Power drill-saw with simultaneous rotation and reciprocation action

The invention disclosed herein is a simple but versatile sawing device for effectively and efficiently cutting or sawing hard solid materials. A driving mechanism consisting of three slidably-associated elements converts a rotational force into a dual rotatory/reciprocatory motion. A cam key may be disengaged to permit the device to be used to drill into a surface. Also disclosed is a novel cutting-rod element that is a hard metal rod with cutting teeth of a unique shape on its surface.

BACKGROUND OF THE INVENTION 
The present invention relates to a device that can be used for both 
drilling and sawing effectively and efficiently in hard or solid 
materials. More specifically, the present invention relates to a saw with 
a unique combination of reciprocating and rotating movements that is 
powered by a rotatory power source. The invention comprises a novel sawing 
element and a driving mechanism therefor that generates a rotating, 
reciprocating stroke. The driving mechanism can be partially disengaged to 
permit rotation without the accompanying reciprocatory action. 
SUMMARY OF THE INVENTION 
The present invention provides a simple but a versatile sawing device for 
effectively and efficiently cutting or sawing hard solid materials. The 
driving mechanism is a combination of three slidably-associated elements 
that convert a rotational force into a dual rotatory/reciprocatory motion. 
The novel sawing element is a hard metal cutting-rod with cutting teeth of 
a unique shape on its surface. The rod-saw of the present invention 
simultaneously rotates and moves the cutting-rod in long rectilinear 
reciprocating movements. Such movements are induced by the action of a cam 
cylinder upon a cam key. The cam cylinder has a cam groove positioned 
diagonally relative to the rotation axis, and that describes an elliptic 
orbit around the cam cylinder. 
An object of the invention is to provide a sawing device that can 
simultaneously impart rotatory and reciprocatory motions to a cutting-rod. 
The invention comprises an outer cylinder, a cam cylinder that fits 
slidably inside the outer cylinder and a drive shaft that is slidably 
connected to the cam cylinder. The cam cylinder has a shaft attached to it 
at the end opposite to the drive shaft and a cutting-rod-holding means 
such as a screw chuck is attached to the shaft. 
The outer cylinder has a single stationary cam key positioned at one side 
that is positioned to fit into a cam groove that is positioned on the 
outer surface of the cam cylinder. The cam groove is diagonally positioned 
so that is traces an elliptical orbit around the cam cylinder. The outer 
cylinder has a base-plate attached to one end with a centrally located 
bearing to support the cam cylinder drive shaft. The base plate also 
serves to protect the cam cylinder. A cover is attached to the end of the 
outer cylinder opposite to the base plate. The cover carries a centrally 
located bearing to support the cam cylinder shaft attached to the cam 
cylinder and also serves to protect the cam cylinder. 
The sawing element of this invention is a cutting-rod that is positionable 
in the cutting-rod-holding means. Rotation of the cam cylinder by the 
drive shaft imparts a reciprocatory motion to the cam cylinder by action 
of the cam groove upon the stationary cam key. The reciprocatory motion of 
the cam cylinder imparts both a reciprocatory and a rotatory motion to the 
cutting-rod positioned in said cutting-rod-holding means. 
A further embodiment of the present invention has a screw chuck mounted on 
the cam cylinder shaft. In this embodiment of the invention the cam 
cylinder drive shaft is slidably-connected to the cam cylinder at by a 
sliding joint mechanism that comprises a noncircular sliding joint portion 
and a compatibly shaped noncircular opening in the rotation center of said 
cam cylinder. 
This form of the invention permits the cam cylinder to move in a 
rectilinear manner along the rotation axis when a rotatory motion is 
imparted to the cam cylinder drive shaft. 
In another embodiment of the invention the cutting-rod is a sawing rod that 
comprises a rod with a drilling tip and sawing teeth helically arranged on 
the lateral surface of the rod. 
In yet another embodiment of the invention the cutting-rod of the rotatory 
sawing device is formed to have two stop notches at the proximal end of 
the sawing rod in order to prevent slipping in the screw chuck. 
In yet another embodiment of the invention the sawing teeth of the 
cutting-rod have the shape of an oblique rhomboidal prism. This unique 
shape permits each tooth to act in a cutting mode so that upon rotation 
and reciprocation of the cam cylinder. 
An objective of the present invention is to provide a replaceable 
cutting-rod. The replaceable cutting-rod can be made in various sizes to 
serve the needs of the user. The replaceable cutting-rod also has uniquely 
designed sawing teeth. 
Another objective of the present invention is to provide a device which 
uses a combination of a cylindrical cam and a sliding joint mechanism to 
effect simultaneous reciprocal and rotational movements by a single 
rotatory power source. 
Yet another objective of the present invention is to provide a saw which 
does not require a separate drill to start sawing on a flat surface. The 
invention disclosed herein is designed so that the cam key may be 
disengaged from the cam cylinder thereby disenabling the reciprocatory 
function of the device. The cutting-rod of this invention has a tip formed 
to allow it to drill into a previously unperforated surface. 
Still another objective of this invention is to provide a simple and light 
weight sawing device which can be used in an extended location. Such a 
device can be used, for example, for trimming tree branches in a high 
position. 
Still another objective of the present invention is to provide a device 
that can be used both as a drilling and as a sawing machine usable for 
different applications. Cutting-rods for such a drilling and sawing 
machine can be made in a variety of sizes such that suitably sized 
cutting-rods may be chosen for particular applications as will be 
appreciated by one of skill in the art. 
Further objectives of the invention are to provide other applications of 
the concurrent rotation and reciprocation mechanism.

DETAILED DESCRIPTION OF INVENTION 
Flat saw blades of various shapes and sizes are commonly used for sawing 
hard materials. Flat saw blades are used in both manual or mechanized 
sawing processes. These flat saw blades cut objects by a one dimensional 
reciprocating movement. U.S. Pat. No. 3,704,517 to Deterling discloses a 
rotating rod saw which has helical arrangement of common saw teeth on a 
metal rod. The rod saw disclosed by Deterling simply rotates like a drill 
and cutting is only achieved in a horizontal mode. U.S. Pat. No. 2,918,955 
to Simas discloses a drill bit with sawing teeth formed and disposed in a 
manner similar to the teeth of a file. The drill bit disclosed by Simas 
has cutting teeth shaped like ordinary file teeth and has a fish scale 
arrangement on a conventional drill bit. Cutting teeth arranged in this 
way do not provide an effective sawing function by simple rotation of the 
bit and the bit of Simas is designed to be operated in conjunction with a 
manually-provided stroke action. U.S. Pat. No. 2,970,483 to Schrum, Sr., 
discloses a rotary impact drill. The rotary impact drill disclosed by 
Schrum, Jr., has a rotor having a sinuous groove, and generates a short, 
pulsating impact to the drill in a manner similar to a pneumatic road 
drill. However, such a vibratory impact device does not provide a suitable 
stroke action that is desirable for an efficient sawing device. U.S. Pat. 
No. 5,052,366 to Kashihara discloses a wire type of saw mounted on a steel 
bow, and a more complex arrangement of wire saw for certain applications. 
The device disclosed by Kashihara has no rotatory function and does not 
have cutting teeth. U.S. U.S. Pat. No. 4,488,840 to Marie, and U.S. Pat. 
No. 4,979,307 to Pollington, disclose rotary cutting tools. However, the 
tools discloses in these applications consist of modified rotary disk saws 
or a metal rod which has a replaceable cutting edge at one end of the rod. 
The present invention operates by a different mechanism and from any of 
previous devices and offers numerous advantages over the previously 
available saws and drills. 
A typical embodiment of the present invention is illustrated in FIG. 1 
which shows a diagram of the internal structure of a 
rotatory/reciprocatory cam mechanism of the present invention. The 
concurrent rotation and reciprocation motion is effected by combining a 
cylindrical cam action and a rectilinear sliding joint action empowered by 
a single motor power or by a common electric hand drill. A sawing rod 1 is 
firmly mounted in a screw chuck 5 on a cam cylinder shaft 6. A cam 
cylinder 13 has a cam groove 10 cut into its surface. The cam groove 10 is 
disposed in a diagonal manner to form an elliptic orbit around the cam 
cylinder 13. A stationary cam key 12 is positioned in a side of the outer 
cylinder 9 so that it fits into the cam groove 10 so that, upon rotation 
of the cam cylinder 13 it causes the cam cylinder 13 to move in a 
rectilinear manner along the rotation axis. A cylinder cover 3 is provided 
at the lower end of the outer cylinder 9 to protect the cam cylinder 13. 
The cylinder cover 3 has a centrally located bearing 7 for supporting the 
cam cylinder shaft 6. A cam cylinder drive shaft 21 is provided to permit 
connection of the device to a conventional drive motor 25. The cam 
cylinder drive shaft 21 drive is formed integrally with of a sliding joint 
shaft 14 that is slidably associated with a compatible sliding joint 
recess 15. The sliding joint essentially consists of a noncircular sliding 
joint shaft 14 and an identically shaped noncircular recess 15 positioned 
at the rotation center of the cam cylinder. In FIG. 1, the sliding joint 
shaft 14 and the sliding joint recess 15 are shown to have a square 
profile. The sliding joint allows the rectilinear motion of the cam 
cylinder 13 along the rotation axis when rotatory motion is induced by the 
drive motor 25. A base-plate 19 is provided at the upper end of the outer 
cylinder 9. The base-plate 19 serves to protect the cam cylinder 13 and 
has a centrally located bearing 17 for supporting the sliding joint shaft 
21. The sliding joint shaft 21 is also provided with a coupling 20 for 
connecting the sliding joint shaft 21 to motor 25. In the embodiment of 
the invention shown in figure i the outer cylinder 13 is extended by 
extension 22 to permit attachment of the invention to the motor 25. 
Rotational power is transmitted through coupling 20 to the sliding joint 
shaft 14. 
FIG. 2 shows a view of a sawing rod 1 with a drilling tip 26 at the distal 
27 end of sawing rod 1 and sawing teeth 28 located on the lateral surface 
31 of sawing rod 1. In the embodiment of the invention shown in FIG. 2, 
sawing teeth 28 are shown helically arranged on the lateral surface 31 of 
the sawing rod 1. Stop notches 29, (one shown) are formed at the proximal 
end 34 of sawing rod 1 to allow engagement of the screw of a screw chuck 
(not shown). 
FIG. 3 shows the details of a sawing tooth 28. The sawing tooth 28 has the 
shape of an oblique rhomboid prism and has two horizontal cutting edges 32 
and a vertical cutting edge 30. The surface 33 of the cutting tooth 28 is 
relieved to enhance the cutting capacity of the cutting tooth 28. 
FIG. 4 shows an enlarged view of a portion of sawing rod 1. The helical 
positioning of the cutting teeth 28 is shown and the cutting edges 32 and 
the relieved surface 33 of cutting teeth 28 is illustrated. 
FIG. 5 shows a cross-section of sawing rod 1 that passes through two 
opposed cutting teeth 28. The cutting edges 30 and 32, and the relieved 
surface 33 of the cutting teeth 28 is illustrated. 
Operation of the Device 
In use, a rod saw of a suitable size is firmly mounted in the screw chuck 
of invention disclosed herein. Upon starting the driving motor the cam 
cylinder is caused to rotate and the action of the cam groove upon the cam 
key the cam cylinder is caused to move in a reciprocatory manner 
rectilinearly along the rotation axis. Since the cam groove is formed 
diagonally around the cam cylinder surface, one full rotation of the cam 
cylinder causes the reciprocatory motion of the cam cylinder to make one 
full excursion. The ratio of the rotation and reciprocation can be varied 
by making cam groove on the cylinder cam in the form of a spiral instead 
of a simple ellipse. The device can be used as a drill machine by 
disengaging the cam key. 
The saw teeth of the present invention is formed on the surface of a steel 
rod and is formed to have the shape of an oblique rhombus or triangular 
prism. The saw teeth are formed to have vertical and horizontal cutting 
edges and are distributed in a helical manner on the rod surface. One 
embodiment of the saw rod has its tip formed as a cutting tool so that 
sawing can be started on any flat surface. Accordingly, the invention 
disclosed in the present application is a simple, effective, efficient and 
multipurpose sawing device that can be used on many solid materials. 
The advantages of the invention disclosed herein are several. First, the 
device permits the effective and efficient sawing of various kinds of 
textured solid materials because of the two dimensional cutting edges and 
rotation/reciprocation mechanism. Second, the device can be used as a 
drill by disengaging the cam key to allow the cylindrical cam to rotate 
without the reciprocatory motion. Third, the device may be powered by most 
existing drill machines. Fourth, the device is of light weight so it can 
be used to saw remote objects at an extended location by attaching the 
device to a long hollow pole through which the rotatory power can be 
transmitted. Fifth, unlike a conventional flat saw blade the device can 
smoothly cut complex shapes and acute angles without excessive stress on 
the saw rod. 
Although the description above contains a detailed description of 
particular embodiments of the invention, these should not be construed as 
limiting the scope of the invention but as merely providing illustrations 
of some of the presently preferred embodiments of this invention. For 
example, the rod saw can be used for different materials such as for 
metals, plastics, wood, etc. Also, the concurrent rotation/reciprocation 
mechanism can be used in other applications. Thus, the scope of the 
invention should be determined by the appended claims and their legal 
equivalents rather than by the samples given.