Note: Descriptions are shown in the official language in which they were submitted.
~058~380
BACKGROU2~D OF THE INVENTION
This invention relates to clamps and the like for holding
an ice skate while grinding the edge of the ice skate blade and,
particularly where the clamp is manually manipulated by an oper-
ator to bring the held skate blade evenly against the edge of a
stationary grinding wheel.
~ eretofore, machines and apparatus have been proposed for
holding an ice skate blade against a grinding wheel to grind the
edge of the blade. The usual arrangement is to provide a clamp
or the like rigidly holding the ice skate and a grinding wheel,
all mounted to a common platform. Usually, the grinding wheel
is fixed on the platform and the clamp holding the ice skate is
moveable along a track on the platform so that the blade of the
skate can be brought against the grinding wheel by moving the
clamp along the track.
In some apparatus, the clamp is attached to the platform
by a combination of hinges or pivots rather than a track, how-
ever, whether a track is used or hinges are used, movement of
the clamp with respect to the grinding wheel is very limited.
Furthermore, in all such prior apparatus, one jaw of the clamp
is at a fixed level above the base and so, it is at a fixed
level with respect to the stationary grinding wheel, and the
other jaw of the clamp is adjustable so that skate blades of
different thicknesses can be gripped by the clamp. Thus, when
the skate blade is relatively thin, the center of the blade
between the two edges of the blade will be positioned slightly
closer to the base than when the blade is relatively thick.
This situation is not particularly troublesome in such
apparatus where the direction of grinding is perpendicular to
the blade or, in other words, where the rotation axis of the
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1 grinding wheel disc lies in the plane of the blade, because the
grinding wheel is usually six inches or more in diameter and the
plane of the blade passing through the center of the blade shifts
only a very small fraction of an inch relative to the grinding
wheel axis when skate blades of different thicknesses are mount-
ed in the apparatus for grinding. However, this small shift in
the plane of the blade relative to the grinding wheel which occurs
when thin or thick blades are mounted in the clamp becomes more
significant in apparatus where the direction of grinding is
parallel to the blade. In that case, the central plane of the
blade is supposed to be aligned with the central plane of the
grinding wheel disc so that they are co-planar. If it is not
so~ aligned, then the two edges of the skate blade will not be
ground evenly.
The finishing grind of an ice skate blade is preferably
parallel to the blade, because grinding then is in the direction
of the blade rather than across it and the edges of the blade are
ground s other, gharper and without burs from end to end. How-
ever, even a slight misalignment of the central plane of the
blade (through the center of the blade) with the central plane
of the grinding disc (through the center of the wheel disc)
could make the edges of the blade uneven.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an im-
proved clamp for holding an ice skate while grinding the ice
skate blade.
It is a further object to provide such a clamp for use in
conjunction with a grinding wheel where at least some of the limi-
tations of prior apparatus and machines for grinding ice skate
blades are avoided.
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1 It is another object to provide a clamp for holding an ice
skate blade in position relative to a grinding wheel so that the
plane of the blade through the center of the blade can be adjust-
ed to align co-planar with the plane of the wheel through the
center of the wheel.
It is a further object to provide a clamp for holding an
ice skate, the clamp being readily manually manipulated by an
operator with reference to a stationary grinding wheel, with
manually operated controls and locks which position the blade
1o so that the plane thereof through the center of the blade can
be precisely positioned relative to the grinding wheel by mere-
ly holding the clamp against a platform.
It is a further object to provide a relatively light weight,
inexpensive mechanism for firmly holding an ice skate by the ice
skate blade to facilitate moving and positioning the blade rela-
tive to a grind wheel which grinds the blade.
It is a further object to provide on such a mechanism means
for adjustment to~facilitate firmly holding the blade even when
the thickness of the blade is not uniform from one end to the
other thereof.
In accordance with the principal features of the present
invention, a manually held clamp is provided which holds an ice
skate by the skate blade between two jaws that grip the blade
along the broad sides of the blade and hold forth the edge of
the blade to be ground. m e jaws are each pivotally attached
to a flat base plate at a pivot axle that connects eccentri-
cally to a disc at each end of the axle- The discs are rotata-
bly held by yokes attached to the base and each can be rotated
and locked to the yoke to fix the position of the axle on the
base. When the axle is locked in position, the jaws are held in
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pivotal position relative to the base plate by a cam attached
to the plate. Rotation of the cam simultaneously pivots both
gripping jaws closed so that they grip the skate blade and hold
it parallel to the base with the central plane of the blade
(midway between the two edges of the blade) at a fixed position
relative to the base, determined by the locked axle.
Then the operator slides the clamp base plate on a fixed
flat platform to bring the skate blade against the edge of a
fixed grinding wheel. The finishing grind of the skate blade
is made parallel to the blade and so, the central plane of the
grinding wheel is parallel to the central plane of the blade
and co-planar therewith.
In order to insure that the central planes of the blade and
the grinding wheel are co-planar, the position of the jaw axle
is adjusted by rotating and locking the discs. The discs can
be independently rotated on separate yokes fastened to the base,
and so the angle and distance between the axle and base can be
adjusted. This is done when, for example, the grinding wheel is
shifted or changed, or for blades that do not mount evenly in the
clamp.
In accordance with another embodiment of the invention, a
separate axle is provided for each jaw and bothaxles, are carried
eccentrically by common discs at each end which are rotated and
locked by the operator. By changing the rotational position of
the discs, the spacing of the twoa-xles from the base is simultan-
eously changed.
These and other objects and features of the present invention
are apparent from the following Description of Embodiments of the
Invention, taken in conjunction with the drawings.
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DESCRIPTION OF THE DRAWINGS
FIGURE 1 is a side view of the clamp holding an ice skate
by the blade supported by a horizontal plat~orm adjacent a
horizontal grinding wheel;
FIGURE 2 is a top view of the clamp holding the ice skate;
FIGURE 3 is a cross section front view of the clamp;
FIGURE 4 is a front view of the clamp showing the upper
and lower jaw gripping plates;
FIGURE S is a front sectional view showing the jaw ~xle
and eccentric mounting discs of the first embodiment;
FIGURES 6 and 7 are representative side views showing the
first embodiment with jaws opened and closed to hold an ice skate
blade aligned with the grinding wheel for the finishing grind;
FIGU Æ 8 is a front sectional view showing the two eccen-
tric axle and eccentric mounting discs of the second embodiment;
FIGURES 9 and 10 are representative side views showing the
, ~ .
second embodiment with jaws opened and closed to hold a relative-
ly thin ice skate blade; and
FIGURE 11 is a three-quarter view of the clamp holding an
ice skate by the blade ln position relative to a grinding wheel
ready to perform the finishing grind.
DESCRIPTION OF EMBODIMENTS OF THE INTENTION
'~ Figures 1 and 2 show the clamp assembly 1 holding a typical
; ice skate 2 by the ice skate blade 3. The clamp assembly includes
the clamp 4 carried on base plate 5 which rests on a table or
platform 6. The clamp holds the ice skate blade between the
upper and lower jaws 7 and 8 so that the edge 10 of the ice skate
bl~e projects clear of the clamp and can be brought to bear against
a stationary grinding wheel 11.
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The position of the stationary grinding wheel 11 to perform
a parallel grind, such as the finishing grind, of the edge of the
ice skate blade is with the central plane of the grinding wheel
co-planar with the central plane of the blade. With this orien-
tation of the blade and wheel, a finishing grind can be obtained
which is longitudinally along the blade rather than across the
blade. The finishing grind produces even, smooth edges without
burs such as cannot be produced where the direction of grind is
perpendicular to the length of the blade.
The finishing grind preferably produces a blade edge surface 12
which is slightly concave and so, the blade consists of two edges
13 and 14 which are smooth, parallel and sharp and have a slightly
concave surface 12 inbetween. Clearly, the degree of concavity
of the blade surface 12 depends upon the curvature of the edge
15 of the grinding wheel, as viewed in the figure.
In order to insure that the two edges 13 and 14 of the blade
are parallel and eyen and the surface 12 inbetween is properly
concave, it is necessary that the central plane 16 of the ice
skate blade and the central plane 17 of the grinding wheel be
co-planar. Hence, the ice skate is held by the blade, as shown
in Figure 1 with the central plane 16 of the blade parallel to-
the table 6 at a fixed distance therefrom and that distance is
the same for the central plane 17 of the grinding wheel disc.
When these dimensions are fixed and equal, then the operator
need only move the clamp assembly by sliding it on the table 6
to bring the edge of the blade into proper alignment with the
grinding wheel to make the finishing grind.
me clamp assembly 1 is preferably made as much as possible
of light weight material, such as aluminum. The upper and lower
jaws 7 and 8 of the clamp are unitary pieces pivotally mounted
~058880
on a common axle or on separate eccentric axles carried by discs
at each end which are rotatably positioned in a yoke 21 that
attaches to the base plate 5. The yoke 21 consists of two ped-
estals 21a and 21b which may be identical to each other and
aligned as shown in Figure 2 so that each supports a disc and
each is firmly fastened to the base plate 5 by, for example,
screws 22.
FIRST EMBODIMENT -- COMMON AXIE
1oIn accordance with the first embodiment of the present
invention, illustrated particularly by Figures 5 to 7, the jaws
are pivotally mounted on a common ax~e 18 carried eccentrically
by discs l9a and l9b at each end. These discs rotate in yoke 21
that attaches to the base plate and includes two pedestals 21a
and 21b which may be identical to each other and aligned as
shown in Figure 2. In this embodiment the jaws may also be
! identical and so the jaws are interchangeable and the pedestals
are interchangeable.
Lever arms 23 and 24 from the upper and lower jaws 7 and 8,
respectively, extend substantially symmetrically of the plane 16
towards the rear of the clamp assembly. Pads 25 and 26 attached
to these arms, respectively, engage a cam 27 (see Figures 6 and
7) carried by the cam yoke 28 attached to base plate 5. The
cam yoke 28 consists of pedestals 28a and 28b fixedly attached
to the base plate by screws 29. This yoke defines the cam axis
30 which is horizontal to the jaw axle and the cam is rotated
on its axis 30 by cam wheel 31.
The purpose of the cam is to cause the two jaws 7 and 8 to
rotate simultaneously together from an open position to a close
position gripping the ice skate blade evenly and holding the
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blade with the central plane 16 of the blade allgned with the
central plane 17 of the grinding wheel, as described above.
A spring 32 which acts between the two jaws 7 and 8 urges the
jaws open so that when the cam is released, the jaws tend to
open releasing the ice skate blade.
As shown in Figure 3, the upper and lower jaws 7 and 8 are
equipped with interleaved fingers which are bored through lat-
erally and held by the common axle 18. For example, the three
fingers 35 to 37 of the upper jaw 7 interleave with the three
fingers 38 to 40 of the lower jaw with all bores aligned and
the common axle is inserted. The fit between these fingers and
the axle is preferably snug, yet allows the jaws to rotate in-
dependently of each other on the axle. The fingers inhibit
lateral motion of the two jaws with respect to each other and
the fit on the axle is sufficiently snug that the pivotal axis
18' of the jaws, defined by the ax~e, is invariable once the
I axle discs are locked in position.
The front or gripping end of each of the jaws of the clamp,
shown in Figure 4, is equipped with a gripping plate. These are
2~
upper jaw gripping plate 41 and lower jaw gripping plate 42. m e
plates are adjustable so that they can be attached to their res-
pective jaws parallel to each other or at a slight angle to each
other. The parallel arrangement is usually preferred. However,
to accommodate ice skate blades of tapered thickness from one
end to the other, it is sometimes necessary to adjust these
gripping plates to insure that they grip the skate blade evenly
and firmly.
Operation of the clamp to hold the ice skate for the fini-
shing grind of the blade is illustrated in Figures 6 and 7.
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These figures exaggerate some of the dimensions of parts of the
clamp in order to illustrate the operation, however, parts which
correspond to the parts described in Figuresl to 6 bear the same
refere~ce number. The a~le 18 can be positioned by loosening
the set screws 43 and 44 and rotating the discs l9a and l9b
on their axis 19'. If the axle and discs form a rigid piece,
it is clear that the discs are rotated together and locking
one, locks both. This rigid structure o~ axle and discs permits
changing the displacement of the axle from the base, but does
not permit changing the angle of the axle to the base.
The axel 18 and discs l9a and l9b need not form a rigid
piece and may be so constructed that the axle can pivot where
it connects to each disc. For example, the axle could connect
to each disc by a ball and socket joint; or, as shown in Figs.
1 and 5, each end of the axle 18 is recessed to provide studs
45a and 45b concentric with the axle. These studs fit very
loosely in eccentric bores 46a and 46b in discs l9a and 19b,
respectively, and so there is some pivotal freedom of the axle
with respect to each disc. That pivotal freedom allows some
independent rotation of the two discs. Thus, from the position
shown in Figure 1, one disc may be rotated clockwise through a
slightly greater angle than the other and then both discs are
locked by the set screws. This action reduces the separation
between axle 18 and base 5 and also tilts the axle so that it is
at an acute angle with respect to the base. Indices, such as
47 on the discs and pedestals may be provided to enable the op-
erator to set the angle.
Where the axle 18 is held slightly pivotally at each disc
l9a and disc l9b, to permit tilting the axle, the fit of the
interlocked jaws (by interlocking fingers 35 to 40) between the
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pedestals 21a and 21b must be loose enough to allow the tilt.
This does not mean, however, that the fingers must fit together
loosely or that the axle must fit 1005ely in the acco~modating
bore through the fingers.
The cam 27 may have any of a variety of shapes. It is
generally required that the cam spread the jaw lever arms 23
and 24 together through the same angle so that the gripping
plates 41 and 42 close to corresponding equidistant positions
on each side of the plane 16, as shown in Figure 7, to grip the
ice skate blade. For example, the cam may be shaped with two
planes of symmetry passing through the cam axis 30 and so, the
cam may be shaped as an ellipse. When the long axis of this
ellipse falls in plane 16, the jaws open as wide as they can
as urged by spring 32. Then when the long axis of the ellipse
is turned perpendicular to plane 16, the gripping plates 41
and 42 close evenly on the ice skate blade 3 gripping and hold-
ing it with the central plane 16 of the blade c~-planar with
the central plane 17 of the grinding wheel 11.
SECOND EMBODIMENT - TWO AX~
In this embodiment, only the jaw axle need be different
from the first embodiment. Even the discs by which the axles
are mounted to the yoke may be the same as in the first embod-
iment and the jaws may be identical and interchangeable as well
as the pedestals.
The double axle 46, shown in Figure 8 includes the upper
jaw eccentric axle 47 that pivotally supports the upper jaw
7 for rotation on upper jaw axis 47' and the lower jaw eccen-
tric axle 48 that pivotally supports the lower jaw 8 for rota-
tion on the lower jaw axis 48'. Both of these axl~s 47 and
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48, are carried by the discs l9a and l9b which defines the disc
axis 19' and the upper and lower jaw axes 47' and 48' are
parallel to and equally spaced from the disc axis 19'. The
sections of each axle 47 and 48 are interleaved like the fingers
of the jaws so that the upper jaw 7 pivots on axis 47' and the
lower jaw 8 pivots on axis 48'.
Where it is intended that the upper and lower jaws be inter-
changeable and each a single piece, the double axle 46 must be
assembled with the jaws. To permit this assembly, the segments
of the upper and lower axels come apart and fasten together
at the assembly so that the axes 47' and 48' are in fixed rela-
tionship to each other. For this purpose, two pins 51 and 52
are inserted through accommodating holes in all the segments of
both axels parallel to the axes. These pins hold the axle seg-
ments together in fixed eccentric position with respect to each
other. At assembly, the segments are inserted in the accommo-
dating bores through the fingers of the jaws, the jaws are then
asse~ibled by inte~leaving the fingers, as shown in Figure 3,
and the two pins 51 and 52 are inserted.
The end segment 48" of axlq 48 has a stud 53 concentric
with axis 48' and this stud fits the accolrunodating bore 46a in
disc l9a. Similarly, the end segment 47" of axl~ 47 has a stud
54 concentric with axis 47' that fits the accommodating bore 46b
in disc l9b.
Operation of this embodiment of the clamp is illustrated
by Figures 9 and 10. These figures exaggerate dimensions to
illustrate the function of the double axle. Before the ice skate
blade is gripped by the clamp, the discs l9a and l9b are rotated
slightly in yoke 21 to decrease the space between the upper and
lower pivot axes 47' and 48' and the central plane 16.
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1 For example, when the discs are rotated slightly counterclock-
wise and then locked by the set screws 43 and 44, the upper and
lower axles 47 and 48 are positioned as shown in Figure 9. At
this position, the lower jaw is moved slightly forward and the
upper jaw is moved slightly backward, causing a slight misalign-
ment of the two plates 41 and 42. However, those plates are~
sufficiently thick that they overlap even when this adjustment
occurs. Then the relatively thin ice skate blade 3' is gripped
and held, as shown in Figure 10 by rotating the cam 27 so that
its major axis is perpendicular to the central plane 16 of the
blade.
One function of the double axle is to provide for adjusting
the gap between the gripping plates at the end of the jaws to
ac~anmo~e for gripping thick and thin blades. The double axle
3hown in Figure 8 spaces the upper and lower axes 47' and 48'
equidistant from the axis 19' of the discs and axis 19' is fixed
with reference to the base. Thus, the plane 16 is at a fixed
spacing above the base 5 and this spacing cannot be changed.
However, where the studs 53 and 54 fit loosely in their accommo-
dating bores 46a and 46b in discs l9a and l9b, respectively, one
disc may be rotated in its yoke more or less than the other and
then when the discs are locked, both axles 47 and 48 will tilt
slightly with reference to the base.
As described above with reference to Figure 8, the double
axle may be constructed in segments which are assembled with the
fingers of the jaws and then the fingers are interleaved and
the pins 51 and 52 are inserted parallel to the axes to lock
the axles with respect to each other. In that construction,
all the segments of both axles; could be identical except the
two end segments 47" and 48" which carry the studs. That con-
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struction of the double a~le permits the jaws to be each a single
piece and the jaws can be identical.
The two axl~s 47 and 48 and studs 53 and 54 could be made
in a single rigid piece. However, that would require that each
jaw be made in at least two pieces. The finger enclosing each
segment of an axle would have to be in two parts.
Another alternative is to make the two axles 47 and 48 and
discs l9a and l9b in a single rigid piece. However, that con-
struction would not permit the tilt variation accomplished in the
10manner described herein.
In all cases, the two axle axes could be unequally spaced
from the axis of the discs. Then, a rotation of the discs would
raise and lower the gripping plates.
It is sometimes the practice to do a rough grind of the
blade to give the blade the desired arc from front to back,
against a grinding wheel oriented with the plane of the wheel
perpendicular to the plane of the blade. Clearly, the clamp
described herein can be used to hold the skate for that purpose
also. However, the clamp is particularly useful for accomp-
lishing the finishing or parallel grind that produces the smooth,
even edges 13 and 14 and slightly concave surface 12 therebetween.
The embodiments of the present invention described herein,
represent the best known use of the invention and incorporate
all of the features of the invention. It is to be clearly un-
derstood, however, that some of these features can be employed
independently of the others to gain at least some of the advan-
tages of the invention. Furthermore, certain minor changes could
be made and other combinations of the features could be used with-
out departing from the spirit and scope of the invention set forth
30in the appended claims.
