U.S. patent application number 10/302568 was filed with the patent office on 2003-05-29 for device for deblocking lenses.
This patent application is currently assigned to Schmoll Engineering GmbH. Invention is credited to Schmoll, Siegfried.
Application Number | 20030100252 10/302568 |
Document ID | / |
Family ID | 3689158 |
Filed Date | 2003-05-29 |
United States Patent
Application |
20030100252 |
Kind Code |
A1 |
Schmoll, Siegfried |
May 29, 2003 |
Device for deblocking lenses
Abstract
A device for deblocking lenses attached to a block has at least
one securing device supporting a lens and having an opening for a
block suspended from the lens. At least one holding-down device is
provided for pressing the lens supported on the securing device
against the securing device. At least one impacting device with a
striking member movable from below against the securing device for
striking the securing device is provided. The securing device and
the holding-down device are supported to be movable against a
spring-elastic restoring force in a striking direction of the
striking member.
Inventors: |
Schmoll, Siegfried;
(Walzenhausen, CH) |
Correspondence
Address: |
Friedrich Kueffner
Suite 910
317 Madison Avenue
New York
NY
10017
US
|
Assignee: |
Schmoll Engineering GmbH
|
Family ID: |
3689158 |
Appl. No.: |
10/302568 |
Filed: |
November 22, 2002 |
Current U.S.
Class: |
451/384 ;
451/365 |
Current CPC
Class: |
B24B 13/0057
20130101 |
Class at
Publication: |
451/384 ;
451/365 |
International
Class: |
B24B 041/06 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 29, 2001 |
AT |
A 1862/2001 |
Claims
What is claimed is:
1. A device for deblocking optical glasses attached to a block, the
device comprising: at least one securing device configured to
support an optical glass and having an opening for a block
suspended from the optical glass; at least one holding-down device
for pressing the optical glass supported on the securing device
against the securing device; at least one impacting device
comprising a striking member movable from below against the
securing device for striking the securing device; wherein the
securing device and the holding-down device are supported to be
movable against a spring-elastic restoring force in a striking
direction of the striking member.
2. The device according to claim 1, wherein the securing device has
a sleeve-shaped upper area facing the optical glass supported
thereon and configured such that the block suspended from the
optical glass projects into an interior of this sleeve-shaped upper
area and has a spacing to an inner wall of the sleeve-shaped upper
area.
3. The device according to claim 2, wherein the securing device
comprises a guide surface located underneath the sleeve-shaped
upper area and extending downwardly, wherein the securing device
has an ejection opening for the block separated from the optical
glass and wherein the guide surface opens into the ejection
opening.
4. The device according to claim 1, wherein the securing device has
a lower side opposite the optical glass supported thereon and the
lower side comprises an anvil for receiving a strike exerted by the
striking member.
5. The device according to claim 4, wherein the anvil is arranged
centrally underneath the lens or the block suspended therefrom.
6. The device according to claim 4, wherein the striking member has
an initial position before carrying out a strike and is positioned
in the initial position at a spacing from the anvil of the securing
device.
7. The device according to claim 1, further comprising: a glide
sleeve, wherein the securing device is supported in the glide
sleeve and is movable relative to the glide sleeve; and a
spring-elastic element configured to exert a restoring force upon
movement of the securing device away from a lower end position.
8. The device according to claim 7, wherein the spring-elastic
element is an elastic rubber ring fastened on the securing device
and resting against an underside of the glide sleeve or a part that
is connected to the glide sleeve.
9. The device according to claim 1, wherein the striking member has
an initial position before carrying out a strike and is positioned
in the initial position at a spacing from the securing device.
10. The device according to claim 1, wherein the striking device
comprises a piston-cylinder unit and wherein the striking member is
attached to a piston rod of the piston-cylinder unit.
11. The device according to claim 1, comprising a pneumatic
piston-cylinder unit, wherein the holding-down device is fastened
on a piston rod of the piston-cylinder unit.
12. The device according to claim 1, further comprising a moveable
slide, wherein several of the securing devices are arranged on the
slide, wherein the securing devices are moveable alternatingly into
a position opposite the striking device.
13. The device according to claim the 12, further comprising an
actuator for a program-controlled automated movement of the
slide.
14. The device according to claim 1, wherein the optical glasses
are spectacle lenses.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a device for deblocking optical
glasses (lenses), in particular, spectacle lenses, which are
fastened on a block, respectively. The device comprises at least
one securing device on which a lens is supported and which has an
opening for the block suspended from the lens. The device comprises
at least one holding-down device for pressing the lens supported on
the securing device against the securing device.
[0003] 2. Description of the Related Art
[0004] When manufacturing lenses of the aforementioned kind, the
concave sides, inter alia, must be machined, for example, by
milling, grinding, or polishing. The lenses to be processed are
fastened by means of a low-melting alloy, whose melting point is
approximately 55.degree. C., on a so-called block. After completion
of the individual processing steps, the lenses must be detached
from the block. This separation of lens and block is commonly
referred to as deblocking. This is carried out presently by hand.
The lens fastened on the block projects laterally past the block.
For deblocking by hand, a piece of tube is employed and the block
is positioned in the tube opening. The diameter of the tube is of
such a size that the lens, which radially projects relative to the
block, will rest on the rim of the opening of the tube. The upright
tube is then struck on a hard surface so that, as a result of the
impact impulse, lens and block will separate. The block then falls
through the tube downwardly, while the lens remains in the hand of
the operator. This manual deblocking process is cumbersome and
monotonous labor.
[0005] Austrian patent 407 967 already discloses a device for
automatic deblocking. In this device, a carriage or slide, on which
at least one holder for a lens with a block connected thereto is
provided, is movable along a guide. The guide is part of a frame
which is supported on a stand to be moveable in the vertical
direction. For receiving the optical glasses (lenses) together with
the blocks fastened thereto, the frame is lowered relative to the
stand, the holders being open during this procedure. After closing
the holders, the frame is again lifted and the carriage or slide is
moved along the guide provided on the frame to the separating
station. The frame is then lowered at great speed so that the jaws
of the holder strike a plate of the separating station, and the
acceleration force acting on the block now separates block and
lens.
[0006] A disadvantage of this known device is that, for lowering
the frame at great speed in order to realize deblocking, special
piston-cylinder units for moving the frame must be employed which
must have special venting valves in order to be able to reach the
required high speed. This leads to increased manufacturing costs.
Also, a change of the impact speed of the holder on the plate of
the separating station is possible only with complex modifications.
For this purpose, the piston-cylinder units have to be exchanged or
the venting valves have to be modified such that a changed venting
action can be achieved. The use of an electric motor drive for
adjusting the frame (instead of the piston-cylinder unit) would
require a relatively great manufacturing expenditure. Moreover, in
this known configuration the mass to be moved for the deblocking
process is relatively great so that high acceleration forces must
be exerted causing great forces to be absorbed by the bearings.
[0007] A device for manual deblocking is also known from U.S. Pat.
No. 3,091,062. The block is inserted into an upright standard so
that minimal play relative to the standard remains. At the upper
end of the receiving standard a ring is arranged which is pivotable
relative to the standard by means of a lever and projects past the
upper edge of the standard on which lens is supported. By pivoting
the ring in the upward direction, the lens is removed from the
block. The block, as a result of the exerted tilting force, is
canted relative to the standard so that no additional securing
device is required for the block. The one-sided force application
onto the lens with this type of deblocking device results in a
relatively great risk of breakage of the lens. Also, an automated
operation of the device of U.S. Pat. No. 3,091,062 is not taught
and, moreover, would not be possible with a device of the this
kind.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide an
improved device of the aforementioned kind which can be produced
less expensively.
[0009] In accordance with the present invention, this is achieved
in that at least one striking device is provided which has a
striking member movable from below against the securing device for
striking the securing device, wherein the securing device and the
holding-down device are movably supported against a spring-elastic
restoring force in the direction of the impact or striking movement
of the striking member.
[0010] In the device according to the invention, the masses which
are to be moved upon deblocking can be reduced, and the device can
be manufactured in a simpler way. Moreover, the deblocking process
can be performed more reliably wherein the number of rejects in the
form of lenses damaged by deblocking is reduced.
[0011] In an advantageous embodiment of the invention, the securing
device in the area of the support of the lens is of a sleeve-shaped
configuration wherein the block suspended from the lens is arranged
within this sleeve-shaped area at a spacing to its inner wall. In
this way, a simple securing device is provided wherein a deblocking
device according to the invention can comprise several such
securing devices with different diameters and/or the securing
devices can be adjusted for receiving different sizes of lenses or
blocks or they can be exchangeable.
[0012] It is expedient to provide the securing device with an anvil
or support on a lower side opposite the lens resting on the
securing device. The anvil should preferably be arranged centrally
underneath the lens or the block suspended therefrom. This anvil or
support serves for receiving the impact exerted by the striking
member so that the impact acceleration detaching the lens from the
block is transmitted via the anvil onto the securing device.
BRIEF DESCRIPTION OF THE DRAWING
[0013] In the drawing:
[0014] FIG. 1 is a side view of the device according to the
invention;
[0015] FIG. 2 is a plan view of the device according to the
invention;
[0016] FIG. 3 shows a section along the line A-A of FIG. 1 (the
holding-down device and the striking device are not illustrated in
section);
[0017] FIG. 4 shows a lens attached to a block in a side view
(enlarged scale);
[0018] FIG. 5 shows the lens on the block in a top view (enlarged
scale); and
[0019] FIG. 6 shows a bottom view of the lens on the block
(enlarged scale).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] FIGS. 4 through 6 illustrate in different views the object
to be manipulated by the deblocking device of the present
intention. On a metal block 1, which in this illustrated embodiment
has a conical portion 2 and a cylindrical portion 3 and is provided
with a depression 4 arranged centrally and open in the downward
direction, is fastened by means of a low-melting alloy 5 to the
spectacle lens 6 to be processed whose concave side is to be
machined. The block 1 can have different shapes and different sizes
depending on the type of the optical glass (lens) to be treated.
The aforementioned block 1 with the easily meltable alloy 5 is an
auxiliary device with which the lens 6 to be processed is
adjustable and positionable relative to the individual tools. The
connection between the lens 6 and the easily meltable alloy 5 is of
satisfactory or sufficient strength so that the reaction power
caused by the tools when processing the lens can be transmitted
safely and reliably onto the block 1 inserted into a machine tool.
After completion of processing of the lens 6, the lens and the
block must be separated. The device described in the following is
provided for this purpose.
[0021] In the illustrated embodiment several securing devices 8 for
blocked lenses 6 are provided on a carriage 7. Two rows of five
securing devices 8 are provided. The carriage 7 is supported to be
movable along guide rails 10 by means of glide shoes 9. The guide
rails 10 are fastened on a machine frame 11. For moving the slide
or carriage 7, a toothed belt 12 is provided on which the carriage
7 is secured by means of a holding part 13. The toothed belt 12 is
of a continuous or closed configuration and runs on one side about
a deflection roller 14 rotatably supported on the machine frame 11.
The other side is provided with a drive roller (not visible in the
illustration) driven by an actuator. In this way, the respective
securing device 8 can be moved in an automated and
program-controlled way into the required position in which
deblocking of the lens 6 resting on the securing device is carried
out.
[0022] Moreover, a loading station can be provided, which is not
illustrated in the drawing, for supplying the securing devices 8
with the blocked lenses. In this connection, the carriage 7 can
also be positioned by program control in order to load the
respective securing device. In place of an electric actuator for
the carriage 7, it is possible to provide a pneumatic adjusting
devices instead.
[0023] For pressing an optical glass or lens 6 to be deblocked
against the securing device, a holding-down device 15 is provided.
In the illustrated embodiment, the holding-down device 15 is
secured on a piston rod 16 of a pneumatic piston-cylinder unit 17
having a piston 18 acting via both ends. In the activate state of
the holding-down device 15, air pressure loading the piston is
present in the cylinder chamber 19. When a force is exerted onto
the piston 18 which acts against this air pressure and is greater
than the air pressure, the piston 18 is moved by reducing the
cylinder chamber 19 against this air pressure so that the air
pressure is increased. In this way, a kind of (pre-tensioned) air
spring is formed against whose spring-elastic restoring force the
holding-down device 15 can be moved when a correspondingly great
force is exerted. In place of such an air spring device, or in
addition thereto, a pressure spring could be provided, for example,
between an adjusting device of the holding-down device 15 and the
holding-down device 15; the holding-down device 15 can then be
moved against the spring-elastic restoring force of this pressure
spring.
[0024] The securing devices 8 are sleeve-shaped at their upper area
facing the support of the lens 6. An inner sleeve part 20 is
provided which is connected with an outer sleeve part 21. A plastic
sleeve 22 is arranged between the inner and the outer sleeve parts
20, 21. O-rings 23, 24 are arranged on the upper end faces of the
inner sleeve part 20 and of the plastic sleeve 22. The lens 6 is
supported on the O-ring 23. The holding-down device 15 rests on the
lens 6 and optionally on the outer O-ring 24. The block 1 suspended
from the lens 6 projects through the opening 45 of the securing
device 8 into the interior of the sleeve-shaped area of the
securing device 8 and is spaced relative to the inner wall 25 of
the inner sleeve part 20.
[0025] The sleeve-shaped upper area of the securing device 8 is
closed off in the downward direction by a slantedly extending guide
surface 26. This guide surface 26 opens into an ejection opening 27
for the deblocked block 1. The block 1 which has been deblocked
from the lens 6 falls onto the guide surface 26 and then glides
along it through the ejection opening 27 into a guide tube 28 which
opens into a receptacle (not illustrated in the drawing) for the
blocks 1.
[0026] The securing device 8 is axially slidably arranged in a
glide sleeve 29 relative to the glide sleeve. The glide sleeve 29
is arranged in a support sleeve 31 which is connected to the frame
of the slide or carriage 7. A coupling nut 32 is threaded onto the
lower end of the support sleeve 31 and forces an elastic ring 33
against the lower end face of the support sleeve 31. The elastic
ring 33 projects inwardly somewhat past the support sleeve 31, and
the glide sleeve 29 rests on the elastic ring 33 in this area. The
support sleeve 31 and the glide sleeve 29 are flush with one
another at their upper ends, and on the upper end faces of these
sleeves a damping ring 34 is positioned. In the lower end position
of the securing device 8, a shoulder 30 of the securing device,
where the diameter is reduced, rests on the damping ring 34. At the
location where the shaft 35 of the securing device 8 projects
downwardly from the coupling nut 32, an elastic rubber ring 36 is
secured on the shaft 35 and surrounds it in a circular ring shape.
This elastic rubber ring 36 provides a spring-elastic element
against whose spring-elastically acting restoring force the
securing device 8 can be moved upwardly in the axial direction by a
small stroke. A bolt 37, secured in the support sleeve 31 and
projecting into a corresponding recess in the area of the shoulder
30 of the securing device 8, provides a securing action against
relative rotation.
[0027] On the lower end of the shaft 35 an anvil or support 38 is
arranged and connected to the shaft 35. It is positioned centrally
underneath the lens 6 or its block 1 suspended therefrom.
[0028] A device according to the invention comprises moreover a
striking device 39 which comprises a striking member 40 in the form
of a type of a hammer. The striking member 40 is secured on the
piston rod 41 of a piston-cylinder unit 42 and, in its inactive
rest (initial) position before carrying out a strike, is positioned
at a spacing from the securing device 8 or its anvil 38. By loading
the piston-cylinder unit 42, the striking member 40 is accelerated
from below in the direction toward the securing device 8 and
carries out a strike onto the securing device 8 when impacting the
anvil 38. By means of this impact, an acceleration is exerted onto
the securing device 8 wherein the shaft 35 is moved relative to the
glide sleeve 29 with compression of the elastic rubber ring 36 in
the direction 46 of the impact movement. Moreover, the holding-down
device 15 is also moved in the upward direction by the upwardly
moved securing device 8. The acceleration exerted onto the securing
device 8 is transmitted onto the lens 6 so that the block 1 as a
result of its inertia becomes detached from the lens 6. After the
impact energy has been received by the spring-elastic bearing
devices of the securing device 8 and of the holding-down device 15,
the devices 8 and 15 return into their lower end position. In this
connection, the securing device 8 is damped by the damping ring 34.
The O-rings 23, 24 are provided for an additional gentle treatment
of the lens 6.
[0029] When attaching a lens on a block, an outwardly projecting
nose 43 (compare FIG. 6) can be produced on a peripheral location.
In order to ensure a proper deblocking action despite of this nose,
a slot 44 may be provided on the inner sleeve part 20 which extends
in the axial direction across the length of the sleeve part 20.
When loading the securing device 8, care must be taken that a nose
43 which may be present is positioned above this slot so that this
nose 43 can move through this slot 44 when the block 1 drops. In
the case that an automated loading device is provided, the lens
which is gripped by a lens holder could be rotated, for securing
the correct angular position of the nose 43, about a central
longitudinal axis extending through the lens and the block until
the nose of the block 1 rests against a stop which will position
the nose properly.
[0030] Different modifications and alterations of the illustrated
embodiment are conceivable and possible without leaving the realm
of the invention. For example, the support of the securing device
that is movable relative to a spring-elastic restoring force could
also be realized in a different way then the one illustrated. For
example, the shaft 35 of the securing device could also be attached
to a bearing block on an elastic material which, in turn, is
fastened on the frame of the carriage. The movement of the securing
device 8 would then be realized against the elasticity of the
material of the bearing block. Also, the bearing device 8, in place
of the sleeve-shaped area on which the lens to be deblocking is
supported, could have a support which is adjustable with regard to
its diameter in order to be able to deblock lenses or blocks of
different diameters with one and the same securing device. A
securing device could be provided in the area of the support of the
lens with several jaws surrounding a receiving opening for the
block and positioned at a spacing from one another in the
circumferential direction, wherein the diameter of the receiving
opening is adjustable by scissor-type members, as disclosed already
in the prior art deblocking device described supra.
[0031] In principle, it would also be conceivable and possible to
eliminate the slide or carriage 7. The securing devices 8 would
thus be stationary relative to the machine frame 11. In this
situation, each securing device 8 would be provided with its own
holding-down device 15 and its own striking device 39. Loading of
one or several securing devices could be carried out by hand.
[0032] While specific embodiments of the invention have been shown
and described in detail to illustrate the inventive principles, it
will be understood that the invention may be embodied otherwise
without departing from such principles.
* * * * *