US2783792A - Free ended saw blade for a power operated saw - Google Patents

Description

March 5, 1957 T. B. KEESLING FREE ENDED SAW BLADE FOR A POWER OPERATED SAW Filed Dec. 1. 1952 4 32 5 G. 2. 1 liim\\\\\\ f&\m1

17 i z in u 19 ll IV A///// INVEN ran THO/14; B. K EJ L/NG A TTOR N E Y United States Patent FREE ENDED SAW BLADE FOR A POWER OPERATED SAW Thomas B. Keesling, Los Gatos, Calif., assignor to C. H. Keesling, San Jose, Calif.

Application December 1, 1952, Serial No. 323,370

1 Claim. (Cl. 143-133) The present invention relates to power-operated reciprocating tools, such as saws, and is concerned more particularly with a power operated tool attachment fordrive means such as an electric drill, which can be manually controlled. in application to the work.

It is the general object of the invention to provide a power operated saw attachment of the above character of'irnproved construction and economical design.

It is another object of the invention to providean improved saw blade which when mounted with reference to its driver provides a desired angular. relation of the saw teeth with respect to the path of movementofthe saw blade.

his a still further object of the invention to provide a power operated attachment of the above character having improved means for shielding the working. parts from particles.

Other objects and advantages "of the invention will be apparent from the following. description of a preferred e'rnliifodirrieritfthereof,v as illustrated. in the accompanying drawings; imwhich'.

Figure 1 is an elevational view of the saw.

Figure 2 is a sectional view taken on the line 22 in Figure 1.

Figure 3 is an elevational view of the saw with the cover portion of the body removed.

Figure 4 is a sectional view taken in a plane indicated by the line 44 in Figure 2.

Figure 5 is an end elevational view taken in a plane indicated by the line 55.

Figure 6 is an elevational view of the saw blade for use in the saw.

Figure 7 is a fragmentary elevational view of the cover.

Figure 8 is a perspective view of the saw clamping head.

Figure 9 is an elevational view of the dirt shield.

Figure 10 is a sectional view taken on the line 1010 in Figure 9.

Figure 11 is a fragmentary sectional view illustrating a modified form of dirt shield.

The power-operated hand-controlled tool of the instant invention comprises a body including a body 10 and a cover 11 both of die cast construction whose parting line lies in a plane parallel to certain working parts of the tool including a reciprocating drive link 12. The cover 11 (Figures 2 and 7) is provided about its periphery with a flat surface 16 which engages flush with a corresponding peripheral edge surface 17 of the body 10. The cover 11 is also provided with an inwardly spaced outwardly projecting rib 18 which seats within a recessed portion 19 of the body in flush engagement with the side wall 21 adjacent the flat peripheral edge portion 17. As seen in Figure 7, the front end portions of the rib 18 of the cover 11 merge with a bearing pad 36 for the reciprocating elements of the tool. The cover 11 is provided with four threaded apertures 22 to receive the threaded ends of a socket cap screws 23 seated in corresponding aligned apertures 24 of the base 10.

The body 10 (Figure 2) is provided. with a boss'or extension 26 to journal internally threaded drive thimble" 27 havinga hexagonal flange portion 27a engagingvone' end face of boss 26. The other end face of boss 26 is engaged by a drive disc 28 secured to and against the" integral pad or bearing portion or pad 36 at itsfrontrein'i;v where it is connected by a pivot pin 33 carried in a slide? 34. The slide 34 is mounted for longitudinal movement? in a track formed by side walls 35* of the bodyris sup;-.

ported at its lower side by walls 35a adjacent sidewalls 35 and by a pad 37 of the body 10. The slide 34 is"en'-' gaged by the side guide flanges 39a of a channel-shaped,

clamping head 39', which flanges are also guided" in the respective guide walls 41 of the body 10; As seen Figures 3 and 8-, the top wall of the head 39 has a concave recess to provide clearance for the link 12, and the sideflanges 39a extend rearwardly in overlapping'rel'a tion therewith. The head 39 has its upper surface en-" gagedwith the-pad 36 which also guides'the link 12 at" its forward end. Thefront edges of the head 39 are made sharp and close-fitting for cleaning out of metal chips: and other particles.

The head 39 (Figures 2, 4 and 6) forms a part of the saw securing means or clamp and for this purposeihas a: countersunk recess receiving a clamping screw 46 threaded into the slide 34. Clearance for'the end. of?

screw 46 is'providedby a recess-38in pad or surface 371 The saw 47 is clamped between the head 39 and the slide 34 having a longitudinal slot 470 which enables endwise positioning of the saw over the screw 46. A molded recess 48 of the cover provides for access to the screw 46 in the extended position of the saw as seen in Figure 2. The straight side edges 47b engage the inner surfaces of the side flanges 39a of the head 39. A shoe 51 forms a work guide or work-engaging piece and is formed with a front edge 51a which is perpendicular to the path of movement of the slide 34 and the head 39 and end portions 51b bent to form an included angle of less than degrees with the straight edge 51a and seated in recesses 52 in the body 10, the depth of such recesses being such that the cover 11 when secured in place securely holds the shoe 51.

The saw blade 47 is thus mounted for a straight line movement with the slide 34 having its edges confined by the side flanges 39a of the head as seen in Figure 4 so that the saw is definitely located in place and is securely held in performing the work. It is preferred to form the teeth 47c of the saw along a line at an angle to the fastening station 47a or to the axis of straight line movement of the slide 34 and this angle is preferably about 3 degrees. For effective cutting it is preferred that this angular relation between the row of teeth of the saw and the path of movement of the saw be not less than 1 degree and be not greater than 5 degrees, this range providing for satisfactory operation in both metal and wood.

Referring to Figures 1, 2, 3, 9 and 10, a dust or dirt shield 56 is shown which is interposed between the teeth of the saw blade 47 and the head 39 and the slide 34. The shield 56 is preferably formed of a resilient flexible material such as synthetic rubber and is provided with a central slit 57 to engage closely over the saw, this slit 57 merging with inclined recessed walls 58a opening toward the operating parts for the saw including the slide 34 and the head 39. The shield 56 is also provided with apertures 58 which engage over the two ends of the shoe 51 to secure the shield in place stretched across Patented Mari. 5; I957 the end of the saw attachment. As seenin Figure 3, for example with the slide 34 projected, the shield 56 is stretched slightly, so that as the slide 34 and the head 39 reciprocate, they vibrate the shield to dislodge particles resulting from the sawing operation from the face thereof. The slit 57 engages closely over blade 47 and tends to open as the blade moves outwardly and to close as it moves inwardly. The tendency of the lips to flex and grasp the blade as it moves inwardly is enhanced by the recessed construction provided by the beveled walls 58a, which extend through a major portion of the thickness so as to provide thinlips.

In Figure 11 there is shown a modified form of shield 59 having outwardly projecting tapered lips 59a defining the slit engaging the saw blade, The shield 59 also has tapering molded side walls around its entire periphery for engaging the walls of the body and the cover 11. The recess 48 is only partially covered by the wall 59b so that access can be had to the screw 46. The shield 59 is secured on the saw attachment in the same manner as the shield 56 and functions in the same manner with respect to the saw blade.

1 Referring to Figures 1 and 3 it is seen that the body and cover form together concave hand grip portions 53 whereby the tool may be gripped in one hand and the other hand can carry the handle of a power drill with which it is used. If it is used with a flexible shaft drive, both hands may be employed in holding the tool with respect to the work. The saw blade shown in Figure 6 is made narrow to enable cutting of small diameter circles and with the size shown in Figure 6 pieces of as little as 1" in diameter can be cut from the work piece.

While I have shown and described a preferred embodi-.

ment of the invention, it will be understood that the invention is capable of variations and modifications from the particular form shown, so that its scope should be limited only by the scope of the claim appended hereto.

I'claimr A free-ended saw blade structure having at one end a pair of parallel outside blade positioning edges, means forming a slot extending into said one end of said blade and midway between said parallel outside edges, said slot having side walls extending parallel to said edges, said one end of said blade providing mounting means for attachment in fixed position to a reciprocatory drive member, with said blade positioning edges parallel to the path of reciprocation and coacting with the walls of a securing member, a linear row of teeth on the opposite end of said saw blade structure extending at an angle with respect to said parallel outside edges with the apex of the angle at said one end, the teeth of said saw blade having their cutting edges on the sides thereof facing said one end, whereby said saw blade structure is adapted to perform a draw cut, and said parallel outside edges and said slot providing means whereby said saw blade structure can be reversely positioned as to the reciprocatory drive member by interchanging the location of said parallel outside edges while maintaining angularity of the row of teeth.

References Cited in the file of this patent UNITED STATES PATENTS 1,542,127 Hastings June 16, 1925 1,574,001 Rogach Feb. 23, 1926 1,882,328 Kinkel Oct. 11, 1932 2,214,827 Boe et a1. Sept. 17, 1940 2,282,728 Kern May 12, 1942 2,535,491 Felton Dec. 26, 1950 2,537,501 Woodward Ian. 9, 1951 2,621,685 Butz Dec. 16, 1952 2,735,458 Buchmann Feb. 21, 1956 FOREIGN PATENTS 100,320 Germany Dec. 15, 1898 208,301 Switzerland Apr. 16, 1940 898,639 France July 10, 1944

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