The invention relates to a securing structure, and more particularly to a securing structure for use in and/or with an apparatus for optical pieces requiring edge-machining, for instance optical lenses, including spectacle lenses.
One purpose of optic piece (e.g., lens) edge-machining is to finish an edge of the piece. For example, a spectacle lens is typically finished in such a way that the lens may be inserted into a spectacle frame. Various arrangements or systems are known which serve to mount the lens for edge-machining and to clamp or otherwise secure it between rotatable holding shafts of a lens edge-machining machine. As used herein, spectacle lenses can mean optical lenses or lens blanks for spectacles made of the usual materials, such as polycarbonate, inorganic glass, CR-39, HI-Index etc., and with circumferential edges of any shape, which lenses or lens blanks may be, but do not have to be, machined on one or both optically effective surfaces prior to machining of the edge thereof.
Lens edge finishing systems can comprise, among other structures, a securing structure (also frequently termed a “block” or “blocking member”), which may be attached detachably to one side of the lens; an adapter for the securing or blocking structure, which may be connected rigidly to one of the holding shafts of the lens edge-machining machine and can be constructed for rotation angle-oriented rotary drive of the securing or blocking structure; and a clamping assembly, which can comprise a fastening portion, connectable rigidly to the other holding shaft of the lens edge-machining machine, and a clamping portion which can be connected to the fastening portion, and which clamping portion can be constructed for force-locking engagement with the other side of the lens. The securing structure can be attached to the optical lens by means of an adhesive film portion or pad which can include adhesive on both sides.
To date, securing structures have suffered from or been susceptible to various drawbacks. For instance, an amount of air may enter between the lens being finished or machined, which can result in reduced bonding or adhesion between the lens and the securing structure. Reduced bonding, in turn, can tend to result in some amount of shifting and/or rotation of the lens (e.g., relative to the securing structure or overall finishing assembly) during a machining operation.
It would be desirable to provide a new securing structure that overcomes the aforementioned and other drawbacks. Further, it would be desirable to provide a new securing structure that can be manufactured in a cost-effective manner.
In accordance with one aspect of the present disclosure, disclosed herein is a securing structure for an optical piece comprising: a hub portion; a surrounding portion connected to the hub portion; a plurality of recess structures formed or otherwise provided in at least one of the hub portion and the surrounding portion and which are at least partially open on at least one side; and a rib structure that at least partially separates the plurality of recess structures.
Other embodiments, aspects, features, objectives and advantages of the present disclosure will be understood and appreciated upon a full reading of the detailed description and the claims that follow.
Embodiments are disclosed with reference to the accompanying drawings and are for illustrative purposes only. The present disclosure is not limited in its application to the details of construction or the arrangement of the components illustrated in the drawings. The present disclosure encompasses other embodiments and is capable of being practiced or carried out in other various ways. The drawings illustrate a best mode presently contemplated for carrying out the invention. Like reference numerals may be used to indicate like components.
In the drawings:
As is revealed by
In accordance with at least some embodiments, tower holding shaft 12 is connected non-rotatably and coaxially to securing structure adapter 18, which is constructed in a manner yet to be described for angle of rotation-oriented rotary drive of a securing structure 14, an exemplary embodiment of which is shown, fitted removably to the securing structure adapter 18. The securing structure 14 may be fixed detachably to one side 16 of the lens L. A clamping assembly 20 is fitted coaxially on the upper holding shaft 10 and comprises a fastening portion 22 connectable rigidly to the holding shaft 10 and a clamping portion 24 connected therewith. The clamping portion 24 is constructed for force-locking engagement with the other side 26 of the optical lens L.
In accordance with at least one aspect of the present disclosure, constructing or otherwise providing the clamping assembly, or similar assembly, according to the embodiments of the present disclosure allows very precise, backlash-free (or at least substantially backlash-free) torque transmission together with very smooth angle adjustment. The spherical head mounted in the receiving portion thereof and having two projections allows, in accordance with at least some embodiments, movements superimposed in the manner of a cardan joint about two tilt axes with virtually backlash-free rotary drive by the associated holding shaft due to, at least in part, the engagement between the projections and the channels in the receiving portion. Since the channel bottom of each of the channels displays, in cross section, a shape complementary and dimensionally matching, respectively, to the end zone of the associated projection, form-fitting engagement is obtained between the projections and the channels when viewed with the channel in cross section and the pin in longitudinal section, which form-fitting engagement is advantageous for backlash-free rotary motion transmission between spherical head and receiving portion. The backlash-free torque transmission thus obtained with low wear and at the same time very smooth angle adjustment is a prerequisite for a highly precise edging of spectacle lenses with machinery suitable for industrial production. Precisely aligned orientation relative to the first tilt axis of the two projections of the spherical head may be achieved, for example, by the introduction of a pin, protruding on both sides beyond the spherical head so as to form, for example, projections, into a through-hole which extends with its central axis through the center of the sphere and encloses the pin in play-free manner,
In accordance with at least some embodiments, the clamping assembly 20, the details of which are revealed clearly in particular by
The projections 28 provided on the spherical head 30 are formed by a pin 36, which extends through a through-hole 38 in the spherical head 30. Each of the two projections 28 provided on the spherical head 30 comprises a cylindrical surface zone 40 protruding out of the through-hole 38. The channels 34 in the receiving portion 32 each have two opposing flat guide surfaces 42, which extend parallel to one another and serve for substantially play-free guidance of the cylindrical surface zones 40 of the projections 28. This guidance is not lost in the event of swivel movements about the second tilt axis B within expected swivel movement limits.
Each of the projections 28 provided on the spherical head 30 comprises an end zone 44, which takes the form of a spherical cap. As is clear from
In contrast to the exemplary construction shown, the channels 34 may also have a rectangular cross section, wherein the channel width is greater only by a small amount of movement play than the diameter of the cylindrical surface zones 40 of the projections 28. In this instance, the channel side walls form the guide surfaces 42. The sphere radii of the end zones 44 do not have to correspond to the radius of the cylindrical surface zones 40 or the radius of the cross section of the pin 36, but may be greater than these. It has merely to be ensured that the length of the pin 36, measured over the end zones, is smaller by an amount of movement play than the spacing of the channel bottoms of the rectangular channels. The sphere radius of the end zones 44 should be, however, smaller than half the pin length.
The pin 36, in accordance with at least some embodiments of the present disclosure, has a cylindrical basic member 48 forming the cylindrical surface zones 40 of the projections 28. The basic member is provided at both sides with the spherical cap-shaped end zones 44. The pin 36 has a length which is smaller by an amount of movement play than the diametrally measured spacing of the channel bottoms 46. The pin 36 may be accommodated in the through-hole 38 in the spherical head 30 in axially displaceable manner.
The receiving portion 32 for the spherical head 30 is provided on the clamping portion 24 of the clamping assembly 20 in accordance with embodiments of the present disclosure. As is clearest from
In accordance with embodiments of the present disclosure, the fastening portion 22 of the clamping assembly 20 comprises a locking means 52, by means of which the clamping assembly 20 may be locked detachably to the corresponding holding shaft 10 (
The fastening portion 22 of the clamping assembly 20 is provided at the end with a channel 54, into which a cross-pin 100 engages for form-fitting rotary drive by the holding shaft 10, which cross-pin 100 is introduced into a transverse bore in the holding shaft 10. This transverse bore passes through diametrically opposing wall areas of the holding shaft 10 defining the blind bore 98. Rotation of the holding shaft 10 is thus transmitted via the cross-pin 100 to the fastening portion 22 and thence via engagement of the projections 28 with the channels 34 to the clamping portion 24.
In accordance with embodiments of the present disclosure, the clamping portion 24 comprises a covering 56 for force-locking engagement with the lens L, which covering 56 is in the shape of a circular ring in the example shown. In at least some embodiments, it consists of or can comprise a material, such as leather or synthetic leather, which is soft in relation to the material of the lens L. The covering may be connected with the tower surface of the clamping portion 24 by adhesion. If an injection-moldable polymeric material is used for the covering 56, the latter may also be constructed on its upper side with projections or the like for form-fitting engagement with corresponding recesses or the like in the tower surface of the clamping portion 24 (not shown). In accordance with at least some embodiments of the present disclosure, the covering comprises good adhesive power relative to the optical lens for torque transmission and for the covering not to be capable of causing any damage to the lens surface or thin layers attached thereto, such as anti-reflection coatings.
In accordance with embodiments of the present disclosure, a groove ring seal 102 in the form of an O-ring ensures a seal between the fastening portion 22 and the holding shaft 10. It seals these elements off from one another in the lower area of the blind bore 98. As is indicated by dash-dotted lines in
Securing structure 14, securing structure adapter 18 and their mutual association together with their connection with tower holding shaft 12 are initially described with reference to
For form-fitting rotary drive of the securing structure 14 by the securing structure adapter 18, these components each comprise rotary drive elements, which in accordance with exemplary embodiments are toothed, and which will be described in more detail below. Furthermore, securing structure 14 and securing structure adapter 18 likewise each comprise positioning elements, exemplary embodiments of which are described in more detail below, and which have the task of orienting or positioning securing structure 14 and securing structure adapter 18 correctly relative to one another with regard to angle of rotation prior to engagement of the rotary drive elements.
In accordance with at least some embodiments of the present disclosure, positioning elements comprise a plurality of asymmetrically arranged projections 58 and a plurality of complimentarily associated, correspondingly asymmetrically arranged recesses 62. The projections 58 may either be arranged on the securing structure 14 or on the securing structure adapter 18. The same is true of the recesses 62, i.e. if the projections 58 are located on the securing structure 14, the recesses 62 are arranged on the securing structure adapter 18. If, on the other hand, the projections 58 are arranged on the securing structure adapter 18, the recesses 62 are arranged on the securing structure 14. As illustrated, the projections 58 are constructed or otherwise provided on the securing structure adapter 18, while the recesses 62 are provided on the securing structure 14.
In accordance with embodiments of the present disclosure, the end faces 60 of the projections 58 lie in a common plane perpendicular to the axis of rotation D (
of the projections 58.
In accordance with embodiments of the present disclosure, the securing structure 14 may be united in the manner indicated below with the securing structure adapter 18 to yield the desired angularly correct engagement situation illustrated in
Further in accordance with at least some embodiments of the present disclosure and to ensure that the end faces 60 lie temporarily in tilt-safe manner against the fiat surface 64, the three projections 58 provided in the exemplary embodiment and naturally also the recesses 62 form the corners of a triangle. However, it must be ensured that the triangle is not equilateral, with the corners thereof at the same radial distance from the axis of rotation, because three different engagement positions displaced by 120 degrees relative to one another would then be possible. The projections and the recesses should be arranged asymmetrically with different radial distances from the axis of rotation.
To simplify introduction of the projections 58 into the recesses 62, the projections 58 and/or the recesses 62 can exhibit or otherwise comprise bezels starting respectively from the end faces 60 of the former or the flat surface 64. Bezels at the inlet openings of the recesses 62 are not shown in the drawings.
As is clearest in
As is clear in particular from
In accordance with at least some embodiments of the present disclosure, the securing structure adapter 18 has a sleeve-shaped rotationally symmetrical member 106 made of metal, e.g. brass, which is provided with a central receiving bore 108 for the shaft end 110 (
Attached to, for example injection-molded onto, the member 106, is an externally conical receiving element 118 for the securing structure 14. The receiving element 118 is or can be molded from a hard thermoplastic, for example polyoxymethylene (PM), and has a cylindrical receiving bore 120 for the hub portion 68 of the securing structure 14. The upper edge of the receiving element 118 is shaped to form the toothing 76. The receiving bore 120 ends at an inner surface 122 oriented perpendicularly to the axis of rotation D, from which surface 122 there protrude the projections 58.
In accordance with at least some embodiments of the present disclosure, the projections are located on the securing member adapter and the recesses on the securing structure.
According to another aspect of the present disclosure, the securing member may comprise a hub portion comprising the positioning elements and an outer or surrounding portion (e.g., an annular portion) connected resiliently integrally formed, integrated, or otherwise provided therewith, which bears or otherwise includes the drive elements (e.g., rotary drive elements) of the securing structure. The resilient connection, forming, integration and/or other provision between or of the surrounding portion and the hub portion allows simplified, improved adaptation of the securing structure to the shape (e.g., convexity) of the lens to be machined.
The above-mentioned connection between or formation of the hub portion and surrounding portion may be achieved in number of ways, for example, by way of a plurality of structures (e.g., webs), distributed about (e.g., evenly about) the perimeter (e.g., circumference). During injection-molding of the securing structure from a suitable thermoplastic material, the various portions and/or structures (e.g., hub portion) may be molded in one piece. By way of example, instead of individual structures, a connection (e.g., a continuous, annular, thin-walled connection) may also be provided, for example, at least partially between hub portion and surrounding portion, which connection allows similar flexible deformation between surrounding portion and hub portion for the purpose of adaptation to lens shape (e.g., convexity).
The drive elements on the securing structure and on the securing structure adapter are constructed, as complementary toothing or toothed portions. This toothing has the effect of centering a securing structure and securing structure adapter due to the radial tooth orientation thereof optionally together with a complementary conical construction of the toothing.
The securing structure 14 may be attached to lens L by way of an adhesive film portion 78 having an adhesive on both sides. The adhesive film portion 78 serves in mounting the lens L by way of the securing structure 14 and is located after mounting and clamping between the securing structure 14 and the lens L, as is clear from
The adhesive film portion 78 shown in
With reference to
Referring to
In accordance with at least some embodiments of the present disclosure, securing structures 14, 220, 230, and 240 comprise one or more planes about which a plurality of respective recesses 200, 222, 234 and 244, respectively are at least partially symmetric, and representative planes of symmetry “PS” are illustrated in exemplary fashion in
Exemplary dimensions are provided in the tables below with respect to the exemplary securing structures illustrated in the Figures and described above in accordance with at least some embodiments of the present disclosure. The exemplary dimensions provided include: (1) a first larger or major diameter “LD” corresponding generally to a circular region or perimeter of a respective securing structure, such as a respective surrounding portion, or a portion of a respective surrounding portion; (2) a second or smaller diameter “SD” corresponding at least generally to a circular region or perimeter of a respective securing structure, such as a respective portion that includes a plurality of recess structures and which can correspond to, for example, a distance separating arcuate (e.g., cylindrical) walls of opposite, symmetrically disposed, recess structures; (3) a first rib structure width “RW1” corresponding at least generally to a width of a rib structure or a portion of the rib structure; (4) a second rib structure width “RW2” corresponding at least generally to a width of a rib structure or a portion of the rib structure, including particularly when the rib structure includes a first rib structure width “RW1”; (5) a recess structure depth, or recess depth, “RD” corresponding to a depth of a respective recess structure, which, for purposes of the drawings, such depth is measured from an outer surface of a respective hub portion (a side opposite a respective optical piece receiving surface) of a respective securing structure to a respective innermost surface of a respective recess structure; (6) a spherical radius “SR” corresponding at least generally to a curvature (e.g., convexity) of a surface, such as the optical piece receiving surface, with such surface itself at least generally considered as coinciding with a surface of an imaginary sphere of having a radius equal to the respective spherical radius; (7) a flat side width “FW” corresponding at least generally to a width of a flat or substantially flat sided, or straight or substantially straight sided, region of a respective securing structure, such as a respective surrounding portion, or a portion of a respective surrounding portion; (8) a length “L” corresponding at least generally to a length of a region of a respective securing structure, such as a respective surrounding portion, or a portion of a respective surrounding portion; (9) a width “W” corresponding at least generally to a width of a region of a respective securing structure, such as a respective surrounding portion; and (10) an end radius “ER” corresponding at least generally to a curvature of an edge or end of a surface, such an end or an edge of a respective optical piece receiving surface, with such end or edge itself at least generally coinciding with a surface of an imaginary circle of having a radius equal to the respective end radius; and (11) a rib structure length “RL” corresponding at least generally to a length of a rib structure, or a portion of the rib structure.
Representative Dimensions for Securing Structure of
Representative Dimensions for Securing Structure of
Representative Dimensions for Securing Structure of
Representative Dimensions for Securing Structure of
The aforementioned dimensions are intended to be exemplary and not limiting. It is understood that one or more of the dimensions may vary to convenience and that the securing structures of the kind disclosed herein can be sized in accordance with a wide number of factors, including the type or size of lens to be machined, the particular machining apparatus in which the securing structure is utilized, among others,
The aforementioned recess structures or recesses disclosed herein can advantageously provide a better form accuracy due to a more even wall thickness of the molded part, resulting in reduced variation from one part to another during manufacture. In addition, it has been found that: a) respective lens contacting surface is increased by of rib structures (including rib structure portions) during edging or finishing of the lens L, resulting in increased adhesion during edging; b) the recess structures or recesses allow trapped air to escape during bonding, further resulting in a stronger adhesion of the lens (since there is little, if any, air inclusions); c) with increased adhesion, increased forces and torque can be transmitted from the lens holding shaft of the edge-machining apparatus to the lens and to resist cutting forces of the tool; d) after edge processing, first-time-fit rate increases (e.g., a spectacle lens that is finished has a increased likelihood of fitting into a desired frame) as rotation or shifting of the lens L during edge processing is reduced.
In accordance with at least one aspect of the present disclosure, a securing structure for an optical piece is disclosed which comprises: a hub portion; a surrounding portion connected to at least partially surrounding the hub portion; a plurality of recess structures formed or otherwise provided in at least one of the hub portion and the surrounding portion and which are at least partially open on at least one side; and a rib structure that at least partially separates the plurality of recess structures. In at least some embodiments, the at least one side is a lens-receiving surface and the surrounding portion includes a contoured surface or edge near and/or adjacent the lens-receiving surface.
In accordance with at least one other aspect of the present disclosure, an apparatus for securing and clamping optical lenses requiring edge-machining is disclosed and which comprises: at least one rotatable holding shaft; a securing structure positionable in relation to the at least one holding shaft, and which is detachably attached to at least one side of the optical lens; a securing structure adapter for the securing structure, which is connectable to the at least one holding shaft; and a clamping assembly connectable to the at least one holding shaft. The securing structure comprises: a hub portion; a surrounding portion connected to the hub portion; a plurality of recess structures formed or otherwise provided in at least one of the hub portion and the surrounding portion and which are at least partially open on at least one side; and a rib structure that at least partially separates the plurality of recess structures. In at least some embodiments, the at least one side is a lens-receiving surface and the surrounding portion includes a contoured surface or edge near and/or adjacent the lens-receiving surface.
Various alternatives are contemplated and considered within the scope of the present disclosure. The securing members of the kind disclosed can have many variations as already noted. In addition, and as shown, the overall shape of the securing (also called block or blocking) member can vary to some degree while maintaining overall functionality. For example, the outer edge can take a variety of forms, which can include (as has been illustrated and/or already noted), an edge or surface (e.g., an outermost edge or surface) that can be generally round, truncated (e.g., round with straight edge or surface portions), or generally oval in shape.
It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
This application claims the benefit of U.S. provisional patent application No. 61/453,513, which was filed on Mar. 16, 2011 and entitled “Securing Structure for Optic Device”, and which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | |
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61453513 | Mar 2011 | US |