U.S. patent number 3,812,626 [Application Number 05/285,627] was granted by the patent office on 1974-05-28 for ice skate sharpening device.
Invention is credited to Arnold M. Thompson.
United States Patent |
3,812,626 |
Thompson |
May 28, 1974 |
ICE SKATE SHARPENING DEVICE
Abstract
A portable ice skate sharpening device in the form of an
attachment for a conventional hand drill and including a rotary
abrasive grinding wheel which is enclosed in a casing having formed
therein an opening which exposes a limited portion of the periphery
of the rotating wheel and renders the same accessible for
application thereto of a skate blade. A removable skate blade
positioning unit is positioned within the opening and defines a
guide slot through which the skate blade to be sharpened is
manually guided to draw the edge of the blade progressively and
transversely across the periphery of the wheel, the unit being so
designed that the lateral thrust which is applied to the blade
incident to its contact with the rotating wheel serves to bring the
general plane of the skate blade into coincidence with the axis of
rotation of the wheel, thus resulting in a hollow ground skate
blade edge the radius of curvature of which lies precisely in the
midplane of the skate blade.
Inventors: |
Thompson; Arnold M. (Wheaton,
IL) |
Family
ID: |
23095050 |
Appl.
No.: |
05/285,627 |
Filed: |
September 1, 1972 |
Current U.S.
Class: |
451/358; 451/241;
451/383 |
Current CPC
Class: |
B24B
23/00 (20130101); B24B 3/003 (20130101) |
Current International
Class: |
B24B
3/00 (20060101); B24B 23/00 (20060101); B24b
009/04 (); B24b 023/02 () |
Field of
Search: |
;51/17R,17PT,102,228 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kelly; Donald G.
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 portable skate blade sharpening device adapted to hollow grind
the effective supporting edge of a skate blade and comprising a
drive shaft having a rear end adapted for connection to a power
drive source, a circular abrasive grinding wheel mounted fixedly on
the front end of the shaft, a tubular casing encompassing said
wheel and a portion of the drive shaft, said casing having a rear
end wall through which the drive shaft projects rearwardly, and a
front wall, bearing means interposed between the drive shaft and
casing and serving rotatably to support the shaft and the wheel,
said casing and rear walls being relieved to provide a
longitudinally extending blade-receiving slot which exposes a
limited peripheral region of the wheel for transverse application
thereto of the skate blade at such time as the edge region of the
latter is drawn progressively and longitudinally through said slot,
and blade positioning means removably mounted within said slot and
defining a secondary slot for sliding reception therein of the
skate blade, one side wall of said secondary slot being laterally
yieldable and normally serving to displace the skate blade and
compress the same against the opposite side wall of said secondary
slot, said latter side wall being fixed with respect to the
casing.
2. A portable skate blade sharpening device as set forth in claim 1
and wherein the yieldable side wall is disposed on the side of the
secondary slot from which points on the periphery of the grinding
wheel recede during wheel rotation.
3. A portable skate blade sharpening device as set forth in claim 2
and wherein said blade positioning means comprises a fixed wear
plate and a movable wear plate, said wear plates defining
therebetween said secondary slot, the opposed faces of said wear
plates establishing said fixed and yieldable side walls
respectively, and spring means yieldingly urging said yieldable
wear plate toward said fixed wear plate.
4. A portable skate blade sharpening device as set forth in claim 3
and wherein the side walls of said secondary slot normally lie in
parallel spaced apart planes which are inclined at a small angle
relative to a diametric plane of the grinding wheel, the direction
of inclination of such walls being such that normally they serve to
guide the skate blade against the periphery of the grinding wheel
at a point in advance of said diametric plane relative to the
rotary motion of the wheel.
5. A portable skate blade sharpening device as set forth in claim 3
and wherein the forward end of the drive shaft is threaded and
projects axially through the grinding wheel, a clamping nut is
received on said threaded end of the shaft and serves to clamp the
wheel against an annular shoulder on the shaft, and said front end
wall is in the form of a removable end cap which seats on the
forward rim of the outer cylindrical casing wall and which, when
removed therefrom, affords access to said clamping nut for grinding
wheel replacement purposes.
6. A portable skate blade sharpening device as set forth in claim 5
and wherein said bearing means is in the form of a sealed ball
bearing unit which is press-fitted centrally in said rear end wall,
and the casing includes an elongated rearwardly extending bearing
sleeve which is concentric with the drive shaft and which carries a
shaft bushing at its rear end.
7. A portable skate blade sharpening device as set forth in claim 6
and wherein said fixed and movable wear plates are operatively
mounted on a frame-like support which fits snugly within said slot
in the casing, and said support is removably secured in position
within said latter slot by means of a clamping screw which is
threadedly received in a laterally offset tapped hole in one of the
walls of said casing whereby reversal of the support, and
consequently, the wear plates, is prevented.
8. A portable skate blade sharpening device as set forth in claim 7
and wherein said spring means comprises a helical compression
spring which is interposed between the movable wear plate and said
frame-like support, and a compression adjusting screw projects
loosely through a portion of said support and also through said
compression spring and is threadedly received in said movable wear
plate.
9. A portable skate blade sharpening device as set forth in claim 3
and wherein the side walls of said secondary slot normally lie in
parallel spaced apart planes which are parallel to a diametric
plane of the grinding wheel and which are equally spaced from a
medial plane which is offset laterally from said diametric plane in
the direction of advancing points on the periphery of the rotating
grinding wheel.
Description
The improved ice skate sharpening device comprising the present
invention is designed for use primarily as a portable electric hand
drill attachment which requires no bench support when in use. The
device also is primarily intended for home use by skate owners and
it is so constructed that it may be manipulated by an operator who,
with one hand, may steady the device, while with the other hand,
the skate blade undergoing sharpening may be operatively drawn
progressively across the periphery of a rotating abrasive grinding
wheel which derives its rotary motion from the chuck which is
associated with the portable hand drill. The invention is, however,
capable of other uses and the same may, if desired and with or
without modification as required, be designed for bench use wherein
the device is fixedly clamped to a suitable bench, stand, or other
support and the abrasive wheel is caused to derive its rotary
motion from a rotary lathe or other chuck or from any suitable
coupling whereby rotary motion is imparted to the abrasive wheel.
Irrespective, however, of the particular use to which the present
invention may be put, the essential features of the invention are
at all times preserved.
Present day ice skate sharpening devices which are intended for
home use or for use in the field are fairly well standardized and
they consist of an elongated tubular shell which encloses a
cylindrical abrasive element or stone of rod-like design, the shell
being slotted longitudinally so as to expose a limited peripheral
area of the abrasive element. Skate blade sharpening operations are
performed by the simple expedient of drawing the skate blade
progressively through the slot in the shell while at the same time
causing the blade edge undergoing sharpening to slide
longitudinally along the abrasive element. Such skate blade
sharpening devices are possessed of certain limitations, principal
among which is the inability thereof to produce linearly straight,
parallel, and uniformly sharp ice-cutting edges on opposite sides
of the hollow ground curvature which extends along the skating
surface or edge of the blade. In order to accommodate varying
widths of skate blades such as obtain where figure skates, hockey
skates, and racing skates are concerned, the blade-receiving slot
is invariably made of a width which will accommodate the widest of
such blades. Actually, such slot is made a few thousandths of an
inch wider than the width of the widest blade so that there will be
a clearance for ease of sliding movement of the blade through the
slot. Thus, with an abrasive element or stone which has the desired
hollow grind curvature, great pains must be taken not to incline
the skate blade as it is being drawn or pulled through the slot,
and also lateral centering of the blade must be preserved otherwise
one of the two parallel ice-cutting edges becomes displaced
vertically with relation to the other edge. The average unskilled
operator is unable to control skate blade rocking in the slot or
skate blade centering and thus such aforementioned prior art skate
blade sharpening devices are seldom relied upon for full skate
blade sharpening operations, but rather, they are used for
"touch-up" jobs. Similar limitations are prevalent in connection
with various jigs which have been devised for presenting a skate
blade to be sharpened to a rotating grinding wheel by drawing the
blade through a slot. In the latter instance, out-of-true skate
blade sharpening is more likely to occur than with pocket-type
sharpening devices inasmuch as one false movement of the skate
blade results in serious, and sometimes deleterious, blade
damage.
The present invention is designed to overcome the above-noted
limitations that are attendant upon the construction and use of
conventional skate sharpening devices regardless of whether the
same be pocket-type or powered. Accordingly, in carrying out the
invention, there is provided a hand drill attachment having a
rotating grinding wheel of a diameter commensurate with the desired
curvature of the hollow grind which is to be applied to the skate
blade, the wheel having a drive shaft which may be conveniently
received in the chuck of an electrically-powered portable hand
drill or the like. A cylindrical casing closely surrounds the
rotary abrasive grinding wheel and is formed with a longitudinally
extending peripheral slot which exposes a limited peripheral area
of the grinding wheel so that a skate blade which is drawn or
pulled progressively through the slot encounters the wheel in a
transverse direction to the end that the wheel will ream out the
desired hollow grind in the skating edge of the blade.
One of the principal features of the present invention resides in
the provision of a skate blade positioning assembly or unit which
is capable of being removably clamped in position within the casing
slot and, when so positioned, defines a secondary skate blade guide
slot which, when the skate blade is drawn or pulled therethrough,
maintains the blade properly addressed to the periphery of the
abrasive wheel so that there will be neither angular tilting of the
blade within the secondary slot during grinding operations nor
lateral displacement of the blade within said slot. Stated
otherwise, the blade will at all times during its traverse of the
secondary slot remain in a true radial plane with respect to the
abrasive wheel so that there will obtain along the skating edge of
the blade a true and symmetrical hollow grind curvature which leans
neither to the right nor to the left and which is uniform
throughout its length. The provision of a skate sharpening device
such as has briefly been outlined above constitutes the principal
object of the present invention.
It is a further object of the invention to provide in connection
with an ice skate sharpening device of the character under
consideration a skate-positioning unit wherein there are provided
adjusting means whereby the width of the aforementioned secondary
slot through which the skate blade is drawn or pulled may be
varied. This adjusting means s provided not for the purpose of
accommodating skate blades of varying widths, but rather for
adjusting the lateral inward spring pressure of the slot sides
against the blade sides to attain ease of skate blade manipulation,
as well as to compensate for any deterioration in spring pressure
which may take place after a prolonged period of use of the
device.
The provision of an ice skate sharpening device which is extremely
simple in its construction and, therefore, may be manufactured at a
low cost; one which is comprised of a minimum number of parts and,
therefore, is unlikely to get out of order; one which is rugged and
durable and, therefore, will withstand rough usage; one which is
capable of ease of assembly and dismantlement for purposes of
inspection of parts, replacement or repair; one which is small and
compact and, therefore, is not only readily transportable but also
may be conveniently operated while being supported entirely on the
person of the user without requiring bench or stand support; one
which requires no particular degree of skill for its successful
operation and, therefore, may be used by unskilled juvenile
skaters; one which is attractive in its appearance and pleasing in
its design; and one which, otherwise, is well adapted to perform
the services required of it, are further desirable features which
have been borne in mind in the production and development of the
present invention.
Other objects and advantages of the invention, not at this time
enumerated, will become readily apparent 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 described and are more particularly pointed out in the
claims at the conclusion hereof.
In the accompanying two sheets of drawings forming a part of this
specification, two illustrative embodiments of the invention are
shown.
In these drawings:
FIG. 1 is a perspective view of a preferred form of skate
sharpening device embodying the principles of the present
invention, such view illustrating the manner in which the device
may be operatively applied to a drill chuck in driven
relationship;
FIG. 2 is a front end view of the device, the casing end plate
being broken away in the interests of clarity;
FIG. 3 is a side elevational view of the device;
FIG. 4 is a longitudinal sectional view taken on the line 4--4 of
FIG. 2;
FIG. 5 is a transverse sectional view of that portion of the device
which has the rotary grinding wheel;
FIG. 6 is a top plan view of the device;
FIG. 7 is an enlarged top plan view of the skate blade positioning
head which is employed in connection with the invention;
FIG. 8 is a sectional view taken on the line 8--8 of FIG. 7, the
view being turned 90.degree.;
FIG. 9 is a transverse sectional view taken on the line 9--9 of
FIG. 7;
FIG. 10 is a sectional view similar to FIG. 5 but showing a
modified form of the skate sharpening device;
FIG. 11 is an enlarged exploded perspective view of the composite
grinding wheel housing which is employed in connection with the
present invention;
FIG. 12 is an enlarged perspective view of the grinding wheel and
shaft assembly which is employed in connection with the
invention;
FIG. 13 is an enlarged, exploded perspective view illustrating the
component parts of a particular skate blade positioning assembly by
means of which a skate blade to be sharpened is caused to address
the grinding wheel in precise grinding position;
FIG. 14 is a diagrammatic view, entirely schematic in its
representation, illustrating certain frictionally-derived skate
blade erecting phenomena which become prevalent when
blade-sharpening operations are initiated by application of a skate
blade to the grinding wheel of the form of the invention which is
shown in FIG. 1; and
FIG. 15 is a diagrammatic view similar to FIG. 14 but illustrating
the involved phenomena when a skate blade is applied to the
grinding wheel of the form of the invention which is shown in FIG.
10 of the drawings.
Referring now to the drawings in detail and in particular to FIGS.
1 to 3, inclusive, and also FIG. 6, a skate sharpening device
embodying the principles of the present invention is designated in
its entirety by the reference numeral 10 and, for proper operation
thereof in the sharpening of a skate blade, it is designed for
cooperation with a rotary chuck assembly such as the assembly which
is fragmentarily illustrated in FIG. 1 and designated by the
reference numeral 12. Preferably, but not necessarily, the skate
sharpening device 10 is designed for home use by the individual
skate owner, utilizing a conventional portable pistol-grip type
hand drill having a chuck assembly such as the one illustrated
herein. Moreover, when so used, the operator will conveniently
support the drill in his or her lap or on a table or other support
while holding the device 10 against rotation bodily with one hand
and while manipulating the skate blade undergoing sharpening with
the other hand, all in a manner that will be made clear presently
when the nature of the invention is better understood. It is within
the purview of the invention, however, that the device 10 may be
employed in the commercial sharpening of skate blades by a small
shop operator, in which case bench support of the hand drill orr
other power tool having a chuck such as the chuck assembly 12 may
be resorted to if desired, while rotation of the skate sharpening
device may be prevented by any suitable torque-arresting reaction
clamping means.
Still referring to FIGS. 1 to 3, inclusive, and FIG. 6, and
additionally to FIG. 4, briefly the skate sharpening device 10
involves in its general organization a tubular casing 14 which is
of generally cylindrical configuration and within which there is
disposed a rotary abrasive grinding wheel 16. The latter is
supported on a drive shaft 18, the rear end of which is designed
for reception by the chuck assembly 12. A major sector of the
grinding wheel 16 is enclosed within and shielded by the casing 14,
but a limited peripheral region of the wheel is exposed for skate
sharpening purposes by reason of the existence of a peripheral slot
20 (see FIGS. 1, 2, 5, and 11) in the casing 14. In order to
control the disposition of the skate blade which is undergoing
sharpening and to apply ti to the grinding wheel 16 for sharpening
purposes at a 0.degree. angle (i.e., so that it lies in the
vertical diametric plane of the grinding wheel axis), a skate blade
positioning unit or assembly 22 is removably received within the
slot 20. This assembly 22 constitutes one of the principal features
of the present invention and, as will be set forth in greater
detail hereafter, the assembly is so designed and is so related to
the grinding wheel 16 positionally that practically no skill is
required in order to bring the skate blade into proper grinding
position, it being necessary only for the operator to introduce the
blade in an approximate tangential relation to the grinding wheel,
after which the frictional force which the periphery of the
rotating grinding wheel offers to the adjacent edge of the skate
blade which is undergoing sharpening, automatically "erects" the
skate blade, so to speak, to a precise vertical position wherein
the plane of the blade and the diametric plane of the grinding
wheel are coincident, thereby resulting in a precise hollow
grinding operation upon the edge of the skate blade wherein the
center of curvature of the blade edge concavity lies precisely in
the median plane of the blade. As will also be made clear
presently, the skate blade positioning assembly 22 is removably
received within the slot 20 for the purpose of head substitution in
order to accommodate skate blades of different widths as, for
example, the blades which are associated with figure skates, hockey
skates, and racing skates.
Considering the skate sharpening device 10 in greater detail, the
casing 14 is comprised of three principal parts, namely, a main
body portion 24, an end cap 26 (see FIGS. 1, 3 and 11), and a
bearing sleeve 28. The main body portion includes an outer
cylindrical wall 30, an annular radial and wall 32, and a
rearwardly extending cylindrical wall 34 of reduced diameter. The
forward rim of the cylindrical wall 30 is closed by means of the
end cap 26 which is telescopically received within the wall 34 and
is provided with a radial rim flange 36 (see FIG. 4) which seats on
the rim of the wall 30. A pair of locking screws 38 (see FIG. 6)
serves releasably to hold the end cap in position on the body
portion 24.
The body portion 24 of the casing 14 establishes a grinding wheel
housing within which the grinding wheel 16 rotates, the latter
being mounted on the forward end of the shaft 18 which projects
axially through the bearing sleeve 28 and into the housing. A
clamping nut 40 which s threadedly received on the extreme forward
end of the shaft 18 serves to force the grinding wheel 18
rearwardly against a washer 41 which, in turn, bears against a
shoulder 42 on the shaft. The shaft 18 is rotatably supported in
the casing 14 by means of a sealed ball bearing assembly 44, the
outer race of which is press-fitted in an annular recess 45 in the
central portion of the annular radial end wall 32, and the inner
race of which is straddled by the aforementioned washer 41 and a
snap ring 46 in an annular groove in the shaft 18. The bearing
sleeve 28 is provided for the purpose of lending axial stability to
the shaft 18 and, accordingly, this sleeve has its forward end
region threadedly received as indicated at 48 (see FIG. 4) within
the rearwardly extending cylindrical wall 34 of the main body
portion of the casing 14 and supports at its rear end a shaft
bushing 50 having a radial rim flange 52 which seats on the rear
circular rim of the bearing sleeve 28. The bushing 50 affords a
bearing support for the rear end of the rotatable shaft 18 at a
region appreciably removed from the bearing 44 so that these two
bearing supports 50 and 44 maintain the shaft 18 in its proper
coaxial relationship with respect to the casing 14. The extreme
rear end of the shaft 18 is formed with a reduced section 54 which
is designed for reception in the chuck assembly 12 of the hand
drill or other power tool by means of which the skate sharpening
device 10 is powered.
Referring now to all views of the drawings, but with particular
reference to FIGS. 1 to 9, inclusive, wherein the preferred form of
the invention is isclosed, the previously mentioned skate
positioning assembly 22 is a self-contained unit and consists of a
rigid, one-piece, frame-like support 60 (see FIG. 13) having two
substantially identical, laterally spaced, arched, side wings 62
and 64, the latter being connected together at their ends by
transverse base struts 66 and 68. The side wing 62 has formed
therein a bore 70 which receives a screw 72 (see FIG. 8) by means
of which a shoe-like wear plate 74 having a tapped hole 76 therein
may be fixedly clamped to the inside face of said side wing 62. The
side wing 64 has formed therein a socket 78 within which there is
seated the outer end of a helical compression spring 80. The inner
end of the spring 80 projects outwards of the inner end of the
socket 78. An adjusting screw 82 projects loosely through a hole in
the bottom wall of the socket 78 and has the free end of the shank
received in a tapped hole 84 in an adjustable shoe-like wear plate
86. The shank of the screw 82 also extends loosely through the
spring, and the head of the screw is located adjacent to the outer
side surface of the side wing 64 and serves to limit inward sliding
movement of the screw and the wear plate 86. The wear plate 86 is
spaced inwards of the inner side surface of the side wing 64 and is
yieldingly held in place by the action of the spring 80.
As best shown in FIGS. 6, 7 and 8 of the drawings, when the two
wear plates 74 and 86 are assembled upon the frame-like support 60,
they assume spaced-apart positions between the two arched side
wings 62 and 64 with the wear plate 74 fitting against the inside
face of the side wing 62 and with the wear plate 86 assuming a
position slightly spaced from the inside face of the side wing 64.
In this assembled position, these two wear plates define
therebetween a skate blade-receiving channel or slot 88 (see FIGS.
6, 7 and 8) through which the blade is adapted to be drawn in a
longitudinal direction during blade sharpening operations while the
edge of the blade which is undergoing sharpening contacts the
periphery of the rotating grinding wheel 16 as shown in FIG. 5.
Referring now to FIGS. 7 and 8, it will be noted that the spring 80
is interposed between the bottom wall of the socket 78 and the wear
plate 86 so that this spring yieldingly biases the wear plate
inwardly of the skate blade-receiving slot 88. By rotating the
adjusting screw 82 in one direction or the other, the wear plate 86
will be drawn toward the side wing 64 or forced away therefrom, as
the case may be, and thus, rotation of the screw 82 serves to
adjust the effective width of the skate blade-receiving slot 88 in
order to accommodate skate blades of varying widths.
In order to supply torque reaction to the two wear plates and
prevent turning motion thereof when either the clamping screw 72 or
the adjusting screw 82 is rotated, each side wing 62 and 64 is
formed with a pair of narrow horizontal ledges 89 (see FIGS. 6, 7,
8, 9 and 13) on which the opposite ends of the wear plates 74 and
86 normally rest when they are operatively installed on the
frame-like support 60.
In order releasably and removably to install the skate blade
positioning assembly 22 within he peripheral slot 20 in the casing
14, one end of the arched side wing 64 is provided with a vertical
bore 90 (see FIG. 13), and a tapped socket 92 is formed in that
portion of the annular radial end wall 32 which defines the bottom
of the slot 20, such socket being for reception of a clamping screw
94 (see FIGS. 1 and 6) by means of which the frame-like support 60,
and consequently, the entire skate blade positioning assembly 22,
may be fixedly secured within the slot 20. The clamping screw 94
constitutes the sole fastening means for the skate blade
positioning assembly 22 within the slot 20 and thus this screw,
which is disposed at one corner of the frame-like support 60, makes
it possible to install the assembly 22 within the slot only in its
effective operative position, reversal of the assembly being
impossible.
A careful consideration of FIGS. 2 and 4 will reveal the fact that
the peripheral slot 20 which is formed in the casing 14 and the end
cap 26 is cut on a small angle bias with respect to a diametric
plane of the grinding wheel 16, which is to say that the central
plane of the slot 20 does not pass through the longitudinal
combined axis of the grinding wheel and the shaft 18. The angle
involved preferably is on the order of 2.degree.. Thus, when the
skate blade-positioning assembly 22 is operatively installed in
this slot 20, the central plane of the blade-receiving slot 88 is
also on a small angle bias inasmuch as the entire assembly 22
becomes angularly disposed when it is inserted in the slot 20.
With the assembly 22 being thus angularly inclined, it is obvious
that when a skate blade such as the blade B of FIG. 5 is initially
inserted in the blade-receiving slot 88 as shown in dotted lines,
and the edge of the blade is brought into contact with the
periphery of the grinding wheel 16, the general plane of the blade
will also be inclined with respect to the vertical diametric plane
of the grinding wheel 16, this inclination being schematically
illustrated by the angle .theta. in FIG. 14. This inclination of
the skate blade is predicated upon the insertion of the blade into
the slot 88 by the average unskilled operator, usually a child, who
will push the blade into the slot in a manner that will give him
the least resistance. The net result of this initial angular
application of the skate blade B to the grinding wheel 16 is
schematically illustrated by dotted lines in FIG. 14 where it will
be observed that one side edge of the blade B will be brought into
contact with the rotating grinding wheel. Ordinarily, if skate
blade sharpening operations were to continue on this angular bias,
an improper hollow grinding of blade would result. However, due to
the relatively great frictional force which is applied transversely
to the skate blade B due to its contact with the periphery of the
rotating grinding wheel which rotates in the counterclockwise
direction as shown by the arrow in FIG. 14, the tendency for the
blade is to erect itself so that it assumes the full-line position
shown in this view whereinthe general plane of the blade passes
through the combined longitudinal axis of the wheel 16 and the
shaft 18. In approaching this vertical position, the side of the
blade B pivots about a horizontal fulcrum axis which is established
by the adjacent lower corner edge of the fixed wear plate 74, this
fulcrum axis being designated by the axis X in FIG. 14. As the
blade B continues to erect itself as previously set forth, the
spring-biased wear plate 86 on the opposite side of the blade B
rides inwardly on the adjacent side of the blade B from the dotted
line position thereof to the full-line position, this wear plate
finally assuming a vertical position alongside the skate blade
while the fixed wear plate 74, of course, remains inclined. In its
final erect condition, the blade assumes a floating condition, the
friction of the grinding wheel 16 tending to force the bottom
portion of the blade to the left as viewed in FIG. 14, and the
spring 80 assimilating the backward force which is applied to the
wear plate 86. The "rate" or strength of the spring 80 is selected
so that a proper condition of "balance" of the blade B is attained
wherein the blade is substantially vertical or at least so nearly
vertical that the hollow grind which is effected upon the skate
blade presents a center of curvature which lies within the vertical
diametric plane of the grinding wheel or so close thereto that no
significant canting of the hollow grind gurvature takes place.
In FIG. 10, a slightly modified form of the invention is shown. In
this view, a skate sharpening device 110 embodies a grinding wheel
16 and a skate blade-positioning assembly 22 which are identical to
those previously described in connection with the form of the
invention shown in FIGS. 1 through 9 and which, therefore, have
been designated by identical reference numerals so that a
description thereof is deemed to be unnecessary. The grinding wheel
casing 114 of the device 110, however, is slightly different from
the casing 14 of the device 10, the only difference being in the
nature of the slot 120 which is formed in the cylindrical wall, the
radial end wall, and the end cap 126 of the device 110. Apart from
the provision of the slot 120, the two skate sharpening devices 10
and 110 remain substantially the same and, therefore, in order to
avoid needless repetition of description, similar reference
numerals but of a higher order have been applied to the
corresponding parts as between the casing structure or arrangements
illustrated in FIGS. 10 and 2.
Whereas, in the previously described form of the invention, the
slot 20 is cut in the casing 14 on a slanting bias as heretofore
mentioned, the slot 120 in the modified form of the invention is
cut in a radial direction so that it possesses no slant. However,
this slot is tangentially offset with respect to the periphery of
the grinding wheel 16 and, as a result, when the skate
blade-positioning assembly 22 of the device 110 is operatively
installed in this slot, the two wear plates 74 and 86 are vertical
and define therebetween a skate blade-receiving slot 188 which is
also vertical. The slot 120, and consequently, the
blade-positioning assembly 122, is offset counter to the direction
of rotation of the grinding wheel 16 as schematically illustrated
in FIG. 15 and, therefore, as is the case in the previously
described form of the invention, a skate blade such as the blade
B', when inserted into the vertical or radially extending slot 188
as shown in dotted lines in FIG. 15 will engage the grinding wheel
16 at one corner of the skate blade. However, immediately upon
frictional contact between the skate blade B' and the grinding
wheel 16, the originally erect blade B' will be urged to the left
as shown by full lines in FIG. 15 so that one side thereof will
pivot about the fulcrum axis X' which is established by the
adjacent lower corner edge of the wear plate 74, and come to rest
in a floating inclined position as shown in full lines in FIG. 15.
In this inclined position, the general plane of the skate blade B'
will line in a diametric plane which passes through the combined
axis of the grinding wheel 16 and its shaft 18.
A brief comparison between the device of FIGS. 2 and 14 on the one
hand, and the device of FIGS. 10 and 15 on the other hand, may be
hade by stating that in the first instance the skate blade B enters
the slot 88 in an angularly-displaced non-radial or secantial
direction and is forced by frictional contact with the grinding
wheel into a truly radial or vertical position. In the second
instance, the skate blade B' enters the slot 188 in a vertical, but
non-radial, secantial direction and is forced by the rotating
grinding wheel into a slanting but truly radial position. In either
event, since the fully sharpened skate blades B andd B' are acted
upon by the grinding wheel for blade-sharpening purposes while they
extend radially of the grinding wheel, the net result is the
same.
It will be understood that the terms "vertical" and "horizontal" as
employed herein refer to directions which obtain when the
skate-sharpening devices 10 or 110 are positioned as shown in FIGS.
2 to 6, inclusive, and FIG. 10 with the slots 20 or 120 being
disposed at the extreme uppermost sector of the casings 14 and 114,
respectively. It will also be understood that when a particular
skate blade is undergoing sharpening with the devices of the
present invention, the blade will be drawn longitudinally through
the slot 88 or 188 in the usual manner of skate-sharpening
operations with skate-sharpening devices having skate
blade-positioning slots which guide the skate blade against a
skate-sharpening stone or wheel. Ordinarily, in using the
skate-sharpening device 10 or 110, after the reduced section 54 of
the grinding wheel shaft 18 has been operatively clamped in the
chuck 12 of an electric hand drill, the trigger control of such
drill will be set to its permanent "on" position and the hand drill
will then be placed in the lap of the user while at the same time
one hand will be applied to the casing 14 to hold the device while
at the same time preventing bodily rotation thereof due to chuck
rotation. With the hand drill and skate-sharpening device thus
supported, the other hand of the user may conveniently be employed
for performing the necessary skate blade manipulation in drawing or
pulling the same longitudinally along the through slot 88 or 188
which is afforded by the skate blade positioning assembly 22 or
122.
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 of the invention.
For example, whereas the slot 20 which is provided in the casing 14
and the end cap 26 is cut on a slanting bias as previously
described, it is within the purview of the invention to fashion the
wear plates 74 and 86, or their mountings, in the assembly 22 so
that these wear plates establish an inclined skate-positioning
channel 88 which initially guides the skate blade against the
grinding wheel in a non-erect or slanting position but in which
these wear plates function when the skate blade is frictionally
engaged by the grinding wheel to bring the skate blade to an erect
grinding position. Therefore, only insofar as the invention is
particularly pointed out in the accompanying claims in the same to
be limited.
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