Assembly and process for a press feed mechanism for providing rapid, efficient and tuned hold and release displacement of an upper feed roller relative to a lower roller and between which is communicated a sheet material for subsequent feeding into a press operation
10118785 ยท 2018-11-06
Assignee
Inventors
Cpc classification
B65H2404/1441
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
A feed assembly for transferring an uncoiled sheet material to a downstream material forming operation. The assembly includes upper and lower feed rolls between which the sheet material passes, the upper roll being actuated between engaging or disengaging positions relative to an upper surface of the sheet material. At least one continuous force applying component is provided for exerting a hold down force against the upper feed roll and, in combination, a programmable counterbalance component is calibrated to counter the hold down force exerted by the force applying component and in order to cycle the upper roller between the engaged and disengaged positions during advance cycling of the uncoiled material to the downstream forming operation.
Claims
1. A feed assembly for transferring an uncoiled sheet material to a downstream material forming operation, said assembly comprising: a frame supporting upper and lower feed rollers between which the sheet material passes, at least one of said rollers being rotary driven, said upper roller being actuated between engaging or disengaging positions relative to an upper surface of the sheet material; a cam shaft with end support cam lobe provided in supported and extending fashion between a pair of side supporting plates; at least one continuous force applying component exerting a hold down force against said upper feed roller; and a programmable counterbalance component calibrated to counter the hold down force exerted by said force applying components and in order to cycle the upper roller between the engaged and disengaged positions during advance cycling of the uncoiled material to the downstream forming operation.
2. The assembly as described in claim 1, further comprising a servo cam and gearbox for operating said cam shaft for providing responsive movement of said upper feed roller relative to said lower feed roller.
3. The assembly as described in claim 2, said servo cam operates in conjunction with a pair of said continuous force hold-down components and said programmable counterbalance component supported between a mounting rail and counter balance mounting beam in order to counter a PSI applied force of said hold down components for accomplishing incremental grip and release motion of said upper feed roller in a repetitive fashion for effectuating transfer of the uncoiled material to the downstream forming operation.
4. The assembly as described in claim 3, said servo cam cycling at a range of 0.020 seconds and at a cycling rate of 80-100 per minute.
5. The assembly as described in claim 4, said servo cam cycling range further comprising being between a 0.000 home position and a 0.400 lift position.
6. The assembly as described in claim 3, further comprising pivot linkages respectively associated with first and second brackets, between which said programmable counterbalance component is supported and which, upon being actuated, exerts a lifting force to said mounting rail which is in turn likewise connected to said pair of continuous force hold down components.
7. A feed assembly for transferring an uncoiled sheet material to a downstream material forming operation, said assembly comprising: a frame supporting a displaceable upper feed roller and a fixed lower feed roller between which the sheet material passes, at least one of said rollers being rotary driven, said upper roll being actuated between engaging or disengaging positions relative to an upper surface of the sheet material; a cam shaft with end support cam lobe provided in supported and extending fashion between a pair of side supporting plates; a spaced apart pair of continuous force applying components exerting a hold down force against said upper feed roll; and a programmable counterbalance component located between said pair of force applying components, said counterbalance component being calibrated to counter the hold down force exerted by said force applying components and in order to cycle the upper roller between the engaged and disengaged positions during advance cycling of the uncoiled material to the downstream forming operation.
8. The assembly as described in claim 7, further comprising a servo cam and gearbox for operating said cam shaft for providing responsive movement of said upper feed roller relative to said lower feed roller.
9. The assembly as described in claim 8, said servo cam operates in conjunction with said pair of continuous force hold-down components and said programmable counterbalance component supported between a mounting rail and counter balance mounting beam in order to counter a PSI applied force of said hold down components for accomplishing incremental grip and release motion of said upper feed roller in a repetitive fashion for effectuating transfer of the uncoiled material to the downstream forming operation.
10. The assembly as described in claim 9, said servo cam cycling at a range of 0.020 seconds and at a cycling rate of 80-100 per minute.
11. The assembly as described in claim 10, said servo cam cycling range further comprising being between a 0.000 home position and a 0.400 lift position.
12. The assembly as described in claim 9, further comprising pivot linkages respectively associated with first and second brackets, between which said programmable counterbalance component is supported and which, upon being actuated, exerts a lifting force to said mounting rail which is in turn likewise connected to said pair of continuous force hold down components.
13. The assembly as described in claim 12, further comprising an extending length of said counterbalance component extending at an intermediate angle between a horizontal axis and a vertical axis.
14. The assembly as described in claim 7, further comprising an overhead and crosswise extending support beam extending above said feed rollers, a pair of horizontal brackets supported by said overhead beam and extending forwardly such that said spaced apart pair of continuous force applying components are anchored thereto in downwardly extending fashion, lower ends of said continuous force applying components being pivotally engaged to a mounting rail associated with said displaceable upper feed roller.
15. A feed assembly for transferring an uncoiled sheet material to a downstream material forming operation, said assembly comprising: a frame including a pair of side support plates, between which a cam shaft with end support cam lobe is provided in supported and extending fashion; a servo cam and gearbox for operating said cam shaft for providing responsive movement of said upper feed roller relative to said lower feed roller; upper and lower feed rollers rotary supported between said side support plates and between which said sheet material passes, at least one of said rollers being rotary driven, said upper roller including a supporting structure with an end support roller in contact with said cam lobe, such that said displaceable roller is actuated between engaging or disengaging positions relative to an upper surface of the sheet material; at least one continuous force applying component exerting a hold down force against said upper feed roller; and a programmable counterbalance component calibrated to counter the hold down force exerted by said force applying components and in order to cycle the upper roller between the engaged and disengaged positions during advance cycling of the uncoiled material to the downstream material forming operation.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Reference will now be made to the attached drawings, when read in combination with the following detailed description, wherein like reference numerals refer to like parts throughout the several views, and in which:
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(29) As will be further described with subsequent reference to
(30) Relevant components of the press feed mechanism described herein include a drive or cam shaft 12 with end support cam lobe 14 (see also enlarged views of
(31) To that end, the description of the gearing and structure associated with the servo motors and associated gearing to rotating shaft 12 connections is only generally shown and understood to operate with the use of conventionally known gears and related structure as generally illustrated in
(32) As will be further described in additional detail, the servo cam lift operates in conjunction with a pair of continuous force hold-down components 28 and 30 (commonly termed air bladders) and a programmable counterbalancing sub-assembly 32 (which is supported between mounting rail 34 and counter balance mounting beam 36) counters the PSI applied force of the air bladders 28 and 30 for accomplishing incremental grip and release motion of the upper feed roller 24 relative to the lower fixed position and rotating roller 26 in a highly timed and repetitive fashion for effectuating rapid and effective transfer of the uncoiled material to the downstream press operation.
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(36) With the above essential structural description, the servo cam operates in combination with one or more (typically a pair of) continuous hold down force assemblies 28 and 30 (depicted as air bladders however potentially including any other type of mechanical, electro-mechanical, hydraulic or other fluidic force applying construction which may be known in the art) which can be arranged proximate opposite and lateral extending ends of the rollers. Also provided is the further programmable counter balancing component (previously described at 32) which operates with the air bladders and servo cam lift for providing highly responsive and fine-tuned lifting of the upper displaceable feed roller 24 relative to the fixed rotating lower roller 26 (via rotation of the eccentric or cam shaped lobe 14 associated with shaft 12 which translates displacement forces to the end supported roller 48) and in order to facilitate transfer of the uncoiled sheet material from the feed assembly to the material press, stamping operation or the like located downstream from the feeding mechanism.
(37) By this construction, lifting motion of the upper feed roller can be controlled to increments as low as 0.001 with a corresponding rate of lift and return response time of 20 ms (milliseconds) or less. As will also be described, and according to one non-limiting preferred embodiment, the present system is equipped with either any of a single, dual or other multiple of force hold down components (e.g. air bladders) which operate to maintain a constant down pressure on the upper roll (programmable) and which allows for material thickness variations as the uncoiled (steel) material is passing between the upper and lower feed rolls.
(38) The air bladder components further act as cushions in response to sensing variations in the thickness of the uncoiled steel (such commonly being known to account for 5-10% variation in mill steel thickness). Additional features again include the provision of a programmable counterbalance assembly, such exerting a reverse (unseating/lifting) force to the upper feed roll in order to counter the continuous force applying hold down components (air bladders) and which further assists the servo cam lift in overcoming the continuous downward applied forces of the air bladders.
(39) In one non-limiting application, the programmable counterbalancing component can be set to a variable minimum for overcoming the mechanical weight of the assembly (feed roller and associated components) and the existing PSI holding force applied through the air bladders/force hold down components. One known range of settings can include a 0-100 PSI down pressure applied to the upper feed roll (assuming a 24 bore upper air cylinder at 80 PSI=3,400 lbs of down force, and an upper roll assembly weight of approximately 1,000 lbs). A non-limiting variant of the present design allows for up to 8,000 lbs of programmable counterforce.
(40) In operation, the servo cam lift can be set to a minimum desirable lift dimension above the material thickness of the uncoiled steel. By example, and in the instance of the assembly running a 0.100 thick stock, a lift variable can be programmed for 0.0101, with a further minimally desirable proper operational protocol suggesting a lift dimension of 0.008-0.010.
(41) During setup, an operator can program into the PC readable component a material thickness which in turn operates the positioning of the cam (with resultant lift-off of the upper feed roller). One non-limiting setting would have the cam retract to allow the upper roll to ride on the uncoiled sheet material surface, free from obstruction from the cam. Then, when actuated, the cam would rotate/lift to achieve the desired (programmed) lifting of the upper feed roller above the material thickness of the uncoiled steel, thereby allowing the material to float for the pilot function. Upon subsequently receiving a signal to close, the cam would then reverse rotate (retract) back to the current home position to allow the sheet material to be gripped and thereby advanced and allowing the force holding components (air bladders) to apply their rated PSI pressure in full.
(42) Referring back to the illustrations,
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(49) The force hold down components 76/78 are further depicted anchored to undersides of the brackets 80/82 in downwardly extending (as opposed to angled fashion as in
(50) See also as further shown bracket supports 88 and 90 which are also depicted in
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(52) Additional key components of the servo pilot mechanism include the servo motor being sized in any desired range (such as 70-600 in-lb), with the corresponding gearbox assembly exhibiting a calculated ratio ranging from 1:1 to 25:1. The gearbox utilized can further exhibit zero or low backlash properties and can further include any of an in-line or right angle type construction.
(53) The camshaft assembly utilized can further be mounted within a housing via taper roll bearings with locknuts and washers. Alternately, other economical assemblies are envisioned which can include any type of bushing arrangement.
(54) The programmable (air) counterbalancing component 32 can also envision utilizing any other type of mechanical (including electro-mechanical servo variant), pneumatic or hydraulic redesign (or can provide a combination of all) such as in order to eliminate the upper roll 24 and assembly weight and to assist in overcoming the PSI down force exerted by the hold down (air bladder 28/30) components. To this end, additional redesigns of the invention contemplate single or dual air bladders utilized for providing feed roll pressure, such further with or without mechanical spring counterbalances.
(55) It is also generally accepted that a servo pilot release provides improvements over standard air release options which define the industry standard. It is further understood that the process or operation of the pilot release cycle function during the stamping process/cycle of the press can have substantial impact on the accuracy of the feed mechanism, such as in which the rapid tuning of the upper roller 24 in effect causing the feeder to release the steel to float.
(56) Additional factors include adjustment to the pilot timing in order to effect part length, mostly due to the Lag time associated with Air release. In this fashion, the timing of the servo release greatly improves this accuracy by minimizing the lift above the steel and the rate of return in which the feed rolls (24 and 26) close or contact.
(57) By virtue of such an arrangement, factors eliminated in a traditional setup of the feed mechanism include energizing the solenoid valve, the time for air to travel to lift cylinders, the time needed to fill the cylinder with air and in order to achieve the proper pressure, the cylinder lift time and, finally, the cylinder lift travel. In reverse operation, time delays include for each of the spool being closed on the solenoid valve, forcing the air from the cylinder dump air, the time for the cylinder to travel from full open back to closed position, and finally for the roller 24 to meet or contact the sheet material (concerns here are force of impact and possible material marking).
(58) The high speed servo mechanism incorporated into the present invention largely eliminates the time it takes for the above pre-existing process, and by the rapid movement of the servo cam lift. The present mechanism also helps reduce long feeds and short feeds associated with the pilot release portion of the press cycle when using an air system, mostly due to timing lag.
(59) A programmable setting allows for a down force applied to the upper feed roll 24, and which again is calibrated in order to absorb variances in material thickness as the uncoiled steel passes through the feed machine to the downstream press or other stamping operation. Other variants include provision of a shaft mount style cam follower. An eccentric shaft can also be incorporated, and which may have less than a 0.006 (torsional) twist with 36,000 inLbs applied.
(60) Yet additional operational considerations include the cycling/response time (such as between the positions of
(61) As also previously described, the air bladder pressure may be programmable within the parameters (job recipe) programmed into the PC component of the assembly, the air counterbalancing pressure (component 32) is also a programmable aspect and can include a minimal pressure setting for countering or eliminating the combined weight of the upper pivot assembly and roller weight (such as approximately 900 lb for a 48 machine with 6 rolls). Other considerations may include incorporating a maintenance program that fully cycles the servo and gearbox to help reduce in wear (factoring that the servo will only be moving back and forth most of the time in small increments). A manual mode may also be utilized to cycle programmed lift during setup.
(62) The associated service screen utilized with the PC component of the servo cam is desirously accessed by authorized personnel only, such as via password input. This functionality can further include each of calibrating to zero, adjusting acceleration/deceleration of the cam lift profile, adjusting velocity, etc. This can further envision different profiles being programmed which, for example, applies to sensitive or pre-painted uncoiled materials in which softer closing or gripping of the upper roller is desired in order to prevent material wear or damage during cycling.
(63) By its construction, the combination of the continuous hold down force applying components 28/30 and the opposing or counter force exerting component 32 operate in order to finely tune or adjust both the force of contact exerted between the rollers 24 and 26, as well as the creation of a minute separate distance therebetween. This combination further permits the inter-communicated sheet of steel material to be precisely advanced and, when initiating the subsequent press operation, to securely and effectively grip the steel sheet in order to prevent bending/creasing to the same or misalignment at the entry location to the adjoining press. In this fashion, the present invention provides for both faster and more accurate feeding of the uncoiled steel sheet in the succeeding press or other stamping/forming operation than has been heretofore possible.
(64) Having described my invention, other and additional preferred embodiments will become apparent to those skilled in the art to which it pertains, and without deviating from the scope of the appended claims.