Butchering saw

A butchering saw (10) particularly suited for splitting hogs is provided. The saw (10) includes a cutting blade (70) which rotates in the preferred embodiment. A drive shaft (48) is provided which has a power take-off location at one end (50) operatively associated with the blade. A motor (38) serves to rotatably drive the drive shaft (48) for turning the blade and performing the cutting operations. A driving mass mechanism (86) is carried by the drive shaft (48) to assist in maintaining a constant motion of the drive shaft during butchering operations in which the blade (70) cuts through soft tissue and bone which apply varying resistances or loads to the cutting motions.

DESCRIPTION 
1. Technical Field 
This invention relates to butchering saws and more particularly concerns a 
butchering saw suitable for use as a hog splitter for dissecting or 
splitting hogs. 
2. Background Art 
Butchering devices and saws for splitting large animals such as hogs have 
long been known in the art. Conventionally, such devices are hydraulically 
driven such that a cutting blade engages the hog during cutting 
operations. As the blade moves through the soft tissue and hard portions, 
such as bones, of a hog, the load level on the blade and its operatively 
associated drive motor varies substantially. Thus, in butchering saws 
powered by hydraulic pressure generating motors, the hydraulic pressure 
varies substantially, which increases the deleterious effect on the motor. 
For example, it has been noted during hog splitting operations that the 
hydraulic pressure indicating needle swings widely during movement of the 
cutting blade through soft tissue and bone. The pressure peaks produced by 
the alternating blade loads increase the wear on the drive motor and 
substantially reduce the useful life of the hog splitters and/or their 
components. 
Accordingly, it is an object of the present invention to provide an 
improved butchering saw which is particularly suitable for splitting hogs. 
It is another object of the present invention to provide such an improved 
butchering saw which incorporates a mechanism that assists in maintaining 
a constant motion/momentum of the drive shaft during butchering operations 
in which the blade load varies as is occasioned by cutting through soft 
tissue and bone. 
Yet another object of the present invention is to provide such a butchering 
saw incorporating a drive mass mechanism operatively associated with the 
drive shaft of the saw which reduces the pressure peaks required of the 
hydraulic drive motor as the blade loads substantially vary. 
DISCLOSURE OF THE INVENTION 
Further objects and advantages will be accomplished by the present 
invention which provides an improved butchering saw particularly suitable 
for splitting hogs. The butchering saw of the present invention includes a 
cutting blade which rotates in the preferred embodiment. A drive shaft has 
a power take off location at one end which is operatively associated with 
the blade. As the drive shaft rotates, rotary motion is imparted to the 
cutting blade. This drive shaft is rotatably driven by a hydraulic motor 
in the preferred embodiment. A drive mass mechanism is carried by, or 
operatively associated with, the drive shaft to assist in maintaining a 
constant motion/momentum of the drive shaft during butchering operations 
in which the blade load varies as it cuts through soft tissue and bone.

BEST MODE FOR CARRYING OUT THE INVENTION 
A butchering saw particularly suitable for splitting hogs is generally 
indicated at 10 in FIG. 1. Since the device illustrated in FIG. 1 is shown 
in operation in connection with splitting a hog 12, it is generally 
referred to herein as a hog splitter. In hog splitting operations, the 
hind portion and legs 14 of the hog are supported by a hook 16 mounted on 
a rolling hook support or carriage 18 of conventional design. This 
carriage 18 includes a roller and moves along a suspended track 20 which 
is supported from a ceiling or rafter 22 by a suitable support bracket 24. 
In this connection, after the splitting or other desired butchering 
operation is complete the hog 12 can be rolled to another location as 
desired. Similarly, the hog splitter 10 is supported by the ceiling or 
rafter 22 through the use of a support bracket 24', a suspended track 20' 
and a carriage 18' which rolls along the track 20' in a direction 
perpendicular to the plane of FIG. 1. This carriage 18' supports a small 
hook 16' which is connected to the hog splitter 10 through a supporting 
cable 26. It will be noted in FIG. 1 that a counter-balance 28 is provided 
between the hook 16' and the hog splitter 10 in order to reduce or off-set 
motion occurring by an operator's use of the hog splitter 10. 
As shown in FIG. 1 and in FIG. 2, the hog splitter 10 includes a housing 32 
which carries the various components described hereinafter. More 
specifically, the housing 32 includes a handle portion 34 which is gripped 
by an operator during use of the splitter 10. This handle 34 is connected 
to a motor cover 36 which includes a hydraulic motor 38 of conventional 
design. This motor is connected through ports 40 and 42 with suitable 
hydraulic connecting hoses (not shown) and a conventional hydraulic 
pressure source (not shown). Hydraulic fluid passing through ports 40 and 
42 in a conventional manner serves to impart and generate rotational 
forces which drive the power take-off shaft 44 of the motor. 
A drive shaft 48 includes a first end portion 50 which is mechanically 
connected and operatively associated with the power take-off shaft 44 of 
the motor 38. More specifically, this drive shaft 48 is mounted in the 
housing 32 such that its end portion 50 is positioned proximate the power 
take-off shaft 44 of the motor. A suitable mechanical coupling 52 is 
carried by end portion 50 of the drive shaft. This mechanical coupling 52 
is fashioned such that it can be bolted through the use of the externally 
threaded end portion of the shaft 44 and nut 54 to the mechanical coupling 
52. It will be noted in FIG. 2 that the mechanical coupling 52 includes an 
opening 56 which allows access to the nut 54 for the bolting operation. 
The connection between end portion 50 of the shaft 48 and the mechanical 
coupling 52 is completed by a small shaft portion 58 in the depicted 
embodiment which is externally threaded at its outboard end portion and 
threadably received within portion 60 of the mechanical coupling 52. The 
opposite end portion of the shaft 58 is directly connected to end of 
portion 50 of the drive shaft 48 as shown in FIG. 2. 
It will be noted from the above that a suitable means for connecting the 
power take-off shaft 44 of the motor 38 and the end portion 50 of the 
drive shaft 48 has been described and illustrated. Alternate embodiments 
of a suitable mechanical coupling will be obvious to those skilled in the 
art. 
The drive shaft 48 is rotatably driven by the motor 38 and is accordingly 
rotatably mounted in the housing 32. In this connection, the drive shaft 
48 is journaled in bearings 62 and 64 which are mounted at spaced 
locations in the housing 32 as is shown in FIG. 2. More specifically, 
bearing 62 is mounted proximate the mechanical coupling 52 which joins the 
power take-off shaft 44 with the end portion 50 of the drive shaft 44. 
Bearing 64 is mounted proximate the distal end portion 66 of the housing 
32 and supports the outboard end portion 68 of the shaft 48. Thus, when 
the motor 38 is driven by conventional application of pressurized 
hydraulic fluid flowing through ports 40 and 42, rotary motion is imparted 
to the drive shaft 48. 
This rotary motion is used to rotatably drive blade 70. More specifically, 
blade 70 is mounted in a blade assembly generally indicated at 72 which is 
carried by the outboard end portion 66 of the housing 32. This blade 
assembly includes a blade guard 74 which assist in shielding the portion 
of the blade proximate the user. It will be noted that the perimeter of 
the blade 70, which is substantially circular in outline, includes a 
plurality of cutting teeth 76 which engage the hog or other animal which 
is to be split during cutting operations. 
Rotary motion is imparted to the blade 70 through the use of a pair of 
beveled gears 78 and 80, in the preferred embodiment, which are mounted 
such that their teeth mesh. Beveled gear 78 is mechanically connected to 
and operatively associated with end portion 68 of the drive shaft 48 
proximate the location at which the drive shaft includes an area of 
reduced cross-sectional outline which is journaled within bearing 64. This 
portion 68 of the drive shaft serves as the power take-off location for 
the blade as will be described in greater detail hereinafter. This beveled 
gear 78 is mechanically connected to beveled gear 80 which has a 
rotational axis substantially perpendicular to the rotational axis of gear 
78. Thus, the axis of rotation of gear 78 is in a plane perpendicular to 
the axis of rotation of the blade 78. The face 82 of gear 80 is provided 
with means for mechanically coupling the blade 70 with the gear 80 such 
that rotation of gear 80 imparts rotational motion to the blade 70. This 
mechanical coupling is of conventional design and normally includes raised 
members 84A and 84B which are received in suitable and registering 
openings in the blade 70. The mechanical connection between gear 80 and 
the blade 70 is completed by a suitable screw or the like which joins 
these two members. Suitable parts and details of various mechanical 
connections and components made herein can be found in the Installation 
Instruction Manual for Model Nos. 764 and 766, Hog Splitter published by 
Best and Donovan, 5570 Creek Road, Cincinnati, Ohio 45242. 
An important feature of the present invention is to provide means for 
maintaining a substantially constant rotary motion/momentum or angular 
velocity of the shaft 48 and the blade 70 during cutting operations in 
which the load on the blade 70 varies substantially. For example, when 
cutting through soft tissue the load on the blade is much less than when 
the blade is used in cutting through bone. These load level variations 
cause wide swings in the power requirements of the hydraulic pump 
supplying pressurized fluids through ports 40 and 42 of the hydraulic 
motor 38. In order to assist and maintain a more constant rotary motion of 
the drive shaft 48 and the blade 70 during application of various loads, a 
driving mass mechanism 86 is provided. This driving mass mechanism in the 
illustrated embodiment is substantially circular in cross-sectional 
outline and mounted such that its mass is substantially equally 
distributed about the longitudinal axis of the shaft 48. The mass 
mechanism 86 is mounted, as shown in FIG. 2, in the enlarged portion 88 of 
the housing 32 and is preferably press fitted onto end portion 50 of the 
shaft 48. In this connection, the mass mechanism 86 is provided with a 
bore 90 having an internal diameter which is substantially equivalent to 
the external diameter of the end portion 50 of the shaft 48. It will of 
course be recognized to those skilled in the art that other suitable means 
can be provided for connecting mass mechanism 86 to end portion 50 of the 
shaft 48. It will also be noted in FIG. 2 that the mass mechanism 86 is 
provided with a bore 90 which includes the section 92 of increased 
cross-sectional diameter having dimensions suitable for receiving the 
mechanical coupling 52 and the end portion of shaft 48 therein. However, 
it will be noted that section 92 of bore 90 has a longitudinal axis 
substantially identical to the longitudinal axis of bore 90 such that the 
mass distributed radially outwardly from the axis of the shaft 48 is 
substantially identical 
FIG. 3 illustrates an alternate embodiment of a driving mass mechanism 86'. 
It will be noted in the embodiment in FIG. 3, the driving mass mechanism 
includes a portion 98 having an enlarged cross-sectional outline which is 
substantially circular. This portion is equally distributed radially about 
its longitudinal axis. The mass mechanism 86' and the mass mechanism 86 
shown in FIG. 2 are preferably fabricated from a substantially rigid 
material such as steel, iron or the like. The alternate embodiment of the 
mass mechanism shown in FIG. 3 includes a forward portion 100 of reduced 
cross-sectional outline which is also substantially circular. A bore 90' 
extends through the forward portion and the rearward portion of the mass 
mechanism shown in FIG. 3 and is proportioned for receiving the drive 
shaft 48 therethrough. Preferably, the mechanical coupling 52 which 
connects the drive shaft 48 with the power take-off shaft 44 of the motor 
38 is positioned external the rearward end portion 102 of the mass 
mechanism 86'. However, an enlarged section 92' of bore 90' is provided if 
it is desired for the coupling 52 to be maintained within mass mechanism 
86'. Further, bores 104A and B can be provided in a slotted portion 106 of 
the mass mechanism to receive suitable screws, bolts or the like to secure 
the mechanism 86' to shaft 48. By mounting coupling 52 inside the mass 
mechanism 86 and/or 86' the effective length of the splitter 10 can be 
reduced. It will of course be recognized, that the internal shape of the 
housing chamber defined by housing 32 can be required to be altered 
slightly in order to receive the mass mechanism 86' shown in FIG. 3. 
It will be noted in FIG. 2 that a suitable handle 94 is mounted proximate 
the blade carrying portion of the housing 32. Thus, an operator by 
gripping handles 34 and 94 can maintain control over the hog splitter 10 
during cutting operations. Further, a hanger mounting bracket 96 serves to 
connect the cable 26 with the hog splitter 10. In this connection, the 
bracket 96 is provided with a pair of openings illustrated in FIG. 2. 
These openings provide locations at which the lower end portion of the 
cable 26 can be connected with the hog splitter 10. The openings are 
spaced along the longitudinal axis of the splitter 10 to provide alternate 
selections for the cable connection to enhance the balance of the device. 
From the foregoing detailed description, it will be recognized that an 
improved butchering saw particularly suitable for splitting hogs has been 
provided. The butchering saw is designed to be easily maintained and 
includes a driving mass mechanism which is operatively associated with the 
drive shaft of the hog splitter. This driving mass mechanism serves to 
maintain a more constant rotational velocity-angular momentum during 
cutting operations in which substantially varying loads are applied to the 
blade. By maintaining a more constant angular momentum and angular 
velocity on the drive shaft, the power peaks required to be produced by a 
hydraulic motor are reduced thereby enhancing the useful life of the hog 
splitter. 
While a preferred embodiment has been shown and described, it will be 
understood that there is no intent to limit the invention to such 
disclosure, but rather it is intended to cover all modifications and 
alternate constructions of a butchering saw and hog splitter falling 
within the spirit and scope of the invention as defined in the appended 
claims.