US 2501542 A
Description (OCR text may contain errors)
March 2?, 195
Filed Oct. 15, 194-7 H. S. SHELDO HAMMER TOOL 2 Sheets-Sheet l INVENTOR, f/mm 0 SSHfla M ATTD RN EYS March 9 19% H. s. SHELDON 2,5m1542 HAMMER TOOL Filed Oct. 15, 1947 2 Sheets-$heet 2 7 A INVENTOR.
ME01055f/[L00 mf a.
ATTD RN EYS Patented Mar. 21, 1950 HAMMER, TOOL I Kai-01a s. sneiaen, Tekoa, Wash. Application October 15, 1947, Serial No. 779,931
1 My present invention relates generally to portable motor-operated and manually controlled'machine tools or implements, and more specifically to an improved hammer tool and operating mechanism of the reciprocating, rotary cam actuated type, and designed for interchangeable use as a portable power-operated hammer, wood chisel, scaling chisel, piercing punch, rock drill, and other similar power tools.
The novel operating mechanism of my invention, as an attachment, is adapted for combination with and receives power from a motor, as an electric motor, which is manually controlled to supply rotary power and motion that is translated, or converted by the operating mechanism into reciprocating motion and power for at olholder having selective interchangeable tools.
The invention consists in certain novel combinations and arrangements of parts that may with facility be manufactured at low cost of production, and assembled with convenience to constitute a quick-acting reciprocating machine tool of the portable type that is simple in construction and operation, and which may be handled with ease in the performance of its required functions.
In the accompanying drawings I have illustrated a complete example of a physical embodiment of my invention in which the parts are combined and arranged in accord with one mode I have devised for the practical application of the principles of my invention. It will however be understood that changes and alterations are contemplated and may be made in these exemplifying drawings and mechanical structures, within the scope of my claim, without departing from the principles of the invention.
Figure 1 is a view in side elevation showing a physical embodiment of my invention mounted as an attachment on a portable motor-operated and manually controlled implement including an electric motor.
Figure 2 is a vertical longitudinal sectional view of the housing and its operating mechanism, separated from its driving mechanism, as at line 2-2 of Fig. 3.
Figure 3 is a top plan view of the implement of Fig. 2.
"1 Claim. (01. 125-33) Figure 4 is a front end view of the implement Figure 6 is a transverse vertical sectional view at line 6-6 of Fig. 3; Figure 7 is a perspective view of the guide for the reciprocating cam-member; and Figure 8 is a perspective view showing a portion of the cam shaft, head, and cam.
In order that the general arrangement and util ity of parts may readily be understood I have shown in the assembly view Fig. 1 an electrically operated and manually controlled, portable, machine tool A having the usual control trigger or lever L, and a rotary chuck or holder R that is operated by the electric motor within the machine tool. 1
Theoperating mechanism of my invention,
which converts or translates rotary motion and power into reciprocating motion and power, is mounted within a housing I having a rear extension 2, and the housing is deta'chably fastened to the tool A b means ofa metallic clamp or arcuate band 3 riveted at 4 to the housing, and
provided with set screws '5, 5 for impingement againstthe exterior cylindrical face of th tool A.
A pair of metallic straps 6 and 1 are attached to the clamp or band 3, and these straps are fastened about the tool A by means of a quick-detachable fastener or clampbolt 8 and its wing nut 9.
The operating mechanism of my invention is connected to and receives power from the tool A through a rotary cam shaft ID that is rigidly fixed, 'as indicated in Fig. l, in the rotary chuck R to rotate therewith, and the cam shaft is journaled in bushings l I and I! of the housing I. a
The interior parts of the housing operate in an oil bath, and the housing bearings are provided with leak-proof gaskets I-3,.and retaining plates l4 attached on the exterior faceof the housing gotseal the bearings and prevent loss of the oil The cam shaft, or rotary output shaft of the operating mechanism, is provided with a head I5 within the front end of the housing, and this cam-head l5 co-acts with a complementary reciprocable arm I6 that is guided in its movements within a U-shaped guide bracket l1 bolted at It to the inner face of the front wall of the housing.
The angular cam arm is rigidly mounted on or integral with an enlarged head IQ of a reciprocating power-bolt, or hammer shaft 20, the rear end of which is slidably mounted in a socketbushing 2| that is adjustably threaded in an opening in the rear end wall of the extension.
An expansible power spring 22 is coiled about the reciprocating bolt and interposed between the bolt head [9 and the inner end of the bushing 2 I. and the bushing may be adjusted to change the tension of the spring and thereby vary the blow of the reciprocating bolt or hammer shaft.
With each revolution of the cam shaft and its transversely arranged cam-head, rotary motion and power from the electric motor is translated through the cam arm into reciprocating motion and power of the spring-projected bolt, and the spring supplies the power blow or out-stroke of the bolt or hammer shaft.
The front end. of the power bolt .20' is slidably mounted in a bushing in the front walli'of the housing, and the leak proof devices l3 and I4 are provided at this bearin to prevent loss of the oil bath.
The front end of the reciprocating bolt, which is longitudinally disposed in the housingandem tension in parallelism with the rotary. camshaft, projects through the front wall of the housing and this end of the bolt is equipped with a-tool 1 holder or socket-barrel 23 that is resliently supported with relationto the housing and adapted toareceive-and retain. a selected tool'Tof -an interchangeable set of tools includedin" theequipment .ofthe implement. A quick=detachable fastener forthe tool T may vinclude a usual spring.
latchldffastened on the exterior .of the holder and provided with a-latch head or detent 25tha-t projects through: aradial. slot in the holder for engagement-with an annular groove or socket in:
the interchangeabletool T.
For resiliently mounting the holder tonreciprocate with-the spring-bolt for. the absorptiorrof shocksand vibrations occasioned in the operating parts ofthe mechanism, the holder is connected with the housing by means of a pair of bolts .25
that pass throughsholes in an exterior flange 26. of the holder with their. rear ends. threadedin-= with a housing, a co-planar rotary shaft and a reciprocating spring-projected bolt mounted in the housing, and a transversely arranged cam on the 'shaft aird'an arm rigid with the bolt for coaction withv thecam for reciprocating the bolt,
'and'a U-sl'i'aped guide for the arm of-a toolholder mounted on an exterior end of the bolt,
a flange on the holder, a pair of bolts rigid with thefl-ange, a pair of springs interposed between the bolt-heads and the flange, and a second-,pair ofsprings interposed. between the flange anda wall ofthe housing.
' HAROLD SJSHELDON;
REFERENCESCITED H The following. references :are of record in thefile of this patent:
UNITED STATES PATENTS Number. Name Date M 1,789;0821 Grutzbach Man-24,1931 1,889,441 Haas l Nov. 29,1932. 2,252,017. McCrery l .Aug; 7 12," 19i1l 2,260,070 Will'iid Oct; 21,1941 Schmied' Oct; 13,1942