BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates generally to a machine for trimming excess materials from manufactured parts, and more particularly, to automatically trimming die castings or castings, forgings, and other formed parts.

It is known to trim flash, excess material, and runner system material from parts manufactured in various ways such as by forging or casting processes. The known devices for trimming the excess material suffer from various drawbacks. Some of these drawbacks include: substantial manual involvement needed; no ease of entry for a part to be placed into the device to be trimmed; difficulty in removing a trimmed part; and, not suited for an entirely automated system to work in conjunction with the part formation (e.g. - die cast machine, a casting cooler, and a conveyor means for taking the trimmed parts away automatically) .

The present invention comprises a hydraulically actuated trim press machine preferably having two cylinder (high force and low force) platen action and also preferably having removable tie bars for both platens. A platen locking cylinder is also a preferred feature of the present invention. The present invention has an open top which allows parts to be loaded into the trim press from the top of the trim press. The present trim press invention also offers horizontal platen action movement. Another benefit of the

present invention is that the tie bars do not extend across the C-frame and thereby do not inhibit accessibility to the machine. This feature provides superior advantages when compared with competitive products in the area of trim access and die change capabilities. These and other objects, advantages and features of the present invention will become apparent in the following detailed description of the preferred embodiment of the invention and the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a front elevation view of one embodiment of the trim press of the present invention;

Figure 2 is an end elevation view of the right side of the trim press shown in Figure 1;

Figure 3 is an end elevation view of the left side of the trim press shown in Figure 1;

Figure 4 is a plan view of the trim press shown in Figure 1;

Figure 5 is a section view taken along line A-A of Figure 4;

Figure 6 is a section view taken along line B-B of Figure

1;

Figure 7 is a detail view of a low force platen of the trim press shown in Figure 1;

Figure 8 is a detail view of a high force platen of the trim press shown in Figure 1;

Figure 9 is a schematic representation of the hydraulic circuit of the trim press shown in Figure 1; and

Figure 10 is a schematic representation of the pneumatic circuit of the trim press shown in Figure 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S) Referring now to Figures 1-6, there is shown a preferred embodiment of the present invention. The hydraulic trim press of the present invention includes a structural steel support frame 20 preferably made of welded steel construction as shown. Secured to the frame 20 is a power supply pump 22, preferably hydraulic. The hydraulic power supply pump 22, with reservoir, is the primary source for supplying hydraulic fluid to the actuating mechanisms of the trim press. An automatic lube system 24 may be included with the trim press to lube tie-bar bearings every predetermined number of cycles.

A programmable controller 26 may be included which may contain the starter for the hydraulic power supply 22, termination switches, output valves, and other control mechanisms which the operator may use to operate the trim press. An Allen Bradley PLC-5 unit was selected for the preferred embodiment but other programmable controllers may be used.

Secured to the frame 20 is a C-frame 28 (named after its shape, which appears as a "C" positioned such that the open side of the "C" is facing up) also preferably made of steel which is fixed in place, preferably bolted, to the frame 20.

A funnel 30 is situated at the center of the C-frame 28 for capturing parts as they are released from the die set and also for capturing flash material trimmed from the parts. A plate 34 moveably attached to the funnel 30 and actuated by a hydraulic cylinder 32 acts in a first position to divert scrap or flash material into exit 36 of the trim press, and in a second position it diverts the parts which have been trimmed to exit 38 of the machine. A pan 40 may be positioned near the exits for collecting die lubricant which may drip down from the press during normal operation.

Mounted to the C-frame are two stationary platens 42. In addition to the stationary platens 42, a high force platen 44 is mounted on one side of the C-frame 28 and a low force platen 46 is mounted on the opposite side of the C-frame 28. A high force cylinder 48 actuates the high force platen 44, while a low force cylinder 50 actuates the low force platen 46. Guide shafts (or tie-bars) 52 are positioned within each stationary platen 42, and pass between bushings 54, and act to guide the paths of movement of the high force platen 44 and low force platen 46 in a horizontal direction wtih respect to the opposite sides of the C-frame 28.

A locking cam 56 may be provided which is actuated by a locking cam cylinder 58. Four locking cam shafts 60 are attached to the low force platen 46. The programmable controller 26 may initiate the locking cam 56 to rotate by actuating the cylinder 58. The piston of the locking cam cylinder 58 is preferrably attached to an arm 64 of the

locking cam 56, so that any movement of the piston causes a corresponding movement of the cam 56. The four arms 64 of the locking cam 56 will move over the top of holes 62 to prevent the locking cam shafts 60 from moving back through the holes once the shafts 60 have extended (thereby horizontally moving platen 46) through stationary platen 42.

An operator control unit 66 may also be provided to offer features such as automatic and manual operation, power on, cycle start and stop, status indicators, push buttons for different sets, etc. Hydraulic control valves 68 may be provided to actuate or control all of the different hydraulicly actuated cylinders in the trim press.

A ground plate 72 may be secured to a portion of the C-frame 28. A vertical support pad 70 may be positioned under each of the low force platen 46 and the high force platen 44 to assist in enabling the platens to slidably move in the C-frame 28 on the ground plate 72. Each platen 44, 46 independently moves horizontally into the center space of the C-frame 28 to meet each other. The pistons of the hydraulic cylinders are driven through the length of the cylinders by hydraulic pressure thereby moving the platens into their respective desired positions. A preferred hydraulic circuit which can be controlled by the operator, and which is capable of driving all of the pistons of the system is shown in Figure 9. The control valves 68 in association with a manifold can control hydraulic fluid flow through the circuit,

A preferred feature of the present invention is the locking cam 56 which locks the low force platen 46 into position. This is advantageous in protecting the die from damage during the trimming operation. The high force platen 44 with a mating die member secured thereto presses against the low force platen 46 having the other die member with the part therein. By being able to adjust the low force platen 46 horizontally, then prevent it from moving backwards, it is possible to bring the two platens close together and stop their movement to make sure the die members are in proper alignment and the part is properly seated before continuing the operation. This assists in the prevention of damage to expensive dies. By finally bringing the high force platen into contact with the low force platen via the die set, the flash material is thereby severed from the part held in the die set.

The present invention is designed for easy access by automation equipment to load and unload parts from the die. A pneumatic system may also be provided as shown in Figure 10 to allow application of a die lubricant and to blow excess flash off the die.

Although a specific embodiment of the invention has been described herein, it is understood that variations may be made thereto by those skilled in the art without departing from the spirit of the invention or the scope of the following claims.