US2030686A - Impact device - Google Patents

Description

1.. KfoAvl s IMPACT DEVICE Feb. 11, 1936.

Filed Sept. 25, 1931 INVENTOR BY 1/9 'ATTORNEYS Patented Feb. 11, 1936 UNITED STATES IMPACT DEVICE Lewis K. Davis, Hampton, N. J.

Application September 6 Claims.

means of rapidly expanding gases of combustion has been utilized heretofore for various purposes, but unless the rate of expansion ofthe gases is controlled in some way to insure complete combustion of the material before utilizing the force thus generated, the maximum power of the gas expansion is not obtained, for the reason that the resistance to movement of the object to be moved is usually relatively low as compared to initial power provided by the partial combustion of the material, so that the reserve power of the remaining unburned material is dissipated in the enlarged space provided by the premature movement of the object.

It is the principal object of this invention to provide a device in which the expansion of gases produced by the rapid combustion of a highly combustible material is retarded a suflicient time to permit of complete combustion of the material whereby the full power of the expanding gases may be utilized to do a greatly increased amount of work. i I

, This object is obtained in a preferred embodiment of the invention in which a cartridge of gunpowder or the like is detonated in a cylinder containingfa piston, whose movement is retarded bynovel means until the powder is completely burned and the resultant gas pressure exceeds a limit determined by the retarding means. More particularly, the retarding means comprises a bar or rod of metal or the like which is sheared off by the piston only when the gas pressure builds'up to a pressure such that the shearing resistance of the rod or bar is exceeded. Thus, ,the

impact of the piston caused by the sudden re-' lease thereof by the shearing of the rod or bar is utilized to do useful work such as punching,

die-pressing or forming metals, pressingtwo or more members together, or the like, and the frame of the device is arranged for receiving dies of different shapes punches of different sizes and shapes and the like for cooperation with the piston. I

By changing the density or character of the powder in the cartridges and providing bars or rods of different shear resistances, any degree of controlled power or force may be obtained with the new deviceof this invention, depending upon requirements.

It will be seen that the new impact press of 23, 1931', Serial No. 564,491

this invention is compact and readily operated without ,the use of outside power, and requires only a supply of powder cartridges and shear rods for procuring repeated operations of the device. Accordingly, the device may be used in outlying districts where power is not readily obtainable and is also admirably adapted as a portable source of power. For a better understanding of the invention, reference is made to the accompanying drawing, in which Fig. 1 is a longitudinal section through the new press as seen along line l-l of Fig. 2;

Fig. 2 is a longitudinal section through the new press as seen along the line 2- -2 of Fig. 1;

Fig. 3 is a transverse cross-section through the cartridge firing mechanism as seen along the line 33 of Fig. 2;

Fig. 4 is a transverse cross-section through the cylinder and piston as seen along the line 4-4 of Fig. l, and

Fig. 5 is a transverse cross-section through the die holder as seen along the line 5--5 of Fig. 1. In the drawing, numeral I0 designates the frame of the press which is supported on four feet II and is provided with a die or other tool chamber l2 at the base with which communicates the lower end of the power cylinder l0 extend ing upwardly from the frame It.

The head of the cylinder I0 is provided with a lateral recess iii in which is removably mounted a block it having a pin l5 extending laterally through the head of the cylinder l0 and having a notch H which is normally engaged by one end of a latch I6. This latch I6 is pivoted on a stud I8 screwed into the side of the head of cylinder l0.

Slidably mounted in an axial passage through the block it is a firing pin l9 which is normally urged in a downward direction by a coil spring 20 seated between a collar l9 on the firing pin l9 and thecap 2| threaded on the upper end of block 14. The firing pin I9 is normally held in retracted position by the locking pin 22' which is inserted through a suitable opening in the firing pin 19 and overlies the cap 2|. In this way the spring is compressed in readiness for advancing the firing pin l9 when it is released by withdrawing locking pin 22". A handle 22 on the firing pin l9 may be pulled outwardly toretract theflring' pinand for the purpose of inserting the locking pin 22' to hold the firing pin [9 in re- .tracted position; Any other equivalent trigger or firing pin'release mechanism may be employed with equal facility.

The upper end of the cylinder I8 is closed gas tightly by a plug or cartridge clip 23 having an axial passage for the reception of the cartridge 25 containing gunpowder, or the like. The percussion cap 26 of the cartridge 25 lies in alignment with the tip 21 of the firing pin I 9 so as to be struck and detonated thereby when the pin is released. The cartridge clip or-plug 23 may be exposed for removing empty cartridge shells and replacing them with unfired cartridges by removing block Hi. This may be done by releasing latch Hi and withdrawing the block from the recess l3 in the head of the cylinder Hi. It will be observed in the section of Figs. 1 and 2 and in cross-section of the block illustrated in Fig. 3 that the head of cylinder I0 is formed with flanges I3 which overlap the block l4 so that it is locked against the recoil shock produced by the firing of cartridge 25.

Slidably mounted in the bore of cylinder I0 is a. piston 28 whose upper end lies adjacent the lower or discharge end of the cartridge 25 when the piston lies in the raised position illustrated in Figs. 1 and 2. The lower end of this piston 28 is provided with an enlarged hammer 29 having side grooves adapted to receive the keys or guides 38 on the frame I0. Passing laterally through the piston 28 is a hardened steel bushing 3|,

which is adapted to align with similar hardened steel bushings 32 and 33 inserted in the opposite side walls of frame If! when the piston 28 and its hammer 29 are raised into the position shown in Figs. 1 and 2. The piston 28 and its hammer 29 may be so raised by means of suitable levers or the like inserted in recesses 34 in thesides so as to hold the piston 28 and its hammer 29 in raised position, is a rod 35 of tough metal or the like having a predetermined resistance to shearing by the shear blades 32' and 33'. Secured to the ends of a small shaft 36 journalled in frame ID are a pair of clips 31 and 38, clip 38 being provided with a lateral handle 39, whereby both clips may be raised from their normal position in which their free ends cover the open ends of bushings 32 and 33. The stop pin 38 locates these clips 31 and 38 in this normal position in which they hold in place the shear rod 35. When it is desired to remove the severed pieces of the sheared rod and replace it with a new rod, it is only necessary to grasp handle 39 to move clips 31 and 38 to expose the openings in bushings 33 and 32 respectively.

Located in the bottom of the die opening l2 .of frame I0 is a combination anvil and. die 40, whose lower edge is provided with a groove through which passes the bolt 4|, this bolt acting as a key for centering the anvil die 48 and also serving to clamp it securely in the frame by drawing together the two sides of the frame as the bolt 48 is tightened.

Slidably mounted in the opening of the frame and centered and guided by the keys is the upper die 42 which cooperates with the lower die 40 in the usual way. These dies 49 and 42 may be shaped to produce any kind of forming operation, punching operation, shearing operation, or the like. For example, as shown in the drawing, the dies 49 and 42 are shaped to embrace a sheath 43 which is adapted to be clamped around the cable 44. Although the dies are shaped in this way to perform this cable sheathing function, they may obviously be arranged and adapted to perform any other function, or they may be substituted by other mechanical elements which are designed to produce work in accordance with the power which is applied thereto. In order to remove these dies the lower one, 48, is raised to clear the bolt 4| and may then be withdrawn, while the upper die 42 then drops down to clear keys or guides 38 and may also be withdrawn.

In operation, the piston 28 and hammer 29 are raisedby inserting a lever or rod in recesses 34 in the hammer 29 and a shearing pin or rod is inserted through aligned bushings 3|, 32 and 33 in order to hold the piston 28 and hammer 29 in this elevated position. Then the clips 31 and 38 are moved downwardly to stop 38' by handle 39 to close the open ends of bushings 32 and 33, so that the shear rod 35 is held in position.

The block I4 is removed from the frame 18 after being unlatched by releasing latch l5, and cartridge 25, containing a charge of gunpowder or other highly inflammable orexplosive mate-- The withdrawal of pin 22' releases firing pinl9 so that spring 20 forces firing pin tip 21 against the cap 25 of cartridge 25 to fire the same. The rapidly expanding gases of combustion of the powder in cartridge 25 tend to force the piston 28 downwardly at once, but the piston is retarded by shear rod 35, until the gas pressure is suflicient to cause the shear blades 32' and 33' to cut relatively slowly through the shear pin 35. This retardation enables the powder to burn completely so that the gases of combustion have full time to exert their greatest force before being released. Accordingly, when blades 32' and 33' finally sever the shear pin 35 the hammer 29 is released suddenly and is forced downwardly I into contact with die 42 with a considerable impact, so that the sheath 43 is instantly clamped around the cable 44 through the cooperation of dies 40 and 42.

It will be seen that the use of the shear rod 35 prevents premature movement of the hammer 25 in response to the initial expansion of the partially burned powder, and allows sumcient time for complete combustion so that the expanding gases exert their greatest accumulated force upon the piston 28 before the hammer 29 is released to strike the dies 42. The relatively slow shear of the rod 35 allows the gas to expand slightly and thus its power is increased before it is released. Thus by this arrangement a greatly augmented power is procured for forcing the two dies 42 and 48 together.

By providing shear rods 35 of different shearing resistances, the time of powder combustion and gas expansion may be increased or decreased within limits in accordance with operating requirements. Also, by arranging the density or character of the powder charge in cartridge 25, the speed of powder combustion may be arranged 2,030,080 to suit all requirements of operation. For example, by increasing the charge in cartridge 25 and providing 1 a rod 35 having a high shear modulus a practically unlimited amount of power may be obtained in a simple fashion and without requiring large or extensive equipment or the use of outside power.

'I'his'invention may therefore be in outlying districts or other places where power is not obtainable, or in such localities where standard- .ized jobs of forming, shearing, punching or the like are done occasionally, and the like. The only supplies necessary to operate the device of this invention comprise a number of cartridges 2! of the same or different strengths, and a corresponding number of shear rods 35 of the same or different shear resistances. Thus, simply by replacing the cartridges 25 as exploded and rods 35 as sheared, the device may be employed any number of times without requiring the use of extensive power equipment or other outside power supply. Also thedeyice may be set up in a short .time and operated instantaneously and readily ceiving a charge of combustible material for gencrating gas to act on said piston and move the same, anda shearable member extending be-' tween the frame and the piston for resisting relative' movement between them, said member being arranged to be sheared at a predetermined gas pressure.

3. In an impact press, the combination of a frame, a piston slidable therein, means for receiving a charge of combustible material for generating gas to act on said piston and move the same, shearing blades between said piston and said frame, and a shearable member cooperating with said blades for severance thereby at a predetermined gas pressure.

4. In an impact press, the combination of a frame, a piston slidable therein. means for receiving a charge of combustible material for generating gas to act on said piston and move the same, said piston and frame having aligned apertures, and a shearable member in the apertures for severance by movement by said piston under a predetermined gas pressure.

5. In an impact press, the combination of a frame, a piston slidable therein, means for receiving a charge of combustible material for generating gas to act on said piston and move the same, said piston and frame having aligned apertures, a shearable member in the apertures for retarding movement of said piston, and shearing blades between said piston and frame cooperating with said member for severance thereby at a predetermined gas pressure.

6. In an impact press, the combination of a frame having a cylinder, a piston slidable therein, a hammer on the piston, means in the frame for cooperation with said hammer, means for receiving a replaceable cartridge of combustible material arranged to discharge gas into said cylinder and having a detonating cap, firing mechanism mounted on said frame for detonating the cap of said cartridge, said mechanism being movable to expose said cartridge, a shearable member extending between said piston and said frame, and blades between said piston and frame for shearing said member at a predetermined gas pressure to release said hammer for impact with said first means.

LEWIS K. DAVIS.

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