Source: http://www.google.com/patents/US5088752?dq=patent:+7360079
Timestamp: 2013-12-11 12:59:47
Document Index: 89127120

Matched Legal Cases: ['arts 44', 'arts 44', 'arts 44', 'art 44', 'arts 44', 'arts 44', 'arts 44', 'art 44', 'art 44', 'art 44', 'art 44', 'art 44', 'art 44', 'art 44']

Patent US5088752 - High strength die support cart having an arched frame - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Advanced Patent Search | Sign inAdvanced Patent SearchPatentsA movable die support cart with a frame structure supported by spaced axles consisting of continuous beams extending parallel to the axles and continuous plate members extending normal to the beams and beneath the beams. Each plate member is configured with an upwardly curved arch between its end portions....http://www.google.com/patents/US5088752?utm_source=gb-gplus-sharePatent US5088752 - High strength die support cart having an arched framePublication numberUS5088752 APublication typeGrantApplication numberUS 07/606,685Publication dateFeb 18, 1992Filing dateOct 31, 1990Priority dateOct 31, 1990Fee statusLapsedPublication number07606685, 606685, US 5088752 A, US 5088752A, US-A-5088752, US5088752 A, US5088752AInventorsRobert E. Henderson, Richard L. SandersOriginal AssigneeChrysler CorporationExport CitationBiBTeX, EndNote, RefManPatent Citations (9), Referenced by (3), Classifications (12), Legal Events (7) External Links: USPTO, USPTO Assignment, EspacenetHigh strength die support cart having an arched frameUS 5088752 AAbstract A movable die support cart with a frame structure supported by spaced axles consisting of continuous beams extending parallel to the axles and continuous plate members extending normal to the beams and beneath the beams. Each plate member is configured with an upwardly curved arch between its end portions. The beams and plate members are attached together by welds to define an upwardly convex die support surface in the unloaded condition and a flatter surface in the loaded condition.
What is claimed is as follows: 1. For supporting and transporting a heavy die set outside a stamping press, a movable die cart, comprising: a high strength fabricated frame structure with opposite end edge portions and opposite side edge portions; means for movably supporting the frame structure, the means including a pair of axles, one extending along each of the opposite end edge portions of the frame structure, the axles being attached to the frame structure in a manner permitting rotation of the axles, the means further including a pair of wheels connected to either end of both axles; the frame structure including a pair of tubular beams extending continuously from one side edge portion of the die cart to the other opposite side edge portion and extending parallel to the axles, each tubular beam being slightly outwardly offset from the center of the cart; additional continuous beams positioned outwardly on either side of the tubular beams thus located between a tubular beam and an axle and extending in substantial parallelism with the tubular beams and additional beams; flat cross-members extending continuously beneath the tubular and additional beams from one end edge portion of the frame structure to the other end edge portion substantially normal to the tubular beams and additional beams; the vertical dimension of the flat cross-members being relatively thin as compared to the vertical dimension of the tubular and additional beams to permit forming an arched configuration with central portions elevated relative to opposite end portions; weldments attaching the beams and the flat cross-members together at edge juncture locations thereby forming a strong frame with an upwardly curved central portion between the end edge portions when the frame is unloaded, whereby the frame is distorted by the weight of a die set placed thereon between the end edge portions so that a loaded cart frame is substantially flat.
2. The high strength frame structure for a die set cart as set forth in claim 1 in which short beams are closely fitted between and extend normal to the continuous beams, these short beams being positioned in substantially end to end alignment thereby forming several non-continuous beams extending from one end edge portion of the cart to the other; the ends of the short beams being welded to the continuous beams to approximate the strength effect of continuous beams.
3. The high strength frame structure for a die set cart as set forth in claim 1 in which the additional beams include outer continuous beams adjacent both end edge portion of the frame structure; a plurality of short stub beam members attached to the outer continuous beams and extend in an outward direction away from the continuous tubular beams, the stub beam members extending outward further than the ends of the flat cross-members, the stub beam members having means connecting the axles to the frame structure for rotation when the frame structure moves.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT The Die Changing System FIG. 1 illustrates a portion of a progressive stamping press line. Specifically, only three presses 10, 12, 14 are shown in FIG. 1 but the line can easily include six presses necessary to form a large and complicated vehicle body part. The presses are aligned in side by side relationship to form a press line. A sheet metal part begins as a flat piece at the right end of press 10. The sheet is formed between upper and lower dies of a die set in the press 10 and then transferred to press 12 where another die set further forms the metal. Likewise, the piece is next transferred to press 14 to be further formed by the die set therein, and so on.
Earlier, it was explained that the general practice in the stamping art is to move each die sets with an overhead crane between a storage area and a loading position between and adjacent the presses. Levers, come-along or chain fall like devices are used to drag the old die sets out of the presses and push the new die sets into the presses. Normally, the die sets are temporarily supported upon a raised platform or the like. Many hours are typically required to change all the die sets of a six press line using this method. In addition to the relatively long time in which to finish a die change, quite often the movement of dies by overhead crane between the narrowly spaced presses will damage vulnerable external portions of the press such as electrical boxes, relays, etc. In addition, some press installations require equipment such as electric motors, for example, to be mounted on the side of the press rather than on top. This produces projecting structure as schematically shown in FIGS. 1, and 3-4, is identified by labels 42 in the drawings. The projecting structure 42 is of course easily damaged by lifting parts of the crane or the die set as it is moved.
Referring to FIGS. 1-4, the subject system and apparatus to change die sets is illustrated. It utilizes movable die carts 44 which are supported by wheels 46. The wheels 46 roll on tracks 48 along the press line floor. While the press line is operative and forming parts, the carts 44 are positioned in a remote or pre-staging area 50. In this pre-staging area, the carts 44 can be unloaded and loaded with die sets by an overhead crane (not illustrated) without likelihood of damage to the presses. Thus prior to shutting down the presses for a die set change, previously used dies can be unloaded from the carts and new dies can be loaded onto the carts for subsequent use.
When finally the press line is shut down for the die change, each cart 44 is moved along the tracks 48 into a side by side adjacent relationship with the faces 26, 28 of the presses as shown in FIGS. 2-4. The height of the die sets on the carts relative to the presses is predetermined so the die sets move substantially horizontally between the carts and the presses. To further facilitate movement of a die set between press and cart, a series of roller assemblies 52 are supported on the upper surface of the cart. These rollers will be better identified and described hereinafter.
Referring specifically to FIG. 2, it can be seen that the above described die cart system and apparatus easily services two parallel press lines. Specifically, presses 10-14 makeup a portion of a first press line. A portion of a second press line is represented by presses 54, 56 and 58. The tracks 48 pass adjacent and between the presses in a single press line and also extend between the first and second press lines. Thus, one cart can alternately service either press line.
Another convenient feature of the subject die changing system is apparent from FIG. 2. When the carts 44 are moved from the remote pre-staging area 50 to spaces between two presses, stop means 60 are provided so that the carts 44 are located and correctly positioned relative to the presses in the direction between press sides 18, 20. Still further, the die support surface or bolster 38 of each press includes projecting guide means 62 and stop means 64. The means 62 and 64 interact, respectively, with a V-shaped notch or slot 66 and end surface 68 formed in the side of plate 36. The guide means 62 and slot 66 finally position the plate 36 in the press. Both the guide and stop means 62 and 64 interact with 66 and 68 to position the plate and die set in the direction between sides 26, 28. The means 62 and 64 may be in the form of upwardly extending pin members or the like. Of course, the members 62, 64 are removed once the die set is properly located and then attached to the press since the removal is necessary prior to pushing out the die-set during a subsequent die change.
To best understand the mechanics of changing a die set using the subject equipment reference is made to FIG. 4. The transporter carts 44 and die sets thereon are in a loading and unloading position with respect to the presses. The group of die sets to be replaced by a new group are labeled 30' and the new group of die sets to be installed in the presses for subsequent use are labeled 30'. The respective mounting plates 36' and 36" of these die sets are each provided with pairs of upstanding attachment means or coffin hooks 70 positioned in pairs along opposite edges of the plates. For more details of the specific attachment structure, attention is directed to the enlarged view in FIG. 9. The attachment means 70 includes an upright post 72 extending from the mounting plate 36'. The post 72 carries a laterally extending cross pin 74.
The Die Set Transfer Apparatus With reference to FIGS. 5-6, each cart 44 includes a pair of spaced die transfer drives 76 which are used to move the dies on and off the cart. The old die set 30' (in the press) can be pulled onto the cart 44 while the new die set 30" is pushed from the cart into the next press. As best shown in FIG. 9, each die transfer drive 76 includes a threaded bearing block or base portion 78 which extends below the upper surface 80 of the cart 44. An elongated threaded shaft 82 extends laterally across the cart from one side 84 of the cart to the opposite side 86. Each shaft 82 is supported to permit rotation thereof and extends through a bearing block 78 of a transfer drive 76. As the shaft 82 is rotated, the transfer drive 76 moves laterally across the cart 44.
In FIG. 10, a variation of the link arm connection is shown. In the view, a new die set 36" has just been pushed into a press by a link 96 with a semi-circular journal portion 98 formed in its end. The journal 98 engages the cross pin 74 to allow the arm to push the die set. With this arrangement, the link arm 96 does not need to be pivoted as before. A height adjustment means in the form of a threaded member 100 is provided so that the elevation of the link arm 96 and specifically the journal 98 can be set relative to the pin 74. Once adjusted, the journal portion 98 should line up with the cross pin 74.
Power for the Cart An air powered or driven motor 128 and a hydraulic pump 130 are shown in FIG. 7. Motor 128 and pump 130 are directly connected by a shaft 132 so that motor 128 drives pump 130. As so far explained, there is no electrical connections to the cart 44. The sole power for the cart 44 and the air motor 128 which generates pressurized oil to the other motors is a pressurized air hose (not visible in the drawings). Specifically, the pressurized air is routed to the central portion of the cart to motor 128 by a conduit 134. An air filter 136 prevents passage of dirt and moisture to the air motor 128.
The above referenced hydraulic pump 130 selectively supplies pressurized oil to the hydraulic motors 108, 110 and 116 through air pressure operated control valves 138 and 140 in the embodiment generally shown in FIG. 7. Control valve 138 directs the flow of pressurized oil to the axle motors 108 and 110. It has selective operative modes to change the flow direction of pressurized oil to motors 108, 110 so that the cart will move in opposite directions as needed. Likewise, the other control valve 140 has selective operative modes to change the flow direction to permit motor 116 to move the pair of transfer devices 76 in opposite lateral directions across the cart 44. In FIG. 7, oil returns from the motors 108, 110 and 116 through conduits 142, 144, 146, respectively. The oil enters a hydraulic reservoir formed in hollow beams of the cart frame as will be described in more detail hereinafter. Hydraulic pump 130 withdraws the stored oil in the reservoir means through a conduit 148.
Structural Frame of the Cart The cart obviously must have great rigidity and strength in order to support very heavy die sets. The cart's strength is achieved through the particular frame structure best shown in FIGS. 11-15. In the lateral direction from side 84 to side 86, the central portion of the frame has continuous tubular steel beams 150, 152. In the illustrated preferred embodiment, these beams are eight inches square and one half inch in wall thickness. On both sides of the cart outward from beams 150 and 152 are three continuous solid steel beams 156, 158 and 160 (two by eight inches).
The frame is strengthened in the end to end direction (normal to the beams 150, 152) by three continuous solid steel beams 162, 164 and 166 having a two by ten inch cross section. The relatively flat beams 162, 164 and 166 extend beneath beams 150, 152, 156, 158 and 160 as shown in FIGS. 11 and 13. The beams are securely attached at their crossing junctions by weldments. Also in the end to end direction, the frame is strengthened by two non-continuous mid-beams consisting of: short pieces 168 of eight by eight tubular steel between beams 150 and 156; between beams 152 and 156 and between beams 158 and 160 (both sides); and short pieces 170 of solid steel extending between beams 150 and 152 and between beams 156 and 158. Pieces 168 and 170 are securely welded to the other beams to complete the formation of a very firm structure. The configuration of the solid short pieces 170 are selected to allow lateral clearance for the die transfer drives as seen in FIG. 14 and to allow communication between various components located between the beams 150, 152 as seen in FIG. 7. Finally, the frame is completed along the opposite sides 84, 86 by short end pieces 172 consisting of two by eight solid steel. The pieces 172 are welded between the various continuous beams 150, 152, 156, 158 and 160 as seen in FIG. 15.
With reference to FIG. 12, an important structural feature is shown. Note that the frame has an arched configuration in the end to end direction between the axle supporting apertures 176. It can be seen that the continuous solid beams 162, 164 and 166 which extend beneath the other beams are curved or arched upward. Thus, the mid-point is higher than the ends when the frame structure is welded together. Of course, for clarity, the arched configuration is greatly exaggerated in FIG. 12. In the preferred embodiment described above, capable of supporting a 150 ton die set, the mid-point of the frame is arched upward about one half inch with respect to the ends and the end to end distance which is about 152 inches. Obviously then, the small pieces 168, 170 and 172 are not perfectly rectangular s that they conform to the arched structure. Resultantly, when a cart is loaded with a heavy die set, the mid-portion of the cart is distorted downward to form a flatter configuration.
As best seen in FIG. 20, the support frame drops into a rectilinear space or recess 192 which in one direction may be formed between beams 158 and 160 and in another direction is formed between beam piece 168 and end member 172 for example. Referring now to FIG. 21, the roller assembly 52 is support on members 194, 195 which are welded to the sides of continuous beams 158, 160, for example. The elevation or vertical height of the assembly 52 relative to the top of the cart or bolster 38 is determined by the dimension of spacer beam members 196, 198 which are positioned between supports 194, 195 and the frame of assembly 52. If more or less height of assembly 52 is respectively desired, spacers (not shown) can be added or a thinner beam can be substituted.
As previously noted with reference to FIG. 1, the press's bolster or support surface 38 includes several recesses. Each recess houses a roller support assembly 40 for supporting a die set. For details of a typical roller support assembly, attention is directed to FIGS. 17-19. These views disclose a base member 200 with a pair of upstanding, spaced arm portions 202, 204 attached thereto (preferably by welding). Each spaced arm portion supports an end of a roller shaft 206. Shaft 206 in turn supports a cylindrical roller 208 thereabout. When a die set is being moved into or out cf a press, roller 208 engages and rotates relative to the underside of the die set mounting plate 36 and supports the plate 36 above the bolster 38.
FIGS. 17, 18 and 19 also reveal details of a typical recess 216 formed in the bolster 38 of the press. A recess 216 is most conveniently formed between the usually provided T-shaped slots 217 (upside down) typically found in base of the press. The slots 217 are typically used to secure the heads .of bolt like fasteners (not shown) which extend upwardly to engage a nut portion of the fastener to secure the mounting plate 36 to the base of the press. The assembly's base 200 is sized and configured to easily fit into the recess 216. A side by side or dual Belleville type washer spring 218 is located in a space formed beneath the base 200. An annular spacer member 220 is located between the spring 218 and the lower surface or bottom wall of the recess 216. Spring 218 is sufficiently stiff to support the weight of the die set 30 and plate 36 above the upper surface 222 of the bolster 38 as shown in FIG. 18. The thickness of spacer 220 can be varied to provide desired spacing of the plate 36 above the bolster surface 222 as discussed in the next paragraph.
Once a die set is in moved into position in the press, the heads of bolt type fasteners are engaged into the T-shaped slots 217 and nut type fasteners are used to secure the plate 36 to the bolster 38. Sufficient force is generated to compress the springs 218 and move the lower surface of the plate 36 against the upper surface 222 of the bolster as shown in FIG. 19.
Each of the oil control valves 138, 140 are fluidly connected respectively by conduits 242, 244 to the outlet 246 of hydraulic oil pump 130. Each of the valves 138 and 140 also has a fluid drain conduit 248, 250 which is connected to an inlet fitting 252 to the interior 152' (see FIG. 16) of beam 152 which serves as part of a hydraulic reservoir. From a previous explanation, it can be recalled that the hydraulic oil in interior 152' of beam 152 passes into interior 150' of beam 150 through the transfer conduit or pipe 178. The inlet 148 of the hydraulic pump 130 is operatively connected to the interior 150' of beam 150.
Internally, the oil control valves 138, 140 each have a movable valving part to selectively connect various outlets with the inlet. This places the valve in one of four modes as follows: a mode blocking pressurized oil flow; a mode directing oil flow to a motor in one direction to produce rotation in one direction; a mode directing oil flow to a motor in an opposite direction to produce rotation in the opposite direction; a mode to drain oil from the motors and conduits back into the reservoir.
It was previously explained that the hydraulic pump 130 is driven by the air motor 128. Pressurized air is directed to the air motor 128 by a line 254. A filter 136 is placed between the air source and the motor 128. Control of air pressure to the motor 128 (on-off) is by an air valve 256. The valve 256 is normally maintained in a closed mode but opens in response to a pressurized air signal through an air signal line 258. The air line 258 is connected to a combination air junction and valve 260.
The air junction valve 260 is used to selectively send pressurized air signals to other devices. Hydraulic control valve 138 responds to signals communicated to an air pressure powered control device 262 through air signal lines 264, 266. Hydraulic control valve 140 responds to signals communicated to an air pressure powered control device 268 through air signal lines 270, 272. Signals are selectively emitted by the air junction valve 260 in response to manual operation of a four button control 274. Control 274 regulates the introduction of pressurized air to the junction valve 260 so as to selectively direct the necessary signals to the devices 256, 262 and 268. Control 274 is connected to air line 254 and junction valve 260 by air transmission means 275 and 276. The four buttons on the control 274 control the following functions: move the cart in one direction; move the cart in the opposite direction; move the die set transfer drive 76 in one direction; and move the drive 76 in the opposite direction.
DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a portion of a press line showing several stamping presses and the subject die set changing apparatus including die set transporter carts and their arrangement relative to the presses during a pre-staging mode of operation; and
FIG. 2 is a planar view showing portions of two separate press lines with the subject die set changing apparatus positioned therebetween in the pre-staging location so as to service both press lines; and
FIG. 12 is an enlarged end sectioned view of the frame structure taken along section lines 12--12 in FIG. 11 and looking in the direction of the arrows and revealing a significant arched pre-loaded configuration which has been exaggerated for clarity; and
FIG. 16 is a sectioned view taken along section line 16--16 in FIG. 11 and looking in the direction of the arrows; and
FIG. 21 is a sectioned view of the roller assembly taken along section line 21--21 in FIG. 20 and looking in the direction of the arrows and showing the means to adjust the elevation of the rollers.
SUMMARY OF THE INVENTION This application discloses apparatus and a system to efficiently and rapidly change die sets in a row of stamping presses. Part of the die change operation begins even while the press line is operating to make a particular part. During this period, movable die carts are positioned in a remote pre-staging area in front of a row of presses. Thus, the carts do not interfere with the movement of sheet metal parts from one press to another as the part is progressively stamped into a desired form. In the pre-staging area, die sets can be removed from the carts and new die sets can be placed on the carts.
The subject efficient die change system locates a first movable cart so that it can be positioned adjacent an outer end of one of the presses located at the end of the press line. Other carts are located so that they can each be positioned between the presses. A particularly efficient use of the above described die carts is to position them with the remote pre-staging area located between two separate and parallel press lines. Thus, one group of die carts can be alternately moved in either direction with respect to either press line from the pre-staging area to a position adjacent a press.
In addition to the powered transport means for moving die sets between the carts and the presses, the carts themselves are furnished with powered axle and wheel means so that they can be easily moved along tracks between the remote pre-staging area to the presses. A desirable power source in the subject embodiment utilizes pressurized air fed to the cart through a flexible hose. The pressurized air operates an air driven motor which is directly connected to a hydraulic pump. The hydraulic pump takes oil from a reservoir and directs pressurized oil to hydraulic motors as directed by control valves. The control valves are actuated by applications of air pressure through a control device which selectively routes air pressure signals to the valves. A hydraulic motor is used to drive screw type devices for the pushing and pulling die set transport. Each of the cart's two wheeled axles are operatively connected to other hydraulic motors so the cart can be moved conveniently and easily , even with heavy die sets thereon.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS729522 *Jul 19, 1902Jun 2, 1903Martin H AndersonStreet-car puzzle.US1846567 *Mar 18, 1929Feb 23, 1932Metropolitan Eng CoManufacture of vehicle framesUS3092396 *Mar 10, 1961Jun 4, 1963Thomas Benjamin FTrailer frameUS3300839 *Jul 1, 1963Jan 31, 1967Lihap IndMethod of making cambered beamsUS3514001 *Aug 20, 1968May 26, 1970Jet Avion CorpFreight pallet carrierUS3720329 *Mar 16, 1971Mar 13, 1973American Air Filter CoPalletized cargo trailerUS4045042 *Mar 30, 1976Aug 30, 1977J. Walter AgTraveling undercarriage for a container or the likeUS4249633 *Mar 1, 1979Feb 10, 1981Dunbar Glenn GScale testing cartUS4934720 *Jan 9, 1989Jun 19, 1990Dobron Frank JMobile cart having adjustable supports* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS5378003 *May 20, 1993Jan 3, 1995Koller Enterprises, Inc.Mechanic's creeperUS7007790 *May 6, 2004Mar 7, 2006Brannon James DLoading platform with twin roller conveyorsUS20110121554 *Nov 23, 2010May 26, 2011Spartan Motors, Inc.Vehicle chassis with anti-camber* Cited by examinerClassifications U.S. Classification280/79.11, 280/796, 280/782, 180/242, 104/242, 180/306, 180/251, 100/918International ClassificationB62D21/02Cooperative ClassificationY10S100/918, B62D21/02European ClassificationB62D21/02Legal EventsDateCodeEventDescriptionApr 13, 2004FPExpired due to failure to pay maintenance feeEffective date: 20040218Feb 18, 2004LAPSLapse for failure to pay maintenance feesSep 3, 2003REMIMaintenance fee reminder mailedJul 20, 1999FPAYFee paymentYear of fee payment: 8Jul 31, 1995FPAYFee paymentYear of fee payment: 4Dec 6, 1990ASAssignmentOwner name: CHRYSLER CORPORATION, HIGHLAND PARK, MI A CORP. OFFree format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:HENDERSON, ROBERT E.;SANDERS, RICHARD L.;REEL/FRAME:005546/0030Effective date: 19901031Dec 6, 1990AS02Assignment of assignor's interestOwner name: CHRYSLER CORPORATION, HIGHLAND PARK, MI A CORP. OFOwner name: HENDERSON, ROBERT E.Owner name: SANDERS, RICHARD L.Effective date: 19901031RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google