Abstract:
The lever press includes various elements such as a lever (3), a fulcrum shaft (4), a crank shaft (5), a crank wheel (6), a forked portion (7), a crank pin (8), a slider (9), a large gear-wheel (10) and a motive gear-wheel (13), etc. which are dimensioned in relation to the ascent/descent stroke (S) of a ram which is set to be 1. The lever press is designed to have the same capacity as the conventional lever presses while remarkably reducing the size thereof.

Description:
BACKGROUND OF THE INVENTION 
     The present invention is related to a lever press in which a fulcrum shaft is provided close to an ascent/descent position of a ram at the upper part of the machine body, and a lower end of a lever hanging down in the machine body obliquely from the fulcrum shaft is formed into a fork shape. A slider is fitted into the forked portion and is linked with a crank so as swing. Also an amplitude of the leverhead is converted into an ascent/descent movement of the ram. The invention is characterized by making the size of the machine as small as possible while letting the machine maintain a pressing capacity equal to that of larger machines. 
     Particular dimensions of various elements of conventional lever presses of different capacities are as shown in Table 1. 
     
                       TABLE 1______________________________________Capacity      220     ton    400  ton  630  tonLength of the ceiling board         2350    mm     3150 mm   3400 mmportionHeight        4100    mm     4730 mm   5050 mmLength of the base         2150    mm     3040 mm   3420 mmWidth of the front         1800    mm     2300 mm   2420 mm______________________________________ 
    
     Currently, effective use of a factory site is very important, and the installation of large machines is not desired in the field of pressing machines. Accordingly, it has become necessary to reduce the size of the machines. 
     For this reason, in the field of lever presses, it has become necessary to make the machines smaller to facilitate installation of the machine without detrimentally affecting the machines. 
     SUMMARY OF THE INVENTION 
     It is the object of the present invention to reduce the size of the machine as much as possible without lowering the capacity of the lever press and to thereby facilitate installation of the machine. 
     For the solution of the abovementioned problems, the present invention provides a lever press in which: when an ascent/descent stroke(S) of a ram is set to be 1, the length from the vent of a leverhead to the center of a fulcrum shaft of a lever is expressed as 2; the diameter of the fulcrum shaft of the lever is expressed as 0.75; the length from the center of the fulcrum shaft to the lower end of the lever is expressed as 4.7; the lateral distance between the perpendicular at the center of the fulcrum shaft and the perpendicular at the center of the crank shaft is expressed as 0.85; the shaft-to-shaft distance between the center of the fulcrum shaft and the center of the crank shaft is expressed as 3.4; the radius of a crank is expressed as 0.85; a forked portion at a lower end of the lever has a groove of 0.8 in width and 0.4 in depth; and to the forked portion is fitted in a slide-free state, a slider in which a pin of 0.5 in diameter is fitted; a large gear-wheel of 3.4 in pitch diameter and 0.35 in thickness is connected directly to a crank wheel of 3.5 in diameter and 0.4 in thickness on the crank shaft. The large gear-wheel is made to engage with a motive gear-wheel mounted on a motive shaft provided through idle wheels with a braze wheel on its one end and with a flywheel pulley having a clutch of 3.5 in diameter on its other end. The pulley is driven by a motor installed on a ceiling board being spaced at 1 in height from the center of the fulcrum shaft of the abovementioned lever. The ceiling board is placed on a base having a width, of 3.2 a length of 2.6+3.25 and a side wall having an inside width of 1.3+0.9 and a height 6.5 to 7. A working table of 2.5 in length and 2.7 in width is disposed at a forward position of the base and positioned downward from the ascent/descent position of the ram. On the working table is disposed a knock-out of 0.85 in arm length and 0.5 in ascent/descent stroke to be driven by a knock-out shaft. The ram, to which the abovementioned leverhead is fitted in and which ascends and descends together with the leverhead at the upper part of the front of the machine body, has a width of 1.75 and a length of 1.1. All of the abovementioned numerical values have respectively a permitted limit of plus/minus 10%. 
     In the lever press of the present invention, by interposing two idle wheels between the large gear-wheel connected directly to the crank wheel and the motive gear-wheel in such way as the idle wheels engage with two wheels respectively and are laid before and behind in a direction of rotation, it becomes possible to double the transmitting power of rotation from the motive shaft to the crank shaft, and to cope with a large load to swing the powerful lever. 
     Further, the lever press of the present invention makes to good use of a space at the rear of the machine body and holds down the height of the whole machine body so as to check a rise of the center of gravity by means of linking the top of the ram with one arm of a balance lever installed on the ceiling board. The arm is two times longer than the ram stroke. Also, an end of the other arm of the balance lever is linked with a balance cylinder exposed on the ceiling board. 
     The particulars of various elements with respect to capacity of the lever press of the present invention, are as shown in Table 2. 
     
                       TABLE 2______________________________________Capacity      220     ton    400  ton  630  tonLength of the ceiling board         2700    mm     3300 mm   3800 mmportionHeight        2800    mm     3400 mm   4000 mmLength of the base         2100    mm     2600 mm   3000 mmWidth of the front         1450    mm     1750 mm   2050 mm______________________________________ 
    
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partially cutaway vertical sectional side view illustrating an embodiment of the present invention; 
     FIG. 2 is a back view of the embodiment shown in FIG. 1; and 
     FIG. 3 is partially cutaway vertical sectional front view of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A working example of the present invention will be explained with reference to the attached drawings. 
     As shown in FIG. 1, in the lever press of the present invention, when an ascent/descent stroke (S) of a ram 1 is set to be 1, the length from the center of a leverhead 2, which is fit into the ram 1, to the center of a fulcrum shaft 4 being the center of swing of a lever 3 is expressed as 2. 
     The diameter of the fulcrum shaft 4 is expressed as 0.75 and the length from the center of the fulcrum shaft 4 to the lower end of the lever 3 hanging down is expressed as 4.7. 
     A crank shaft 5, being laid sideways at the lower portion of the machine body (F) in a rotation-free state, take its position at 0.85 in a lateral direction from the center of the fulcrum shaft 4 to the rear portion of the machine body (F) and at 3.4 downward in a shaft-to-shaft distance while the effective radius of a crank wheel 6 is expressed as 0.85. 
     At the lower portion of the lever 3 is provided a forked portion 7 having on its inner side a groove having a width of 0.8 and a depth of 0.4, and a slider 9 fitted to the forked portion 7 in a slide-free state. Crank pin 8 of 0.5 in diameter is fitted to the slider 9. The crank wheel 6 diameter is expressed as 3.5 and its thickness as 0.45. The crank wheel 6 is connected directly to a large gear-wheel 10 of 3.4 in pitch diameter and 0.35 in thickness as one body on the crank shaft 5. 
     The large gear-wheel 10 is driven to rotate through two idle wheels 13, which are disposed between the large gear-wheel 10 and a motive gear-wheel 12 mounted on a motive shaft 11 laid side-ways in parallel with the crank shaft 5 at the upper part of the rear of the machine body (F). The idle wheels 13 are situated before and behind each other in a direction of rotation of the motive gear wheel. The idle wheels engage respectively with the large gear-wheel 10 and the motive gear-wheel 12. 
     The motive shaft 11 is provided on its one end with a brake wheel 14 and on its other end with a flywheel pulley 15 having a diameter of 3.5 and a clutch. The flywheel pulley 15 is rotatably driven by a conveyor belt 18 by a motor 17 installed on a ceiling board 16 which is located at a height of 1 being at 1 above the center of the fulcrum shaft 4 of the abovementioned lever. 
     The ceiling board 16 is disposed on a base 20 of 3.2 wide and 2.6+3.25 long. The base 20 has a side wall 19 of 1.3+0.9 in inner width and 6.5 to 7 in height. 
     A work table 21 is installed at a forward location of the base 20 and in front of the left-hand portion of FIG. 1 and below the ascent/descent position of the ram 1. The work table 21 is 2.5 long and 2.7 wide, and the work table 21 is provided with a knock-out 23 of 0.85 in arm length and 0.5 in ascent/descent stroke to be driven by a knock-out shaft 22. 
     The leverhead 2 is fitted into the abovementioned ram 1, which is disposed at the upper part of the front of the machine body (F). The ram has a width of 1 and a length of 1.1. A top end 24 of the ram is linked with a balance lever 26 having one arm of 2 in length and being supported in slide-free state by a bracket 25 in about the middle of the ceiling board 16. 
     The balance lever 26 is connected at its other end to a balance cylinder 27 disposed in an open space at the upper portion of the rear of the machine body (F) and exposed on the ceiling board 16. Through the movement of the cylinder 27, it is possible to remove a gap (shaking) between the ram 1 and the leverhead 2 and to prevent the generation of sounds and vibrations during a pressing operation. 
     The abovementioned numerical values of the various elements are all expressed by setting an ascent/descent stroke (S) of the ram 1 to the above, and the elements each have a permitted limit of plus/minus 10%. 
     The present invention has made it possible to reduce the size of the machine body without lowering the machine&#39;s pressing capacity. The reduction is obtained by means of setting the numerical value of each element as above against the ascent/descent stroke of the ram. 
     Table 3 and Table 4 indicate respectively the particulars of the conventional lever press and that the lever press of the present invention, both being of the same capacity. 
     
                       TABLE 3______________________________________Main capacities of the conventional lever press______________________________________Capacity       220    ton    400  ton  630  tonCapacity generating position          7      mm     7    mm   7    mmLength of stroke          160    mm     200  mm   200  mmAmount of slide control          30     mm     50   mm   50   mmCapacity of a low-type          10     ton    20   ton  30   tonknock-outLength of a low-type          70     mm     90   mm   90   mmknock-out______________________________________ 
    
     
                       TABLE 4______________________________________Main capacities of the lever press of the present invention______________________________________Capacity       220    ton    400  ton  630  tonCapacity generating position           nominal capacity generation at all           positions in the length of strokeLength of stroke          360    mm     440  mm   510  mmAmount of slide control          45     mm     55   mm   65   mmCapacity of a low-type          22     ton    40   ton  63   tonknock-outLength of a low type          180    mm     220  mm   250  mmknock-out______________________________________