Heavy-duty demolition apparatus with replaceable crushing and shearing tip

A heavy-duty shearing and crushing demolition apparatus for attachment to a boom structure and hydraulic system of an excavator. The apparatus includes a lower jaw with a primary blade, an upper jaw with primary and secondary blades oblique with respect to each other, and a shearing and crushing tip on the upper jaw secondary blade with a shearing point, a crushing point, and a support and shearing tip blade portion between the shearing point and the crushing points. This structure exposes the crushing point for crushing when the upper jaw is open from the lower jaw with the shearing tip out of the way and also exposes the shearing tip for shearing when the upper jaw is closing into the lower jaw. This permits shearing beginning at the shearing tip and shearing rearwardly. The support and shearing tip blade portion supports the workpiece while shearing it, producing a substantially flat non-contoured or twisted workpiece.

BACKGROUND OF THE INVENTION 
A fuller understanding of the operation of the demolition apparatus of the 
present invention may be achieved by studying U.S. Pat. No. 4,519,135, 
hereby incorporated by reference. This invention relates to a heavy duty 
demolition apparatus, especially adapted to be mounted on a rigid boom of 
a mobile vehicle and particularly adapted to be mounted on the dipper 
stick of an excavator, with a blade stabilizing device to keep the upper 
jaw of the apparatus from moving laterally relative to the lower jaw and 
breaking during the shearing operation on a workpiece. 
The invention also has a replaceable crushing and shearing tip on the 
movable upper jaw. 
Heavy duty shears of the type that are powered by hydraulic cylinders are 
proving more and more useful in handling scrap and especially metal scrap 
of all sorts. Such scrap comes in many different forms, and may be in the 
form of pipes made of steel or soft iron or cast iron, ranging in sizes 
from 2 inches or smaller, and up to 8 or 10 inches in diameter or larger; 
structural beams such as I-beams, channels, angle beams in a large range 
of sizes, up to 8 or 10 inches across and larger; rods and heavy cables 
having diameters of 2 to 3 inches and larger, metal sheets and plates and 
formed metal of all sorts including wheels and automobile and truck 
frames, and a myriad of long and short pieces of stock and metal pieces 
that are cast, rolled, stamped or otherwise formed, both singly and in 
various types of assembly. 
The prior art has included numerous shears such as that illustrated in U.S. 
Pat. No. 4,198,747; U.S. Pat. No. 4,188,721; U.S. Pat. No. 4,897,921; U.S. 
Pat. No. 4,543,719; U.S. Pat. No. 4,558,515 and U.S. Pat. No. 4,104,792. 
Typically, these heavy duty shears mount on the dipper stick of an 
excavator so that the shears may be controlled fairly well in handling 
various types of scrap and cutting the scrap into smaller twisted and 
contorted pieces and lengths as the scrap is drawn into the throat of the 
shear. 
Typically, these shears have a fixed lower jaw and a movable upper jaw that 
pivots on the lower jaw, with shear blades of hardened steel on both the 
upper jaw and the lower jaw. The workpiece is sheared by closing the upper 
jaw against the lower jaw under hydraulic pressure, with the shear blades 
cutting the workpiece. The movable upper jaw may also have a fixed, 
hardened shearing tip integral with the upper jaw. The tip is not suitable 
for removal and replacement due to the high lateral forces exerted on the 
tip as the movable jaw flexes laterally. Great tension is also exerted 
upon the tip, which may be wedged tight with scrap, upon opening the jaws. 
Direct shear bearing loads are also on the tip when shearing. All these 
factors will cause a removable tip to readily break off the upper jaw. 
As stated, great lateral as well as vertical pressures develop against the 
movable upper jaw as it contacts and proceeds to cut the workpiece. This 
lateral pressure can cause the upper jaw to crack or otherwise experience 
structural failure. The lateral pressure exists from the moment the upper 
jaw contacts the workpiece until the workpiece is cut and the upper jaw 
meets the lower jaw and becomes supported by the lower jaw in a slot in 
the lower jaw. This lateral force develops analogously to when a person 
tries to cut too heavy an object with a pair of scissors. The scissors' 
blades are forced laterally apart and may break. 
There is a need for a heavy duty demolition shear with a blade stabilizing 
device that prevents lateral movement of the upper jaw relative to the 
lower jaw and which supports the upper jaw against this lateral pressure. 
Such a shear should produce relatively clean or flat pieces of scrap which 
will allow the reduced scrap to stack and allow for more reduced scrap wad 
density. 
In rebuilding highways for motor vehicle travel, and in the demolition of 
structures which are largely made of or incorporate reinforced concrete as 
structural members, the disposal of large pieces of concrete paving or 
reinforced concrete structure becomes a significant problem. Many 
governmental regulations and practical considerations relating to the 
operation of landfills prohibit the disposal of concrete slabs and large 
reinforced concrete structures by simply burying them in the landfills. 
Accordingly, it becomes necessary to dispose of such concrete material in 
other ways. 
Crushing of the concrete is one alternative so that the concrete slabs and 
structures may be reduced to smaller particle sizes which accommodates the 
reuse of such concrete as fill and as aggregate base for roadways and the 
like. 
It has been possible in the past to reduce concrete into particles and 
chunks by use of heavy duty shears, but such shears which are primarily 
designed for shearing steel and other metallic and wood structures have 
sharpened blades and are rather expensive for the purpose of reducing 
concrete slabs and structures which is thought to be accomplished in other 
ways. Such crushers are shown in U.S. Pat. Nos. 5,478,019; 4,512,524; 
5,183,216; 5,044,569; and 4,951,886. Many of these crushers have crushing 
teeth rather than shearing blades. 
Furthermore, crushing concrete may result in the development of lateral 
pressure against the movable upper jaw of a demolition shear in the same 
way that shearing metal does. 
There is a need for a demolition shear apparatus with a replaceable 
crushing and shearing tip for both crushing concrete and shearing scrap 
metal. 
SUMMARY OF THE INVENTION 
A blade stabilizer device for a heavy-duty material handling demolition 
tool for shearing and crushing scrap material which includes a lower jaw 
with an elongate primary shearing blade. The lower jaw is connected to the 
boom structure of a hydraulic system of an excavator. The total has an 
upper jaw pivotally connected and closeable upon the lower jaw beginning 
at the distal end from the pivot point. The blade stabilizing device 
consists of a wear guide supported by the lower jaw adjacent the pivot 
point slidably engaging the upper movable jaw to keep the upper jaw in 
close engagement with the lower jaw. The wear guide is mounted behind the 
pivot point. A second wear guide may be mounted in front of the pivot 
point on the opposite side of the upper jaw to cross-brace the upper jaw. 
The upper jaw has a replaceable crushing and shearing tip. The tip is held 
in place by bolts and retaining bushings. 
An object and advantage of the invention is to provide an improved 
heavy-duty material handling demolition tool for shearing and crushing 
scrap material with a blade stabilizing device which prevents the upper 
jaw from moving relative to the lower jaw, thus improving the cutting 
ability of the tool for heavy scrap material. 
Another object and advantage of the present invention is to provide a blade 
stabilizing device for a heavy-duty demolition tool which reduces lateral 
stress on the upper jaw caused due to shearing the workpiece. 
Another object and advantage of the present invention is that the blade 
stabilizing device is removable and replaceable when worn due to friction 
with the upper jaw. 
Another object and advantage of the present invention is that the clearance 
between the blade stabilizing device and the upper jaw is adjustable to 
compensate for wear. 
Another object and advantage of the present invention is that the blade 
stabilizing device contacts a wear surface on the upper jaw and the wear 
surface is dimensioned such that the blade stabilizing device does not 
contact the wear surface once the upper jaw is securely received in the 
lower jaw. 
Another object and advantage of the present invention is that the blade 
stabilizing device may comprise a first stabilizer mounted to the rear of 
the pivot point and a second stabilizer mounted in front of the pivot 
point, thereby providing cross-bracing to the upper jaw. 
Another object and advantage is that the upper jaw has a replaceable 
crushing and shearing tip. 
Another object and advantage is that the replaceable tip is held in place 
by nuts and bolts passing through retaining bushings which will hold the 
tip in place despite high direct and lateral/forces, as well as stress 
shearing forces and tensional forces exerted on the tip when opening the 
shear with jammed scrap pieces about the tip. 
Another object and advantage is that the shear produces relatively clean 
and flat reduced scrap for easy stacking of the reduced scrap and 
increased load densities for transportation of the reduced scrap due to 
the upper jaw blades and tip shape in relation to the elongate lower jaw 
primary shearing blade.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The heavy-duty demolition apparatus of the present invention is generally 
referred to in the Figures as reference numeral 10. 
Referring to FIGS. 1 through 6, the heavy-duty demolition apparatus 10 
comprises a lower jaw 12, an upper jaw 14, pivot means 16 interconnecting 
the lower jaw 12 and upper jaw 14, and means 18 for attachment to the 
excavator (not shown). The means 18 may further include a rotator unit 20 
allowing rotation of the demolition unit 10 about a longitudinal axis. The 
apparatus 10 also includes means 30 for attachment to the hydraulic system 
of an excavator (not shown) for closing and opening the upper jaw relative 
to the lower jaw. More specifically, the means 30 includes a cylinder 30a 
having a reciprocating piston 30b within the cylinder 30a. The cylinder 
30a is connected to the hydraulic system of the excavator (not shown). The 
piston 30b connects to the upper jaw 14 at a knuckle 32. 
The upper jaw 14 has a first side 22, and a second side 24. The lower jaw 
12 has a first mounting plate 26 adjacent the first side 22, and a second 
mounting plate 28 adjacent the second side 24. The first mounting plate 26 
and second mounting plate 28 receive the pivot means 16 between them. 
The upper jaw 14 has upper shear blades 33 and 34 meeting at apex 35 and 
the lower jaw 12 has lower shear blades 36 and 37 extending along each 
other for shearing a workpiece when the upper shear blades 33 and 34 are 
closed upon the lower shear blades 36 and 37. Preferably, the shear blades 
33, 34, 36 and 37 are replaceable. FIG. 1 shows a configuration in which 
the apparatus 10 has only shear blades mounted thereon. FIG. 2 and the 
other figures show a configuration in which one or more of the upper shear 
blades 34 and lower shear blades 36 are replaced with breaker teeth 112 
for crushing materials. It will be appreciated that lower shear blade 36 
is at least twice as long as secondary shear blade 37 which assists in 
creating flat reduced scrap pieces. Primary blade 36 may be two to four 
times longer than secondary blade 37. Two and one-half times in length 
works quite well. 
A blade stabilizing device 38 for the apparatus 10 engages the upper jaw 14 
to prevent the upper jaw 14 from moving laterally with respect to the 
lower jaw 12 while shearing the workpiece. 
Preferably, the blade stabilizing device 38 further comprises a first blade 
stabilizer 40 attached to the first mounting plate 26 and slidably 
engaging the upper jaw 14 on the first side 22 of the upper jaw 14; and a 
second blade stabilizer 42 attached to the second mounting plate 28 and 
slidably engaging the upper jaw 14 on the second side 24 of the upper jaw 
14. 
Preferably, the apparatus 10 further comprises a first arcuate wear surface 
44 on the first side 22 and contacting the first blade stabilizer 40 and a 
second arcuate wear surface 46 on the second side 24 and contacting the 
second blade stabilizer 42. The second arcuate wear surface 46 may be on a 
hub 64 or reinforced section of the upper jaw 14. The wear surfaces 44, 46 
may preferentially be constructed of a different material from the upper 
jaw 14 in order to better resist sliding friction cause by the first blade 
stabilizer 40 and second blade stabilizer 42. 
Preferably, the apparatus 10 further comprises a guide blade 48 on the 
lower jaw 12 lying along the lower shear blade 36 and in spaced relation 
therewith, the outer end 50 of the guide blade and outer end 52 of the 
shear blade being adjacent each other, and rigid means 54 securing the 
outer ends 50, 52 together. The rigid means 54 is preferably a tie plate 
56. 
An open slot 58 preferably exists between the lower shear blade 36 and the 
adjacent guide blade 48 to receive the upper shear blade 34 therein, the 
open slot 58 having a width wider than the thickness of the upper shear 
blade 34 to maintain open space between the upper shear blade 34 and the 
guide blade 48 when the upper shear blade 34 is in the open slot 58. 
Preferably, the first arcuate wear surface 44 and second arcuate wear 
surface 46 are of such dimensions that the first blade stabilizer 40 and 
also perhaps the second blade stabilizer 42 move off the first arcuate 
wear surface 44 and second arcuate wear surface 46, respectively, when the 
upper shear blade 34 is received in the open slot 58. This is because the 
first blade stabilizer 40 and second blade stabilizer 42 are no longer 
needed to brace the upper jaw 14 once the upper shear blade 34 is received 
in the slot 58. To further brace the upper jaw 14, the lower jaw 12 has 
guide plates 60 adjacent the slot 58 which bear upon wear plate 62 on the 
upper jaw 14. 
Preferably, the first blade stabilizer 40 and second blade stabilizer 42 
are removable and replaceable when they become worn due to frictional 
contact with the upper jaw 14. The first blade stabilizer 40 and second 
blade stabilizer 42 may also be adjustable to provide variable clearance 
between them and the upper jaw 14, as for example as the blade stabilizers 
become worn. 
In the preferred embodiment, the first blade stabilizer 40 further 
comprises a wear guide or pad assembly 66 located rearwardly of the pivot 
means 16. FIGS. 3 and 7 show the details of the pad assembly 66. 
The wear guide or pad assembly 66 comprises a guide 68; an adjustable first 
slide screw 70 receiving the guide 68; guide connectors 72 for mounting 
the guide 68 to the first slide screw 70; the adjustable first slide screw 
70 further comprising a guide mounting disc 74 for mounting the guide or 
pad 68, an externally threaded body 76, and a bolt end 78 opposite the 
guide; an internally threaded first slide screw retainer 80 mounted in the 
first mounting plate 26, the first slide screw body 76 threadingly 
engaging the first slide screw retainer 80 and being prevented from 
over-extension by seats 81 and the guide 68 being adjustably spaced from 
the first side 22 by means of turning the bolt end 78; and a first lock 
plate 82 mounting to the first slide screw retainer 80 by lock plate 
retainers 84, the first lock plate 82 having a slide screw aperture 86 
receiving the bolt end 78 of the first slide screw 70 and adapted to 
prevent the first slide screw 70 from turning. Preferably, the slide screw 
aperture 86 has cut-outs 88 which prevent the bolt end 78 from turning. 
In order to prevent the guide connectors 72 from shearing off due to 
pressure from the upper jaw 14, the guide mounting disc 74 preferably has 
a central depression 90, and the guide 68 has a raised boss 92 indexing 
the central depression 90, as best seen in FIG. 7. 
The second blade stabilizer 42 (FIGS. 5 and 7) may preferably comprise a 
wear guide or pad assembly 66 located forwardly of the pivot means 16. The 
first blade stabilizer 40 and second blade stabilizer 42 thus provide 
cross-bracing to the upper jaw 14 across the pivot means 16. 
The second blade stabilizer 42 further comprises a guide or pad support 94 
of integral construction with the second mounting plate 28; an internally 
threaded slide screw aperture 96 in the guide support 94; an adjustable 
externally threaded second slide screw 98 threadingly engaging the slide 
screw aperture 96, the guide 95 being mounted on the second slide screw 
98; the adjustable second slide screw 98 further comprising an externally 
threaded body 100 and a bolt end 102 opposite the guide 95; and a second 
lock plate 104 mounting to the guide support 94, the second lock plate 104 
having a slide screw aperture 106 receiving the bolt end 102 and adapted 
to prevent the second slide screw 98 from turning. Preferably, the slide 
screw aperture 106 has cut-outs 88 restraining the bolt end 102 from 
turning. 
In order to prevent the guide connectors 72 from shearing off due to 
pressure from the upper jaw 14, the guide 95 preferably has a central 
depression 110, and the second slide screw 98 has a raised boss 108 
indexing the central depression 110, as best seen in FIG. 7. 
Operation of the present invention may best be seen by viewing FIGS. 8-10. 
In FIG. 8, the upper jaw 14 is in the open position, preparatory to 
shearing the workpiece. It will be seen that the guide or pad or guide pad 
68 rests at one end of the first arcuate wear surface 44 and the guide or 
pad or guide pad 95 rests at one end of the second arcuate wear surface 
46. In FIG. 9, the upper jaw has partially closed on the workpiece (not 
shown) and has begun to shear the workpiece. The guides 68, 95 are still 
supported by the wear surfaces 44, 46 respectively. In FIG. 10, the upper 
shear blade has been entirely received in the slot 58 and is supported by 
the guide plates 60 (not visible in FIG. 10). Consequently, the support of 
the guide pads 68, 95 is no longer required and the guide pad 68 has moved 
off the first arcuate wear surface 44. Although not shown in the Figure, 
the second arcuate wear surface could also be dimensioned so that the 
guide pad 95 has moved off it at this point. 
Before beginning operation, the guides 68, 95 may initially be set at a 
clearance of about 0.01 to 0.02 inches from the upper jaw by means of a 
feeler gauge. This clearance may be adjustable as the guide becomes worn 
by turning the bolt ends 78, 102 with a wrench. This clearance also allows 
the guides 68, 95 to clear the wear surfaces 44, 46 when the upper jaw 14 
is opened. 
Referring to FIGS. 11 through 18, the heavy duty demolition shear 10 with 
the replaceable crushing and shearing tip 150 may be seen and appreciated. 
Again, shear 10 has a lower jaw 12, upper jaw 14 and pivot means 16 to 
permit the upper jaw 14 to open and close. Shear 10 has connecting or 
attaching means 18 which may include a rotator unit 20. The shear 10 has a 
first shearing side of the upper jaw 22 and a second guide side of the 
upper jaw 24. 
FIG. 11 shows the shear 10 with the blades and wear plates exploded away 
for ease of understanding of assembly and fitting of the blades and wear 
plates with bolts 174 and hardened bushings 172. 
On the first shearing side 22, the upper jaw will receive the upper primary 
shear blade 31 and the upper secondary shear blade 33. The shear blades 31 
and 33 meet at the upper shear blade apex 35 which is the last point 
wherein the upper jaw 14 shears a workpiece against lower elongate shear 
blade 36. On the lower jaw 12, the lower primary shear blade 36 and lower 
secondary shear blade 37 are received. 
Along the guide blade 48 is guide blade wear plate pocket 49 at the outer 
end 50 of the guide blade which receives guide blade wear plate 51 for 
guiding the upper jaw 14 into the lower jaw 12 and to further assist in 
resisting lateral forces upon the upper jaw 14, together with the blade 
stabilizing device 38 and puck assembly 66 previously disclosed. The guide 
blade wear plate 51 is opposite the outer end 52 of the lower jaw 12. 
Connecting the guide blade 48 and outer end of the shear blade 52 is the 
tie or nose plate 56 which suitably has a nose or tie wear plate pocket 
57. Within the pocket 57 is situated the nose or tie longitudinal insert 
wear plate 59 which further protects the nose plate 56. 
Referring to the exploded and assembled FIGS. of 11 through 14, the upper 
secondary shear blade 33 has integral therewith the upper secondary blade 
shearing and crushing tip 150. Tip 150 comprises a crushing point 152 and 
a shearing point 154 with a recessed support and shearing tip blade 
support portion 156 therebetween. FIG. 17 shows the angular relationship 
between the blade support and shearing portion 156 and that of the lower 
secondary blade 37 illustrated by angle A. This angular relationship may 
be approximately 15.degree. but may be in a range of 3.degree. to 
45.degree. to assist in the shearing action from shearing point 154 and 
along support and shearing tip blade portion 156 against lower secondary 
shear blade 37. Thereafter, shearing is upon the elongate lower shear 
blade 36 as the scrap or workpiece is sheared by upper primary and 
secondary shear blades 31 and 33. This shearing action creates a flat 
reduced piece of scrap. 
The recessed center tip blade 160 is located and secured between the upper 
shearing blade tip 150 and guide blade side shearing and crushing blade 
tip 162. The center tip blade 160 is slightly recessed as further 
illustrated in FIG. 18 to begin shearing after shear points 154 and 166 
have pierced the workpiece. The center tip blade 160 is also recessed to 
remain out of the way of the two crushing points 152 and 164 which will 
initiate crushing of concrete 180 and 182. 
With reference to the guide side 24, the guide blade side shearing and 
crushing blade tip 162 takes the place of wear plate 62 in the first 
embodiment illustrated in FIG. 5. The blade tip 162 has crushing point 
164, shearing point 166 and support a nd shearing tip blade portion 169. 
Apertures 170 pass through the respective blades and wear plates, as well 
as the jaw structures through which pass and are secured bolts and nuts 
174. With respect to the upper blade tips 150, 160 and 162, guide blade 
wear plate 51 and lower secondary blade 37, retaining bushings 172 
suitably may be utilized. The retaining bushings 172 are hardened suitably 
by heat treatment while the blades and wear plates are similarly hardened 
on a Rockwell c scale of 50 to 55 Rc. 
Referring to FIGS. 15 and 16, it can be readily appreciated that the 
crushing points 152 and 164 provide two points of direct pressure upon a 
concrete column 180 or a concrete slab 182 for crushing of the concrete 
work piece 180 or 182 without any contact of the shearing point 154 and 
the tip blade portion 156. 
With respect to metal scrap 184 which must be reduced to salvageably small 
stackable pieces, refer to FIGS. 17 through 20. The metal workpiece or 
scrap 184 is initially grabbed by the upper 14 and lower jaws 12 as they 
close down upon the workpiece. The shearing points 154 and 166 begin to 
pierce and shear the workpiece 184 as it is held by the support and 
shearing tip blade portion 156. The recessed center tip blade next pierces 
the scrap 184. The tip blade portion 156 next begins to shear. Then 
shearing continues rearwardly within the jaws with some shearing beginning 
at the upper primary shear blade 31. On the lower jaw, shearing is now 
along the primary blade 36. Shearing then is complete as the upper shear 
blade apex 35 passes below the lower elongate blade 36. The result of this 
shearing action is a substantially flat non-contorted or twisted 
workpiece. 
The present invention may be embodied in other specific forms without 
departing from the spirit or essential attributes thereof, and it is 
therefore desired that the present embodiment be considered in all 
respects as illustrative and not restrictive reference being made to the 
appended claims rather than to the foregoing description to indicate the 
scope of the invention.