[0001] This invention relates to a lens grinding apparatus.
[0002] In a lens edging or bevelling machine used as a lens grinding apparatus, there are
two kinds of tools : one is a coarse grinding tool or coarse grinding wheel having
a large grinder grain size and the other is a finish grinding tool or finish grinding
wheel having a fine grinder grain size. According to such conventional lens grinding
apparatuses, a lens is roughly ground by the coarse grinding wheel copying a template
and, thereafter, is subjected to a V-edging or V-bevelling treatment using the finish
grinding tool.
[0003] A lens edging machine according to the prior art portion of claim 1 is disclosed,
for instance, in EP-A-0 143 468.
[0004] Because of the foregoing reason, since the grinding quantity of stock removal using
the coarse grinding wheel is much larger than that of the finish grinding wheel, the
wearout quantity of the coarse grinding wheel becomes larger than that of the finish
grinding wheel.
[0005] Because of the foregoing reason, when such grinding wheels are used for a long time,
the grinding quantity of the finish grinding wheel is increased, thereby to necessitate
a longer working time.
[0006] In view of the above, the conventional lens edging or bevelling machine are provided
with a mechanism for manually adjusting the height of a template receiver for each
grinding wheel in order to correct the wearout quantity (hereinafter simply referred
to as wearout-correction) of the above-mentioned grinding wheels.
[0007] In general, an operator of the grinding wheels has a difficulty in finding the changes
of working state due to the difference in wearout quantities of the grinding wheel.
Because of the foregoing reason, it is an actual practice that the wearout-correction
is not performed on the grinding wheels, but the lens worked is measured in diameter
to merely correct the finish size. In this way, the lens was often worked in an incorrect
state.
[0008] When the grinding is performed in the foregoing state, since the coarse grinding
wheel is more rapidly worn than the finish grinding wheel, the difference of diameter
between the coarse grinding wheel and the finish grinding wheel becomes larger and,
therefore, the quantity ground by the finish grinding wheel becomes larger, which
invites the drawbacks in that the grinding time is increased and the finish grinding
wheel, which is more expensive, is worn out more quickly.
[0009] Further, when the wearout-correction is performed, it is difficult for the operator
of the grinding wheel to effect the correction directly and it is a usual practice
that a service man who is an expert in this field chiefly takes care of it.
[0010] The present invention was accomplished in order to eliminate the afore-mentioned
drawbacks of the prior art.
SUMMARY OF THE INVENTION
[0011] It is therefore the object of the present invention to provide a lens grinding apparatus,
wherein the outer diameter of a grinding wheel is automatically measured with a simple
constitution and, based on the measurement, the wearout-correction of the grinding
wheel is performed during grinding operation.
[0012] EP-A-0 131 743 describes a gauge for measuring the wearout quantity of a grindstone,
but which is somewhat complicated.
[0013] In order to achieve the above object, there is essentially provided a lens grinding
apparatus according to claim 1 and a method for obtaining a wearout quantity of a
grinding wheel of a lens apparatus according to claim 4.
[0014] With the above-described constitution of the present invention, when the positions
of the periphery of the grinding wheel, etc. are measured by the outer diameter measuring
means, the outer diameter of the grinding wheel and the wearout quantity are computed
by the arithmetic means from the measured value of the outer diameter measuring means.
And, the adjusting means are controlled based on the wearout quantity of the grinding
wheel to adjust the intershaft distance between the lens rotating shaft and the grinding
wheel at the final grinding position of the lens to be ground.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a better understanding of the present invention, together with other and further
objects thereof, reference is made to the following description, taken in connection
with the accompanying drawings, wherein:
Figs. 1 through 7 show one embodiment of the present invention, in which;
Fig. 1 is a perspective view, partly omitted, of a lens edging or bevelling machine
(lens grinding apparatus);
Fig. 2 is a front view of the reference template of Fig. 1;
Fig. 3 is a side view of Fig. 2;
Fig. 4 is a front view of the lens to be ground of Fig. 1;
Fig. 5 is a left side view of Fig. 4;
Fig. 6 is an electric circuit of the lens edging or bevelling machine of Fig. 1;
Figs. 7(A), 7(B) and 7(C) are flow charts of the lens edging or bevelling machine
of Fig. 1.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0016] One preferred embodiment of the present invention will be described hereinafter with
reference to the accompanying drawings.
[0017] Figs. 1 through 7 illustrate one embodiment of the present invention.
[0018] Fig. 1 illustrate a perspective view, partly cut out, of a lens edging or bevelling
machine as a lens grinding apparatus. In Fig. 1, 1 denotes a housing-like main body
opened up upwardly of a lens edging or bevelling machine, 2 denotes a rear wall of
the main body 1, and 3 denotes a bottom wall of the main body 1. The rear wall 2 is
integrally provided at its generally central portion with bearing projections 4, 4
projecting upwardly therefrom. On upper portions of the bearing projections 4, 4,
a carriage revolving shaft 5 is rotatably and movably held through a bearing 6 for
movement in the axial direction. On both ends of the carriage revolving shaft 5, rear
side pieces 7a, 7b projecting from both sides of the rear end of the carriage 7 are
fixed.
[0019] At both side portions of the rear wall 2, pulley shafts 8, 9 extending upwardly are
fixed. On upper end portions of the pulley shafts 8, 9, pulleys 10, 11 are rotatably
held. On the rear wall 2, a cross feed motor 12 disposed adjacent to the pulley shaft
8 is fixed. On an output shaft 12a of the cross feed motor 12 extending upwardly,
a drive pulley 13 is fixed. And, on the rear side pieces 7a, 7b of the carriage 7,
both end portions of a wire 14 looped around the pulleys 10, 11 and the drive pulley
13 are fixed. As the cross feed motor 12, a pulse motor is used.
[0020] At both sides of a free end portion of the carriage 7, projecting portions 7c, 7d
for holding the shaft are integrally provided. On the projecting portion 7c, a lens
rotating shaft 15A parallel with the carriage revolving shaft 5 is revolvably and
longitudinally unmovably held. While, on the other projecting portion 7d, a lens rotating
shaft 15B having an axial line in alignment with the lens rotating shaft 15A is rotatably
and movably held for movement in the axial direction. In the figure, 16 denotes a
handle adapted to adjust the movement of the lens rotating shaft 15B in the axial
direction, and 17 denotes a reference circular plate made of metal or hard plastic
and held between the lens rotating shafts 15A, 15B. The reference circular plate 17
is provided with a V-block portion 17a having the same angle as a V-groove of a V-edge
grinding wheel 23 (finish grinding wheel) on its periphery and a mounting seat 17b
at its center (see Figs. 4 and 5). 18 denotes a reference template detachably attached
to an outer end portion of the lens shaft 15A. The reference template 18 has the same
diameter as that of the reference circular plate 17 (see Figs. 2 and 3). The lens
rotating shafts 15A, 15B are rotated by a motor (not shown).
[0021] Under the free end portion of the carriage 7, a bracket 19 projecting from the bottom
wall 3 of the main body 1 is provided. On the upper end portion of the bracket 19,
a grinder shaft 20 parallel with the lens rotating shafts 15A, 15B is rotatably held.
On the grinder shaft 20, a grinding wheel 21 is detachably fixed. The grinding wheel
21 comprises a coarse grinding wheel 22 and a V-edge grinding wheel 23. Under the
reference template 18, a template receiver 24, a template receiver lifting motor 25
and a power transmission mechanism 26 are provided.
[0022] The template receiver 24 comprises a pedestal 27, a movable type template receiving
piece 28 provided on the pedestal 27, a pivot shaft 29 pivotally supporting the movable
type template receiving piece 28 on the pedestal 27 so that the movable type template
receiving piece 28 can pivot up and down, and a spring 30 for energizing the movable
type template receiving piece 28 upwardly. The movable type template receiving piece
28 is formed in an arcuate shape in its side view, and the curvature of its upper
surface 28a is the same as the curvature of the outer periphery of the grinding wheel
21. On the pedestal 27, a microswitch 31 as an outer diameter measuring means is fixed.
[0023] The template receiver lifting motor 25 is fixed on the bottom wall 3 of the main
body 1. As the template receiver lifting motor 25, a pulse motor is used.
[0024] The power transmission mechanism 26 includes a pinion 32 fixed to the output shaft
of the template receiver lifting motor 25, a gear 33 meshed with the pinion 32 and
rotatably supported by the bottom wall 3 through a template receiver supporting table
(not shown), and a feed screw 34 threadedly engaged with the center of the gear 33
for reciprocal movement and fixed to the under surface of the pedestal 27. Between
the pedestal 27 and the template receiver supporting table (not shown), a guide means
adapted to vertically guide the pedestal 27 while preventing the horizontal pivot
of the pedestal 27 is provided.
[0025] Next, an electric circuit of the V-edging or bevelling machine will be described
with reference to Fig. 6.
[0026] In Fig. 6, the arithmetic control circuit 35 is inputted with an on-off signal from
the microswitch 31 through a NOT circuit (inverter) 36 and also with on-off signals
from a correct quantity input switch 37 and a correction start switch 38.
[0027] The arithmetic control circuit 35 is adapted to control the generation and stop generation
of pulse of a pulse generator 39 and change over a change-over switch 40 to any one
of the positions at the normal rotation side/neutral position/reverse rotation side,
so that the pulse outputted from the pulse generator 39 is inputted into the template
receiver lifting motor 25 through the change-over switch 40, while the pulse outputted
from the pulse generator 39 is inputted into the cross feed motor 12 through the change-over
switch 41. Moreover, the pulse outputted from the pulse generator 39 is inputted into
a resettable counter 42 by the arithmetic control circuit 35, and the pulse quantity
counted by the counter 42 is inputted into the arithmetic control circuit 35.
[0028] The arithmetic control circuit 35 is adapted to input the pulse quantity counted
by the counter 42, when the template receiver lifting motor 25 is at work, into a
template receiver lifting data memory 44 and to calculate the respective wearout quantities
of the coarse grinding wheel 22 and the V-edge grinding wheel 23 based on the data
inputted, and then to input the calculated results into a wearout-correction data
memory 43. And, when the wearout quantity of the grinding wheel 21 becomes a predetermined
value and more, the arithmetic control circuit 35 actuates an indicator 45 to inform
the time for exchanging the grinding wheel 21. Moreover, the arithmetic control circuit
35 is adapted to calculate the cross feed quantity of the cross feed motor 12 according
to the input from the correction quantity input switch 37 and input the calculated
results into a cross feed data memory 46. On the other hand, the arithmetic control
circuit 35 is adapted to read a lifting data from the wearout-correction data memory
43 to control the pulse number to be inputted into the template receiver lifting motor
25 and also the read data from the cross feed data memory 46 to control the pulse
number to be inputted into the cross feed motor 12.
[0029] Such calculation and control are progressed in the order shown in the flow charts
of Figs. 7(A), 7(B) and 7(C) according to memory memorized in a program memory 47.
[0030] The carriage 7 is held in the initial position by a carriage lifting position supporting
apparatus (not shown) known per se, and an operator mounts the reference circular
plate 17 and the reference template 18 on the lens rotating shafts 15A, 15B in the
Step S₁.
[0031] In usual grinding, a lens to be ground is ground at the center of a grinding surface
of a coarse grinding wheel.
[0032] However, in general, since the coarse grinding wheel 22 is wide enough compared with
the lens to be ground, the portion excluding the center of the grinding surface is
hardly worn.
[0033] Therefore, the operator properly changes the position from where the lens to be ground
is dropped on the grinding surface of the coarse grinding wheel 22 (i.e., correction)
so that the grinding surface is evenly worn out, thereby to prolong the service life
of the coarse grinding wheel 22.
[0034] Accordingly, in the Step S₂, in order to designate a position of the grinding surface
of the coarse grinding wheel 22 which is to be measured in outer diameter, the operator
inputs this correct quantity into the arithmetic control circuit 35 through the correct
quantity input switch 37 on a key board. Due to the foregoing, the arithmetic control
circuit 35 allows the cross feed data memory 46 to memorize the correct quantity as
carriage feed quantity data.
[0035] Next, in the Step S₃, when the correction start switch 38 is turned on, the arithmetic
control circuit 35 changes over the change-over switch 40 to the normal rotation side
and, at the same time, actuates the pulse generator 39, then causes the template receiver
lifting motor 25 to rotate normally, then causes the template receiver 24 to move
upwardly, then causes the template receiving surface 28a to abut against the reference
template 18 and then turns the microswitch 31 on. The "on" signal from the microswitch
31 causes the output of the inverter 36 to the arithmetic control circuit 35 to become
low level. Receiving the low level state of the inverter 36, the arithmetic control
circuit 35 changes over the change-over switch 40 to the neutral position and, at
the same time, stops the generation of the pulse from the pulse generator 39. Furthermore,
it cancels the carriage support of the carriage lifting position supporting apparatus
(not shown) known per se.
[0036] Then, in the Step S₄, the arithmetic control circuit 35 changes over the change-over
switch 41 to the normal rotation side and, at the same time, actuates the pulse generator
39 and counter 42. Due to the foregoing, the cross feed motor 12 is rotated normally
to cause the carriage 7 to move laterally. When the arithmetic control circuit 35
interprets that the count value of the counter 42 reached the predetermined cross
feed quantity, i.e., the quantity for which the reference circular plate 17 is positioned
at an upper part of the center of the grinding surface of the coarse grinding wheel
22, it causes the change-over switch 41 to return to its neutral position and, at
the same time, causes the pulse generator 39 to stop and resets the counter 42. Due
to the foregoing, the reference circular plate 17 is positioned at the upper part
of the coarse grinding wheel 22.
[0037] Then, in the Step S₅, the arithmetic control circuit 35 interprets whether the measurement
on the outer diameter of the coarse grinding wheel has been completed or not. When
the measurement is interpreted as completed, it goes to the following Step Sʹ₆. Since
the measurement is not completed in this description of the operation, it moves to
the following Step ₆ in which the arithmetic control circuit 35 interprets whether
the correction is necessary or not depending on whether the data are memorized in
the cross feed data memory 46 or not and, when necessary, it goes to the following
Step S₇ but, when unnecessary, it goes to the Step S₉.
[0038] When the cross correction is interpreted as necessary in the preceding Step S₆, the
arithmetic control circuit 35 changes over the change-over switch 41 to the normal
rotation side or reverse rotation side according to the memory of the program memory
47 and causes the pulse generator 39 to generate a pulse to rotate the cross feed
motor 12 normally or reveresly. Due to the foregoing, the output of rotation of the
cross feed motor 12 is transmitted to the wire 14 through the output shaft 12a and
drive pulley 13 and the carriage 7 is moved toward the pulley 11 or 10 of Fig. 1.
In such movement, the counter 42 counts the pulse from the pulse generator 39 and
inputs the count quantity into the arithmetic control circuit 35. And, the arithmetic
control circuit 35, when the count quantity became the quantity corresponding to the
cross feed data of the cross feed data memory 46, stops the generation of pulse from
the pulse generator 39 and returns the change-over switch 41 to the neutral position
side to stop the actuation of the cross feed motor 12. The cross feed position of
the reference circular plate 17 is brought to be in alignment with the outer diameter
measuring position on the grinding surface which is to be ground.
[0039] When the Step S₇ is completed, the arithmetic control circuit 35 causes the pulse
generator 39 to generate a pulse according to the memory of the memory program 47
in the Step S₈ and changes over the change-over switch 40 to the reverse rotation
side to rotate the template receiver lifting motor 25 reversely. The rotation of the
template receiver lifting motor 25 causes the power transmission mechanism 26 to be
actuated, the template receiver 24 is moved downwardly, and then the free end portion
of the carriage 7 and the reference circular plate 17 held thereon are moved downwardly
by a predetermined quantity. In such downward movement, the counter 42 counts the
pulse from the pulse generator 39 and inputs the count quantity into the arithmetic
control circuit 35.
[0040] The above-mentioned action is consecutively performed in the Steps S₈, S₉ until the
microswitch 31 is turned off. In this way, the free end portion of the carriage 7
and the reference circular plate 17 held thereon are moved downwardly and the reference
circular plate 17 is abutted against the periphery of the coarse grinding wheel 22.
[0041] And, the action of the template receiver 24 is repeated until the reference circular
plate 17 is abutted against the coarse grinding wheel 22 and the microswitch 31 is
turned off. Moreover, the pulse generated from the pulse generator 39 according to
the action of the template receiver lifting motor 25 is counted by the counter 42
and inputted into the arithmetic control circuit 35. And, when the microswitch is
turned off, the inverter 36 becomes high level and the arithmetic control circuit
35 makes the change-over switch 40 neutral to stop the rotation of the motor 25 and,
at the same time, to stop the generation of a pulse from the pulse generator 39. Then,
it goes to the Step ₁₀, in which the arithmetic control circuit 35 calculates the
outer diameter of the coarse grinding wheel 22 and the difference between such outer
diameter measuring value and a known outer diameter value of an unused coarse grinding
wheel as a wearout quantity based on the pulse number from the counter 42 and inputs
the wearout quantity into the wearout-correction data memory 43.
[0042] Thereafter, the arithmetic control circuit 35 interprets whether the wearout quantity
of the coarse grinding wheel 22 is within the predetermined value or not (i.e., whether
the grinding wheel must be exchanged or not) in the Step ₁₁ and, when the wearout
quantity is the predetermined value and more, actuates the indicator 45 to warn the
necessity of the exchange of a grinding wheel in the Step S₁₂. On the other hand,
when the wearout quantity is within the predetermined value, it goes to the Step ₁₃
in which it is interpreted whether the measurement on the outer diameter of the V-edge
grinding wheel 23 is completed or not. And, when not completed, it goes to the Step
S₅. After it is interpreted that the measurement on the outer diameter of the coarse
grinding wheel is completed in the Step S₅, it goes to the Step S'₆.
[0043] In the Step S'₆, the change-over switch 41 is changed over to the normal rotation
side as in the same procedure in the Step S₄, the cross feed motor 12 is rotated normally,
the carriage 7 is moved toward the pulley 11, and the V-edge 17a of the reference
circular plate 17 and the V-groove grinding surface of the V-edge grinding wheel 23
are brought to be in alignment with respect to each other. When this action is completed,
the control action of the arithmetic control circuit 35 goes to the Step S₆. Then,
the procedures of the Steps S₈ to S₁₂ are performed, and the measurement on the outer
diameter of the V-edge grinding wheel 23 and the wearout correct value are computed.
[0044] On the other hand, when the measurement of the V-edge grinding wheel 23 is completed,
it goes to the Step S₁₄ in which the change-over switch 40 is changed over to the
normal rotation side, the template receiver lifting motor 25 is rotated normally according
to the pulse from the pulse generator 39, the cross feed motor 12 is rotated reversely
after the template receiver 24 is lifted upwardly by a predetermined quantity, the
carriage 7 is moved to its initial position side, the reference template 18 and the
reference circular plate 17 to be ground are returned to their initial positions in
the Step S₁₅, the carriage supporting apparatus (not shown) known per se is actuated
to hold the carriage 7 in the lifted position and, thereafter, the template receiver
24 is moved downwardly to the initial position. By this, the measurement on the outer
diameters of the coarse grinding wheel 22 and V-edge grinding wheel 23 and the calculation
of the wearout quantity are completed.
[0045] When the lens is ground, the respective wearout-correction values of the coarse grinding
wheel 22 and V-edge grinding wheel 23, which are memorized in the memory of the wearout-correction
data memory 43, are added to the predetermined downward movement quantity of the template
receiver 24 to move the template receiver 24 downwardly and the known lens grinding
action is started in the foregoing state.
1. A lens grinding apparatus comprising a lens rotating shaft (15) for holding and rotating
a lens to be ground and for mounting a lens template on a one end thereof, a grinding
wheel (21) having a rotating shaft (20) for grinding said lens, means for measuring
the outer diameter of the grinding wheel (21) independently of or prior to a lens
grinding phase performed by said lens grinding apparatus and for adjusting an intershaft
distance between the lens rotating shaft and the grinding wheel rotating shaft, arithmetic
means (35) for calculating a wearout quantity of the grinding wheel based on a measurement
made by said measuring means, characterized in that
said measuring and adjusting means further comprise : a reference plate (17) made
of metal or hard plastic, comprising a mounting seat (17b) at its center and held
by said lens rotating shaft (15) instead of the lens to be ground ;
a reference template (18, 47) which is a plate being similar in shape to that of
said reference plate (17) and having a diameter which is identical or less than a
diameter of said reference plate (17), the reference template (18, 47) being mounted
at the one end of the lens rotating shaft instead of a lens template which is mounted
when the lens is ground ;
a template receiver (24) adapted to come into contact with said reference template
(18, 47) and driving means (25, 26) for shifting said template receiver (24) ;
and a switch means (31) disposed in said template receiver (24) for sensing whether
or not said template receiver (24) comes into contact with said reference template
(18, 47) and a counter (42) for counting the displacement value of said template receiver
(24) ;
the arithmetic means (35) being adapted to calculate the wearout quantity of the
grinding wheel (21) based on said displacement value.
2. A lens grinding apparatus as claimed in claim 1, wherein said reference plate (17)
is provided on its periphery with a V-block portion (17a) having the same angle as
a V-groove of a V-adge grinding wheel (23).
3. A lens grinding apparatus as claimed in claim 1 or 2 further comprising control means
(35) for controlling said adjusting means based on the wearout quantity and performing
a wearout correction in a lens grinding phase performed thereby.
4. A method for obtaining a wearout quantity of a grinding wheel of a lens grinding apparatus
according to any one of claims 1 to 3, comprising steps which include a step for measuring
the outer diameter of the grinding wheel (21) and a step for calculating a wearout
quantity of the grinding wheel (21) based on a measurement made in said measuring
step,
characterized in that said steps comprise :
a first step for holding said reference plate (17) by said lens rotating shaft
(15) instead of the lens to be ground and for mounting on the one end of said lens
rotating shaft (15), instead of the lens template, said reference template (18) ;
a second step for contacting said reference plate (17) onto the outer diameter
of said grinding wheel (21) ;
a third step for coming into contact said templace receiver (24) of said adjusting
means with said reference template (18) and for counting the displacement value of
said template receiver (24) by when said template receiver (24) has been contacted
with said reference template (18) ; and
a fourth step for calculating the wearout quantity of the grinding wheel (21) based
on said displacement value obtained by said third step.
5. A method for obtaining a wearout quantity of a grinding wheel of a lens grinding apparatus
as claimed in claim 4 further comprising a fifth step for controlling said adjusting
means based on the wearout quantity and for performing a wearout correction in the
lens grinding phase performed by said lens grinding apparatus.
1. Linsenschleifvorrichtung mit einer Linsendrehwelle (15) zum Halten und Drehen einer
zu schleifenden Linse und zum Befestigen einer Linsenschablone an dem einen ihrer
Enden, einem Schleifrad (21) mit einer Drehwelle (20) zum Schleifen der Linse, Mitteln
zum Messen des Außendurchmessers des Schleifrades (21) unabhängig von oder vor einer
von der Linsenschleifvorrichtung durchgeführten Linsenschleifphase und zum Einstellen
eines Zwischenwellenabstandes zwischen der Linsendrehwelle und der Schleifrad-Drehwelle,
arithmetischen Mitteln (35) zum Berechnen der Größe des Verschleißes des Schleifrades
auf der Grundlage der von den Mitteln zum Messen durchgeführten Messung,
dadurch gekennzeichnet,
daß die Mittel zum Messen und Einstellen weiterhin aufweisen:
eine Bezugsplatte (17) aus Metall oder Hartkunststoff mit einem Befestigungssitz (17b)
in ihrer Mitte, die von der Linsendrehwelle (15) anstelle der zu schleifenden Linse
gehalten wird;
eine Bezugsschablone (18,47), die eine in ihrer Gestalt der Bezugsplatte (17) ähnliche
Platte ist und einen Durchmesser aufweist, der gleich dem oder geringer als ein Durchmesser
der Bezugsplatte (17) ist, wobei die Bezugsschablone (18,47) an dem einen Ende der
Linsendrehwelle befestigt ist anstelle einer Linsenschablone, die befestigt ist, wenn
die Linse geschliffen wird;
einen Schablonenempfänger (24), der geeignet ist, mit der Bezugsschablone (18,47)
in Kontakt zu kommen, und Antriebsmittel (25,26) zum Verschieben des Schablonenempfängers
(24);
und eine im Schablonenempfänger (24) angeordnete Schalteranordnung (31) zur Erfassung,
ob der Schablonenempfänger (24) mit der Bezugsschablone (18,47) in Kontakt kommt oder
nicht, und einen Zähler (42) zum Zählen des Versetzungswertes des Schablonenempfängers
(24);
wobei die arithmetischen Mittel (35) geeignet sind, die Größe des Verschleißes des
Schleifrades (21) auf der Grundlage des Versetzungswertes zu berechnen.
2. Linsenschleifvorrichtung nach Anspruch 1, worin die Bezugsplatte (17) an ihrem Rand
mit einem V-förmigen Prägebereich (17a) versehen ist, der den gleichen Winkel aufweist
wie eine V-förmige Nut eines Schleifrades mit V-förmiger Kante (23).
3. Linsenschleifvorrichtung nach Anspruch 1 oder 2, die weiterhin Steuermittel (35) aufweist
zur Steuerung der Mittel zum Einstellen auf der Grundlage der Größe des Verschleißes
und zur Durchführung einer Verschleißkorrektur in einer dabei durchgeführten Linsenschleifphase.
4. Verfahren zum Erhalten der Größe eines Verschleißes eines Schleifrades einer Linsenschleifvorrichtung
nach einem der Ansprüche 1 bis 3, das Schritte umfaßt, die einen Schritt zum Messen
des Außendurchmessers eines Schleifrades (21) und einen Schritt zum Berechnen der
Größe eines Verschleißes des Schleifrades (21) auf der Grundlage einer im Schritt
zum Messen durchgeführten Messung enthalten,
dadurch gekennzeichnet,
daß die Schritte umfassen:
einen ersten Schritt zum Halten der Bezugsplatte (17) durch die Linsendrehwelle (15)
anstelle der zu schleifenden Linse und zum Befestigen der Bezugsschablone (18) an
dem einen Ende der Linsendrehwelle (15) anstelle der Linsenschablone; einen zweiten
Schritt zum Herstellen eines Kontaktes zwischen der Bezugsplatte (17) und dem Außendurchmesser
des Schleifrades (21);
einen dritten Schritt zum Herstellen eines Kontaktes zwischen dem Schablonenempfänger
(24) der Mittel zum Einstellen und der Bezugsschablone (18) und zum Zählen des Versetzungswertes
des Schablonenempfängers (24), nachdem der Schablonenempfänger (24) mit der Bezugsschablone
(18) in Kontakt gebracht wurde; und
einen vierten Schritt zum Berechnen der Größe des Verschleißes des Schleifrades (21)
auf der Grundlage des durch den dritten Schritt erhaltenen Versetzungswertes.
5. Verfahren zum Erhalten der Größe eines Verschleißes eines Schleifrades einer Linsenschleifvorrichtung
nach Anspruch 4, das weiterhin einen fünften Schritt umfaßt zur Steuerung der Mittel
zum Einstellen auf der Grundlage der Größe des Verschleißes und zur Durchführung einer
Verschleißkorrektur in der von der Linsenschleifvorrichtung durchgeführten Linsenschleifphase.
1. Dispositif de meulage de lentille comportant un arbre (15) d'entrainement en rotation
de la lentille pour maintenir et entrainer en rotation une lentille à meuler et pour
monter un gabarit de lentille sur sa première extrémité, une meule (21), présentant
un arbre (20) d'entrainement en rotation, pour meuler ladite lentille, des moyens
pour mesurer le diamètre extérieur de la meule (21) indépendamment de, ou avant, une
phase de meulage de lentille effectuée par ledit dispositif de meulage de lentille
et pour régler une distance interaxiale entre l'arbre d'entrainement en rotation de
la lentille et l'arbre d'entrainement en rotation de la meule, des moyens arithmétiques
(35) pour calculer une quantité d'usure de la meule sur la base d'une mesure effectuée
par lesdits moyens de mesure, dispositif caractérisé
en ce que lesdits moyens de mesure et de réglage comportent en outre: un disque
de référence (17), fait en métal ou en plastique dur, présentant un siège pour montage
(17b) en son centre et maintenu par ledit arbre (15) d'entrainement en rotation de
la lentille, au lieu de la lentille à meuler;
un gabarit de référence (18, 47) qui est un disque de forme semblable à celui dudit
disque de référence (17) et dont le diamètre est identique, ou inférieur, au diamètre
dudit disque de référence (17), le gabarit de référence (18, 47) étant monté à la
première extrémité de l'arbre d'entrainement en rotation de la lentille au lieu d'un
gabarit de lentille qui y est monté lors du meulage de la lentille;
un siège (24) de gabarit conçu pour venir en contact avec ledit gabarit de référence
(18, 47) et des moyens d'entrainement (25, 26) pour décaler ledit siège (24) de gabarit;
et des moyens formant rupteur (31) disposés dans ledit siège (24) de gabarit pour
détecter si, oui ou non, ledit siège (24) de gabarit vient en contact avec ledit gabarit
de référence (18, 47), ainsi qu'un compteur (42) pour compter la valeur de déplacement
dudit siège (24) de gabarit;
les moyens arithmétiques (35) étant conçus pour calculer la quantité d'usure de
la meule (21) sur la base de la valeur de déplacement.
2. Dispositif de meulage de lentille comme revendiqué dans la revendication 1, dans lequel
ledit disque de référence (17) comporte sur sa périphérie une portion en bloc en V
(17a) présentant le même angle qu 'une rainure en V d'une meule de biseautage en V
(23).
3. Dispositif de meulage de lentille comme revendiqué dans la revendication 1 ou 2, comportant
en outre des moyens de commande (35) pour commander lesdits moyens de réglage sur
la base de la quantité d'usure et pour effectuer une correction d'usure dans une phase
de meulage de lentille à laquelle procède le dispositif.
4. Procédé pour obtenir une quantité d'usure d'une meule d'un dispositif de meulage de
lentille conforme à l'une quelconque des revendications 1 à 3, comportant les étapes
comprenant une étape pour mesurer le diamètre extérieur de la meule (21) et une étape
pour calculer une quantité d'usure de la meule (21) sur la base de la mesure fait
dans ladite étape de mesure,
procédé caractérisé par le fait que lesdites étapes comportent:
une première étape pour faire porter ledit disque de référence (17) par ledit arbre
(15) d'entrainement en rotation de la lentille au lieu de la lentille à meuler et
pour monter, sur la première extrémité dudit arbre (15) d'entrainement en rotation
de la lentille, au lieu du gabarit de la lentille, ledit gabarit de référence (18);
une seconde étape pour faire venir ledit disque de référence (17) en contact sur
le diamètre extérieur de ladite meule (21);
une troisième étape pour faire venir ledit siège (24) de gabarit desdits moyens
de réglage en contact avec ledit gabarit de référence (18) et pour compter la valeur
du déplacement dudit siège (24) de gabarit au moment où ledit siège (24) de gabarit
est venu en contact avec ledit gabarit de référence (18); et
une quatrième étape pour calculer la quantité d'usure de la meule (21) sur la base
de ladite valeur du déplacement obtenue par ladite troisième étape.
5. Procédé pour obtenir une quantité d'usure d'une meule d'un dispositif de meulage de
lentille comme revendiqué dans la revendication 4, comportant en outre une cinquième
étape pour commander lesdits moyens de réglage sur la base de la quantité d'usure
et pour procéder à une correction d'usure dans la phase de meulage de lentille à laquelle
procède ledit dispositif de meulage de lentille.