SHOVEL TOOTH

DENT DE PELLE

English Abstract

ABSTRACT OF THE DISCLOSURE:
A shovel tooth for use in combination with a construc-
tion machine of the type having a shovel blade having an inner
surface and a front edge comprising a unitary tooth holder inclu-
ding a rear portion attachable to the inner surface of the blade
and formed as a half shell having a generally U-shaped cross sec-
tion, the half shell defining a recess opening toward the blade
inner surface when attached thereto and having closed forward and
rearward ends, the V-shaped cross section having a bight and two
legs extending from each side of the bight, the legs and the rear-
ward end terminating in a continuous edge which is rigidly atta-
chable to only the inner surface of the blade so that the half
shell and the inner surface of the blade define a cavity there-
between when attached, the cross-sectional area of said recess
taken in planes parallel to the inner surface of the blade and
bounded by said legs and ends constantly increasing from said bight
to said continuous edge. A transverse web extends across the for-
ward end of the half shell with one side thereof integrally atta-
ched thereto and forming the closed forward end of the recess.
The entire surface area of the recess is exposed from the under-
side of the half shell with no other portion of the shovel tooth
extending rearwardly from the lower edge portion of the web. A
forward projecting portion is integrally connected to the opposi-
te side of the web from the half shell. And, a tooth cap de-
tachably mounted on the forward projecting portion.

Claims

The embodiments of the invention in which an exclu-
sive property or privilege is claimed are defined as follows:
1. A shovel tooth for use in combination with a
construction machine of the type having a shovel blade having
an inner surface and a front edge comprising:
a unitary tooth holder including
a rear portion attachable to the inner surface of
the blade and formed as a half shell having a generally U-shaped
cross-section, said half shell defining a recess opening toward the
blade inner surface when attached thereto and having closed forward
and rearward ends, said U-shaped cross section having a bight and
two legs extending from each side of said bight, said legs and said
rearward end terminating in a continuous edge, said continuous edge
being rigidly attachable to only the inner surface of the blade
so that said half shell and the inner surface of the blade define
a cavity therebetween when attached, the cross-sectional area of
said recess taken in planes parallel to the inner surface of the
blade and bounded by said legs and ends constantly increasing from
said bight to said continuous edge;
a transverse web extending across the forward end
of said half shell with one side thereof integrally attached the-
reto and forming said closed forward end of said recess, a lower
edge portion of said web extending partly along and covering a
portion of the front edge of the blade when said half shell and
the inner surface of the blade are attached;
the entire surface area of said recess being expo-
sed from the underside of said half shell with no other portion
of the shovel tooth extending rearwarldy from said lower edge por-
tion of said web;
a forward projecting portion integrally connected
tothe opposite side of said web from said half shell, said forward
projecting portion extending away from the front edge when said
half shell and the inner surface of the blade are attached; and

a tooth cap detachably mounted on said forward
projecting portion, said cap having an interior cavity shaped to
receive and substantially mate with said forward projecting por-
tion.
2. A shovel tooth according to claim 1, wherein
said continuous edge is rigidly attachable to the inner surface by
means of welding.
3. A shovel tooth according to claim 1, wherein
said forward projecting portion has a symmetrical profile and said
interior cavity of said cap is symmetrical to receive said forward
projecting portion in either of two positions separated by 180° of
cap rotation.
4. A shovel tooth according to claim 1, further
including a shovel blade of a construction machine having an inner
surface and a front edge, said tooth holder being rigidly attached
to said inner surface.
5. A shovel tooth according to claim 1, wherein
only said continuous edge is attachable to said inner surface.
6. A shovel tooth according to claim 1, wherein
said projecting portion has root bearing portions adjacent said
shell and tip bearing portions at its distal end, said bearing
portions being dimensioned to frictionally engage the interior of
said cap, said bearing portion tapering inwarldy from said root
portion to said tip portion symmetrically with respect to a central
axis of said projecting portion.
7. A shovel tooth according to claim 1, wherein
said projecting portion includes reinforcing webs extending along
the outer surfaces thereof generally parallel with the longitudi-
nal axis of said tooth, and
said tooth cap includes edge reinforcing webs substantially ali-
gned with and supported by said reinforcing webs on said projec-
ting portion.

Description

1055548
This invention relates to a shovel tooth for use in
combination with a construction machine, particularly of the earth-
moving ti~é, having a shovel blade having an inner surface and a
front edge.
It is well recognized that teeth on a construction ma-
chine shovel are subject to wear and that they must be periodical-
ly replaced. Numerous forms of shovel teeth for this purpose are
known. In such prior art, teeth are generally made with a detacha-
ble cap portion so that only the cap needs to be replaced. How-
ever, because of the non-uniform wear of tooth caps, considerable
material waste occurs.
An object of the present invention is to provide a sho-
vel tooth of the general type described wherein a completely sa-
tisfactory and firm attachment of the structure to the shovel bla-
- de is insured and wherein the tooth cap can be removed and rotated
so that the side worn by use is replaced by the side of the tooth
cap which has not been exposed to significant wear.
According to the present invention, there is provided
a shovel tooth for use in combination with a construction machine
of the type having a shovel blade having an inner surface and a
front edge comprising, a unitary tooth holder including a rear por-
tion attachable to the inner surface of the blade and formed as a
half shell having a generally U-shaped cross section, the half
shell defining a recess opening toward the blade inner surface
when attached thereto and having closed forward and rearward ends,
the U-shaped cross section having a bight and two legs extending
from each side of the bight, the legs and the rearward end termi-
nating in a continuous edge, the continuous edge being rigidly
attachable to only the inner surface of the blade so that the
half shell and the inner surface of the blade define a cavity
therebetween when attached, the cross-sectional area of the recess
taken in planes parallel to the inner surface of the blade
d `
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~055548
and bounded by the legs and ends constantly increasing from the
bight to the continuous edge; a transverse web extending across
the forward end of the half shell with one side thereof integral-
ly attached thereto and forming the closed forward end of the re-
cess, a lower edge portion of the web extending partly along and
covering a portion of the front edge of the blade when the half
shell and the inner surface of the blade are attached; the entire
surface area of the recess being exposed from the underside of the
half shell with no other portion of the shovel tooth extending
rearwardly from the lower edge portion of the web; a forward
projecting portion integrally connected to the opposite side of
the web from the half shell, the forward projecting portion exten-
ding away from the front edge when the half shell and the inner
surface of the blade are attached; and a tooth cap detachably
mounted on the forward projecting portion, the cap having an in-
terior cavity shaped to receive and substantially mate with the
forward projecting portion.
An embodiment of the invention will be described with
reference to the accompanying drawings, wherein:
Fig. 1 is a side elevation in section of a shovel tooth
in accordance with the invention;
Fig. 2 is a plan view of the tooth assembly of Fig. l;
and
Fig. 3 is a section along lines III-III of Fig. 1.
The invention will be described in connection with a
typical shovel blade of the type used for a dredging shovel. As
seen in the figures, the shovel blade 1 has at its front edge a
chamfered portion 2 and an inner surface 3. The rear portion 4
of a shovel tooth indicated generally at 5 is fixedly attached
to the inner surface 3 of blade 1 as, for example, by welding.
Tooth 5 has a front or projecting portion 6 which projects beyond
the front edge of blade 1, portion 6 being generally wedge shaped
1~
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1055548
in vertical section, as seen in Fig. 1. Also, as will be seen
in Fig. 1, the front portion 6 is symmetrical with respect to a
central axis 7, the axis being rearwardly inclined with respect
to the shovel blade`so that the axis lies in a plane which forms
an acute angle with the inner surface of the blade.
For strength purposes, it is important that rear portion
4 of the tooth holder 5 is constructed as a U-shaped half shell
having side walls or legs 8 and 9 which extend substantially lon-
gitudinally with respect to tooth holder 5. Constructing rear
portion 4 of holder 5 as a half shell gives the shovel tooth the
necessary large yield strength and also permits solid welding of
the legs 8 and 9 to the inner surface /r
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1055548
~ of blade 1. A web 10 extends across the end of rear shell
portion 4, this web extending over the edge of blade 1 and
~ubstantially closing the shell portion and providing a point
of definition bctween the two portions of the tooth holder.
The front portion 6 of tooth holder 5 has bearing
portions or surfaces 13 and 14 arranged symmetrically with
respect to axis 7~ bearing portions 13 being at the root area
of portion 6 and surfaces 14 being at the tip of portion 6, the
bearing portions having a slight taper. As can be seen in
Fig. 2~ which shows the tooth holder without the cap, further
bearing portions 15 are provided laterally of portion 6 on
root 11 which is integrally formed with web 10.
Bearing portions 13, 14 and 15 serve to fixedly engage
a tooth cap 16 having an inner cavity 17 which is dimensioned
to frictionally engage the corresponding counter surfaces of
bearing portions 13~ 14 and 15. Cap 16 is secured to front
portion 6 by means of a bolt, such as a spring cotter, the
bolt not being shown. The bolt passes through a bore 17a in
the vicinity of root 11 of front portion 6 and through bores
18 in cap 16. As a result of the multiple engagement of the
bearing surfaces of cap 16~ it is possible to obtain a con-
nection between the tooth cap and front portion 6 of holder
5 which is free of play when the bolt is applied therethrough.
It is important that the bearing portions 13, 14 and 15 are
constructed with a slight taper which makes high frictional
engagement of the various mating surfaces possible.
As a result of the symmetrical disposition of bearing
portions 13~ 14 and 15, it is possiblc to remove the cap and
rotate it 180 and restore it onto the tooth holder, even
though the outer surface of the tooth may not be symmetrical~
thereby exposing the unworn outer surfaces thereof for further
useO
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1055548
It will be observed that web-like reinforcements
19 are provided on the outer surface of rear portion 4 and on
the two outer surfaces of tooth cap 16. Reinforcements 19 of
cap 16 are supported by web-like reinforcements 20 of front
portion 6 which are approximately aligned with reinforcements
19 as shown in ~igo 30 This results in a direct transmission
of force from tooth cap 16 into front portion 6 so that por-
tions 21 between reinforcements 19 can be dimensioned smaller.
Similar web-like reinforcements 22 can also be provided along
the sides of cap 16.
While one advantageous embodiment has been chosen to
illustrate the invention, it will be understood by those
skilled in the art that various changes and modifications can
be made therein without departing from the scope of the
invention as defined in the appended claims~