Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02310206 2000-OS-24
Patent Application o~
Georges-Aime Bergeron for:
HAMMER HEAD HAVING A DEFORMABLE STRIKING SURFACE
FIELD OF THE INVENTION:
The present invention relates to the general field of hammers and is
particularly
concerned with a hammer provided with a hammer head having a deformable
striking
surface.
BACKGROUND OF THE INVENTION:
The field of tools is replete with various hammer structures each including a
head
substantially at right angle to a handle and used for multiple purposes such
as driving
nails, chipping objects and the like.
In many trades and crafts specific hammer configuration are necessary for the
efficient practice of the art.
One example amongst many of such particular trade is the field of welding. In
the welding industry, waste material commonly referred to as slag is typically
produced
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proximate to a weld-line as a by-product of the welding process. This so-
called slag
must be removed quickly, with minimal interruption to the welder and without
causing
damage to the surfaces surrounding the weld.
One common method for removing slag from the weld area is a two-handed
chipping and scraping operation utilizing a hammer and chisel.
During such an operation, the welder repeatedly aligns the chisel blade
abutting a
given section of often thick and strongly adhering slag and strikes the chisel
head with the
hammer.
A second method utilized either alternatively or in conjunction with the
hammer
and chisel method involves the use of a conventional chipping hammer. Such
chipping
hammer typically has a long handle and a curved head with a thick end and a
chisel end.
The chisel hammer is repeatedly swung at the weld site, again in an attempt to
chip away at the slag. Both the use of either a hammer and chisel combination
or a
dedicated conventional chipping hammer inherently present numerous
disadvantages.
For example, when a hammer and a chisel combination is used, the two handed
operation requires repeated exchange of tools and welder repositioning,
thereby
decreasing welder productivity.
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Also inevitable chisel blade slippage and inaccurate blade realignment again
inherent in a two handed operation often causes damage to the weld site and
surrounding
surfaces.
Furthermore, welds often extend into obstructed areas necessarily thwarting
hammer and chisel access. This is further aggravated by welder left or right
handedness.
Still further, the shock from inordinately repeated blows due to the
inefficiency of
this method causes unnecessary shock to the welder's hand and other body
parts. The
use of a conventional chipping hammer also inherently leads to the above
mentioned
disadvantages further compounded by the fact that the control of the hammer is
extremely
limited given the force of the blow required to remove slag.
Another major problem associated with conventional methods of removing slag
using conventional chipping hammers or hammer and chisel combinations resides
in that
the surface to be impacted is often irregular.
Indeed, the slag typically presents a somewhat irregular contour which
inherently
further complicates the operation in at least two major aspects. First, since
the slag outer
contour is substantially irregular, it greatly increases the risks of having
either the chisel
or the hammer slip away from the slag during impact thus potentially causing
material
damage as well as potential human injury.
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Second, since the slag contour is typically somewhat irregular, the contact
between the striking surface of the hammer head and the slag is not evenly
distributed.
The contacting force between the hammer head and the slag being uneven it
creates localized high pressure points which may create stress concentrations
in the weld
ultimately weakening the latter.
Of course, the uneven distribution of the contacting force between the hammer
head and the slag, metallic scales or other matter resting on the weld is
further
compounded in situations wherein the weld itself has a generally arcuate
configuration
such as for example a convex type weld or a concave-radiused crown.
There exists at least one other situation also in the field of welding wherein
conventional welding tools have proven to be unsatisfactory. In certain
situations, it is
desirable to hammer the weld-line prior to its complete cooling. Indeed, in
specific
situations this reduces the risk of creating heat shrinkage stresses within
the weld-line.
For example, when cast-iron is used for uniting steel components the latter
being
generally more ductile tends to shrink more than the cast-iron thus creating
an inner
shrinkage stress concentration that may eventually lead to a stress fracture.
The conventional method of reducing the heat shrinkage stress consists in
lightly
hammering the cast-iron prior to its solidification and thus prior to its full
contraction.
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The light hammering stretches the weld-line. In order to provide a uniform
stretch again,
proper mating between the hammer head and the weld-line is crucial. Since the
weld-line
may vary in shape, diameter and relief it is again highly desirable to obtain
a hammer
head having an integral means for conforming to the configuration of the
surface being
struck.
Accordingly, there exists a need for an improved hammer tool.
Advantages of the present invention include the fact that the proposed hammer
tool is provided with a hammer head having a deformable striking surface that
is
adapted to substantially deform upon contact with an object so as to conform
within a
predetermined range to the contour of the contacted object. This reduces the
risk of
damaging the contacted object by creating local high pressure stresses and
ensures an
even distribution of the impacting pressure.
Furthermore, the proposed tool is specially designed so as to create an
inertia
effect about its striking head when in use.
Also, the proposed tool is less susceptible to being thwarted by obstructed
and
tight areas and is less affected by lack of dexterity.
Furthermore, the proposed tool is provided with shock absorbing features that
reduce hand and bodily damage due to excessive repeated stress.
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The proposed tool is specifically well adapted to effectively remove slag
without
damage to welding site. It is also well adapted to stress weld-lines in order
to reduce
inherent heat shrinkage stress within the weld-line.
Still further, the proposed tool is adapted to be manufactured using
relatively
simple and conventional forms of manufacturing so as to provide a tool that
will be
economically feasible, long lasting and relatively trouble free in operation.
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Summary of the Invention:
In accordance with an embodiement of the invention there is provided a hammer
having a
deformable main striking surface for striking an object, the object having an
object outer
surface defining an object contour, the hammer comprising an elongated handle,
the
handle defining a handle first longitudinal end, a handle second longitudinal
end and a
handle longitudinal axis; a hammer head attached to the handle adjacent the
handle first
longitudinal end, the hammer head including at least two plates, each of the
plates having
a generally elongated and flat configuration; each of the plates defining a
pair of opposed
and generally smooth plate sliding surfaces, a pair of plate side peripheral
edges, first and
second plate end peripheral edges and a plate longitudinal axis; the plates
being attached
to the handle in side by side relationship relative to each other and with the
plate
longitudinal axis in a generally perpendicular relationship relative to the
handle
longitudinal axis;- an attachment means for attaching the hammer head to the
handle, the
attachment means allowing the plates to slide relative to each other in a
direction parallel
to the plate longitudinal axis within a predetermined plate sliding range
while preventing
other movements of the plates relative to each other; whereby the first plate
end
peripheral edge of adjacent plates together form the deformable hammer main
striking
surface, the plates being adapted to slide relative to each other within the
plate sliding
range upon the main striking surface contacting the object outer surface so
that the main
striking surface substantially conforms to the object contour.
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Preferably, the attachment means includes an elongated attachment rod
extending from
the handle first longitudinal end, the attachment rod having a rod external
surface and
defining both a rod diameter and a rod longitudinal axis; an attachment
aperture
extending through each of the plates, each of the attachment apertures having
an aperture
peripheral edge and defining an aperture diameter; the rod diameter being
smaller then
the aperture diameter thereby defining a plate aperture clearance between the
rod external
surface and each of the aperture peripheral edges, the plate aperture
clearance allowing
relative movement between the plates and the attachment rod within the plate
sliding
range; an alignment means for maintaining the plates in a predetermined axial
position
along the attachment rod and only allowing the plates to slide relative to
each other in a
direction parallel to the plate longitudinal axis; whereby upon the main
striking surface
contacting the object outer surface the plate aperture clearances defined
between the rod
external surface and each of the aperture peripheral edges allow for each of
the plates to
move independently relative to the attachment rod and whereby the aperture
peripheral
edges provide limiting means for limiting the individual movement of the
plates to the
plate sliding range.
Conveniently, the plate side peripheral edges have a generally rectilinear
configuration,
each of the plate side peripheral edges being in a generally parallel
relationship with a
corresponding plate longitudinal axis;
the alignment means includes an abutment structure, the abutment structure
being
configured and sized for abuttingly and slidably contacting the plate side
peripheral
edges.
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Preferably, the abutment structure includes a first abutment component, the
first abutment
component having a generally "U"-shaped cross-sectional configuration defining
a first
component base wall. and a pair of first component flanges extending
perpendicularly
therefrom, the first abutment component being provided with a first component
mounting
means for mounting the first abutment component on the attachment rod; a
second
abutment component, the second abutment component having a generally flat
configuration defining a second component base wall and a pair of opposed
second
component flat peripheral edges, the second abutment component being provided
with a
second component mounting means for mounting the second abutment component on
the
attachment rod; the first and second abutment components being configured and
sized
such that when both mounted on the attachment rod with the distal section of
each of the
first component flanges attached to one of the second component flat
peripheral edges
and the plates sandwiched between the first and second component base walls,
the first
component flanges abuttingly and slidably contact the plate side peripheral
edges.
Conveniently, the first component mounting means includes a first component
aperture
extending through the first component base wall, the first component aperture
being
configured and sized so as to be substantially fittingly slidable on the
attachment rod; the
second component mounting means includes a second component aperture extending
through the second component base wall, the second component aperture being
configured and sized so as to be substantially fittingly slidable on the
attachment rod.
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In one embodiment, each of the first plate end peripheral edges has a
generally pointed
configuration. In another embodiment, each of the first plate end peripheral
edges has a
generally jagged configuration. Preferably, the hammer head is further
provided with an
auxiliary striking surface, the auxiliary striking surface being defined by
the second plate
end peripheral edges of adjacent plates.
Conveniently, each of the plate side peripheral edges defines a generally
centrally
disposed rectilinear segment interposed between a first and a second beveled
segment, the
first beveled segment of both the side peripheral edges of each of the plates
leading
inwardly towards the first plate end peripheral edge and the first plate end
peripheral edge
having a generally pointed configuration, the second beveled segment of both
the side
peripheral edges of each of the plates leading inwardly towards the second
plate end
peripheral edge and the second plate end peripheral edge having a generally
jagged
configuration.
Preferably, the rod diameter has a value substantially in the range of three-
eight of an
inch and the aperture diameter has a value substantially in the range of one-
half of an
inch. Conveniently, each of the plate aperture clearance is filled with a
resiliently
deformable material. Preferably, the resiliently deformable material is an
elastomeric
resin.
Conveniently, the handle is provided with a handle longitudinal channel
extending at
least partially therethrough, the handle longitudinal channel defining a
longitudinal
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channel diameter, the attachment rod being partially inserted within the
handle
longitudinal channel and protruding outwardly therefrom, the attachment rod
being
anchored in a predetermined position within the handle longitudinal channel by
a rod
anchoring means.
Preferably, the longitudinal channel diameter is greater then the rod diameter
thereby
creating a longitudinal channel clearance therebetween, the rod anchoring
means
preventing a relative axial displacement between the attachment rod and the
handle in the
direction of the rod longitudinal axis while allowing angular relative
movement between
the attachment rod and the handle within a predetermined angular motion range.
Conveniently, the rod anchoring means includes a rod transversal channel
extending
transversally through the attachment rod, the rod transversal channel being
located at a
section of the attachment rod inserted within the longitudinal channel, the
rod transversal
channel defining a rod transversal channel diameter;
a handle transversal channel extending transversally through the handle, the
handle
transversal channel being positioned substantially in register with the rod
transversal
channel, the handle transversal channel defining a handle transversal channel
diameter; a
locking pin inserted within both the rod transversal chamiel and the handle
transversal
channel, the locking pin having a configuration and size such that it is
frictionally locked
within the handle transversal channel while defining a transversal clearance
between the
locking pin and the handle transversal channel , the transversal clearance
allowing
relative angular movement of the attachment rod relative to the locking pin
and relative to
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the handle. Preferably, the transversal clearance is filled with a transversal
generally
resilient deformable material. Conveniently, the transversal generally
resilient deformable
material is an elastomeric resin.
In accordance with the present invention, there is also provided a hammer
having a
deformable main striking surface for striking an object, the object having an
object outer
surface defining an object contour, the hammer comprising: an elongated
handle, the
handle defining a handle first longitudinal end, a handle second longitudinal
end and a
handle longitudinal axis; a hammer head attached to the handle adjacent the
handle first
longitudinal end, the hammer head including at least two plates, each of the
plates having
a generally elongated and flat configuration; each of the plates defining a
pair of opposed
and generally smooth plate sliding surfaces, a pair of plate side peripheral
edges, first and
second plate end peripheral edges and a plate longitudinal axis; the plates
being attached
to the handle in side by side relationship relative to each other and with the
plate
longitudinal axis in a generally perpendicular relationship relative to the
handle
longitudinal axis; an attachment means for attaching the hammer head to the
handle, the
attachment means allowing the plates to slide relative to each other in a
direction parallel
to the plate longitudinal axis within a predetermined plate sliding range
while preventing
other movements of the plates relative to each other, the attachment means
including an
elongated attachment rod extending from the handle first longitudinal end; the
attachment
rod being pivotally attached to the handle so as to allow relative angular
motion between
the hammer head and the handle.
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Preferably, the attachment rod has a rod external surface and defines both a
rod diameter
and a rod longitudinal axis; the attacment means further including an
attachment aperture
extending through each of the plates, each of the attachment apertures having
an aperture
peripheral edge and defining an aperture diameter; the rod diameter being
smaller then
the aperture diameter thereby defining a plate aperture clearance between the
rod external
surface and each of the aperture peripheral edges, the plate aperture
clearance allowing
relative movement between the plates and the attachment rod within the plate
sliding
range; an alignment means for maintaining the plates in a predetermined axial
position
along the attachment rod and only allowing the plates to slide relative to
each other in a
direction parallel to the plate longitudinal axis.
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BRIEF DESCRIPTION OF THE DRAWINGS:
An embodiment of the present invention will now be disclosed, by way of
example, in reference to the following drawings in which:
FIGURE 1: in a perspective view, illustrates a hammer having a deformable head
in
accordance with an embodiment of the present invention.
FIGURE 2: in a partial elevational view with sections taken out, illustrates
part of the
hammer head shown in Figure 3;
FIGURE 3: in a partial side view with sections taken out, illustrates part of
the hammer
head shown in Figure 1;
FIGURE 4: in a longitudinal cross sectional view, illustrates the hammer shown
in
Figure 1 with its blades in a neutral position;
FIGURE 5: in a partial exploded view with sections taken out, illustrates part
of the
hammer shown in Figures 1 through 4.
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DETAILED DESCRIPTION OF THE DRAWINGS:
Referring to Figure 1, there is shown a hammer 10 having deformable striking
surface for striking an object 12.
Although the object 12 shown in Figure 1 schematically illustrates a welding
line
it should be understood that the hammer 10 could be used in many context
without
departing from the scope of the present invention. The object 12 has an outer
surface 14
defining an object contour.
The hammer 10 has an elongated handle 16. The handle 16 defines a handle first
longitudinal end 18, a handle second longitudinal end 20 and a handle
longitudinal axis
22.
A hammer head 24 is attached to the handle 16 typically adjacent the handle
first
longitudinal end 18. The hammer head 24 include at least two (2) and
preferably five
(5) plates 26. Each of the plates 26 have a generally elongated and flat
configuration.
As illustrated more specifically in Figure 5, each of the plates 26 defines a
pair of
generally smooth and opposed plate sliding surfaces 28, a pair of plate side
peripheral
edges 30, first and second plate end peripheral edges 32, 34 and a plate
longitudinal axis
36.
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The plates 26 are attached to the handle 16 in a side by side relationship
relative to
each other to the plate sliding surfaces 28 of adjacent plates 26 in an
abutting relationship
relative to each other. The plates 26 are also attached to the handle 16 with
their
respective plate longitudinal axis 36 in a generally perpendicular
relationship relative to
the handle longitudinal axis 22.
An attachment means is provided for attaching the hammer head 24 to the handle
16. The attachment means allows the individual plates 26 to slide relative to
each other
in a direction generally parallel to the plate longitudinal axis 36 within a
predetermined
plate sliding range. Simultaneously, the attachment means prevents other
movements of
the plates 26 relative to each other.
In a preferred embodiment of the invention, the attachment means include an
attachment rod 38 extending from the handle first longitudinal end 18. The
attachment
rod 38 has a rod external surface defining a rod external diameter 40. The
attachment
means also include an attachment aperture 42 extending through each of the
plates 26.
Each of the attachment apertures 42 has an aperture peripheral edge defining
an
aperture diameter 44.
The rod diameter 40 being smaller than the aperture diameter 44, a plate
aperture
clearance is defined between the rod external surface and each of the aperture
peripheral
edges.
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A plate aperture is indicated by the reference numeral 46 in Figure 4 allows
relative movement between the plates 26 and the attachment rod 38 within the
plate
sliding range.
The attachment means typically also includes an aligrunent means for
maintaining
the plates 26 in a predetermined axial position along the attachment rod 38
and for also
only allowing the plates 26 to slide relative to each other in a direction
parallel to the
plate longitudinal axis 36.
Preferably, the plate side peripheral edges 30 have a generally rectilinear
configuration. Each of the plate side peripheral edges are typically in a
generally parallel
relationship with a corresponding plate longitudinal axis 36.
The alignment means typically includes an abutment structure. The abutment
structure is configured and sized for abuttingly and slidably contacting the
plate side
peripheral edges 30.
Typically, the abutment structure include a first and a second abutment
component 48, S0. The first abutment component 48 preferably has a generally
"U"-
shaped cross sectional configuration defining a first component base wall 52
and a pair of
first component flanges 54 extending perpendicularly from peripheral edges
thereof. A
first abutment mounting means for mounting the first abutment component, the
attachment rod 38 is further provided. The i-lrst abutment component mounting
means
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preferably takes the form of a first component aperture 56 extending through
the first
component base wall 52. The first component aperture 56 is configured and
sized so as
to be substantially fittingly slidable on the attachment rod 38.
The second abutment component 50 has typically has a generally flat
configuration defining a second component base wall 58 and a pair of opposed
second
component flat peripheral edges 60. The second component has a second
component
mounting means for mounting the second component to the attachment rod 38.
Preferably, the second component mounting means include a second component
aperture 62 extending therethrough. The second component aperture 62 is
configured
and sized so as to be substantially fittingly slidable on the attachment rod
38.
The first and second abutment components are configured and sized such that
when they are properly mounted on the attachment rod 38, the distal section of
each of
the first component flanges 54 is attached to one of the second component flat
peripheral
edges 60 and the plates 26 are sandwiched between the first and second
component base
walls 52, 58.
In such a position, the inner surface of the first component flanges
abuttingly and
slidably contacts the plate side peripheral edges 30.
The hammer head 24 may further be provided with an auxiliary striking surface.
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The auxiliary striking surface is typically defined by the second plate end
peripheral edges 34 of adjacent plates 26. In one embodiment of the invention,
the first
plate end peripheral edges have a generally pointed configuration while the
second plate
end peripheral edges 34 have a generally jagged configuration.
Typically, each of the plates side peripheral edges 30 defines a generally
centrally
disposed rectilinear segment interposed between a first and a second beveled
segment.
The first beveled segment of both the side peripheral edges 30 of each plate
26
leads inwardly towards the first plate end peripheral edge. In such
circumstances, the
first plate end peripheral edge of each plate 26 has a generally pointed
configuration.
Also, the second beveled segment of both the side peripheral edges 30 of each
plate 26 leads inwardly towards the second plate end peripheral edge 34 and
the second
plate end peripheral edge 24 has a generally jagged configuration.
Typically, although by no means exclusively, the rod diameter 40 has a value
substantially in the range of 3/8", while the aperture diameter 44 has a value
substantially
in the range of 1/2".
Also, in one alternative embodiment of the invention, at least one and
preferably
all of the plates aperture clearances 46 are filled with a generally resilient
deformable
material. Typically, the resilient deformable material is an elastomeric
resin. Typically,
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although by no means exclusively, the second component 50 is formed out of a
conventional hexagonal type nut type component.
As shown in greater details in Figures 4 and 5, the handle 16 is preferably
provided with the handle longitudinal channel 62 extending at least partially
therethrough. The handle longitudinal channel 62 defines a longitudinal
channel
diameter.
The attachment rod 38 is preferably at least partially inserted within the
handle
longitudinal channel 62 and protrudes outwardly therefrom. The attachment rod
38 is
anchored in a predetermined position within the handle longitudinal channel 62
by a rod
anchoring means.
Typically, the longitudinal channel diameter is greater than the rod diameter
40
thereby creating a longitudinal channel clearance 64 therebetween. The rod
anchoring
means is adapted to prevent a relative axial displacement between the
attachment rod 38
and the handle 16 in the direction of the rod longitudinal axis 22 while
allowing angular
relative movement between the attachment rod 38 and the handle 16 within a
predetermined angular motion range. The angular relative movement between the
attachment rod 38 and the handle 16 is schematically illustrated by arrows
LXVI in
Figure 4.
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The rod anchoring means typically includes a rod transversal channel 68
extending transversally through the attachment rod 38. The rod transversal
channel 68
is located at a section of the attachment rod 38 inserted within the
longitudinal channel
62. The rod transversal channel 68 defines a corresponding rod transversal
channel
diameter.
The rod anchoring means also typically includes a handle transversal channel
70
extending transversally through the handle 16. The handle transversal channel
70 is
positioned substantially in register with the rod transversal channel 68. The
handle
transversal channel 70 defines a corresponding handle transversal channel
diameter.
The rod anchoring means typically further includes a locking pin 72 inserted
within both the rod transversal channel 68 and the handle transversal channel
70. The
locking pin 72 has a configuration and a side such that is frictionally locked
within the
handle transversal channel 70 while defining a transversal clearance between
the external
surface of the locking pin 72 and the handle transversal channel .
The transversal clearance is adapted to allow relative angular movement of the
attachment rod 38 relative to the locking pin 72 and relative to the handle 16
as indicated
by arrows LXVI in Figure 4.
Optionally the transversal clearance may be filled with a transversal
generally
resilient deformable material such as an elastomeric resin.
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In use, the first plate end peripheral edge 32 of adjacent plates 26 together
form
the deformable hammer main striking surface. The plates 26 adapted to slide
relative to
each other as shown in Figure 4b, within the plate striking range upon the
main striking
surface contacting to object outer surface 14 by the main striking surface
substantially
conforms to the object contour. Upon the main striking surface contacting the
object
outer surface 14, the plate aperture clearances 46 defined between the rod
external surface
and each of the aperture peripheral edges allow for each of the plates 26 to
move
independently relative to the attachment rod 38. However, the aperture
peripheral edges
provide limiting means for limiting the individual movement of the plates 26
to the plate
sliding range.
Upon the hammer handle being raised and lowered according to a conventional
hammering motion, the inertia created by the hammer head 24 causes the
attachment rod
38 to pivot according to arrow LXVI relative to the handle 16. The relative
pivotal
movement between the handle 16 and the combination of the attachment rod 38
and
hammer head 24 attached thereto, reduces the amplitude of motion required on
behalf of
the intended user in order to obtain a given striking amplitude of the
striking head 24. In
other words, a small hammering motion imparted on the handle 16 will cause a
greater
hammering amplitude of the hammering head 24. Furthermore, this relative
angular
motion between the attachment rod 38 and the handle 16 reduces the stress on
the hand of
the intended user upon impact of the hammer head 24 on a given surface.
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Optional resilient deformable material within the clearances 46 and the
transversal
clearance further cushion the impact and potentially improve ergonomical
features of the
hammer 10.
