Note: Descriptions are shown in the official language in which they were submitted.
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DEVICE FOR ALIGNING A SKATE SHARPENING JIG
WITH A GRINDING TOOL
Background of the Invention
The present invention relates to ice skate sharpening devices and in
particular to skate sharpeners operating with a skate clamping jig having two
support legs and a planar, downwardly directed guide surface parallel with the
planes of the clamps of the jig.
An example of such jig or clamp is shown in Figure 1. It comprises a
lower clamping member having an L-shaped cross section defined by a
horizontal flange 11 and a vertical lower jaw 12. The downwardly facing
underside 1 1 a formed by a stainless steel layer affixed to the flange 1 1 is
precisely ground to a planar shape parallel with the narrow, likewise planar,
clamping edge 13. A first corner column 14 is fixedly secured to one end of
the clamping member 10. An integrally formed leg 15 projects rearwards from
the column 14. It comprises a generally horizontal portion 16 and a vertical
portion 17 terminating at a downwardly turned slide surface 18 provided with
a Teflon (T"") layer. The teflon layer normally rests on a planar top of a
table of
a skate sharpening apparatus as will be described. The opposite end of the
clamping member 10 is similarly structured with the corresponding parts 15a -
18a. Each corner column 14 carries an upwardly projecting threaded stem (not
visible in the drawings) passing through a respective cylindric end member 19,
19a integrally formed with an inverted L-shaped upper clamping member
including a horizontal flange 21 and a downwardly dependent upper jaw (not
visible in Fig. 1 ). The threaded stem of each column 14, 14a passes freely
through the associated end member 19, 19a and is engaged by a hand nut 22,
22a. The jig presents a simple holder of the skate ready for sharpening. With
the runner 23 secured between the clamping jaws, the downwardly facing side
of the runner is parallel with the underside of the lower clamping member.
Accordingly, when the underside 1 1 a is slidably supported by a column, while
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the teflon surfaces 18, 18a slide on the planar base or table of the
sharpening
apparatus, the jig is held in a position shown in Fig. 1. Such position can be
finely adjusted by raising or lowering the support post or column (not shown
in Fig. 1 ~ to vertically align the edge of the runner 23 with the respective
sharpening tool.
The described type of jigs is known to have been used with a skate
sharpener having a planar table, a grinding disc and a supporting post having
a top face spaced vertically above the table and adapted to support the jig
holding the skate, by slidably supporting the guide surface. The jig is of a
simple structure. Several jigs of different size may be provided for a given
sharpening device, to accommodate the desired variety of ice skates, for
instance, figure skating, ice hockey, or recreational ice skates.
In competitive or professional sports involving ice skating, e.g. figure
skating, ice hockey, speed skating, it is of utmost importance that the skates
of the performer be sharpened within very close tolerances to the specific
requirements of the skater or skaters. While the ice hockey skates are usually
sharpened to provide a radius of the groove at the edge of the skate runner of
about 1 /2", the radius of figure skating blades varies from about 3/8" to
about
3/4", depending on the performer's preferred skates. In any event, the concave
longitudinal groove in the edge of the runner of the skate must be perfectly
centred with respect to the cross-section of the edge.
An accurate skate sharpening is significant for success in ice skating
sports. Some of hockey teams involved in top competition even bring their own
technician with a specific sharpening device to keep the players' skates
sharpened to their liking. Indeed, cases have been reported, where the
performance of a hockey team participating in a world championship was
seriously hampered as its sharpening technician's machine could not be used
for difference in voltage of the electric network at the championship venue.
The situation is even more serious and demanding in figure skating. A very
slight deviation from the required shape of the edge of the skate runner may
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inhibit the performance of the competitor and result in substantially lower
marks in a competition, often with serious financial consequences where a
future professional carrier of a competitor is at stake.
The accuracy of the ice skate sharpening depends on the accuracy of
alignment of the edge of the runner with the sharpening disc or roller. To
this
end, many complex skate clamping jigs exist. However, such jigs have a
complicated structure and thus are expensive. Also, they require considerable
skill of the operator to adjust.
The jig shown in Fig. 1, provided with two separate legs integrally
formed with the lower clamping jaw 12, combined with a support post fixedly
secured to the sharpening device near the grinding tool is known to possess
the advantage of relatively low production costs while securing the desired
flexibility and accuracy.
The jig of this kind requires a supporting post close to the grinding tool.
In prior art devices, the post is threaded into an inner thread of a vertical
bore
in the table of the sharpening device. A locking nut is used to secure the
post
at an adjusted height. If it is desired to raise or to lower the post to
properly
align the clamped skate runner, the jig is removed from the post, the locking
nut released and the post turned in the desired direction, followed by the
tightening of the locking nut. This is a much simpler operation than the
adjustment of other known jigs.
Summary of the Invention
It is an object of the present invention to further advance the art of ice
skate sharpening by further facilitating the operation of alignment of the
skate
runner being sharpened with the sharpening or grinding tool.
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In general terms, the invention provides a skate sharpening device for
use with a skate holding clamp which clamp includes a planar, elongated guide
surface parallel with a side surface of an ice skate runner when the latter is
clamped in said clamp. The device comprises a base which defines a planar
support table having a front, operator's end portion and a rear end portion.
The
base also defines a top surface coincident with a generally horizontal
reference
plane. The base supports, at a point remote from the operator's end, a
rotatable grinding tool disposed at a spacing above the reference plane. A
post
is mounted on said base proximate to the grinding tool between the grinding
tool and the operator's end. It projects vertically upwardly from said table
to
define an upwardly turned support face spaced vertically above the reference
plane. According to the invention, the post is operatively associated with a
remote control device secured to said base and including a control member,
preferably near said operator's end portion, adapted to selectively adjust the
distance between said support face and said reference plane, whereby an
instant vertical position of said support face is adjustable from a point
remote
from said grinding tool.
Brief Description of the Drawings
The invention will now be described by way of an operative prototype
with reference to the accompanying drawings. In the drawings:
Figure 1 is a diagrammatic perspective view showing the skate clamping
jig or clamp for use with the present invention;
Figure 2 is a diagrammatic perspective view of a skate sharpening device
showing the jig or clamp in use with one of two skate sharpening
tools, a large number of obvious parts such as drive motors
debris, exhaust covers of the grinding tools or switches being
omitted for clarity;
Figure 3 is a sectional view taken along the section line III-III of Figure 2;
and
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Figure 4 is an enlarged partial sectional view taken along the section line
IV-IV of Fig. 2
Detailed Description of Preferred Embodiments
A base 30 defines a support table 31. In the embodiment shown, the
table 31 is of a rectangular configuration. It includes a front, operator's
end
portion 32 and an opposed rear end portion 33. The top surface 31 a is planar
and coincides with a generally horizontal reference plane 34 (Fig. 3).
At a point remote from the operator's end 32, the base 30 supports a
rotatable grinding tool or disc 35 mounted on a driven spindle 36 which
maintains the disc 35 spaced above the plane 34. A post 37 is mounted to the
base 30 proximate to the grinding disc 35 between the grind disc 35 and the
operator's end 32. The post 37 includes an upwardly turned support face 38.
In a preferred embodiment, a second rotatable grinding tool 39 is
provided at a lateral spacing from the disc 35. The second tool 39 has a
cylindric grinding surface of the diameter twice the required radius of the
runner edge groove of the skate. As mentioned above, such radius is about
1 /2" for an ice hockey skate and is from about 3/8" to about 3/4" for figure
skating skates. Thus, the diameter of the grinding tool 39, if used for ice
hockey skates (where it may not be required), is about 1 inch and, if used for
figure skates, from about 3/4" to about 1 '/2 ". Since the grinding surface of
the
tool 39 is cylindric, the tool 39 may also be referred to as a "grinding
roller"
even though the shape shown is a very short roller and thus resembles a disc.
A driven spindle 40 maintains the roller vertically above the reference plane
34.
A second post 37a is mounted to the base 30 proximate to the roller 39.
The post 37a is of identical structure with the post 37. It includes an
upwardly
turned support surface 38a.
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For clarity, the post 37 is referred to as "a first post" and the post 37a
as "a second post" it being understood that the structure of both the first
and
the second post and of their control devices to be described is identical.
Therefore, it will suffice if only one control device is described, namely the
control device of the "second" post 37a shown in Fig. 3. The representation
of this figure shows the post 37a in an operative position where it supports
the
jig as also indicated in broken lines of Fig. 2.
The control device shown includes a horizontal threaded shaft 41
mounted for rotation and for free axial displacement along its axis, relative
to
the base 30. The shaft 41 is disposed below the table 31 and includes a
threaded portion 42. With particular reference to Fig. 4, a guide nut 43 is
engaged with the thread 42. The guide nut includes a pair of axially aligned
pivot pins 44, 45, projecting horizontally to both sides of the nut 43 and
pivotally mounted to a lower end of a pair of links 46, 47 of a first drive
link
arrangement. Two locking clips such as a circlip 48 retain the links 46, 47 on
the pivots 44, 45.
The upper end of the link arrangement 46, 47 is pivotably secured to a
lower end of the post 37a by means of a pivot pin 49 with retaining circlips,
of which only the clip 50 is visible in Fig. 3. The lower end of the post 37a
is
pivotably secured, in the embodiment shown, by the same pivot pin 49, to a
pair of links 51 ( 52 the lower ends of which are pivotably secured to a
bearing
sleeve 53 via sideways projecting journals 54, 55 and circlips 56. Two
circlips
57, 58 secured to the smaller diameter end 41 a of the shaft 41 retain axial
position of the sleeve 53 while permitting its pivoting on the shaft.
Thus, the link arrangements 46-47 and 51-52 are pivotable about lateral
axes which are perpendicular to the elongation of the shaft 41. They generally
define an inverted V-shaped arrangement having an upper, apex portion 59
which is pivotable about a transverse axis parallel with the said lateral
axes.
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A hand wheel 60a (functionally identical with the hand wheel 60 in Fig.
2) serves the purpose of turning the shaft 41 in one direction or another. The
turning of the wheel 60a results in spreading or narrowing the angle between
the link arrangements 46-47, 51-52 at the apex portion 59 and thus raises or
lowers the post 37 to align the runner 23 with the grinding roller 39 or - in
case of the first grinding tool - with the disk 35 rotating about a vertical
axis.
The corresponding axial displacement of the shaft 41 takes place at the same
time.
In operation, the skate is fixed in the clamp or jig by placing the runner
23 between the clamping jaws and tightening hand nuts 22, 22a. The precisely
ground underside 1 1 a of the flange 1 1 is then placed on the support surface
38a and the alignment with the grinding disc 35 or roller 39 checked. Any
misalignment is compensated for by manipulating the control wheel 60a with
the resulting raising or lowering of the post 37a and thus of the support
surface 38a. The skate is then sharpened by sliding the jig supported on the
surface 38a with the skate across the roller 39. This provides a precise
radius
of the groove at the edge of the runner. The grinding roller 39 grinds the
runner
transversely of its elongation. The grinding roller 39, being of a small
diameter,
is used only for very few pairs of skates, sometimes only one pair, and is
often
replaced by a fresh roller.
With the skate having been sharpened by the roller 39, a similar
alignment, if required, is made at the post 37 of the grinding disc 35. Again,
the alignment can be made quickly and readily by simply operating the hand
wheel 60 in a desired manner. The disc 35, whose circumference is dressed
to the desired convex cross-sectional radius, is then used to smoothen the
groove previously ground by the roller 39. This finishes the sharpening
operation by fine grinding tangentially of the elongation of the skate runner.
The described mechanism of alignment of the support surfaces 38, 38a
has been tested and surprisingly found to provide quick and precise operation
despite its structural simplicity and ease of manufacture. This is not to say
that
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it could not be substituted by many obvious modifications of a mechanism for
raising or lowering the post 36 by operating a remote control which does not
necessarily have to be a hand wheel 60. Just as an example, a modification
comes to mind which would use two counter-directed threads on the rod 41
engaged with compatible guide nuts, one at each end of the links of the
inverted V. Another example may have a mechanism of a raising or lowering
nut driven by a bevel gear combined with an upright threaded stem. Even a
hydraulic or electrical device may be used for the same purpose providing
remote control means for the same purpose. Furthermore, while the use of the
two sharpening tools as described is clearly preferred, the principle of
remotely
controlled raising of the support column can be used in machines having only
a single sharpening tool which would preferably use a grinding disc such as
disc 35. Such arrangement may be suitable for ice hockey skate sharpening.
The shape of the post is optional as well. While a cylindric column is
preferred,
other shapes, for instance prisms, can also be used as the supporting posts.
Another readily conceivable modification, while not preferred for complexity,
would change the pivoting of the apex portion of the links such that each link
arrangements would have a separate transverse pivot axis at the column.
These and many other obvious modifications may differ from the
structure described but they do not depart from the scope of present invention
as defined in the accompanying claims.
