invisible pulsed beam 32 will be reflected back to the perimeter obstruction scanner system 31 and detected by the system. The machine control system will use the information received from the perimeter obstruction scanner system 31 to determine what course of action to take to keep any person from harm. Another use of the perimeter obstruction scanner system 31 is to detect the presence or absence of any substrate in the machine. Thus, the machine 1 can determine if there is a substrate to be pressed and if the already pressed substrate has been removed from the machine or not. This will help the operator from mistakenly pressing the same substrate twice.
[0071] FIG. 5B depicts a subassembly of the perimeter obstruction scanner system 31. This system uses a perimeter sensing module 36 which is a Time-of-Flight type of sensor similar to Pololu Corp’s #2490 VL53LOX Time-of-Flight Distance Sensor Carrier. In the embodiment shown, the perimeter sensing module 36 is mounted to a sensor circuit board 37 which is attached to the scanning motor 35 shaft by use of a mechanical clamp 38. The machine control system causes the scanning motor 35 to rotate clockwise then counterclockwise which causes the invisible pulsed beam 32 to scan the entire area over the lower platen 3 as described above. This type of sensor can detect presence of an object in the invisible pulsed beam 32 path and the distance of such object from the perimeter sensing module 36. Thus, the machine control system can use the feedback from this perimeter sensing module 36 in combination with the known angular rotation of the scanning motor 35 shaft to sense the exact location of foreign objects.
[0072] While the perimeter obstruction scanner system 31 has been shown and described herein as being located behind the rear edge of the lower platen 3, it will be appreciated that the perimeter obstruction scanner system 31 may alternatively be located at various other positions suitable for detecting the presence of foreign objects or substrates within the machine. Moreover, while the perimeter obstruction scanner system 31 has been shown and described herein as utilizing invisible pulsed beams to detect objects and substrates, it will be appreciated that various other types of devices suitable for non-contact detection of objects and/or substrates within the machine may alternatively be used. For example, light curtains or other types of detecting devices could be used.
[0073] FIG. 6 is a top rear view of the machine 1 showing the primary movement assembly 39. In the embodiment shown, there are two primary movement linear actuators 40. These can be typical linear actuators similar to those made by HaydonKerk part # E21H4U-2.5-900, which have an integral lead screw as their rotor and an external lead nut to drive the load linearly. The primary movement linear actuator 40 motor is mounted to a primary actuator mounting bracket 41. This primary actuator mounting bracket 41 extends past the back of the motor on the primary movement linear actuator and has a hole through it which acts as a rear mount clevis bracket. There is a primary actuator pivot pin 42 through this hole in the primary actuator mounting bracket 41 that also protrudes through a specified hole in the lock link guide plate 21, thus supporting the outside of the primary actuator pivot pin and allowing the primary movement linear actuator to pivot about this point. On the opposite side of the primary lift linear actuators 40 from the lock link guide plates 21 are mounted primary actuator load cells 46 which can accept the opposite end of the primary actuator pivot pin 42 onto their top section. The bottom section of the primary actuator load cells 46 are rigidly mounted to the force actuator bracket 30. This system will allow the primary movement linear actuator 40 to freely pivot about the primary actuator pivot pin 42 and have the primary actuator load cell 46 measure the direct force being exerted by the primary movement linear actuator 40. The machine control system can use the signal from the two primary actuator load cells 46 to determine if there is an obstruction in the movement of the primary movement and when the heated platen 5 has made contact with the specified substrate.
[0074] As discussed herein, each primary movement linear actuator 40 has a primary actuator lead screw 43 which causes liner movement in conjunction with the primary actuator lead screw nut 44. Primary actuator lead screw nuts 44 are mounted into respective ends of the primary actuator guide pin bar 45. Each end of the primary actuator guide pin bar 45 had integral to it pivot joint 17. This pivot joint 17 protrudes through the guide slot 18b in each lock link guide plate 21. Thus, as the lead screw 43 of each primary movement linear actuator 40 rotates and causes linear movement with the primary actuator guide pin bar 45, movement is created along the path of each guide slot 18b. This movement of pivot joint 17 along guide slot 18b is reflected through the locking mechanism 13 through connecting link 23 which causes the upper heated platen assembly 4 to be lifted, lowered, or locked in place.
[0075] FIG. 7 is a section view of the upper heated platen assembly 4 detailing the motion/level sensing and adjusting system 47. This system uses a level adjusting motor 48 to adjust the heated platen 5 based on the feedback that the control system receives from the level/motion sensor 54. This sensor is similar to readily available sensor packages from Mouser.com, part #MPU-6050, which has an internal accelerometer and gyroscope circuits to measure six axes of motion. The level/motion sensor 54 is mounted directly to the top cover of the heated platen 5 so that it can monitor position and movement of the heated platen 5. If the machine control system receives a signal from the level/motion sensor 54 that the heated platen 5 is out of level with the lower platen 3, the level adjusting motor 48 can be commanded to rotate the level adjusting motor lever arm 51 which will push or pull on the level adjusting connecting rod 52 which transitionally pushes or pulls on the heated platen 5 due to the anchoring of the level adjusting connecting rod capture plate 53 mounted on the top cover of the heated platen 5. Therefore, this is a closed loop auto leveling system for the heated platen 5.
[0076] The level/motion sensor 54 devices are extremely sensitive and accurate so they can give the machine control system highly accurate movement and location feedback. Using this data, the machine control system can determine if the heated platen 5 is out of level, where it is in space throughout the primary movement and if there is any disturbance to the movement of the upper heated platen assembly 4. For example, as the upper heated platen assembly 4 is being lowered by the primary movement assembly 39 toward the lower platen the machine operator may decide to cancel the cycle by bumping the upper heated platen assembly 4 to indicate to the machine control system that an interference has occurred in the primary movement and the machine should open to its original position. Using the level/motion sensor in this fashion creates an incredibly safe and functional heat press.
[0077] FIG. 8 shows a mostly frontal and slightly upward view of an embodiment of the exemplary machine 1. Just under the front edge of the upper heated platen assembly 4 cover there may be provided two non-contact process start sensors 55. These can be similar the VL53L0X Time-of-Flight Distance Sensor mentioned above in the perimeter obstruction scanning system 31. Once an operator has loaded the substrate onto the lower platen 3, the operator can use specific hand gestures in front of the machine which will break the invisible sensing beams 56 to initiate various commands. The machine control system can use feedback from the two process start sensors 55 to determine a command the machine operator is wanting to initiate. Thus, the interaction with the heat press machine 1 is extremely ergonomic since there are no push buttons or levers needed to actuate in order to initiate the process.
[0078] While FIG. 8 illustrates an exemplary embodiment wherein non-contact sensors are used to facilitate inputting commands for operation of the machine 1, it will be appreciated that various other structures and methods may be provided for inputting commands to the machine 1. As a non-limiting example, an exemplary embodiment of a machine in accordance with the principles of the present disclosure may include one or more sensors provided at suitable locations on the machine 1 and configured to detect actuation by a user to input commands to the machine 1. Such actuation may include, but is not limited to, pressing a button, turning a dial, sensing a touch, and/or detecting an electric current caused by a touch.
[0079] FIG. 9 depicts another exemplary embodiment of a machine in accordance with the principles of the present disclosure, wherein four force actuators 25 are mounted in each corner of the upper heated platen assembly 4 to accomplish vertical movement of the heated platen 5 with respect to the lower platen 3. In this embodiment, the function of the machine 1 is similar to the description discussed above, except there is no need for the leveling adjusting motor 48 and associated level adjusting motor lever arm 51 and level adjusting connecting rod 52 as the four force actuators can accommodate leveling through the feedback of the level/motion sensor 54. Other operations and functions are similar to those discussed above.
[0080] Another exemplary embodiment of a machine in accordance with the principles of the present disclosure is depicted in FIG. 10. Similar to the embodiment of FIG. 9, there are four actuators, one on each corner of the heated platen assembly 4. In this embodiment, however, the four force actuators 25 are replaced by compressed air bladders 57. The compressed air bladders 57 are contained between the top of the heated platen 5 and an enclosed framework 58 integral to the upper heated platen assembly 4. When the upper heated platen assembly 4 is in the closed position and the heated platen 5 is in intimate contact with the subject substrate, the machine control system commands solenoid valves within the machine to direct compressed air into the compressed air bladders 57. Since there is a compressed air bladder 57 on each corner the heated platen 5 is pressed vertically downward and onto the substrate.
[0081] In the embodiments shown and described herein, the lower platen 3 has been depicted as being generally stationary on the lower platen support frame 2. It will be appreciated that in some embodiments, the lower platen 3 may alternatively be configured to move relative to the lower platen support frame 2 and/or the upper platen assembly 5. As a non-limiting example, the lower platen 3 may be configured for movement in a fore-aft direction relative to the lower platen support frame 2 (i.e., along a longitudinal direction of the lower platen support frame 2). Such motion of the lower platen 3 is typically referred to in industry as a “drawer pull” type motion, which motion can further expose the lower platen 3 for access by an operator. As another non-limiting example, the lower platen may be configured for movement in a vertical direction relative to the lower platen support frame 2. Such vertical motion may be advantageous to facilitate and/or control clamping or pressing a substrate between the upper, heated platen 5 and the lower platen 3, as may be desired.
[0082] While the present invention has been illustrated by a description of various embodiments, and while these embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit and scope of the general inventive concept.
