US2886886A - Method of pressing or stamping articles - Google Patents

Description

May 19, 1959 V R. E. HARTUNG 2,886,886

' METHOD OF PREISSING OR STAMPING ARTICLES Filed April 23, 1953 3 Sheets-Sheet 1 Fig.

8? V INVEN TOR.

RA YMO/VD 6. HAR TVA/6 Z/M9-QM A torneyls May 19, 1959 E. HARTUNG 2,885,886

METHOD OF PRESSING OR STAMPING ARTICLES Filed April 25, 1953 :s Sheets-Sheet 2 9 0g INVENTOR.

I70 RA YMO/VD E. HAR TUNG A attorney ls May 19, 1959 R. E, HARTUNG 2,

METHOD OF PRESSING 0R STAMPING ARTICLES 7 Filed April 25, 1953 I 3 Sheets-Shet 3 INVENTOR. RA YMO/VD E. HARTU/VG A t t or)? cyb- United States Patent METHOD OF PRESSDIG 0R STAMPING ARTICLES Raymond E. Hartung, Minneapolis, Minn.

Application April 23, 1953, Serial No. 350,591

2 Claims. (Cl. 29553) My invention relates to improvements in a method of pressing or stamping articles, each of which requires more than one pressing or stamping operation between the formation of the blank and the finished article.

In the pressing or stamping of articles under present conditions the operation is frequently dangerous and even under the best conditions is inefiicient and time-consuming. customarily each blank or article is manually placed on an appropriate die situated on the bed of the press and a complementary die is mounted on a reciprocating ram that is moved in contact with the bed supported article whereafter the ram is retracted and the pressed article is replaced by another blank. The operation of manually placing the articles on the bed supported die and removing the stamped or punched article is interrupted by the operation of the ram. Not infrequently punch presses are provided with safety arrangements to assure that the operators hands will be free of the article or its supporting die at the time the same is engaged by the ram and these safety arrangements further slow up the stamping or punching operation. In some cases these safety appliances consist of suitable guards that are positioned or moved close to the dies, and in other instances arrangements are provided whereby both hands of the operator must be in engagement with levers or switching devices before movement of the ram is permitted to assure that the operators hands will not be in a dangerous position. In all of these previous arrangements the safety precautions have through experience been made so extensive as to materially reduce the output of the press to favor the avoidance of accidents, thereby materially increasing the cost of the stamping or pressing operation.

In certain stamping or punching operations the same article must receive a multiplicity of individual stampings, as an example, a thermostat case used in connection with a household heating apparatus requires several stamping and punching operations between the formation of the original blank and the production of the finished article. In some instances as many as ten different punching or stamping operations are required to complete the thermostat case. Not infrequently these multiple stampings are handled in batches thereby requiring multiple handling and storing of the articles as well as providing the necessary storage space for the articles during the various stages of processing. This multiple handling not only delays production schedules but materially increases the cost of the stamping or punching operation.

In the present invention I have provided improve ments in a method which will simplify operations and reduce costs without increasing the likelihood of injury to operators. I have also devised a system of operation whereby the articles are continuously and progressively converted from blank material to finished articles. The improvements comprise the utilization of a punch press having a rotatable press bed whose operation is coordinated with the reciprocal movement of the ram so as to bring articles in proper alignment with the ram just "ice prior to the stamping operation. Between stamping operations additional blanks or partially completed articles are properly and safely arranged on the rotatable press bed without interferring with the movement of the ram and the movement of the press bed is coordinated with the movement of the ram so that there is a proper and exact indexing of the article before it is engaged by the ram. After the stamping operation the article is automatically disposed of, and in due time replaced by another blank or partially finished article. The invention also contemplates the arrangement of a number of presses embodying these principles, which are so related to one another that blanks may be progressively stamped or punched and transported between the various machines in such a manner as to provide a substantially continuous operation, thus materially reducing costs.

The invention contemplates a press containing the combination of a reciprocating ram, a polygonal faced rotatable bed supported for movement on an axis transverse to the axis of the ram, together with suitable indexing means operably connected between the ram and the rotatable bed for accurately indexing these members with each other to assure a speedy and accurate processing of the articles.

An object of the invention is to provide in a punch press or the like a reciprocating ram and rotatable bed cooperable with the ram, together with indexing means operably connected between the ram and. the bed for controlling the movement of the bed in such a manner as to properly index the bed with respect to the ram, together with a brake for holding the bed stationary during the stamping or punching operation.

Another object of the invention is to provide in a punch press or the like having a driven ram and a rotatable bed having a plurality of polygonal faces thereon, indexing means mechanically connecting the ram and the bed to provide for a proper step-by-step rotation of the bed in one direction and in proper relationship to the movement of the ram.

Another object is to provide in a punch press embodying a vertically reciprocating ram and a horizontally rotatable bed with independent means for driving the ram, and rotating the bed, together with a control system operably connected to the ram for rotating and indexing the bed in a step-by-step operation with respect to the ram.

Another object is to provide in combination with a punch press embodying a reciprocating ram and an independently motor driven bed, an electrical control system operably connected between the ram and the motor for operating the motor between reciprocating move ments of the ram, and indexing means between the ram and the bed for exactly aligning the bed with the ram, together with a brake effective to hold the bed in a stationary position.

A further object is to provide a system for continuously processing articles that normally require multiple stamping operations by properly arranging the disposition of a number of presses having rotatable beds together with a suitable conveyorsystem to provide for the prompt and eflicient movement of articles from the outlet or discharge side of one press to the inlet side of another press to thereby provide a cheap and efiicient method of handling articles.

Other and further objects may become apparent from the following description and claims, and in the appended drawings in which:

Fig. 1 is a front elevation of one form of punch press embodying my invention;

Figs. 2, 3 and 4 are detail views of the parts making up the structure shown in Fig. 1;

Fig. dis a schematic showing of an electrical control 8 system for assuring proper and efficient operation of the press shown in Fig. 1;

Pig. 6 is a front elevation of another modificatlon of my invention;

Fig. 7 is a side view taken on line 7-7 of Fig. 6 of a portion of the device; and,

Fig. 8 is a schematic plan view of arrangement of a plurality of presses such as are shown in either Fig, 1 or Fig. 6 for continuously processing articles requiring a multiplicity of stamping or punching operations.

Referring to the several views of the drawings, the 1nvention will now be described in detail.

Referring first to Fig. 1, general reference numeral 10 indicates a punch press embodying the usual frame 12. Shown in dotted lines and indicated at 14 is a crankshaped driving shaft which eccentrically reciprocates a ram 16 in a vertical direction. The ram 16 has the usual head 18 which is guided on the frame by lateral guides 20, 22. On its lower surface the head 18 supports a die plate 24; As best seen in Fig. 2, the die plate 24 contains a pair of conical shaped aligning recesses one of which is indicated at 26.

Supported by frame 12 below the lower limit of the movement of ram 16 is a rotatable bed 28 which is supported by bearings 30 and 32 in the sides of frame 12. Bed 28 is of polygonal configuration and as here shown is of hexagonal shape. Each of the six sides of bed 28 supports a die plate 34 and on the opposite rear edges of each of the die plates 34 are a pair of conical shaped aligning pins 36 that are intended to register with the conical shape aligning recesses 26 in the ram plate 24.

In the modification of the invention shown in Fig. l, at the left hand side of the frame and. designated by general reference numeral 38 is a means of independently rotating the bed 28, which is shown in detail in Fig. 3. Referring to Fig. 3, a shaft 40 which extends from the left hand side of bed 28 is secured by a key 42 to a gear 44 supported within a casing 46 and driven by a worm gear 48 situated on a drive shaft 50 extending from a motor 52.

On the right hand side of the disclosure of Fig. 1 is a brake mechanism indicated by general reference numeral 54 and shown in detail in Fig. 4. Referring to Fig. 4, one end of the main shaft of the rotatable bed 28 is secured by a hexagonal bolt 56 to a brake drum 58 that is surrounded by a brake shoe 60 containing a brake band 62. A bolt 64 penetrates one end of the brake band and is anchored to a bracket 66. A coil spring 68 is situated on one end of bolt 64 between a nut 70 and one end of the brake shoe 60.

Referring now to Fig. is shown an electrical control system for operating motor 52 in conjunction with the reciprocal movement of ram 16. A cam 72 is normally mounted on the driven shaft 14 at one side of frame 12 and is intended to be driven by shaft 14. Cam 72 is provided with a dwell 74- that is intended to move a movable switch blade 76 into engagement with a stationary contact 78. A spring 80 which is anchored at one end, is connected to the switch blade 7 6 to hold the same in contact with cam 72 and to open the switch when dwell 74 has moved beyond the switch. A conductor 82 extends from a source of power 83 to switch blade 76. Extending from conductor 82 are a pair of switch blades 84, 86 having contacts 88 and 90 adapted to engage stationary contacts 100, 1612. A conductor 104 extends from the stationary contact 78 to a relay or induction coil 106 containing an armature 108 that is connected to the switch blades 84, 86. Extending from induction coil 106 is a conductor 110 that connects to a movable switch blade 112 that cooperates with a stationary contact 114. Extending from contact 114 is a conductor 116 which at its other end joins a conductor 118 forming a return to the source of power 83. Extending from stationary contact 102 is a conductor 120 which connects to one pole of motor M, which in reality is motor 52. Extending from the other pole of motor M is a conductor 122 which joins the return conductor 118. A branch conductor 124 extends from conductor 82 to a movable switch blade 126 that is adapted to engage a stationary contact 128. A short conductor 130 extends from contact 128 to conductor .128. Situated between switch blades 112, 126 is a cam 132 having a dwell 134 which is capable of moving switch blades 112, 126 to an open position with respect to their stationary contacts. Cam 132 as here shown would be driven by the rotating bed 28, and through a gear system would be arranged to make one complete rotation when bed 28 moved only one-sixth of a rotation. If desired, two independent cams could be provided to operate switches 112, 126 and still further, each cam could be provided with six dwells and thereby rotate at the same speed as bed 28.

Referring now to Figs. l-S, the operation of the press will now be explained. It will be assumed that the plate 24 has a suitable die mounted thereon, and that the several plates 34- all contain suitable similar complementary dies mounted thereon for punching or stamping similar articles. It is assumed that the driven shaft 14 will receive power from any suitable source, such as a motor, not shown, and that ram 16 is reciprocating the head 18 on the guides 20, 22. Cam 72 would be suitably mounted on shaft 14 at one side of frame 12 and so situated that its dwell 74 would move into engagement with switch blade 76 immediately after ram 16 started its movement in an upward direction. Upon the closing of switch 76 with respect to contact 78, a starting circuit is established which may be traced as follows: From the source of power 83, through conductor 82, switch blade 76, contact 78, conductor 104, coil 106, conductor 110, switch blade 112, contact 114, conductor 116, and conductor 118 back to the source of power. When this occurs coil 106 moves the armature 108 to the right, thereby moving switch blades 84, 86 and engaging contacts 88, 100 and contacts 90, 102. Since the spring will break the engagement of blade 76 and contact 78, the engagement of contacts 88, establishes a holding circuit for the relay which may be traced as follows: From the source of power 83, through conductor 82, switch blade 84, contact 88, 100, thence through the short conductor to induction coil 106, conductor 110, switch blade 112, contact 114, conductor 116 and conductor 118 back to the source of power. Simultaneously power would also flow from conductor 82 through switch blade 86 and contacts 90, 102 through conductor to the motor M and thence back to the source of power through conductors 122, 118. With the closing of this circuit motor M (or 52) would be placed in operation, and through the gear connections shown in Fig. 3 the rotatable bed 28 would be moved in a counterclockwise direction, as shown in Fig. 3. It is desired that the bed be rotated only one-sixth of a cycle in a step-bystep operation and therefore means are provided to terminate the operation of motor 52 after the bed has rotated one-sixth of its cycle.

Referring again to Fig. 5, and assuming that cam 132 is geared in a six to one ratio with respect to bed 28, when the cam has rotated less than a quarter of a turn, it will permit switch 126 to close with respect to contact 128. This establishes a second or by-pass circuit between the source of power and motor M which may be traced as follows: From the source of power 83, conductor 82, conductor 124, switch blade 126, contact 128, conductor 130, conductor 120, motor M, and conductors 122, 118 back to the source of power. As cam 132 continues its rotation its dwell 134 engages switch blade 112, thereby breaking the holding circuit and also the power circuit through switch blade 86, and contacts 90, 102, but since power is now supplied through conductor 124, switch 126, contact 128 and conductor 130, the opening of the holding circuit has no effect on the operation of motor M, and merely prepares the circuit for the next operation. When the cam 132 has rotated one full cycle, its dwell 134 will open switch 126, thereby de-energizing the cirtion. All of the foregoing operation will have been completed before ram 16 has completed its reciprocal movement, and the pins 36 cooperating with the recesses 26, will properly align the bed 28 with respect to ram 16.

Under these conditions, the only work necessary to be performed by an operator is the placing of blanks or unfinished articles onto die 35 located on the forward upper surface of bed 28, said surface being identified in a particular position by reference numeral 136 in Figs. 1 and 2. After the stamping or punching operation, the bed rotates one-sixth of its cyclic turn rearwardly and the bed plate designated in Fig. 2 at 138 is then in a position to discharge its article by gravity or other suitable means from the rotatable bed.

Referring now to Figs. 6 and 7, is shown another modification of the invention. General reference numeral 140 designates a punch press which is of the same general arrangement as that shown in Fig. 1 and for simplicity of understanding the same reference numerals applied to Fig. 1 are re-applied here. To the left of frame 12 is shown another arrangement for rotating the rotatable bed. A bevel gear 142 is secured to one end of shaft 14, and this gear meshes with another bevel gear 144 which is supported on the upper end of a shaft 146. Suitable brackets 148, 150 provide spaced apart bearing surfaces for shaft 146. At the lower end of shaft 146 a bevel gear 152 meshes with a bevel gear 154 that is mounted on a shaft 156. Referring now to Fig. 7, shaft 156 carries a cam 158 which is provided with a dwell 160 and a slot 162. Secured to the outer end of the bed 28, as shown in Fig. 6, is a plate 164 which contains six pins 166, disposed at equally spaced distances about the periphery of disk 164.

The operation of the press shown in Fig. 6 will now be explained. Assuming the driven shaft 14 to be in operation, reciprocating ram 16 in the usual manner and transmitting power through the gears 142, 144 to shaft 146 and through the gears 152, 154 to shaft 156. With each rotation of the driven shaft 14, cam 158 makes one rotation and its dwell 160 is brought into contact with one of the pins 166 on disk 164. The dwell 160 forces the pin to slidably move in its arcuate path into the slot 162, and the bed is rotated for one-sixth of its cycle whence the respective pin 166 then held within slot 162 will be freed therefrom and cam 158 passes in lost motion throughout the rest of its cyclic rotation until dwell 160 again engages the next pin 166. During the lost motion of cam 158 the brake 54 will operate to hold the rotatable bed in a stationary position, and the stamping operation occurs as previously described.

Referring now to Fig. 8, is shown a method of disposing of a plurality of punch presses to effect a continuous punching operation on articles requiring a multiplicity of stampings between the formation of the blank and the finished article. Reference numeral 170 indicates a press which is capable of taking raw material from a roll indicated at 172 and cutting the same into blanks, not shown, of a suitable size. These blanks would be delivered by a trough 174 to a horizontally running conveyor belt 176 which is situated in front of a punch press 178 which may be a press of the type shown in Figs. 1-4, or of the type shown in Figs. 6 and 7. A suitable trough 180 extends from the discharge end of the rotatable bed of press 178 to a conveyor 182 which conveys the finished product of the first stamping operation to the next press 184. Press 184 is provided with a discharge chute 186 which discharges the partially finished articles to conveyor 188 which in turn conveys the articles to another press 190. Press 190 is provided with a discharge chute 192 that discharges to a conveyor 194 which carries the then uncompleted article to the final press 196. Press 196is provided: with a discharge chute 198 that leads to a suitable container 200 for the finished article.

Assuming that an article requires four punching operations between the formation of the blank and the finished article, the arrangement shown in Fig. 8 discloses four presses arranged with respect to each other and a suitable conveying system so that articles may be continuously processed through the necessary stamping operations. Each of the presses 178, 184, and 196 are of the type shown in either Fig. 1 or Fig. 6 and the rate of operation of the several presses would be identical. Since each of the presses is performing a specific stamping or punching operation, the dies used on each press would be of a different character than the dies used on the other presses, but in each case a die of one specific character would be mounted on the ram and 6 similar mating dies would be mounted one each on the several phases of the rotating bed. Therefore it is only necessary to have one operator in front of each of the presses who would place the necessary article or blank on the die plate having the position of plate 136 of Fig. 2, whereby the article is processed and suitably discharged when it reaches the position shown by the bed plate 138 of Fig. 2 into the respective discharge chute. In this manner articles can be continuously processed at a much lower cost than by methods now in use.

The advantages of my invention are in providing a stamp or punch press in which operations are simplified in that the operator need only place the blank or unfinished article onto a safe and remote surface of the rotatable bed without the possibility of endangering his hands. Through a properly timed indexing mechanism the bed is rotated in a step-by-step manner permitting discharge of the articles by gravity or otherwise, thereby effecting a material reduction in operating costs.

My invention is defined in the terms of the appended claims.

I claim:

l. A method of continuously stamping work pieces each of which requires a multiplicity of stamping operations between the formation of the blank and the finished article, comprising aligning a multiplicity of punch presses with vertically reciprocating rams, mounting a polygonal faced rotating bed in each press for rotation on a horizontal axis from front to rear in each press, alternately disposing said presses in a row with the rear side of one press adjacent the front side of the next successive press, mounting a die on each ram, mounting complementary dies on each of the polygonal faces of the rotatable bed, indexing the rotatable bed with the recipro cating ram, feeding blanks to the first of said presses, and conveying the discharge of articles from each press to the next successive press in the line of presses to thereby form a succession of articles that are progressively stamped in a step-by-step operation.

2. A method of continuously stamping work pieces each of which requires a multiplicity of stamping operations between the formation of the blank and the finished article, comprising providing an individual press for each of the stamping operations containing a vertically reciprocating ram and a polygonal faced rotating bed disposed for rotation on a horizontal axis from front to rear, mounting a different die on the ram of each press, mounting complementary dies on each of the polygonal faces of the rotatable bed of each press, indexing the rotation of the beds of said presses to a uniform rate of rotation, arranging said presses in an orderly arrangement in accordance with the several operations to be performed on each work piece, feeding a work piece to the first of said presses, and mechanically conveying the discharge of articles from the rotating bed of each press to the forward side of the next succeeding press to thereby form asuccession of articles that are progressively stamped in a step-by-step operation by said several presses.

References Cited in the file of this patent UNITED STATES PATENTS McGrew Nov. 26, 1872

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