US2177821A - Die spotting press - Google Patents

Description

Oct. 31, 1939. R. w. DINZL.

DIE SPOTTING PRESS Filed March 18, 1937' 4 Sheets-Sheet l sh l INVENTOR Bierman W Dl/vzL OC. 31, 1939. R- W D|NZL DIE SPOTTING PRESS Filed March 18, 1937 4 Sheets-Sheet 2 Oct. 31, 1939. R, w, D|NZ| 2,177,821

DIE SPOTTING PRESS Filed March 18, 1937 4 Sheets-Sheet 3 my-7 E 46 t 48 47, 5)

( INVENTOR BlcHmanW U/NZL A TONE Oct. 31, 1939. R, W D|NZL 2,177,821

DIE SPOTTING PRESS Filed March 18, 19:57 v4 sheets-sheet 4 l V 6 6 l j j 5 i i 53 f se 4 6 5 57 n j L J j :mur

Fig. T l ww//W/ m//f ,//f/fwz INVENTOR AOE Patented Oct. 31, 1939 DIE SPOTTING PRESS Richard W. Dinzl, Narberth, Pa., alsiznor to Baldwin-Southwark C of Delaware orporation, 5 corporation Application March 18, 1937, Serial No. 131,692

l 11 Claims.

This invention relates generally to die spotting presses and more particularly to apparatus for insuring that the die bases will be maintained in parallelism during a spotting operation and for l determining.v the general location of high spots.

It is well known that dies must have substantially perfect mating surfaces in order to properly stamp or press material, particularly sheet metal material, this being of especial importance l with large dies such, for example, as are used in the stamping of automobile bodies or other large sheet metal products. The operation of bringing dies together to determine their high spots or irregularities and then separating the dies to all low the workmen to grind or otherwise remove the high spots is very laborious, painstaking and repetitions.

One difliculty with large dies when spotted in accordance with prior practice is that after they have been properly matched, the upper and lower supporting surfaces may not be in parallelism, thereby requiring machining of such surfaces to make them parallel. However, this is usually accompanied by the vertical guiding surfaces of the dies being thrown on an angle which destroys the desirable vertical guiding action between the dies as they move toward and away from each other in actual use. y

It is an object of my invention to provide im- I0 proved means for determining, during a die spotting operation, when a high spot of a die surface comes into contact with the opposed die surface and also to determine substantially the location of such high spots.

A further object is to provide an improved die spotting apparatus that will facilitate maintaining the upper and lower die bases in parallelism and thereby maintain the cooperating vertical guiding surfaces of the dies in true perpendicular.

Another object is to provide an improved die spotting apparatus that is relatively ,simple and economical in construction, operation and maintenance and that may be adapted to existing presses as well as permitting the spotting operations to be carried on with convenience and dispatch while still maintaining a high degree of accuracy and sensitivity. The diiliculty of obtaining accuracy and sensitivity is readily appreciated when it is considered that certain dies, such as for automobile bodies, are not only very large in size but also very heavy, weighing up to several tons.

A further object is to provide improved means for controlling the movable die when it is raised after a spotting operation, thereby to prevent `ing certain features of my invention;

Fig. 2 is a plan view of Fig. l partially in sec- V tion; v

Fig. 3 is an enlarged sectional view on the line 3-3 of Fig. 1;

Fig. 4 is a transverse section taken on the line 4-4 of Fig. 1;

Fig. 5 is a fragmentary sectional elevation of a press embodying' a modified arrangement of my invention;

Fig. 6 is a still further modification;

Figfl is a sectional view showing the platen latching means;

Fig. 8 is a horizontal section on line 8-8 of Fig. 5.'

In the particular embodiments of my invention such as are disclosed herein merely for the purpose of illustrating certain speciiic forms among possible others that the invention might take in practice, I have shown in Fig. l a die spotting press of a conventional type having a base platen I, an upper stationary crosshead 2 and sidecolumns 3 and 4 all rigidly secured together. A vertically movable die supporting platen 5 is slidably guided on columns 3 and 4 by a series of vertical guideways 6. Platen 5 is moved vertically by a piston 1 and cylinders 9, one ormore of which are located Within each of the columns 3 and 4, the piston rods being connected to suitable bosses 8 formed on platen 5 and projecting inwardly of the columns'while the cylinders are secured to base I. The structure so far described is typical of any conventional die spotting press.

Assuming that complementary dies are supported in a usual manner on platens I and 5, iluid pressure is then gradually discharged from cylinders 9 to allow the dies to come into contact. To determine with accuracy and sensitivity when the dies contact each other and also to determine substantially the location of said contact caused by a high spot on the die, I haveY provided the following improved die contact determining means. Four vertical rods I0, II, I2 and I3, are located at different points of thc platen, such as its corners as seen in plan view, Fig. 2. Inasmuch as the details of construction of each of the rods and their associated apparatus are identical, it will sliiilce to describe only one. As shown in Fig. 4, rod I0 is suitably immovably secured at its lower end I4 to platen 5, while the upper end of said rod is provided with a collar I5, Fig. 1, having preferably a down turned flange I6. This rod extends upwardly through a sleeve I1. the sleeve being prevented from rotating by a key I8 slidable in a keyway I9 of the non-rotatable rod l0. The upper end of sleeve I1 has secured thereto an enlarged collar 20 carrying a switch 2|. This switch is preferably of the well-known so-called micro type requiring very minute pressure and movement to establish a circuit. Sleeve Il has threaded engagement with a rotatable nut 22 formed as part of a bevel gear 23 contained within housing Zia, this being suitably journalled in an L-shaped bearing 24 which in tuin is supported on a pair of opposed transverse channel beams 25 and 26. The gear 23 and its corresponding gear for the other rods II, I2 and I3 are driven from a common motor 2'I through shafts 28, 29, 30 and 3l together with necessary bevel gears connecting said shafts together and to the rods Ill-I3.

In operation, all of the collars on sleeves I'I have the same elevation which may be adjusted by motor 21 commonly and simultaneously operating all of the rotatable nuts 22 thereby causing sleeves I1 to be raised or lowered' to any given elevation. After the dies are inserted in the machine, the sleeves I'I and the collars 20 are adjusted to any selected elevation. Movable platen 5 is then gradually lowered by exhausting fluid from the interconnected piston cylinders 9, the rods |0449 moving with the platens and collars I5 moving toward switches 2l. If the elevation of switches 2l is too high, then they will be simultaneously closed by collars I5 before the dies come into contact. The closure of each switch will be individually indicated by the lighting of lamps'32, one for each switch. Each lamp and switch are in a circuit such as diagrammatically indicated by wires 32'. The exhaust of ,iluid from cylinders 9 can then be stopped and the screw sleeves lowered. The platen is then again lowered and if all the lamps 32 again light, the screws and platen are continued to be lowereduntil finally a high spot on the die say near rod I0, Fig. 2, prevents the platen from moving down at this point and consequently the collar I5 of rod I0 cannot close its switch 2i. However, all other portions of the platen adjacent the other rods II-I3 will minutely settle down very slightly out of parallelism and just sumciently to close the micro switches associated therewith. The three closed switches will instantly close their electric circuits to light three of the four lamps 32. The fourth lamp by remaining unlighted gives the operator a visible indication that the dies have contacted and that the general location of the high spot is in the area surrounding rod Ill. Fluid pressure is then supplied to cylinders 9 to raise the pistons and platen 5 together with its die, whereupon a mechanic proceeds to grind off or otherwise remove the high spot. The foregoing cycle of operations is then repeated, the operator gradually lowering the elevation of the threaded sleeve I1 and collars 20 and noting according to the lamps 32 the location of the varying high spots as they are successively removed until iinally the entire die surfaces are in complete contact with each other. When the dies have uniform contact, all four of the lamps 32 will light simultaneously. To protect the switch apparatus and to insure that the movable die platen cannot be substantially tilted out of parallelism with base I, the collars I5 have substantial hubs 33 adapted to engage and be supported on the collars 2U. The axial length of hubs 33 is such that only minute movement thereof can occur after the switches are closed by flanges I5. This minute tilting movement is inherently corrected by the press operating means and guideways immediately when the platen is raised. Hence there is no cumulative tilting error involved.

In a modified arrangement, each of the ram cylinders may be provided with individual pressure gauges 34, Fig. 5. In a die spotting operation, the fluid is uniformly gradually exhausted from all of the cylinders. So long as the platen moves uniformly downward, there will not be any change in the individual pressure gauge readings. However, when the dies come together on a high spot adjacent any one or more of the cylinders, the ram therein will stop and accordingly the pressure gauge for that cylinder will not record any pressure. The operator will then immediately know that the dies are in contact on a high spot and know that the location of the high spot is adjacent that particular cylinder. Fluid pressure will then be admitted to the cylinders to move the platens upwardly so that the operator may grind or otherwise remove the high spot.

The forgeoing arrangement permits dies to be spotted in an extremely simple and effective manner with a high degree of accuracy and sensitivity while at the same time insuring that the upper and lower die bases willbe maintained in parallelism at all times during the die spotting operation, thereby avoiding or minimizing the necessity for machining these bases. My improved apparatus also insures that the usual cooperating vertical guiding surfaces of the two dies will be maintained normal to the parallel surfaces of the die bases.

FIG. 5.-Modicatio11.-Instead of having the adjustable elevational means, such as the screw sleeves, carried by a stationary part of the press, I may incorporate the same in the platen so as to be movable therewith. The platen 5 in this modification is guided and actuated in the same manner as in the preferred form, although a housing 36 is secured to the under side of the platen and die mounting tools 3l are secured to the housing. A series of rods 38 located in plan view similar to rods Ill-I3 are mounted in housing 36 so as to project .upwardly into platen 5. Each of these rods is vertically slidable but nonrotatably keyed as at 39 to the platen. Description of one rod and its associated means will sufce for all inasmuch as they are identical. A sleeve nut 40 has threaded engagement with rod 38 and is suitably journalled in housing 36 to be rotatably driven through bevel gears 4I and shaft 42 by a common motor 43.

Supported upon base I is a stop column 44 adapted to positively limit downward movement of the upper platen upon engagement of rod 38 with stop 44. A micro switch 45 is carried by stop column 44 to be engaged by any suitable lip or ange 46 on rod 38. rl'he operation of this arrangement is identical to the preferred form.

Upon lowering of the upper die, any irregular 177,821 switches re `still open, thereby lighting certain of the dies with consequent throwing out of parallelism of their upper and lower surfaces as well as destroying their vertical guiding surfaces.

From this modification it will also be noted that platen is maintained in ahorizontal position during raising or lowering by virtue of an equalizer system including a pair of shafts 41 journalled in bearings ,48 which are supported by platen 5. The outer ends of shafts 4'I are provided with interconnected. gears 48 certain of which mesh with stationary racks 49 secured to the ` side columns 3 and 4. This equalizer system insures that every precaution isltaken to obtain absolute accuracy in the operation of the high spot indicating means.

FIG. 6.-Modificatio1z.-In this modication, a

. plurality of vertical rods 50 are supported by the indicating lights controlled by the switches 52 will operate in identically the same manner as in the previously described modifications and also the rods 50 are adapted to serve as limit stops. The platen 5 may be raised or lowered by a conventional ram -1 and cylinder 9 or by mechanical means such as a series of screws 62 secured to platen 5 and having threaded engagement with rotatable nuts 63. The nuts for the series of screws 62 are supported by an upper stationary crosshead 64 and are adapted to be simultaneously driven through any suitablemechanical means such as bevel gears and shafts generally indicated at 65. If the dies should come into contact at a high spot, it is apparent that the normal clearance in the threads and nuts would permit theremaining portion of the platen to settle down lveryslightly so as to actuate certain of the light switches 52' in a manner as previously described for the other modifications.

When the dieis elevated to remove a high spot, it is highly desirable that every precaution be exercised to' prevent the heavy die and platen from falling down onto the workmen. To prevent this as far as possible, I have provided an improved control means comprising a latch arm 56 pivotally supported at 51 to the sides of the press and normally urged in a counterclockwise direction by a spring 58 secured to a bellcrank arm of latch 56, the other end of the spring being connected to the frame. The latch arm is adapted to engage an abutment 59 formed on the platen 5 at each end thereof. To release the latch, an air cylinder and piston 6I) is connected to the bellcrank latch arm and is controlled in any suitable manner. When the press is raised, thefair pressure is exhausted from cylinder 60 to control spring 58 to throw arm 56 into engagement with latch abutment 59 when the platen is fully raised.

From the foregoing disclosures, it is seen that my improved dleyspotting apparatus and indicating means will eifectively permit rapid and accurate spotting without throwing the vertical guiding surfaces out of normal and at the same time minimizing or eliminating machining of the base surfaces.

It will of courseibe understood that various changes in details of construction and arrangement of parts may be made by those skilled in the art without departing from the spirit of the invention as set forth in the appended claims.

I claim:

1. The combination in a die spotting press comprising, opposed relatively movable platens,

for supporting complementary dies, means whereby one of said platens normally moves in parallelism toward the other but is adapted to have slight deflection from. said parallelism,-

means for effecting said platen movement, and means responsive to movement of the movable platen out of parallelism caused by the dies engaging each other at a high spotthereon which discontinues movement of said platen adjacent said high spot while allowing continued slight movement of the remaining portions of said platen thereby indicating the presence of a high spot on the dies.

2. 'I'he combination in a die spotting press comprising, opposed relatively movable platens forA supporting complementary dies, means whereby one of said platens normally moves n parallelism toward the other but is adapted to have slight deection from said parallelism, means for effecting said platen movement, rand means responsive to movement of the movable platen `out of parallelism and to the direction of said non-parallel movement caused by the dies engaging each other at a high spot thereon which discontinues movement of said platen adjacent said high spot while allowing continued slight movement of the remaining portions of said platen, thereby indicating the presence and Substantial location of a high spot on the dies.

3. 'Ihe method of determining the presence of a high spot on complementary dies consisting in moving one of said dies toward the other with their bases in substantial parallelism until the dies first engage each other at a high spot thereon thereby to discontinue movement of that dies at said high spot while allowing continued slight movement between the remaining portions o f said dies thereby to throw their bases out of parallelism, and then determining substantially instantly when said non-parallel condition occurs and immediately stopping movement of the dies.

4. The combination in a die spotting press comprising relatively movable opposed platens for supporting complementary dies, means whereby said platens normally move in parallelism with each other but are adapted to have slight deflection from said parallelism, means for effecting said normal relative movement, a plurality of position responsive elements, and means whereby said responsive elements are dilferentially operated when said platens move out of parallelism with each other caused by a high spot on said dies engaging each other so as to discontinue movement of said platens `adjacent said high spot while allowing continued slight movement of the 'remaining portions of said platens, thereby to indicate the presence of a high spot on said dies.

5. The combination set forth in claim 4 further characterized by the provision of means for successively adjusting said responsive elements so as to allow successive incremental movement of the dies toward each other so long as said platens remain in parallelism and whereby upon partial or complete removal of a high spot the dies can be brought closer together to determine the continued presence of said high spot or other high spots.

6. The combination in a die spotting press having opposed normally parallel platens adapted to carry complementary dies, means for moving one of said platens, a plurality of rods operably secured to one of said platens, a plurality of di'erentially responsive elements one for each of said rods, means for operatively supporting said responsive elements by the other of said platens so that said responsive elements are operable by said rods upon a predetermined movement of'said movable platen, and means for effecting relative adjustment. between said rods and their respective responsive element.

7. The combination set forth in claim 6 further characterized in that said means for eiecting relative adjustment between said rods and said responsive elements is carried by and movable with said movable platen.

8. The combination in a die spotting press comprising, a stationary platen and an opposed movable platen, means for effecting movement of said movable platen, a plurality of rods secured to said movable platen, each of said rods having a surrounding normally stationary threaded sleeve and a normally stationary nut in threaded engagement therewith, means for simultaneously operating said nuts to adjust the elevation of said sleeves, and a plurality of differentially operated position responsive elements supported by and movable with said sleeves for operation by said rods, whereby said dies are brought closer together if said responsive elements are simultaneously operated by said rods, but failure of one of said responsive elements to be operated While others thereof are operated as an indication that said dies are in contact at a high spot and thereupon should not be brought closer together.

9. The combination in a die spotting press comprising a stationary platen and an opposed movable platen, means for eiecting movement of said movable platen in substantial parallelism with said stationary platen, a plurality o! electrical switches located at different positions with respect to said platens in plan view, means for operating said switches individually or simultaneously in accordance with the movement of said movable platen and the degree of parallelism it maintains, and indicating lamps connected respectively to said switches, whereby the failure of one lamp to light is an indication that the dies are in contact at a high spot as well as an indication of the location of said high spot.

10. The combination in a die spotting press comprising a stationary platen, an opposed movable platen, means whereby said platens normally move in parallelism with each other b-ut are adapted to have slight deiiection from said parallelism, a plurality of hydraulic pistons and cylinders for effecting movement of said movable platen away from said stationary platen and for allowing said movable paten to move downwardly under gravity upon release of pressure from said cylinders, and means for indicating the individual pressures in said cylinders whereby when said dies contact each other at a point and accordingly discontinue relative movement between said platens at said point while all other portions of said platen continue to move uniformly the pressure in certain of said cylinders will vary from that in others thereby giving an indication that the dies are in contact at a high spot.

1l. The combination in a die spotting press comprising a stationary platen and an opposed movable platen, means for effecting movement of said movable platen, a plurality of threaded rods supported by said movable platen, normally non-rotatable nuts having respectively threaded engagement with said threaded rods and carried by said movable platen, means also carried by said movable platen for effecting relative rotation between said nuts and threaded rods to adjust the elevation thereof, normally stationary means adapted for cooperation with said rods, and responsive means adapted to be operated in response to said cooperation and to be differentially operated 4when said platens are out of parallelism with each other thereby indicating the presence of a high spot on said dies.

RICHARD W. DINZL.

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