Apparatus for sawing different materials

An apparatus for sawing different kinds of materials has a supporting frame including a girder-type construction defining an opening for the feed-through of materials to be cut in longitudinal direction by a saw blade. A supporting platform for materials to be cut includes a carriage platform for materials to be cut includes a carriage displaceable in longitudinal direction, and a clamping arrangement for materials to be cut is located on the carriage. At least one supporting bracket is positioned laterally of the saw blade in front and back regions of the frame and mounted on said carriage, and an upper and lower cross-beam is provided for each supporting bracket, with each lower cross-beam being arranged at a distance from the carrier. Vertically movable rods are arranged between the upper and lower cross-beams and carry a clamping device for materials to be cut. The saw blades may be slanted for increased efficiency and durability.

BACKGROUND OF THE INVENTION 
Field of the Invention 
The subject invention relates to sawing apparatus and systems and, more 
particularly, to apparatus for sawing different materials, including 
building materials, such as bricks, walls, stone plates, wood, pipes and 
the like. By way of example, the sawing apparatus may be of a type 
including a reciprocating saw blade mounted in a housing or frame and 
driven by a motor, and including a supporting platform for the material to 
be cut. 
Though the utility of the subject invention is not limited to any 
particular field, it may be noted that the necessity of separating or 
cutting materials, to reduce them in size or provide apertures or openings 
therein, is particularly prevalent at building or construction sites. For 
example, it is frequently necessary to reduce walls or bricks as to 
height, width and length, at corners, in window and door areas, in ceiling 
regions and at gables, where even angle cuts are required at times. 
Moreover, boards and planking often have to be cut lengthwise and 
transversely to specific dimensions required in concrete casting and 
molding work. 
For lack of suitable equipment, bricks and wall stones typically have been 
reduced in size by means of a hammer or voids in walls were filled with 
stone fragments. Such prior-art methods frequently produced insulating 
gaps or defects, particularly in work with wall stones equipped with a 
temperature insulating layer, such as, for instance, shown in German Pat. 
No. 1 708 765. Moreover, such practices eventuated higher material costs. 
In particular, bricks and stones frequently became useless during an 
attempted size diminution and many worthless fragments resulted. 
For these reasons, a saw for stone work pieces was proposed in the German 
Utility Model No. 77 02 782. That saw was, however, only suitable for 
sawing stones of small hardness or rigidity. Stones of large hardness or 
rigidity cannot be handled by that prior saw. Moreover, cutting with a saw 
adjustable in a corresponding mount is awkward and demanding in effort. 
Also, that prior proposal is only conditionally suitable for cutting other 
materials, such as wood, for example. Long boards, for instance, cannot be 
cut longitudinally thereby. 
Furthermore, the there proposed means for clamping stones to be cut are not 
sufficiently stable and capable of withstanding larger forces. 
In the case of reciprocal and similar saws, saw blades generally have bits 
or cutting plates brazed onto a foundation body. This raises the danger 
that the bits or cutting plates fracture or separate from their foundation 
during the return stroke, especially if rough or hard substances, such as 
present in building materials, are being cut. For this reason, special saw 
blades provided with two rows of cutting plates arranged for bidirectional 
cutting operations have been employed. Such special blades, 
disadvantageously, are very complex in their manufacture, and therefore 
rather expensive. 
SUMMARY OF THE INVENTION 
It is a general object of this invention to meet the needs and overcome the 
disadvantages expressed or implicit in the above disclosure statement or 
in other parts hereof. 
It is a related object of this invention to provide improved sawing methods 
and equipment, including improved saws and saw blades. 
It is a germane object of this invention to provide improved reciprocal 
saws. 
It is a specific object of this invention to provide universally applicable 
sawing apparatus for executing longitudinal and transverse cuts and even 
angle cuts, in large and long work prices or parts of different materials. 
It is also a specific object of this invention to provide a reciprocal saw 
capable of cutting rough and hard materials even with relatively simple 
saw blades. 
Other objects of the invention will become apparent in the further course 
of this disclosure. 
From a first aspect thereof, the subject invention resides in apparatus for 
sawing different kinds of materials, and, more specifically, resides in 
the improvement comprising, in combination, a supporting frame including a 
girder-type construction defining an opening for the feed-through of 
materials to be cut in longitudinal direction by a saw blade, a supporting 
platform for materials to be cut including a carriage displaceable in 
longitudinal direction, a clamping arrangement for materials to be cut on 
the carriage, at least one supporting bracket positioned laterally of the 
saw blade in front and back regions of the frame and mounted on said 
carriage, an upper and lower cross-beam for each supporting bracket, with 
each lower cross-beam being arranged at a distance from the carrier, and 
vertically movable rods arranged between the upper and lower cross-beam 
and carrying a clamping device for materials to be cut. 
From another aspect thereof, the subject invention resides in apparatus for 
sawing different kinds of materials, and, more specifically, resides in 
the improvement comprising, in combination, a supporting frame, a 
supporting platform for material to be cut displaceable in said supporting 
frame, a reciprocating saw blade slanted at a free end for a length 
corresponding to a return stroke of said blade, so that said blade 
diminishes in width toward said free end, a roller positioned at said free 
end in a cutting plane, and at a back side, of the saw blade, and having 
an axle mounted in the supporting frame and extending transversely to said 
cutting plane, a spring acting on said free end of the saw blade and being 
connected to the supporting frame for pressing of the saw blade against 
said roller, and means for articulately mounting the saw blade at a second 
end opposite said free end. 
From a similar aspect thereof, the subject invention resides in apparatus 
for sawing different kinds of materials, and, more specifically, resides 
in the improvement comprising, in combination, a supporting frame 
including a girder-type construction defining an opening for the 
feed-through of materials to be cut in longitudinal direction, a 
supporting platform for materials to be cut including a carriage 
displaceable in longitudinal direction, a clamping arrangement for 
materials to be cut on the carriage, a reciprocating saw blade mounted in 
said supporting frame and slanted at a free end for a length corresponding 
to a return stroke of said blade, so that said blade diminishes in width 
toward said free end, at least one supporting bracket positioned laterally 
of the saw blade in front and back regions of the frame and mounted on 
said carriage, an upper and lower cross-beam for each supporting bracket, 
with each lower cross-beam being arranged at a distance from the carrier, 
vertically movable rods arranged between the upper and lower cross-beams 
and carrying a clamping device for materials to be cut, a roller 
positioned at said free end of the saw blade in a cutting plane, and at a 
back side, of the saw blade, and having an axle mounted in the supporting 
frame and extending transversely to said cutting plane, a spring acting on 
said free end of the saw blade and being connected to the supporting frame 
for pressing of the saw blade against said roller, and means for 
articulately mounting the saw blade at a second end opposite said free 
end.

DESCRIPTION OF PREFERRED EMBODIMENTS 
The saw according to the illustrated preferred embodiments of the invention 
is of a reciprocating type, sometimes known as "sabre saw" and herein 
generically referred to at times as "reciprocating saw." This type of saw 
typically has a saw blade 1 mounted in the forwardly projecting upper free 
end of a supporting frame 2 and driven in a usual manner by an electric 
motor 3 via gearing which converts the rotary motion of the motor 3, which 
may in given arrangements drive also a hydraulic pump for hydraulic 
installations, into a stroke movement. The supporting frame 2 has a sawing 
table or sliding carriage 4 which is movable in the direction of the saw 
cut and which effects the conveyance or feed of the material to be cut. 
The supporting frame is at its rear end (i.e. behind the saw blade 1) 
completely open, thereby leaving an opening 5 for the feeding of work 
pieces or materials. With the vertical girder-type construction shown in 
FIGS. 1 and 2, the space in the region of the saw blade also is 
unobstructed in transverse direction. Due to the design of supporting 
frame 2 and sliding carriage 4, even long work pieces, such as boards, may 
be placed transversely on the sliding carriage 4 and may thus be cut. 
Two racks 6 and 7 may be provided for the forward propulsion of the sliding 
carriage 4. They may be provided on the sliding carriage 4 and may 
cooperate or mesh with corresponding pinions 8 and 9 which are arranged on 
a shaft 11 in the mounting frame 2. 
The advance of the sliding carriage 4 may, for instance, be effected 
manually by the operator via a handle 10 attached directly to the carriage 
4, or then via the shaft 11 having the pinions 8 and 9 attached thereto. 
The shaft 11, in turn, may be rotated via a suitable connection to a hand 
wheel or by a motor drive. A hydraulic propulsion via a hydraulic cylinder 
is also possible. 
The material to be cut is clamped fast on the sliding carriage 4 by a 
clamping arrangement which has support brackets 12 and 13 that are mounted 
on the sliding carriage 4 laterally of the saw blade 1 in the front and 
back regions, respectively. Each support bracket 12 and 13 is provided 
with an upper cross-beam 18 and 19 and with a lower cross-beam 20 and 21, 
respectively. The two lower cross-beams 20 and 21 are arranged above the 
sliding carrier 4 at a vertical distance therefrom. This distance is 
dimensioned so that the usually employed boards may be slid through the 
gap formed thereby. Longitudinal or vertical rods 15a and 15b are arranged 
between the upper cross-beam 18 and 19 and the lower cross-beam 20 and 21, 
respectively. The vertical rods 15a and 15b are longitudinally slidable in 
bores of the cross-beams. A spring 16 is located between the lower 
cross-beam 20 and 21 and discs 23 and 24, respectively. The discs 23 and 
24 are fixedly located on the longitudinal rods 15a and 15b by a cotter 
pin 25 which extends through the particular rod 15a or 15b. In this 
manner, the rods 15a and 15b are resiliently mounted in the cross-beams. 
At least one clamping strip 26 extends between the rods 15a and 15b. The 
strip 26 is clamped to the rods 15a and 15b by clamping screws 27 and 28. 
Moreover, a rotary shaft or rod 29 extends between the upper cross-beams 18 
and 19 and is mounted in cross-beam bores. As seen particularly in FIG. 3, 
the rotary rod 29 is provided with two eccentric cams 30 located directly 
above the upper end of the longitudinal rod 15a and 15b, respectively. The 
rotary rod 29 moreover is provided with a handle 14. 
The work piece clamping equipment operates as follows: 
The work piece to be sawed or cut is placed on the sliding carriage 4. The 
clamping strip 26 is then placed onto the work piece. By tightening the 
clamping screws 27 and 28, the strip 26 is fastened to the two 
longitudinal rods 15a and 15b. Subsequently, an eccentric clamping action 
is effected via handle 14. By suitable angular movement of the rotary 
shaft 29, the eccentric cams 30 depress the longitudinal rods 15a and 15b 
against the bias of spring 16, whereby the work piece is securely clamped. 
After completion of a sawing operation on the work piece, springs 16 
effect an automatic release of the clamping apparatus. For an improved 
clamping action, the clamping strip 26 may be provided with an elastic 
layer, such as of rubber, on its lower side. 
As seen especially in FIGS. 3 and 4, a board 32, indicated in dotted lines, 
may longitudinally be slid through in a simple manner at any desired 
length, by virtue of the distance between the sliding carriage 4 and the 
lower cross-beams 20 and 21, respectively. If necessary for reasons of 
stability, the lower cross-beams 20 and 21 may be correspondingly extended 
beyond the mid-portion of the frame and an additional support, shown in 
dotted lines in FIG. 1, may be provided on the other side of the sliding 
carriage 4. 
Instead of a disc 23, on which the spring 16 rests, a cross-pin, notch or 
corresponding stepped portion of the longitudinal rod 15a may be employed. 
A rotatable roller 37 may be clampable on the strip 26 in order to 
facilitate a sawing of wood in longitudinal direction. The roller 37 is 
arranged with its axis of rotation extending horizontally and transversely 
to the cutting plane. A clamping screw 34 as shown in FIG. 2, or an 
eccentric clamping device 35 as shown in FIG. 3, may serve the clamping of 
the roller 37 with a suitable mount 35 on the clamping strip 26. 
If now, for instance, a long board is to be sawed longitudinally, it is 
merely necessary to lower the clamping strip 26 to such an extent that the 
roller 37 lies on the board 32. If desired, the roller 37 may be equipped 
with a drive motor (not shown). In this manner, the board 32 may be 
transported by a powered drive or automatically. As drive motor, there 
may, for instance, be employed a hydraulic motor which is connected by a 
suitable hydraulic line to a hydraulic pump which is preferably driven by 
motor 3. 
For an improved propulsion of the work piece being sawed, the roller 37 may 
at its circumference be provided with teeth, points 36 or the like. 
The reciprocal saw may be moved as desired with the aid of a pair of 
retractable swing-out wheels 17 mounted on the supporting frame 2. 
The saw blade 1 has a foundation onto which hard metal cutting plates 24 
are brazed in such a manner as to effect a cutting action during the 
downward stroke of the saw blade. 
Reference may now be had to FIGS. 5 to 13 for further embodiments according 
to the invention. 
The saw blade 1 shown in FIG. 6 in a customary manner has a constant width 
b over almost its entire length. Only in its lower region does the saw 
blade possess a beveled or chamfered edge, or a slant, which in length 
corresponds at least to the return stroke of the blade. Moreover, a pulley 
or roller 19 is rotatably mounted in that region and is located on an axle 
20 in the supporting frame 2. Further particulars are seen in FIG. 7. A 
spring 21 acts on and is with one end attached to the lower end of the saw 
blade 1 in a bore 22 and with its other end to a mounting support of the 
frame 2. By virtue of this arrangement, there results a traction on the 
saw blade 1 directed away from the material to be cut. 
The bevel or slant 181 and spring 21 effect a release of the saw blade 1 
and a retraction thereof from the work piece. FIG. 3 shows the saw blade 1 
approximately in the middle position of its stroke. When the saw blade is 
in its lowermost position, then the point P is approximately level with 
the axle 20 of the roller 19. If now the upward stroke of the saw blade 1 
commences, then it is forced away from the material 5 to be cut, by virtue 
of the bevel or slant 181 and by force of the spring 21. To this end it is 
necessary that the saw blade is pivotally or flexibly mounted at its upper 
end or clamping point. 
The roller 19 moreover has a circumferential groove 125 on its rolling 
surface. In this peripheral groove 125, the saw blade 1 slides with its 
backside and in this manner is securely guided by the lateral walls of the 
circumferential groove 125. Stability and cutting accuracy of the saw are 
thereby increased. 
Beside the main function of the spring or springs 21, namely the recurring 
retraction of the saw blade, such spring serves a further purpose. In 
particular, the spring is stretched or tensioned during the return stroke, 
that is in the idling condition of the motor and is thus enabled to effect 
during the forward or downward stroke of the saw blade a relief of the 
motor, since the spring force or bias then acts additionally in the 
forward travel or downward direction of the spring. In practical terms, 
this means that the motor is not loaded as much or, if desired, may be 
dimensioned for lower output power. 
Wood pieces which are to be cut longitudinally, such as planking or molding 
boards, may in a simple manner be pushed through from the front. 
FIGS. 8 and 9 show the reciprocating drive 2 in further detail. This drive 
is conventionally composed of a crank gear or crankshaft assembly 
comprising a pinion 130 driven by the motor 3 and a gear wheel 131 meshing 
with the pinion 130 and having a guide bolt 132. The guide bolt or 
cross-pin 132 slides in a slot 133 of a carrier plate 134. The carrier 
plate 134 is provided with two bushings or guide bearings 135 and 136 
which are located one above the other in the cutting plane. The bushings 
135 and 136 slide on a tube 56 which is attached to the supporting frame 2 
of the saw and extends in the cutting plane. In this manner, a 
reciprocating movement of the carrier plate 134 is effected. 
The saw blade 1 is connected to the carrier plate 134 in an articulate 
manner via a clamping plate 137 provided with a screw 138 and a bearing 
139. The saw blade 1 is itself pivoted on a bolt 45. Instead of the 
bearing 139, a simple sliding guide may self-evidently be provided. 
The guide bolt 132 is provided with a bearing 40. A bronze disc 42 is 
located between the carrier plate 134 and the gear wheel 131, whereby the 
carrier plate 134 is well guided with the bushings 135 and 136. 
If the carriage or saw table 4 is equipped with a hydraulic drive, a 
hydraulic pump 44 may further be driven via a pinion 43 and may propel the 
saw table 4. 
In FIGS. 10 and 11 an embodiment of the invention is shown for a saw blade 
with which curved cuts may be made, as with a scroll saw. The saw blade 
according to this embodiment includes a spring steel rod 46 as a core 
surrounded or enclosed by a jacket bushing 47 carrying a plurality of 
cutting plates or bits 24. These bits 24 are preferably brazed on the 
jacket 47. The bits 24 may be mounted in a simple manner by providing the 
jacket 47 with corresponding cuts or notches in which the bits are 
inserted to be brazed therein. The bits 24 thereby may have any desired 
form or shape. 
At the upper end, the spring steel rod 46 and jacket 47 are attached or 
clamped via a clamp 48 on a head 49, whereby a firm connection is 
simultaneously created between the spring steel rod 46 and the jacket 47. 
The saw blade shown in FIG. 10 includes a terminal piece 50 attached to the 
lower end of the steel spring rod 46 and jacket and being slanted as at 
181 at a free end thereof. The attachment of the terminal piece 50 to the 
lower end of the steel spring rod 46 and jacket 47 takes place in the same 
manner via a clamp 51. For a return movement of the saw blade according to 
the invention, the terminal piece 50 also is provided with a slant 18 on 
its back side. 
Instead of a clamp attachment of the saw blade at the head 49 and terminal 
piece 50, other fastening means may be employed within the scope of the 
invention. In case of wear of the bits 24, the jacket 47, together with 
the worn bits may be removed and exchanged against a new part in a simple 
manner. 
Within the scope of the invention, the bits may be formed as entirely round 
discs, as indicated in dotted outline in FIG. 11. In this case, the jacket 
is formed as a plurality of short sections with interdigitated cutting 
plates. 
The embodiment shown in FIG. 12 is of essentially like construction as the 
embodiment described above, so that like reference numerals have been 
employed. In the embodiment of FIG. 12, the axle 20 and thereby the roller 
19 is transposed forwardly by a small amount, whereby the slanted position 
of the saw blade is amplified. The slant of the saw blade is strongest in 
the lowest reciprocating position of the saw blade, that is at the end of 
the saw blade stroke. 
Oblong holes 60 on both sides of the supporting frame 2 enable an 
adjustability of the axle 20. In the embodiments of FIGS. 12 and 13, the 
saw blade thus is slanted forward toward material to be cut relative to a 
vertical line through the second or upper end of the saw blade at 45. In 
particular, the saw blade may, for instance, be slanted by the position of 
the roller 19. 
In FIG. 13 an embodiment is shown in which the saw blade 1 also in its 
upper region spaced from its free end has a second slant or indentation 61 
which in terms of dimension and angular position corresponds to the first 
slant 181 in the lower region of the saw blade. The saw blade is shown on 
an enlarged scale, with its length having been foreshortened for reasons 
of space. In the region of the indentation 61, there is provided at the 
back side of the saw blade a roller, wheel, rod 62 or the like mounted in 
a part of the supporting frame of the reciprocating saw. This in 
similarity to the roller 19. Similarly, a spring 63 biases the saw blade 1 
in its upper region for the same purpose as the spring 21. While one end 
of the spring 63 rests at the supporting frame, the other end is suspended 
in a bore 64 of the saw blade. In this manner, a retractive force also 
exists in the upper region of the saw blade 1 and applies the saw blade 
with a continuous pressure to the roller 62. Accordingly, the spring 63, 
acting on an upper region of the saw blade, applies this saw blade to the 
second roller 62. 
By virtue of this feature, the saw blade is retracted in a parallel fashion 
from the work piece to be sawed during its return stroke by a width b' in 
proportion to the angular degree of the slant. To this end, it is merely 
necessary that the mounting or suspension with which the saw blade 1 is 
connected to the reciprocating drive according to FIGS. 12 and 13 is 
adjustable in the cutting direction of the saw. To this end, the bolt 45 
may be located in an oblong hole of a part of the reciprocating drive. For 
instance, the oblong hole may be provided in the carrier plate 134 or the 
clamping plate 137. Alternatively or additionally, the oblong hole may be 
provided in the saw blade itself. FIG. 13 shows the oblong hole at 65 in 
dotted outline. 
If necessary, the roller 62, for a better guidance of the saw blade 1, may 
also have a circumferential groove, similar to the circumferential groove 
125. 
In FIG. 13 the saw blade is shown in its upper position immediately prior 
to the start of the downward work stroke, or at the end of its return 
stroke. The dotted representation of the saw blade shows the position 
which it assumes at the end of the work stroke. Since the saw blade 
defines a relative motion in the cutting direction (by the width b') a 
sensing device 66 may in a simple manner be arranged at the saw blade. 
This sensing device has a saw blade position sensor 67 extending in 
cutting direction at the saw blade to enable control of the advance of the 
saw table or carriage 4. 
For example, a switching device connected to the sensing device 66 may be 
employed for terminating the displacement or advance of the saw table 4 at 
the end of the work stroke when the saw blade is located in its lowest 
position and the sensor 67 projects to a maximum extent from the device 
66. In this manner, the hard metal cutting plates are protected from wear 
during the return stroke. 
In practice, the work pieces to be sawed or cut are positioned on the 
sliding carriage 4 and are clamped thereon. For the sawing operation, the 
carriage 4 is merely displaced in cutting direction. This may be effected 
with a manual drive with adequate transmission, or through a direct 
displacement of the carriage or then through a hydraulic or electric motor 
drive. 
By virtue of the girder-type construction of the housing or frame of the 
illustrated saw, with the saw blade being preferably mounted in the 
forwardly projecting portion of the upper part of the housing or frame, 
and due to the through-put opening effective in longitudinal direction, 
long boards, for instance, may be cut transversely as well as put through 
the machine longitudinally. Since the lower cross-beams 20 and 21 are 
positioned above the sliding carriage 4 at a distance therefrom, and since 
the two support brackets 12 and 13 are attached laterally in the front and 
rear region of the carriage 4, boards of desired lengths may be cut. To 
this end, it is merely necessary to slide the boards in longitudinal 
direction through the machine, without actuation of the clamping 
equipment. 
According to illustrated embodiments of the subject invention, a load 
reduction on, or relaxation of, the saw blade during the return stroke is 
accomplished in a simple manner. By virtue of the fact that the width of 
the saw blade diminishes at the free end thereof, and that the saw blade 
is pulled back by a spring, the saw blade can remove itself slightly from 
the material to be cut, thereby being temporarily removed from the load. 
Due to the illustrated slant 181, the saw blade is pulled backward by the 
spring from the material to be cut in the lower region where the teeth do 
not cut. 
By provision of a slant at the back side of the blade, the saw blade is 
thus simply and effectively subjected to load reduction during the return 
stroke. In this manner, the saw teeth or bits are not pulled out during 
the sawing of hard materials. When soft materials are sawed, sawdust or 
shavings may readily fall out of the cut because of the mentioned 
retraction of the saw blade during the return stroke. 
As a further advantage, the spring or springs 21 and/or 63 serve as 
vibration equalizers and dampen oscillations of the saw blade. 
Surprisingly, a fracture or breaking out of the material at the end of the 
saw cut is practically eliminated, if the saw blade, as shown in FIGS. 12 
and 13, is slightly slanted relative to the vertical. Otherwise, there 
exists the danger that material to be cut is broken off objectionably, as 
the saw blade exerts pressure whereby material tends to break out within 
the final centimeters of a saw cut. 
Proportionably to the degree of slant, such as of the slant 181, the saw 
blade is progressively slanted forwardly as the working stroke progresses. 
This is accomplished with the roller 19 which guides or presses the saw 
blade forwardly; that is, in the direction of the sawing operation. There 
is thus, at the beginning of a working stroke, a slightly slanted position 
of the saw blade which is increased in the course of the stroke. The 
degree of slant to which the saw blade is adjusted depends on the 
particular situation or material to be sawed, and is easily determined 
empirically. 
A very substantial advantage in terms of simplicity of saw blade clamping 
or suspension and drive results from the guidance of the saw blade by the 
roller 19 or rollers 19 and 62 and/or from the load discharge or removal 
effected by the tension or bias of the spring 21 or springs 21 and 63. In 
this manner, it is possible according to an embodiment of the invention 
that the saw blade at its clamping or suspension side is articulately 
mounted in a carrier plate 134; with such carrier plate preferably having 
guide bushings 135 and 136 located one after or above the other in the 
cutting plane and sliding on or encompassing a tube 56 extending in the 
cutting plane of the saw blade or parallel therto. The carrier plate 134 
may have a slot 133 where it is engaged by a guide bolt or cross pin 132 
of a crank drive. In comparison to the proposal according to the above 
mentioned German utility Model No. 77 02 782, which suggests a saw blade 
mounting or guidance system with two tubes equipped with slide bushings 
which, additionally, have to be articulated for reasons of tolerance, 
embodiments of the subject invention enable operation with only one tube 
extending parallel to the cutting plane, by virtue of the lower support of 
the saw blade disclosed herein. 
With the aid of the disc 42 and the two bushings 135 and 136 at the tube 
56, the carrier plate 134 is perfectly mounted and guided without 
problems. In this manner, tolerance inaccuracies may further be equalized. 
If now the saw blade in its upper region, as seen in FIG. 13 according to 
an embodiment of the subject invention, is provided with an indentation or 
slant 61, a roller or guide 62 and a spring 63 as in its lower region, and 
the mount of the saw blade is made adjustable in the direction of the saw 
cut, then the danger of a fracture or breaking out of the saw teeth, 
particularly in the upper region, is still further diminished. In 
particular, instead of a pendulum movement of the saw blade, the blade 1 
is now retracted in a parallel fashion; namely, in proportion to the 
reduction of its width b due to the slant or indentation. 
The features herein disclosed with the aid of any of the FIGS. 5 and 6, 7, 
8 and 9, 12 and/or 13 are of independent significance, and have utility 
separate from, the other embodiments herein disclosed. Alternatively, any 
of these features may be combined with the features of the other 
embodiments, such as those of FIGS. 1 and 2 and/or 3 and 4. 
The same applies in principle and in practice to the saw blade construction 
and structure according to FIGS. 10 and 11. 
In particular, a very advantageous construction of the saw blade according 
to a further embodiment of the subject invention resides in the provision 
of a round spring steel rod 46 as saw blade foundation or core, which is 
surrounded or enclosed by a bushing or jacket 47 on which the cutting 
plates or bits 24 are mounted or attached, and in the equipment of such 
saw blade with a chucking part or head 49 at one end and with an end piece 
at its other, free end; with such end piece 50 being provided on its back 
side with a slant or taper extending toward its own free end. 
This construction or configuration of the saw blade also is enabled by its 
being supported at its free end according to embodiments of the subject 
invention. Since no cutting plates or bits may be brazed onto the spring 
steel rod 46, the jacket 47 is provided thereon. The jacket 47 thus 
accepts the bits 24. If the head 49 and the end or terminal piece 50 are 
correspondingly configured, conventional as well as novel saw blades, such 
as the saw blade according to FIGS. 10 and 11, may be utilized in the same 
saw or cutting apparatus. The novel round or cylindrical saw blades 
according to FIGS. 10 and 11 advantageously permit the execution of curved 
cuts or scrolls. For instance, semi-circular openings in wall stones for 
pipes and the like may be cut in a close-fitting fashion. In this manner, 
defects in the insulating or tightness structure of the wall, caused by 
excessive apertures or break-outs, as provided so far by manual knock-out 
methods, are elegantly avoided. 
The features of the subject invention and its embodiments are of special 
utility with respect to reciprocating saws, which--within the spirit and 
scope of the subject invention--include saw types wherein a saw blade 
executes essentially a linear up and down or forward and backward movement 
or stroke. This includes, for instance, saws with strapped free ends. 
While specific embodiments and aspects of the invention have been herein 
disclosed and shown, this subject extensive disclosure suggests or renders 
apparent to those skilled in the art various modifications and variations 
within the spirit and scope of the invention.