US 3620311 A
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United States Patent lnventor Lowell N. Brown 11612 Bowling Green, St. Louis County, Mo. 63141 Appl. No. 54,892
Filed July 15, 1970 Patented Nov. 16, 1971 AIRHAMMER CONSTRUCTION 8 Claims, 2 Drawing Flgs.
US. Cl 173/136. 173/169.173/171. 310/50 lnt.Cl 1323b 45/04 Field olSearch 1. 173/134,
 References Cited UNITED STATES PATENTS 1,245,860 11/1917 Black et al. 173/170 2,512,763 6/19 50 Bergmann 173/134 Primary Examiner -James A. Leppink Attorney-Joseph A. Fenlon, Jr.
ABSTRACT: This invention relates to an airhammer. the barrel ofwhich is constructed by assembling in axial registration a plurality of stamped discs. each held in axial registration by a pair of aligning rods, and each provided with complementary apertures which define the necessary air passages and piston chamber.
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INVENTOR LOWELL N BROWN OL FW ATTY PATENTEUuuv 16 I97! 3,620,131 1 sum 2 0F 2 2 INVENTOR LOWELL N BROWN ATTY AIRHAMMER CONSTRUCTION It is the object of this invention to provide a new construction for an airhammer barrel which provides for selectively variable barrel lengths, and inexpensive construction and as sembly.
With the above and other objects in view, which will become immediately apparent upon reading the specifications, my invention resides in the unique and novel form, ar rangement, construction and combination of parts shown in the drawings, explained in the specifications, and claimed in the claims.
In the drawings:
FIG. 1 is a side elevational view of a preferred embodiment of my invention.
FIG. 2 is a sectional view taken along lines 2--2 of FIG. 1;
F IG. 3 is a fragmentary sectional view taken along lines 3- 3 of FIG. 2;
FIG. 4 is an enlarged front view of a barrel disc;
FIG. 5 is an enlarged front view of an external exhaust disc;
FIG. 6 is an enlarged front view of an internal exhaust disc. Referring now in more detail and by reference characters to the drawings, which illustrate a preferred embodiment of my invention A designates an airhammer comprising a handle 10, a barrel 12 in which a piston 14 is slidably mounted, and a tool attachment end 16. The handle includes a trigger valve 18 which, upon depression, supplies air under pressure to the bar rel 12 through an air passage 20. The tool attachment end 16 comprises an annular sleeve 22 threaded externally to receive a conventional tool-attachment device (not shown) and provided on its inner face with two inwardly presented threaded bores 24, 26, ineach of which is inserted an end of one of a pair of elongated aligning rods 28, 30, all for purposes presently more fully to appear.
The barrel 12 comprises a plurality of substantially identical core discs 32, a centrally located external exhaust disc 34, and an internal exhaust disc 36, all stacked in axial registration.
Each disc 32 is provided with a pair of diametrally separated alignment bores 38, 40; a pair of smaller, diametrally separated channel bores 42, 44; and a larger center bore 46. Similarly, each disc 34, is provided with a pair of diametrally separated alignment bores 48, 50; a pair of smaller, diametrally separated channel bores 52, 54; and a larger center bore 56. Also, each disc 36 is provided with a pair of diametrally separated alignment bores 58, 60; a pair of smaller diametrally separated channel bores 62, 64; and a larger center bore 66. In the external exhaust disc 34, an exhaust passageway 68 provides communication between the center bore 56 and the outer periphery of the disc 34. In the internal exhaust disc 36, a pair of internal exhaust passageways 70, 72 provide communication between the channel bores 62, 64, respectively and the center bore 66. The alignment bores 38, 48 and 58 are each sized for receiving snugly the aligning rod 28, and similarly the alignment bores 40, 50 and 60 are each sized for receiving snugly the aligning rod 30. The channel bores 42, 52 and 62 are located in such manner that when the discs 32, 34 and 36 are disposed on the aligning rods 28, 30, a continuous air passage 74 is defined by those bores which extend axially along the barrel l2, and similarly the channel bores 44, 54 and 64 are located to define a second continuous air passage 76 which also extends axially along the barrel 12. Also similarly, the center bores 46, 56 and 66 define a continuous piston chamber 78 in which the piston 14 can be moved when the discs 32, 34 and 36 are disposed on the aligning rods 28, 30. As can be seen by the drawings, the barrel 12 comprises a plurality of stacked discs 32, a centrally located external exhaust disc 34, and an internal exhaust disc 36 located at the outer end of the barrel l2. Disposed on the aligning rods 28, at the inner end of the barrel 12 is a conventional flutter valve 80 including a center port 82 in communication with the piston chamber 78,'a first return port 84 in communication with the air passage 74, a second return port 86 in communication with the air passage 76, and an inlet port 88 in communication with the conventional trigger valve 18 which supplies air under pressure to the flutter valve upon activation. As can be seen from the drawings, the aligning rods 28, 30 extend through the handle 10 and the hammer A is held in the assembled condition by nuts 92, 94 which are secured to the ends of the aligning rods 28, 30.
The operation of the hammer A is conventional. When the piston 14 is located outwardly of the disc 34, the flutter valve senses the decrease in pressure behind the piston 14 and supplies air to the return passages 74, 76, which passes into the piston chamber 78 forwardly of the piston 14 through the internal exhaust passageways 70, 72 and urges the piston 14 to the back of the chamber 78. As the piston passes back past the disc 34, the flutter valve senses the decrease in pressure forwardly of the piston 14 and the flutter valve shifts the pressurized air to the center port 82 and into the rear of the chamber 78 which propels the piston 14 against the tool (not shown), being held in the tool-attachment end 16.
The uniqueness and novelty in my invention is not in the creation of an airhammer per se, but rather in the creation of an airhammer which may be assembled using conventionally stamped parts, as opposed to the more complex and expensive castings. The utilization of the discs 32, 34 and 36 to fabricate the barrel 12 not only reduces the cost and simplifies the procedures of manufacture, but also permits the use of the same parts to provide a multiplicity of hammers of varying lengths using said same parts.
It should be understood that changes, alterations and modifications in the form, construction, arrangement, combination of various parts of my invention hereinshown may be made and substituted without departing from the nature and principle of my invention.
Having thus described my invention what I claim and desire to secure by Letters Patent is recited in the specifications, shown in the drawings and claimed in the claims.
1. An airhammer comprising a barrel, a toolholder attached to one end of the barrel, and a handle attached to the other end of the barrel and including a flutter valve and trigger means for selectively supplying air under pressure to the flutter valve said barrel comprising a plurality of first discs each provided with a first center bore and also provided with a first intermediate bore, a second disc provided with a second center and a second intermediate bore and an external exhaust passageway establishing communication between the second center bore and the periphery of the second disc; a third disc provided with a third center and a third intermediate bore and an internal exhaust passageway establishing communication between the third intermediate bore and the third center bore, said first, second and third discs being stacked in registration in such manner that their respective center bores define a continuous center chamber between the toolholder and the flutter valve and their respective outer bores define a continuous intermediate chamber between the toolholder and the flutter valve, said third disc being located near the toolholder and said second disc being located in substantially the center of the stacked discs, said flutter valve including a center port in communication with the center chamber and a return port in communication with the intermediate chamber, a piston movably mounted in the center chamber between the toolholder and the flutter valve, and securing means for bolding the discs and the flutter valve in aligned registration between the toolholder and the handle.
2. The device of claim 1 in which the first, second and third discs are annular.
3. The device of claim 1 in which the securing means includes an alignment rod secured at one end to the toolholder and at the other end to the handle, and which projects through, in snug-fitting disposition, alignment bores located in each of the three types of discs.
4. The device of claim 1 in which each of the discs is annular and substantially smaller in thickness than in diameter, and in which the vast majority of discs used to construct the barrel comprises first discs.
5. A barrel for an airhammer including a tool-attachment device and a handle, said barrel comprising an elongated stack of waferlike discs which are assembled in face-to-face registratron,
an elongated piston chamber extending longitudinally along the stack and which is defined an aperture in each of said discs,
an air passageway extending longitudinally from the handle end of the barrel to the tool-attachment device end of the barrel and which is defined by a bore located in each of said discs,
a first port located near the tool-attachment device end of the barrel which establishes air communication between the piston chamber and the air passageway,
a second port located near the center of the barrel which establishes air communication between the piston chamber and the outside atmosphere whereby to provide an exhaust outlet for the piston chamber, a piston movably disposed in the piston chamber, valve means for alternately providing air under pressure to the front and back portions of the piston for driving the piston backwardly and forwardly respectively past the second port, and means for holding the discs in such face-to-face registration and for simultaneously securing the tool-attachment device and the handle to the stack of discs and the valve means. 6. The device of claim 5 wherein the discs are annular. 7. The device of claim 5 wherein the first port is integrally included in one of the discs.
8. The device of claim 5 wherein the second port is integrally included in one of the discs.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 20,311 Dated November 16, 1971 Inventor(s) L N 3:
It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
On the cover sheet,  under the title ,AIB AM R CONSTRUCTION, "8 Claims, 2 Drawing Figs." should read 8 Claims, 6 Drawing Figs. Column 2, line 41, after "valve" insert a comma. Column 3, line 6, after "defined" insert Signed and sealed this 31st day of October 1972.
EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents )RM PC4050 (0459) uscoMM-oc cove-pee ,5. GOVERNMENT PRINTING OFF|CE1 I," Q J."JJI.