Transfer mechanism for forging machines

A transfer mechanism for use in forging machines including a bolster comprising a pair of substantially parallel transfer bars, each supporting gripper means adapted to grip blanks to be transferred, said transfer bars being supported for operation through a cycle including movements in three dimensions, each dimension of movement being substantially perpendicular to the other two directions of movements. Three separate drives are interconnected so as to move the transfer bars and all can be actuated by a single power source and are arranged to operate without adversely affecting the operation of the other drives. The transfer mechanism, further includes a pair of U-shaped casings mounted at both ends of said transfer bars so as to provide enough space to accommodate said transfer bars as well as loading and unloading devices therein.

BACKGROUND OF THE INVENTION 
This invention relates to an automatic transfer mechanism for use in 
forging machines. The U.S. Pat. No. 3,422,657, disclosed an arrangement 
made such that transfer bars can be moved in three different directions, 
each direction being substantially perpendicular to the other two 
directions. 
There is disclosed in the above-mentioned U.S. Patent a transfer for use in 
forging machines having a plurality of die stations comprising a beam 
assembly including a pair of substantially parallel beams extending past 
said die stations, each being adapted to support gripper means for 
gripping blanks to be transferred between said die stations, said beams 
being supported for operation through a cycle including movements in three 
different directions, each direction of movement being substantially 
perpendicular to the other two directions of movements, and three 
independent driving means operable in timed relationship so as to move 
said beams in the manner such that the movement produced by each driving 
means is not adversely affected by the operation of the other driving 
means, each being operable to move said beams in one of said directions. 
In the device of the above-mentioned patent, however, there is not provided 
an enough space to accommodate loading and unloading means because of its 
construction per se. 
SUMMARY OF THE INVENTION 
It is, therefore, an object of the present invention to provide a transfer 
mechanism for use in forging machines having a pair of U-shaped casings 
accommodating driving means for the transfer mechanism so as to provide an 
enough space to accommodate loading and unloading means therein. 
It is another object of the present invention to provide a transfer 
mechanism for use in forging machines wherein a pair of transfer bars can 
be intentionally lifted and/or unclamped by the actuation of the pneumatic 
cylinder means so as to make changing of die sets easier. It is still 
another object of the present invention to provide a transfer mechanism 
for use in forging machines wherein the height of the pair of transfer 
bars can be adjusted in response to the height of the die or the die set. 
It is a further object of the present invention to provide a transfer 
mechanism for use in forging machines wherein advancing and returning 
motions of the transfer bars can be automatically stopped when the loading 
imposed on the transfer bars exceeds a predetermined value, thereby 
preventing occurrence of an accidental damage to the transfer bars. 
According to the present invention, there is provided a transfer mechanism 
for use in forging machines including a bolster comprising a pair of 
transfer bars mounted in substantially parallel relationship with each 
other, each being adapted to support gripper means for gripping blanks to 
be transferred, said transfer bars being supported for operation through a 
cycle including movements in three directions, each direction of movement 
being substantially perpendicular to the other two directions of 
movements, first, second and third driving means operable in timed 
relationship so as to move said transfer bars, each driving means being 
operable to move said transfer bars in one of said directions, said first 
and second driving means including four cylinders and a pair of cams, 
respectively, whilst said third driving means including a pair of 
cylinders and a pair of cams, two out of four cylinders of either of said 
first and second driving means and the pair of cylinders of said third 
driving means being adapted to urge cam followers against said cams during 
the cycle of operation so as to transmit driving force to move said 
transfer bars in one of said directions, and a pair of U-shaped casings 
mounted at both ends of said transfer bars so as to provide an enough to 
accommodate said transfer bars as well as loading and unloading means 
therein. 
Other objects, features and advantages of the present invention will be 
readily apparent from the following description taken in conjunction with 
the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Reference numeral 1 denotes a forging machine, 2 a bed frame, 3 an upright 
4 a tie rod, 5 a slide, 6 a bolster, and 7 a die set. Reference numerals 
8, 9 denote transfer units mounted on the left and right side of the 
forging machine, respectively. Transfer bars 10, 10 are mounted between 
the transfer units 8 and 9 and across and over the bolster 6. The transfer 
bars 10, 10 are adapted to effect three-dimensional motions i.e., clamping 
motion "a", lifting motion "b" advancing motion, "c" descending motion 
"d", unclamping motion "e" and return motion "f", as shown in FIG. 5. 
Reference numerals 11 and 12 represent boxes for accommodating the transfer 
units 8 and 9 mounted on the left and right sides, respectively. The boxes 
11 and 12 are formed in U-shape with open central portion, respectively, 
when viewed from the side thereof and have a front portion divided into 
portions 11a and 12a and a rear portion divided into portions 11b and 12b, 
each having an open-top space 13 formed in the central part thereof as 
shown in detail in FIG. 4. Projecting symmetrically and horizontally into 
the spaces 13 are clamping rods 14a, 14b, 14c and 14d which support the 
above-mentioned transfer bars 10, 10. 
FIGS. 6 to 13 show the structure of the left and right hand transfer units 
8 and 9. Reference numeral 15 denotes a nonstepping variable speed 
reduction gear which is mounted within the left hand transfer unit 8 and 
which is connected to an electric motor not shown. The reduction gear 15 
is connected to a driving shaft 16 which is connected through a bevel gear 
mechanism to a power transmission shaft 17. The power transmission shaft 
17 is connected through a propeller shaft 18 to a power transmission shaft 
19 of the right hand transfer unit 9. The above-mentioned shafts 16, 17 
and 19 have pinions 20, 21 and 22 fitted thereto, respectively. The 
pinions 20, 21 and 22 are arranged to mesh with gears 26, 27 and 28 which 
are fixedly secured to shafts 23, 24 and 25, respectively. Fitted to each 
of the shafts 24 and 25 are clamping cam 29 and lifting cam 30 so that the 
latter can be rotated together with the gears 27 and 28, respectively, as 
integral parts of them. Reference numeral 31 denotes lever shafts mounted 
in parallel with the above-mentioned shafts 24 and 25, each of which has a 
clamping lever 32 fixedly secured thereto by mean of an wedge, and also 
has a lifting lever 33 rotatably carried thereby. FIG. 7 shows a driving 
unit for clamping and lifting the left hand transfer unit 8. This driving 
unit has the same construction as that of the right hand transfer unit 9. 
In FIG. 7, the clamping operation lever 32 is fitted with a cam follower 
34 arranged to abut against the above-mentioned clamping cam 29. Connected 
to one end of the clamping lever 32 is a link 35, the other end of which 
is connected to a bracket 36 fixedly secured to a clamping rod 14b. 
On the other hand, as shown in FIG. 9, the lifting lever 33 has a cam 
follower attached thereto and which is adapted to abut against a lifting 
can 30. The lifting lever 33 has a link 38 connected to one end thereof. 
Reference numerals 39 and 40 denote L-shaped lever interconnected by means 
of a link 41. The above-mentioned link 38 is connected to one end of the 
L-shaped lever 39. The above-mentioned L-shaped levers 39 and 40 are 
fitted to shafts 42 and 43 carried within the box 11. The levers 39 and 40 
are connected at the other ends thereof to a holder 44 which slidably 
suspended and carries the clamping rod 14b, as shown in FIG. 7. 
The above-mentioned clamping lever 32 and lifting lever 33 are connected at 
the lower ends thereof through connecting rod means 45, 45 and linkage 
means 46 to unit clamping lever 32' and lifting lever 33' which are 
mounted within the front box 11a and which are adapted to move in response 
to movements of the above-mentioned rear operating levers 32 and 33. 
As can be seen from FIG. 10, shafts 43, which are one of shafts supporting 
the above-mentioned L-shaped levers 39 and 40, project from the boxes 11a 
and 11b, respectively, and each of which has a lever 47 fixedly secured 
thereto. As shown in FIG. 4, connected to the levers 47 are pneumatic 
cylinder means 48, 48 which are connected at one end thereof to the boxes 
11a and 11b, respectively. Further, pneumatic cylinder means 50, 50 are 
connected in the similar manner through levers 49, 49 to one end of the 
lever shaft 31 carrying the clamping lever 32 and the lifting lever 33. 
Fixedly secured to the clamping rods 14a, 14b, 14c and 14d are screen 
plates 52 which are fitted in guide plates 51 secured to the end faces of 
the boxes and which are adapted to slide freely in the vertical direction. 
Reference numeral 53 denotes a packing. (Refer to FIG. 7). 
As can be seen from FIG. 6, the shaft 23 mounted in parallel with the 
driving shaft 16 has a feed cam 54 which is fixedly secured thereto so as 
to be rotated with the gear 26 as an integral part thereof. Mounted in 
parallel with the above-mentioned shaft 23 is a lever shaft 55 which has a 
feed operation lever 56 fixedly secured thereto as shown in FIG. 12. The 
feed operation lever 56 has a cam follower 57 mounted on the leading end 
thereof and which is adapted to abut against the feed cam 54. The lever 
shaft 55 is arranged to project as shown in FIG. 6, from the box 11b and 
is connected to a shaft 58 which is connected in turn to the lever shaft 
of the front transfer unit. 
As can be seen from FIGS. 2 and 3, feed levers 59, 59 are fixedly secured 
to the connecting shaft 58 at locations corresponding to the transfer bars 
10, 10. 
As shown particularly in FIG. 13, a link 60 having a cam 60a formed as an 
integral part thereof is pivotally mounted in the feed lever 59. Fixedly 
secured to the link 60 is a bracket 61 which is connected through a 
turn-buckle mechanism 62 to a transfer bar rod 63 slidably supported by 
the clamping rods 14a, 14b, 14c and 14d. The above-mentioned feed lever 59 
is connected to pneumatic cylinder means 64 which is connected at one end 
thereof to the box. The cam portion 60a of the link 60 has a notch 65 
formed therein which is engaged with a projection 66 loaded by a spring. 
The arrangement is made such that, when an overloading ia exerted on the 
transfer bar 10 in the direction of feed, the above-mentioned projection 
66 is disengaged from the notch 65 so that the cammed link 60 can be 
rendered inoperative or put under a free state. Such condition can be 
detected by means of a limit switch 67. Reference numeral 68 indicates a 
screw for adjusting the resilient force of the spring. 
The transfer bar 10 is connected to the transfer bar rod 63 in the manner 
as shown in FIGS. 14, 15 and 16. In brief, the transfer bar 10 is engaged 
with the transfer bar rod 63 so that the former can be slidably moved 
relative to the latter. The transfer bar 10 can be fixedly secured to the 
transfer bar rod 63 by pushing a wedge 69 by means of a bolt 70. Further, 
a bolt 72, which is rotatably carried by a plate 71 fixedly secured to the 
transfer bar rod 63, is screw-threaded with the screw formed in the 
transfer bar 10. Turning the bolt 72 enables the transfer bar 10 to be 
moved up and down relative to the transfer bar rod 63. 
Further, the pneumatic cylinder means 48, 50 and 64 connected to the 
above-mentioned shafts can be rendered operative by manipulating 
respective solenoid valves, respectively. 
In the arrangement mentioned hereinabove, when the driving shaft 16 is 
rotated by way of the reduction gear 16, then the gears 26, 27 and 28 will 
rotate. The rotation of the gears 26 and 27 permits rotation of the 
clamping came 29 and the lifting cams 30 of the left and right hand 
transfer units 8 and 9 so that the operating levers 32 and 33 abutting 
against the cams 29 and 30 can be rotated. As a result, the clamping rods 
14a, 14b, 14c and 14d can be rendered operative longitudinally and in 
symmetrical relationship so as to effect repeatedly clamping motion "a", 
lifting motion "b", descending motion "d" and unclamping motion "e" as 
previously mentioned. 
The rotation of the gear 26 permits rotation of the feed cam 54 so that the 
lever 56 can be turned by the cam follower 57 engaging with the cam 54. In 
consequence, the clamping rods 14a, 14b, 14c and 14d are permitted to move 
to the left and right thereby enabling the transfer bars 10, 10 to effect 
the advancing motion "c" between the lifting motion "b" and the descending 
motion "d", and the returning motion "f" between the unclamping motion "e" 
and the clamping motion "a". 
The cam followers 39 and 37 abutting against the clamping cam 29 and the 
lifting cam 30 are loaded, by the pneumatic cylinder means 48 and 50 
connected to the lever shafts 31 and 43 in the direction of engagement. 
However, actuation of the pneumatic cylinder means 48 and 50 by 
manipulating respective solenoid valves in the opposite direction enables 
the cams 29 and 30 to be disengaged forcibly from the cam followers 34 and 
37, respectively. Stating in brief, actuation of the pneumatic cylinder 
means 48 enables the L-shaped levers 39 and 40 to be rotated so that the 
holder 44 can be moved upwards thereby forcibly lifting the clamping rods 
14a, 14b, 14c and 14d. Further, rendering another pneumatic cylinder means 
50 operative permits rotation of the shaft 31 so that the clamping lever 
32 can be turned in such a direction as to move the cam follower 34 away 
from the cam 29 thereby permitting unclamping operations of the clamping 
rods 14a, 14b, 14c and 14d. 
In the operation mentioned hereinabove, the transfer bars 10, 10 can travel 
across the bolster 6 so as to convey in turn articles moulded by die sets 
by their three-dimensional motions. However, in the case the height, of 
the die set 7 is changed, adjustment should be made by loosening the wedge 
69 and moving up or down the transfer bars 10, 10 relative to the transfer 
bar rod 63 by means of the bolt 72. 
Further, turning of the lever 56 enables rotation of the feed lever 59 
fixedly secured to the connecting shaft 58 which is coupled with the lever 
56. At that time, the cammed link 60, which is pivotally mounted on the 
feed lever 59 and which is connected at one end thereof to the transfer 
bar 10, has the notch 65 of the cam 60a engaged by the spring loaded 
projection 66, so that the link 60 can oscillate together with the feed 
lever 59 as an integral part thereof, thereby permitting feeding 
operations of the transfer bars 10, 10. 
In the course of the above-mentioned operation, when an overload is exerted 
on the transfer bar 10, 10 in the direction of feed, the projection 66 is 
disengaged from the notch 65 so that the cammed link 60 can be rendered 
free relative to the feed lever 59 thereby stopping the feed operation 
thereof. Such condition can be detected at the same time by means of the 
limit switch 67 as previously mentioned. 
It is to be understood that the foregoing description is merely 
illustrative of the preferred embodiment of the present invention and that 
the scope of the present invention is not to be limited thereto, but is to 
be determined by the scope of the appended claims.