Abstract:
A device on a slider crank for generating a motion relative to the a slider (press ram  5 ) of a part (ejecting spring pin  6 ) mounted on the slider, wherein such motion is taken off a crankpin ( 1 ) upon rotation of the crankpin around a crankshaft axis and transmitted along a pushrod (connecting rod  4 ) to the part (ejector spring pin  6 ). For this purpose, revolving parts (wheel  22, 34, 38;  disk  98, 100,  belt  102;  disk  142, 148,  belt  150 ) transmit rotary motion on the connecting rod ( 26, 28; 144 ) (FIG.  1 ).

Description:
The invention concerns a device on a slider crank for the purpose of generating a motion relative to the slider of a part supported on the slider. 
     BACKGROUND OF THE INVENTION 
     For powering an ejector pin on the die of a forming press, it has been a familiar technique for quite some time to introduce, from the outside, a motion into the slide that is reciprocal to the return travel of the press slide in order to eject the workpiece from the pressing die, such as hexagonal head dies, by means of an ejector pin. Due to the many components between the point of introduction of the force and the ejector, such systems are very elastic. In addition, they also usually involve reciprocating movements. 
     The device known from DE 195 21 041 A1 has the purpose of reducing this mechanical complexity. This device serves for controlling auxiliary devices such as die ejector pins, strippers, or die carriers in an oscillating press ram of single and multi-stage presses. This is accomplished by a cam attached to the crankpin of the crankshaft of a forming press that controls a pushrod sliding inside the connecting rod; via a spring pin, the motion of this pushrod is transferred to the die, causing the tip of the spring pin to eject the workpiece from the die. When the crank performs one revolution, the cam also performs one revolution in relation to the pushrod. The point of contact between the pushrod and the spring pin is in the center of rotation of the bearing pin connecting the connecting rod with the press ram. 
     In this DE 195 21 041 A1, an oscillating motion is introduced into the slide. 
     To be sure, DE 34 12 147 A 1 refers to a centric slider crank, with a transmission that also consists of rotating parts (intermediate gear wheel  24 , gear wheel  25 ), but with one gear wheel ( 25 ) fixed on a crank pin ( 16 ) that rotates in a crank disk ( 12 ) with a centric drive shaft ( 13 ); however, part of this transmission is a stationary gear wheel ( 18 ) that is coaxial in relation to the shaft axis, and also a rotating gear wheel ( 23 ) supported on the crank disk ( 12 ) that is located between the stationary gear wheel ( 18 ) and the rotating gear wheel ( 25 ), and meshes with both of them. 
     That means that a rotary motion of the crank disk ( 12 ) causes a rotary motion of the crank arm ( 15 ) relative to the rotated crank disk ( 12 ), with said motion depending not only on the crank radius but also on the gear ratio (e.g. 2:1) of the stationary gear wheel ( 18 ) and the rotating gear wheel ( 25 ). Moreover, this familiar type of transmission does not extend, via the crank arm  15 , to the slide ( 4 ), so that the generation of a motion—relative to the slide—of a part (such as the slide bar  28 ) supported on the slide (slider) was not part of the considerations at all. 
     This is also true for DE-GM 1 864 599 (FIGS. 3 and 4) where, in order to produce two superimposed motions of the pushrod (pushrod  9 ), on the crank side this pushrod is supported by means of an additional cam ( 8 ) on a gear wheel ( 6 ) on the main cam (crank pin  5 ), with the gear wheel ( 6 ) meshing with a centrically stationary gear wheel ( 7 ). 
     SUMMARY OF THE INVENTION 
     This invention now addresses the problem of eliminating the disadvantages described above by producing a rotary motion. 
     Starting with a device of the type referred to at the beginning, the invention solves this problem by means of a slider crank with a device for the purpose of generating a motion relative to a slider of a part supported on the slider, with said motion being taken off a crankpin upon rotation around a crankshaft axis and transmitted along a connecting rod to the part from which an operating motion is taken off, characterized by the feature that in order to generate a rotary motion of that part on the slider around a single axis of rotation relative to both the slider and the connecting rod, a transmission consisting of revolving parts is provided on the connecting rod. 
     Due to the fact that the rotary motion is transmitted from the crankshaft along the pushrod of the slider crank into the press slide, and that the operating motion is derived directly from this press slide, the invention can be applied universally and makes it possible to transmit large transmission forces in a direct power flow to the operating motion required in each case. Since, except for the tool movement, no additional sliding motions but only rotary motions are involved in transmitting the motion, the device proposed by the invention operates with extremely little wear. 
     All motions can be produced that can be derived from a rotary motion via appropriate gears. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is explained in detail on the following pages with the help of the five design variants shown in schematic form by the drawings. 
     FIG. 1 shows a front view of a first design variant for controlling the ejector pin of a forming press. 
     FIG. 2 shows a top view of the design variant in FIG. 1 as a partial view. 
     FIG. 3 shows a front view of a second design variant for controlling the ejector pin. 
     FIG. 4 shows a front view of a third design variant for controlling the ejector pin. 
     FIG. 5 shows a front view of a fourth design variant for controlling an additional operating motion that is merely indicated. 
     FIG. 6 shows a front view of a fifth design variant for controlling a wire clamping device, as used, for example, in the feeder slide of a wire processing machine. 
    
    
     DETAILED DESCRIPTION 
     FIGS. 1 and 2 show the first design variant of the device proposed by the invention. It serves as the driver for an ejector pin  62  on the die side that is integrated in the crank gear of a single or multiple stage press. Here, a press slide  12  that slides back and forth in a guide has the purpose of producing, by means of slide-mounted forming tools and stationary dies, finished workpieces such as screws, bolts, etc. from blanks in multiple steps. 
     The press slide  12  is driven by a crankshaft  14  supported by a main crankshaft bearing that is not shown. Via an eccentric crankpin  20 , the crankshaft  14  drives two connecting rods  26 ,  28  that act on a bolt  18  supported in the slide  12 . On the crankpin  20  of the crankshaft  14 , a stationary drive gear wheel  22  is mounted that rotates in opposition to the connecting rods  26 ,  28 . 
     In FIG. 2, the connecting rod  26  is located above the drive gear wheel  22 . The other connecting rod  28  is located below the gear wheel  22 , separated by a spacer bushing  30 . The drive gear wheel  22  meshes with an intermediate gear wheel  34  that rotates freely on a pin  36  that is mounted in the connecting rods  26 ,  28 . The intermediate gear wheel  34  meshes with a driving gear wheel  38  that is mounted on a pin  18  at that end of the connecting rods  26 ,  28  that is opposite of the crankpin  20 . 
     A cam  44  is connected in fixed position to the gear wheel  38  that freely rotates on the pin  18 . For the purpose of transmitting a stroke movement, the cam  44  rotating in the press slide  12  acts on a cam roller  46  rotating on a pin  48  that is attached to the lower end of a roller lever  50 . The other end of the roller lever  50  pivots on a pin  54  that is mounted in a roller lever bearing  56  on the press slide. With its lateral surface  58 , the lower end of the roller lever  50  contacts the ejector pin  62 . The ejector pin  62  is driven in an oscillating fashion by the roller lever  50 . The ejector pin  62  is supported in a rear bearing bushing  64  and a front bearing bushing  66 , with the bearing bushing  66  forming the back rest for a coil spring  68 . The force of the coil spring  68  presses the ejector pin  62  and the cam roller  46  against the control cam  44 . 
     FIG. 3 shows a second, modified design variant of the device proposed by the invention for driving the ejector pin  62  of a forming press that is located on the die side. Here, the driving gear wheel  38  meshes with a driven gear wheel  72  that rotates on a pin  74  above the gear wheel  38 , with the pin  74  mounted in a bearing  76  on the press slide  12 . In this variant, the cam  44  attached to the driving gear wheel  38  in FIGS. 1 and 2 has been replaced by a cam  44 ′ that is now firmly attached to the driven gear wheel  72 . The cam disk  44 ′ acts on a cam roller  82  rotating on a pin  84  that is mounted on an arm  88  of a two-arm roller lever  90 . The roller lever  90  itself pivots on a pin  92  on the press slide  12 . In order to perform the ejection motion, the free end of the lever  90  acts on an ejector pin  62 ′ whose design and function is identical to that in the first design variant. 
     In the design variant shown in FIG. 4, the gear drive  22 ,  34 ,  36  of the first and second variant has been replaced by a toothed belt drive  96 . Here, instead of the driving gear wheel  22 , a toothed driving disk  96  is mounted in fixed position on the crankpin  20  of the crankshaft  14 . In alignment with this toothed disk  96 , a driven toothed disk  100  rotates on pin  18 . A toothed belt  102  connects both toothed disks  98  and  100 . 
     Next to the driven toothed disk  100 , a driven gear wheel  106  rotates on the pin  18 . The driven gear wheel  106  is attached in fixed position to the driven toothed disk  100 , performing the same rotations as the toothed disk  100 . Here, the driven gear wheel  106  and the driven toothed disk  100  both have approximately the same exterior diameter. Thus, their outlines coincide in FIG.  4 . The driven gear wheel  106  meshes with the gear wheel  72  mounted on the press slide  12 , and in terms of location and function, the gear wheel  72  as well as the other components  44 ′,  82  to  92 , and  62 ′ to  68  correspond to the device shown in FIG.  3 . 
     Of course, instead of the toothed disks  98  and  100  and the toothed belt  102 , it is also possible to use a chain drive consisting of a set of chain sprocket wheels and a chain. 
     In the fourth variant shown in FIG. 5, the driven gear wheel  72  is firmly connected with a driving bevel gear  110  that drives a driven bevel gear  112 . The driven bevel gear  112  is fixed in position on a shaft  114  that rotates in a bearing block  116  sitting on the press slide  12 . 
     FIG. 6 shows the fifth design variant of the invention. It serves to clamp wire or strip-shaped material  122  with a slide  124 , as used, for example, as a feeder slide of a wire or strip processing machine. This requires an adjustable feeder stroke. In a previously known fashion, the stroke adjustment is achieved by a drive crank  128  that has a T-groove block  130  which, after loosening the nut  138 , is adjusted in a T-groove block guide  132  by means of an adjusting screw  136  either away from the center of the drive crank  128  or towards it. The T-groove block  130  is pin-shaped, and, according to FIG. 4, an driving toothed disk  142  is mounted in fixed position on its round section  134  representing the crankpin. In addition, a connecting rod  144  is supported on the round section of the T-groove block  130 , and the opposite end of this connecting rod is linked read to the slide  124  by means of the pin  146 . A driven toothed disk  148  rotates on the pin  146 . A toothed belt  150  connects both toothed disks  142  and  148 . A cam disk  152  is mounted in fixed position on the driven toothed disk  148 , and this cam disk actuates a roller cam  158  rotating on a roller lever  156 . A clamping jaw  162  is connected with the roller lever  156 ; it clamps the wire or strip  122  to be fed against the counter jaw  164  during the feeding motion of the slide  124 , resulting in a wire feed. The clamping force required for this is exerted on the wire  122  via a spring holder  186  attached to the slide  124  by a compression spring  168  that acts on the wire via the roller lever  156 . The shape of the cam disk  152  is designed so that the wire  122  is released from the movable clamping jaw  162  during the return motion of the slide. 
     In all design variants shown here, the gear ratios may be selected as desired.