US2132148A

US2132148A - Impact press

Info

Publication number: US2132148A
Application number: US123223A
Authority: US
Inventors: Lewis K Davis
Original assignee: GRACE P DAVIS
Current assignee: GRACE P DAVIS
Priority date: 1937-01-30
Filing date: 1937-01-30
Publication date: 1938-10-04
Anticipated expiration: 1955-10-04

Description

Oct. 4

, 1938. l.. K, DAvls 2,132,148

IMPACT PRESS Filed Jan. 30, 1937 2 Sheets-Sheet 1 Fl 'E l V3845 +o 44 4,8 57| 55 5 l 4b q zo, 'e '5 |7 24 L5 3o `zo u y t! 'u i o 5 l l l 4 h l INVENTOR.

LEWIS K .DFW/5.

A TTORNY L. K. DAVIS IMPACT PRESS Oct. 4, 1938.

2 Sheets-Sheet 2 Filed Jan. 50, 1937 muni l IN V EN TOR.

LEWIS K. .DAV/5,

A TTORNEY Patented oct. 4, 193s UNITED sfrA'ras IMPACT PnEss Lewis K. Davis, Hampton, N. J., assignor to Grace P. Davis, Hampton, N. J. f/ Y Application January 30, 1937, Serial No. 123,223

12 Claims.

This invention relates to improvements in impact presses of the type suitable for splicing cable and performing other operations involving the forceful driving of a hammer, plunger or die, into engagement with work supported in operative relation to the hammer, plunger or die. In my prior co-pending application, Serial No. 63,072, filed February l0, 1936, I have described an impact press for this purpose in which the motive force is supplied by the combustion of a charge of propellent powder. The present invention contemplates certain improvements and renements in the device of my former application.

It has been found, as a result of extensive testing under actual working conditions, that the temperatures and pressures developed within the cylinder of a device of this character are such as to cause undesirable erosion of the surfaces of the cylinder and/or the head of the piston.

The present invention contemplates novel means and combinations of means, first, for reducing and controlling initial pressures; and second, for effecting a reduction in pressure immediately upon completion of the power stroke of the piston;

thereby obviating the erosion due to the maintenance of pressures in the cylinder at a time when such pressure does not serve any useful purpose.

'Ihe invention further contemplates a new and improved breech mechanism which securely and effectively closes the breech end of the iiring chamber or cylinder and at the same time is readily removable to effect reloading.

The invention further contemplates a barrel or cylinder which is removably held in the machine frame and may be quite readily removed and replaced when excessive use has impaired its functioning.

In the drawings:

Fig. 1 is a side elevation, partly in section, of

an impact press embodying the present invention.

Fig. 2 is a plan view of the same press.

Fig. 3 is a front elevation of the press.

Fig. 4 is a horizontal section substantially on the line 4-4 of Fig. 1.

The machine comprises a main fra'me, identied generally bythe numeral I0, the lower portion of lwhichis formed in a c -shape to provide a work supporting anvil. The upper portion of the frame comprises a lateral extension II forming a handle. The body I2 of the frame above the anvil forming portion is of generally cylindrical exterior shape with such reinforcing and part supporting extensions and projections as may be desirable. This portion of the frame comprises a cylindrical bore and counterbore adapted to receive and support the barrel or cylinder I3, the lower end of said cylinder resting on the shoulder I4 joining the bore through the lower end of the 5 frame I2 with the larger counterbore extending the greater part of the lengtliof the body of said frame.

In my prior co-pending application, aboveidentified, the machine frame comprises a cylin- 10 drical bore which receives the hammer or piston. When the wall of this bore becomes pitted or eroded it is necessary to discard the entire frame. According to the present invention, the cylinder or barrel is made a separate member supported ll and held in the frame proper in the manner just described; thus, a worn or eroded cylinder is capable of ready replacement.

The barrel or cylinder I3 comprises at its upper end a chamber I5 adapted to receive a cartridge 20 such as I6. The chamber I5 communicates with the larger cylindrical chamber I1 adapted to receive a piston-like' member I8, which member,

'according to the embodiment of the invention illustrated in the drawings, is provided with a 25 hammer face particularly designed to impact and indent a cable splicing sleeve of a material such as copper or brass. The piston I8 is yieldingly held in retracted or elevated position in the cylinder I3 by suitable devices, one form of which 30 may be as follows:

At an appropriate position in the length of the piston a circular groove I9 is formed in its periphery. -When the piston is elevated this groove stands opposite a somewhat deeper groove 20 in 35 the interior wall of the cylinder I3. Within the grooves I 9 and 20 is placed a broken elastic metal ring 2 I, the stock of such ring preferably being of circular cross section, so that the ring may be spread or cammed outwardly by engagement with 40 the camming upper surface of the groove I9. The ring tends to spring inwardly into the groove I9, which groove is of such depth that when it is occupied by the ring the outer portion of the ring projects outwardlyinto the groove 20. When 45 suiiicient downward force is exerted on the piston, the ring will be cammed out of the groove I9 into the groove 20, the periphery of the piston sliding through it in the upward and downward movement of the piston. The parts are so propor- 50 tioned and the ring is of such rigidity as to relquire a substantial build up of pressure above the piston before the ring is displaced and the piston' permitted to move. This type of piston restraining means has for certain types of work 55 been found an effective substitute for the shear pin illustrated in my application above-identied and also in my `Patent No. 2,030,686

It has likewise been discovered that .erosion of cylinder and piston can be substantially eliminated without loss of emciency by providing a vent through the wall of cylinder I3 and the surrounding frame I2, which vent is opened when the piston reaches its lowermost or advanced position. When the piston has reached this position the blow has been delivered to the work upon the anvil and, while it is desirable to prevent an immediate rebound of the piston from the work, it has been found possible to so vent the cylinder as to materially relieve burning the cylinder and piston while still maintaining such a pressure on the piston as will preclude an immediaterebound of the piston and a consequent springback of the work upon the anvil which has been deformed by the piston. Accordingly, the present invention provides an aperture 22 extending transversely through the wall of cylinder I3 just above the lowermost position of piston I8, and an aperture 23 through the wall of the frame I2 in alignment with the aperture 22.

Since tools of this character may be used in places where the air contains considerable amounts of inflammable gases, it is desirable to damp and extinguish such powder combustion flame as might otherwise be projected into the air. For this purpose, there is associated with the apertures 22 and 23 a ame arrester which may be constructed as follows:

The adjacent portion of frame I2 is formed into a suitable boss 24 which is counterbored and threaded to receive a threaded portion 25 of a llame arrester identified generally by the numeral 28 and comprising a passage 21 aligning with the aperture 23. The passage 21 is suitably divided to distribute and transmit the flame passing therethrough to a chamber 28 which is lled with a suitable flame arresting and absorbing material. A number of thicknesses of copper screen have been found very effective for this purpose. In

l the embodiment illustrated in the drawings, the

chamber 28 is occupied by several superposed layers of copper s creen of 100 mesh. The outer portion of the body 26 of the flame arrester is threaded to receive a cap 30 which covers the chamber 28, the portion of said cap over such chamber comprising a plurality of apertures such as 3| through which the gases cooled by the ame arrester finally escape. The joint between the threaded end 25 of the flame arrester and the boss 26 of the frame may be sealed by a rubber gasket 32, said gasket being apertured to provide a passage from aperture 23 to flame arrester passage 21. A device of this character has been found to be very effective in reducing burning and erosion of the piston and cylinder without the undesirable transmission of flame and heated gases to the exterior.

'Ihe improved breech mechanism may be constructed as follows:

The upper end 35 of the frame I2 conforms to the exterior configuration illustrated in Fig. 2, the cylinder receiving bore extending through the upper end of the frame and being intersected by a transverse slot of greater width and length than the cylinder bore and adapted to receivea transversely moving breech block 36. The breech block comprises an aperture adapted to receive a firing pin 31, firing pin retracting spring 38, and firing pin holding nut 39. 'Ihe firing pin is adapted to be struck by a hammer 310 pivoted at 31| and controlled by a trigger 312. Said breech block is heldin breech closing position and against movement in its slot in the frame by a plunger i0 comprising an enlarged foot 4| adapted to be received in a recess d2 in the surface of the upper end of the cylinder I3, said cylinder being, as shown in the drawings, immediately adjacent the breech block. 'I'he foot I is urged into recess 42 by suitable means such as a spring 83 encircling the shank of plunger 40. Means are provided for withdrawing the foot @I and thus unlocking the breech for movement transversely out of the frame, which meansA may comprise a head M on the plunger 40 adapted for engagement by the forked end 45 of a lever pivoted at d6 in ears 41 upstanding from the breech block 38. 'I'he front end d8 of said leverforms a handle, the depression of which elevates the plunger fill, this operation being facilitated. by a handle 89 projecting outwardly from the body 36 of the breech block and adapted to be grasped along with handle d8. By grasping these handles and depressing handle 48, plunger d is lifted to withdraw foot 6I from recess 42 and thereupon the breech block can be moved laterally out of the slots in frame l2 to permit the insertion of a cartridge into chamber I5.

It is to be understood that this invention is not limited to the details of construction illustrated in the accompanying drawings but includes such modifications thereof as fall within the scope of the appended claims.

What is claimed is:

1. An impact press comprising a frame having an aperture adapted to receive and support a replaceable cylinder, a cylinder in said frame comprising a bore adapted to receive a piston, a piston in said cylinder, means associated with said frame adapted to hold and ignite a piston propelling charge, and means for retarding movement of said piston comprising matching grooves in the peripheries of said cylinder and said piston respectively and a ring elastically held in both said grooves and displaceable from one of them by pressure on said piston.

2. An impact press comprising a frame apertured to receive a replaceable cylinder, a cylinder in said frame, a piston in said cylinder, means for propelling said piston from a normal position through a power stroke, and means for initially retaining said piston against the force of said propelling means comprising a peripheral groove in said cylinder, a matching peripheral groove in said piston, a ring of elastic material normally lresting in said matching grooves and thereby retaining the piston in normal position but adapted to be displaced out of one of said grooves when the force tending to propel said piston from normal position exceeds a predetermined amount.

3. An impact press comprising a frame apertured to receive a replaceable cylinder, a cylinder in said frame, a piston in said cylinder, means for closing said cylinder comprising a transverse slot in said frame, a breech block adapted to be slidably received in said slot and to abut the upper end of said cylinder, and means for retaining said breech block in said slot.

4. An impact press comprising a frame apertured to receive a replaceable cylinder, a cylinder in said frame, means for closing one end of said cylinder comprising a transverse slot in said frame open at one end, a breech block adapted to be received in said slot, and means for retaining said breech block in cylinder closing position comprising a plunger extending through said breech block and a recess in said frame adapted to receive a portion of said plunger.

5. An impact press comprising a frame apertured to receive a replaceable cylinder, a cylinder in said frame, means for closing one end of said cylinder comprising a transverse slot in said frame open at one end, a breech block adapted to be received in said slot, means for retaining said breech block in cylinder closing position comprising a plunger extending through said breech block and a recess in said frame adapted to receive a portion of said plunger, and means for retracting said plunger to permit removal of said breech block comprising a lever pivoted to said breech block and engaging said plunger.

6. An impact press comprising a frame apertured to receive/a replaceable cylinder, a cylinder in said frame, means for closing one end of said cylinder comprising a transverse slot in said frame open at one end, a breech block adapted to be received in said slot, a spring pressed plunger extending through said breech block, a recess in said frame adapted to receive a portion of said plunger, and means for retracting said plunger against the force of its spring comprising a lever pivoted to said breech block and engaging said plunger.

7. An impact press comprising a frame apertured to receive a replaceable cylinder, a cylinder in said frame, means for closing one end of said cylinder comprising a transverse slot in said frame open at one end, a breech block adapted to be received in said slot, a spring pressed plunger extending through said breech block, a recess in said frame adapted to receive a portion of said plunger, and means for retracting said plunger against the force of its spring comprising a lever pivoted to said breech block and engaging said plunger and a handle projecting from said breech block and adapted to be grasped by the operator along with said lever.

8. An impact press comprising a frame apertured to receive a replaceable cylinder, a. cylinderv in said frame, a piston in said cylinder, means for retaining said piston in normal position comprising matching grooves in the periphery of said cylinder and said piston respectively and an elastic ring normally occupying portions of both of said grooves but adapted to be displaced into one of them by adequate pressure to permit movement oi.' the piston, means for closing said cylinder above said piston comprising a transverse groove in said frame open at one end, a breech block slidably received in said groove and abutting said cylinder, pressure generating means carried by said breech block, and means for retaining said breech block in cylinder closing position comprising a plunger extending through said breech block and a recess in said framel adapted to receive a portion of said plunger.

9. A unitary portable tool for the splicing oi' cables and the like comprising a work support, a piston cylinder mounted in alignment with said work support, said piston cylinder being held in a frame rigidly connected to said work support, a piston in said cylinder, pressure generating means for moving said piston comprising an explosive device, means for ring said explosive device, an exhaust vent for the gases of explosion extending through said cylinder and said frame, said vent being normally covered by said piston and opened by the movement of said piston, and means associated with said vent for preventing the passage of iiame while permitting the escape of gas, said means comprising a body of foraminous heat conducting material and a housing therefor.

10. A unitary portable tool for the splicing of cables and the like comprising a work support, a piston cylinder mounted in alignment with said work support, said piston cylinder being held in a frame rigidly connected to said work support. a piston in said cylinder, pressure generating means for moving said piston comprising an explosive device, means for firing said explosive device, an exhaust vent for the gases of explosion extending through said cylinder and said frame, said vent being normally covered by said piston and opened by the movement of said piston, and means associated with said vent for preventing the passage of iiame while permitting the escape of gas, said means comprising a housing threaded to said frame, a body of ioraminous metal in said housing, and a perforated cover threaded to said housing.

1l. In a unitary portable tool for the splicing of cables and the like. the combination with a work support, a piston cylinder mounted in alignment with said work support, said piston cylinder being held in a frame rigidly connected to said work support, a piston in said cylinder, pressure generating means for moving said piston comprising an explosive device, and means for nring said explosive device; of means for preventing erosion of said piston by the gases of explosion and permitting the escape of said gases from said cylinder while preventing the escape of ame, said means comprising aligned apertures in said cylinder and said frame. and a ame arrester secured to said frame, said flame arrester comprising a body of foraminous metal and a housing therefor.

12. In a unitary portable tool for the splicing of cables and the like, the combination with a work support, a piston cylinder mounted in alignment with said work support, said piston cylinder being held in a frame rigidly connected to said work support, a piston in said cylinder, pressure generating means for moving said piston comprising an explosive device, and means for firing said explosive device; of means for preventing erosion of said piston by the gases of explosion and permitting the escape of said gases from said cylinder while preventing the escape of ame, said means comprising aligned apertures in said cylinder. and said frame, and a name arrester secured to said frame, said flame arrester comprising a housing threaded to said frame, a body of foraminous metal in said housing, and a perforated cover threaded to said housing.

LEWIS K. DAVIS.