U.S. patent number 3,881,280 [Application Number 05/518,235] was granted by the patent office on 1975-05-06 for ice skate sharpening device with a floating skate guiding member.
Invention is credited to Arnold M. Thompson.
United States Patent |
3,881,280 |
Thompson |
May 6, 1975 |
Ice skate sharpening device with a floating skate guiding
member
Abstract
A bench-mounted skate sharpening device embodying a base plate
on which there is mounted an electric motor having a drive shaft
which carries a rotary abrasive grinding wheel. A casing on the
base plate encloses the grinding wheel and has an opening in its
top wall which exposes a limited portion of the grinding wheel and
renders the latter accessible for application thereto of a skate
blade. A cradle member which is capable of limited oscillation
within the opening adjustably receives thereon a skate blade guide
assembly which defines a guide slot through which the skate blade
to be sharpened is manually pushed longitudinally in order to draw
the edge of the blade progressively and transversely across the
periphery of the grinding wheel, the assembly being so designed
that the lateral frictional thrust of the grinding wheel against
the blade tends to bring the latter into coincidence with the
general plane of the wheel. Micrometer-type adjustment is provided
for shifting the skate blade guide assembly laterally on the cradle
member in order to compensate for skate blades of varying
thicknesses. The base plate, when loosely positioned on a bench or
other subjacent supporting surface, is capable of limited rocking
movement thereon and is spring-biased in a direction so that it
will yield to the downward pressure exerted by the skate blade on
the grinding wheel.
Inventors: |
Thompson; Arnold M. (Wheaton,
IL) |
Family
ID: |
24063132 |
Appl.
No.: |
05/518,235 |
Filed: |
October 29, 1974 |
Current U.S.
Class: |
451/241;
451/383 |
Current CPC
Class: |
B24B
3/003 (20130101) |
Current International
Class: |
B24B
3/00 (20060101); B24b 009/04 () |
Field of
Search: |
;51/102,17R,17PT,228
;76/23 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kelly; Donald G.
Assistant Examiner: Godici; Nicholas P.
Attorney, Agent or Firm: Gerlach; Norman H.
Claims
Having thus described the invention what I claim as new and desire
to secure by Letters Patent is:
1. A skate blade sharpening device adapted to hollow grind the
effective supporting edge of a skate blade and comprising a base
plate adapted for positioning on a bench top or the like, an
electric motor mounted on said base plate and having a drive shaft
projecting forwardly therefrom, a circular abrasive grinding wheel
fixedly mounted on the forward end of said shaft, a casing
emcompassing said wheel and a portion of the shaft, the upper
region of said casing being provided with an opening which exposes
a limited peripheral region of the wheel for transverse application
thereto of the skate blade at such time as the supporting edge of
the latter is drawn progressively and longitudinally through the
slot, a floating cradle member at least in part encompassing said
shaft and capable of limited free oscillation about the axis of the
shaft, and a blade-positioning and guide assembly defining a
blade-receiving slot for sliding reception therein of the skate
blade and adjustably mounted on the cradle member for small
increments of lateral adjustment in a generally tangential
direction with respect to the grinding wheel.
2. A skate blade sharpening device as set forth in claim 1 and
wherein one side wall of said blade-receiving slot is laterally
yieldable and normally serves to displace the skate blade and
compress the same against the opposite side wall of the slot, said
latter side wall being fixed with respect to the blade-positioning
and guide assembly.
3. A skate blade sharpening device as set forth in claim 2 and
wherein said blade positioning and guide assembly is slidable
bodily on said cradle member, and means are provided for releasably
clamping said assembly in selected positions of lateral
adjustment.
4. A skate blade sharpening device as set forth in claim 3 and
wherein a micrometer adjusting screw is provided for adjusting the
position of the blade-positioning and guide assembly on said cradle
member when the clamping means is released.
5. A skate blade sharpening device as set forth in claim 4 and
wherein bearing means are interposed between said motor shaft and
floating cradle member and are effective at least in part movably
to support the latter on the motor shaft during rotation of the
latter.
6. A skate blade sharpening device as set forth in claim 5 and
wherein a housing is provided for the electric motor and is mounted
on the base plate, the housing includes a front wall having a
circular opening therein, and the cradle member includes a rearward
tubular extension which projects loosely into said circular
opening, said tubular extension and circular opening constituting
additional bearing means for movably supporting the cradle
member.
7. A skate blade sharpening device as set forth in claim 6 and
wherein said housing for the motor is provided with a top wall the
general plane of which is horizontal and is disposed approximately
in tangential relationship with respect to the grinding wheel, and
an elongated longitudinally extending clearance slot is formed in
said top wall for guiding the skate blade through said
blade-receiving slot.
8. A skate blade sharpening device as set forth in claim 7 and
wherein spring means are provided for yieldingly supporting said
base plate on said bench top, said spring means being designed to
assimilate the downward thrust of the skate blade on the grinding
wheel during skate-sharpening operations.
9. A skate blade sharpening device as set forth in claim 8 and
wherein said spring means is effective between the forward end
region of the base plate and the bench top, whereby when the rear
end region of the base plate is effectively positioned on the bench
top, the base plate is supported on the latter for limited fore and
aft rocking movement.
10. A skate blade sharpening device as set forth in claim 1 and
wherein spring means are provided for yieldingly supporting said
base plate on the bench top, said spring means comprising a
plunger-like foot member projecting through an opening adjacent to
the forward end region of the base plate, and a compression spring
encompassing said foot member and yieldingly urging the latter
downwardly.
Description
The present invention relates to ice skate sharpening device and
has particular reference to a novel bench-mounted device embodying
a skate blade positioning or guiding assembly of the general type
which is described in U.S. Pat. No. 3,812,626, granted to me on May
28, 1974, and entitled "ICE SKATE SHARPENING DEVICE." However, in
the present ice skate sharpening device, the skate blade
positioning or guiding assembly is adjustably mounted on a floating
oscillatable cradle member which is possessed of limited
circumferential movement in either direction about the axis of the
grinding wheel to the end that the skate blade positioning or
guiding assembly itself is similarly oscillatable and to the
further end that said assembly may be effectively clamped in any
selected position of adjustment on the cradle member in order to
center the skate blade to be sharpened and bring it into
coincidence with a diametric plane of the grinding wheel during
skate blade sharpening operations.
In the skate sharpening device of my aforementioned patent, the
function of the aforementioned skate blade postioning or guiding
assembly, when considered as a unit, is to define a skate blade
guide slot through which the skate blade undergoing sharpening is
adapted to be drawn in a lengthwise direction and which, when so
drawn, maintains the skate blade properly addressed to the grinding
wheel so that there will be neither angular tilting of the blade
within the slot nor lateral displacement of the blade within such
slot. In either event, angular tilting or lateral displacement of
the blade would result in obliteration of one of the two sharp
longitudinal edges of a properly hollow ground skate blade. The
blade-receiving guide slot of both the patented device and the
device of the present invention is established by the provision of
a pair of wear plates which straddle the skate blade and one of
which is yieldingly biased against the skate blade. The tendency of
such yieldingly biased wear plate is to urge the skate blade toward
an erect position where the general plane of the skate blade
coincident with the plane of the grinding wheel where skate blades
of varying width are concerned, it is necessary to maintain an
inventory of different width wear plates and to effect wear plate
substitution whenever a change in the thickness of a skate blade
which is to be sharpened is encountered. Stated otherwise, in the
patented device, assuming that a given pair of wear plates, when
installed in the skate blade positioning or guiding device, will
function properly to maintain a given skate blade not only erect,
but also to cause its general plane to coincide with that of the
grinding wheel, then a uniform and symmetrical hollow grind will
obtain on the skate blade. These same wear plates will thereafter
function properly for skate blade erection purposes, providing that
the thicknness of successive skate blades undergoing sharpening is
not changed. Assuming now that a wider skate blade is to be
sharpened, if such blade is forced into the slot defined by the
opposed wear plates, skate blade erection will take place, but
because only one of the wear plates is yieldable, the skate blade
will become offset laterally by a distance equal to one-half the
thickness differential between the original skate blade and the
wider skate blade. The extent of this later offset, although
relatively small and on the order of only five-thousandths of an
inch, nevertheless is of sufficient magnitude as to shift one of
the two sharp skate blade skating edges on opposite sides of the
previously formed hollow grind directly onto the periphery of the
grinding wheel, thereby eradicating such sharp skating edge
altogether. For this reason, it is necessary with the patented
device to make a substitution of wear plates, utilizing wear plates
which are of lesser thickness.
Another and important feature of the present invention resides in
the provision of a floating support for the entire device, such
support being in the form of a spring mounting for the forward end
of the elongated base plate on which the operative skate sharpening
instrumentalities are effectively mounted. The rear end region of
the base plate is tiltably or pivotally supported directly on the
bench or other subjacent surface which supports the device while
the front end region of the base plate is floatingly supported by
means of a compression spring which yields under the weight of the
device, as well as under the downward thrust which is exerted on
the grinding wheel during skate-sharpening operations. By such an
arrangement, unequal or varying downward thrust of the skate blade
on the grinding wheel during skate blade traverse is equalized and
a more uniform hollow grind of the skate blade is obtained.
The provision of a skate blade sharpening device such as has
briefly been outlined above constitutes the principal object of the
present invention.
Another object of the invention is to provide an ice skate
sharpening device which is generally of new and improved
construction and is characterized by ease and high efficiency of
operation.
Further objects and advantages of the invention, not at this time
enumerated, will readily suggest themselves as the nature of the
invention is better understood from a consideration of the
following detailed description.
The invention consists in the several novel features which are
hereinafter set forth and are more particularly defined by the
claims at the conclusion hereof.
In the accompanying three sheets of drawings forming a part of this
specification, one illustrative embodiment of the invention is
shown.
In these drawings:
FIG. 1 is a perspective view of an ice skate sharpening device
embodying the principles of the present invention, such view
showing a skate blade in the process of being sharpened;
FIG. 2 is a side elevational view of the device of FIG. 1;
FIG. 3 is an enlarged exploded perspective view of the major
operating components of the device;
FIG. 4 is a front end elevational view of the device of FIG. 2, the
skate blade being shown in transverse section;
FIG. 5 is an enlarged fragmentary sectional view taken on the line
5--5 of FIG. 2;
FIG. 6 is a longtitudinal sectional view taken on the line 6--6 of
FIG. 4; and
FIG. 7 is an enlarged transverse sectional view taken on the line
7--7 of FIG. 6.
Referring now to the drawings in detail and in particular to FIGS.
1 and 2, a skate sharpening device embodying the principles of the
present invention is designated in its entirety by the reference
numeral 10, the device being essentially a bench model type, which
is to say that, when it is being used for skate-sharpening
purposes, it is adapted to be positioned on a bench, table top, or
other planar horizontal supporting surface such as that which is
designated by the reference numeral 12 in FIGS. 1 and 2.
Functionally, the device 10 is of the general type wherein a skate
blade which is to be sharpened is drawn longitudinally through a
slot which is defined by a skate blade positioning, guiding and
supporting assembly, and the skate blade, in so moving, has its
edge drawn progressively and transversely through the slot and over
the periphery of a rapidly rotating grinding wheel.
Referring additionally to FIGS. 4 and 6 of the drawings, the device
10 involves in its general organization a rectangular base plate 14
on which there is fixedly mounted a housing 16 for an electric
motor M. The base plate 14 also has mounted thereon a casing 18
which is located directly in front on the housing 16 and defines an
enclosure for a grinding wheel 20, the latter being mounted on the
forward projecting end of the shaft 22 of the motor M. The housing
16 is of rectangular box-like configuration and includes front and
rear walls 24 and 26, louver-equipped side walls 28 and 30, and a
top wall 32, the latter being provided with a centrally disposed
longitudinally extending groove 34 (see in particular FIG. 3) which
serves a function that will be made clear presently.
The bottom portion of the box-like housing 16 is open so that the
base portion of the motor M may seat directly on the base plate 14
as clearly shown in FIG. 6. An electric lead-in cable 36 extends
through the rear wall 26 of the housing 16 and said rear wall
serves to support the usual off-on switch 37 for effecting manual
control of the motor M. The front wall 24 of the housing is
provided with a circular opening 38 therethrough and the front end
portion of the motor shaft 22 projects forwardly through this
opening. The latter is appreciably larger in diameter than the
diameter of the motor shaft 22 by reason of the fact that it serves
rotatably to receive therein the rear projecting end of a tubular
extension 40 (see also FIG. 3) which is provided on a
circumferentially shiftable or oscillatable floating cradle member
42, the nature and function of which will be described in detail
hereafter.
As best shown in FIG. 3 of the drawings, the casing 18 is
preferably formed of a suitable plastic material, if of box-like
configuration, and includes a front wall 44, side walls 48 and 50,
and an interrupted top wall 52, the bottom and rear end portions of
the casing being open. The lower rim of the casing 18 is adapted to
seat on the upper face of the base plate 14 with the rear open end
portion of the casing abutting against the front wall 24 of the
housing 16 so that the housing and casing assume a contiguous
relationship on the base plate 14. The casing 18 is maintained in
its longitudinally centered position on the base plate by means of
a pair of side members 54 and an end plate 56, these members and
plate, in combination with the front wall 24 of the housing 16,
providing in effect a pilot space for the lower rim region of the
casing 18. A locking screw 58 with a knurled head extends through
the end plate 56 and serves releasably to secure the casing 18 in a
fixed position on the base plate.
Referring now to FIGS. 4 and 6 of the drawings, it will be observed
that the elevation of the motor shaft 22 above the base plate 14
and the diameter of the grinding wheel 20 are such that the
periphery of the grinding wheel lies slightly below the horizontal
level of the upper face of the top wall 32 of the motor housing 16.
The top wall 52 of the casing 18 lies slightly below the level of
the top wall 32 of the housing 16, while the peripheral region of
the grinding wheel 20 projects upwardly through a generally
rectangular opening 59 (see FIG. 3) which is formed in the top wall
52 (see FIGS. 1 and 3) where it is exposed for skate
blade-sharpening purposes.
The aforementioned cradle member 42, of which the tubular extension
40 forms a part, is best illustrated in FIG. 3 and is preferably
but not necessarily formed of a suitable plastic material. This
cradle member 42 functions as a rocking support for a skate
blade-positioning or guide assembly 60, the latter being adjustably
mounted on the cradle member in a manner and for a purpose that
will become clear presently. The cradle member 42 is in the form of
a metal casting and has a body portion 62 from which there projects
forwardly a pair of wing-like shields 64 (see FIGS. 3 and 7) which
straddle the upper region of the grinding wheel 20. The
aforementioned tubular extension 40 of the cradle member 42 has
formed therein a central cylindrical bore 66 (see FIGS. 3, 6 and 7)
through which the front end portion of the motor shaft 22 projects
and this bore is provided with a forward counterbore 68 which
receives therein a bearing sleeve 70. The latter surrounds the
motor shaft 22 and constitutes a means for rockably supporting the
cradle member 42 on the shaft for limited swinging movement from
side to side throughout a small arc of movement. A washer 72 is
disposed immediately forwardly of the sleeve 70, bears against an
annular shoulder 73 of the shaft 22, and cooperates with a clamping
washer 74 and a nut 76 on the forward end of the shaft fixedly to
secure the grinding wheel on the shaft.
The aforementioned skate blade guide assembly 60 is adjustably
mounted on the cradle member 42 for limited sliding movement in a
generally tangential direction with respect to the periphery of the
grinding wheel 20. This assembly, when secured in any selected
position of adjustment on the cradle member 42, is thereafter
movable bodily with such cradle member as the latter is oscillated
in either circumferential direction under the influence of manual
skate blade movements during a skate sharpening operation. As will
become readily apparent when the nature of the skate blade guide
assembly 60 is set forth, this assembly defines an adjustable width
blade-receiving slot 80 (see FIGS. 3, 4 and 7) through which a
skate blade, such as the blade B of FIGS. 1, 2, 4 and 5, is adapted
to be drawn longitudinally, while at the same time such blade is
maintained in frictional contact with the upper peripheral portion
of the grinding wheel 20. The width of the slot 80 is adjustable to
accommodate skate blades of varying widths. It is obvious that,
regardless of skate blade width, it is essential when skate
blade-sharpening operations are in progress, that the plane of the
skate blade be maintained in true diametric relationship with
respect to the rotating grinding wheel 20 so that the sharp skating
edges of the hollow grind which is created in the skate blade edge
will lie in the same horizontal plane when the skate blade is
vertical. This necessitates that for any given width of the slot
80, the medial plane of the skate blade must coincide with a
diameter of the grinding wheel. The function of the skate blade
guide assembly 60 is to inhibit angular inclination of the skate
blade from side to side, while the function of the cradle member 42
is to center the skate blade so that, as aforesaid, it will be
coincident with a diametric plane of the rotating grinding wheel 20
during skate blade-sharpening operations.
Accordingly, and as best illustrated in FIG. 3, the skate blade
guide assembly 60 involves in its general organization a rigid
one-piece guide block 82 having two substantially identical,
laterally spaced, arched side wings 84 and 86, the latter being
connected together near their ends by a front base strut 88 and a
rear base strut 90. The side wing 86 has formed therein a smooth
bore 92 (see FIGS. 5 and 7) which receives a horizontally extending
adjusting screw 94 by means of which a shoe-like wear plate 96
having a tapped hole 98 therein may be fixedly clamped to the
inside face of the side wing 86. The side wing 84 has formed
therein a horizontally extending socket 100 within which there is
seated one end of a helical compression spring 102. The other end
of the spring 102 projects a small distance outwards of the open
end of the socket 100. A horizontally extending screw 104 projects
loosely through a hole in the inner end wall of the socket 100 and
has its left-hand end as viewed in FIG. 5 received in a tapped hole
106 in a second shoe-like wear plate 108. The other end of the
screw 104 has an enlarged kerf-equipped head which abuts against
the outer side face of the side wing 84. The spring 102 maintains
the wear plate 108 spaced from the inside face of said side wing 84
of the guide block 82 and in opposed relationship with respect to
the wear plate 96.
As best shown in FIG. 7 of the drawings, when the two wear plates
96 and 108 are assembled on the guide block 82, they assume spaced
apart positions between the two arched side wings 84 and 86 with
the wear plate 96 fitting against the inside face of the side wing
86 and with the wear plate 108 assuming a position slightly spaced
from the inside face of the side wing 84. In this assembled
position, the two wear plates 96 and 108 define therebetween the
aforementioned blade-receiving slot 80 through which the skate
blade is adapted to be drawn in a longitudinal direction during
skate blade sharpening opertions while the edge of the blade
contacts the upper portion of the periphery of the rotating
grinding wheel 16 as shown in FIG. 5.
The arrangement of parts thus far described insofar as the guide
block 82 and its associated movable and fixed wear plates 108 and
96 are concerned is substantially identical with the guide block
assembly of the skate sharpening device of my aforementioned U.S.
Pat. No. 3,812,626 and no claim is made herein to any novelty
associated with such assembly per se, the novelty of the present
invention residing to a large extent in the mounting of such
assembly on an oscillatable cradle member, such as the member 42,
in order to allow for limited freedom of side sway of the guide
block assembly during skate blade-sharpening operations, thus
inhibiting any tendency of the skate blade B undergoing sharpening
to tilt out of the general or medial plane of the grinding
wheel.
The manner in which the skate blade guide assembly 60 is adjustably
clamped to the cradle member 42 and the manner in which it may be
adjusted in its positional relationship on such cradle member 42 is
best shown in FIG. 3. The end portion of the arched side wing 86
which is nearer the housing 16 is provided with a transverse slot
110 which receives therethrough a clamping screw 112, the lower end
of which is threadedly received in a tapped hole 114 in that
portion of the body portion 62 which is directly beneath the slot
110. The rear end portions of each of the two side wings 84 and 86
rests squarely on the flat upper surface of said body portion 62 of
the cradle member 42 and, when the clamping screw 112 is tightened,
this screw constitutes the sole means for retaining the guide block
82 in position in its adjusted position on the cradle member.
In order to adjust the position of the guide block 82 on the cradle
member 42, an upstanding leaf spring 120 (see FIGS. 3 and 7) is
provided and this projects upwardly from the flat upper surface of
the body portion 62 of the cradle member 42, the lower portion of
the leaf spring being suitably embedded in the material of which
the cradle member is formed. The upper portion of the leaf spring
120 bears against one end portion of the rear base strut 90 of the
guide block 82 and receives the reaction thrust of a horizontally
extending micrometer-type adjustment screw 122. The latter has a
threaded shank portion 124 which passes through a horizontally
extending threaded bore 126 in an upstanding post 128 which is
formed on the body portion 62 of the cradle member 42. At one end
the adjustment screw 122 is provided with an enlarged
indicia-bearing head 130, and its other end the adjustment screw is
provided with a circular thrust plate 132 which bears against the
side of the body portion 62 of the cradle member 42 that is
opposite the leaf spring 120. A pointer 134 which is fastened to
the upstanding post 128 overlies the indicia on the cylindrical
body of the head 130 and cooperates with the same in the usual
manner of micrometer adjusting members. The post 128 is offset
laterally and outwardly of the body portion 62 of the cradle member
42 and a correspondingly offset cut-out or notch 136 (see FIG. 3)
is associated with the opening 59 in order to accommodate such post
when the various heretofore mentioned parts are assembled.
Generally speaking, the blades of commercially available ice skates
are made in three widths representing figure skates, racing skates,
and hockey skates. The difference between the widest blades of
these skates and the narrowest is approximately three-tenths of an
inch and the adjusting screw 94 for the wear plate 96 is so
designed that it will accommodate the transition of the width of
the slot 80 from one width blade to another.
In order that after a change in the adjustment of the width of the
slot 80 has been effected, such change will offset the slot, and
consequently, the skate blade B which is drawn through the slot by
a distance which is equal to one-half of the difference between the
change in skate blade and slot width. To compensate for this, and
also to bring the centerline of the slot 80 into coincidence with a
vertical diametric plane of the grinding wheel, it is necessary to
loosen the clamping screw 112 and actuate the micrometer adjustment
screw 122 accordingly, after which the clamping screw 112 is
adapted to be retightened in order to cause the various parts to
remain in the respective adjusted positions. The adjustment of the
micrometer adjusting screw 122 is a relatively small one, the
change from one size thickness of skate blade to the next larger or
smaller size being only on the order of five-thousandths of an
inch. Therefore, only three indicia marks need be applied to the
indicia-bearing head 130 of the micrometer-type adjusting screw
122, there being one indicia for each type of skate blade.
It has been pointed out that the heretofore described rocking
cradle member 42 by means of which limited side-to-side oscillation
of a skate blade being pulled for forced through the slot 80 is
made possible, constitutes another principal feature of the present
invention. The micrometer adjustment of the skate guide block 82 on
the cradle member 42 constitutes another principal feature of the
invention. A third and important feature of the invention resides
in the provision of a floating mounting for the base plate 14, and
consequently, for the entire skate sharpening device. This floating
mounting is established by the provision of a three point
suspension for the base plate 14 wherein the rear end region of the
base plate is tiltably or pivotally supported by way of a pair of
rear fixed foot members 140 (see FIGS. 1, 2, 3 and 6) at the two
rear corners of the rectangular base plate, and the front end
region of the base plate is yieldingly supported by way of a single
floating plunger-like front foot member 142. Each rear foot member
is in the form of a rubber or other elastomeric pad 144 having an
upstanding metal shank 146 which is threadedly received in one of
the rear corners of the base plate 14. The front foot member 142
includes an elastomeric button-like pad 148 and an upstanding
headed shank 150 which passes loosely through a vertically
extending opening 152 in the central portion of the front end
region of the base plate 14. A helical compression spring 154
encompasses the shank 150, is interposed between the base plate and
the pad 148, and serves to assimilate the weight of the forward end
region of the entire skate sharpening device. By reason of the
floating front foot member 142, the downward thrust which is
transmitted to the base plate 14 due to downward pressure on the
skate blade when the latter is manually drawn through the slot 80
and against the grinding wheel 20 is assimilated by the compression
spring 154, the arrangement being such that sudden changes in
downward pressure against the grinding wheel are dissipated in the
spring 140, thereby tending to distribute the abrasive action which
is applied to the skate blade undergoing sharpening equally along
its longitudinal extent. It is comtemplated that in the use of the
skate sharpening device 10, the operator will not exert undue
downward pressure on the grinding wheel in excess of that which
ordinarily would cause the compression spring to go solid.
In the operation of the herein described skate sharpening device 10
preparatory to performance of the sharpening operation on any given
skate, the type of skate blade to be sharpened will be noted and
the adjusting screw 104 will be manipulated to regulate the width
of the skate blade-receiving slot 80 accordingly. Thereafter, if
necessary and in order to center the slot 80 with respect to the
grinding wheel 20, i.e., to insure that a diametric plane of the
grinding wheel passes centrally and radially through the slot, the
clamping screw 112 will be loosened and the micrometer adjusting
screw 122 will be manipulated in the proper direction to slide the
entire skate blade guide assembly 60 laterally on the cradle member
42 to a centered position, after which the clamping screw 112 will
be again tightened. The device 10 is then conditioned for the
commencement of skate blade-sharpening operations.
After the switch 37 has been shifted to its "on" position and the
electric motor M has become energized to cause rapid rotation of
the grinding wheel 20, the skate blade B will be introduced into
the slot 80 between the two wear plates 96 and 108 and brought to
the substantially horizontal position in which it is shown in FIG.
1, the slot 34 affording a clearance region so that the housing 16
for the motor M will not interfere with free movement of the skate
blade back and forth longitudinally through the slot 80. During
such back and forth longitudinal movement of the skate blade B, the
sides of the elongated slot 34 will, to a large measure, preclude
any tendency for the operator to twist the skate blade horizontally
out of the general plane of the grinding wheel 20.
It has previously been stated that the skate blade guide assembly
60 is substantially identical with the guide block assembly which
is disclosed in my U.S. Pat. No. 3,812,626, and that its function
remains substantially the same. For a full description of such
function, reference may be had to such patent, the entire
disclosure of which, insofar as it is consistent with the present
disclosure, is hereby incorporated in and made a part of the
present specification. Briefly, however, it is pointed out that an
unskilled operator, usually a child, will push the skate blade B
into the slot 80 and and apply the same to the grinding wheel 20 in
a manner that will give him the least resistance. The net result of
this is an initial angular application of the blade to the grinding
wheel. Ordinarily, a continuance of sharpening operations on this
angular bias would result in the obliteration of one of the two
sharp skating edges of the hollow grind which it is intended shall
be preserved and sharpened. By reason of the particular skate blade
guide assembly 60 which includes the spring-biased wear plate 108,
the tendency for the skate blade is to erect itself to a position
of coincidence with the general plane of the grinding wheel. With
the skate blade thus erect, the floating oscillatable cradle member
42, which is capable of limited circumferential motion about the
axis of the motor shaft 22 due to the bearing sleeve 70 and the
rotational fit of the tubular extension 40 in the circular opening
30 in the front wall 24 of the housing 16, may freely follow any
side-to-side displacement of the skate blade, thus further
inhibiting any tendency for the operator to incline the skate blade
and insuring that the latter at all times lie in the general plane
of the grinding wheel 20.
As previously described, the front floating foot member 142 allows
for a limited rocking movement of the entire skate-sharpening
device 10 about the horizontal axis subtended by the two fixed foot
members 140, thereby tending to equalize the application of
downward force against the grinding wheel by the skate blade.
The invention is not to be limited to the exact arrangement of
parts shown in the accompanying drawings or described in this
specification as various changes in the details of construction may
be resorted to without departing from the spirit or scope of the
invention. Therefore, only insofar as the invention is particularly
pointed out in the accompanying claims is the same to be
limited.
* * * * *