Abstract:
An improved mount for, and methods of mounting an, optical structure are provided. The mount has a protruding member extending from a surface of the optical structure, a base element having a mounting structure for mounting the mount to another structure and an upper element extending from the base element having a first opening extending therethrough for receipt therein of at least a portion of the protruding member. The first opening defines first and second arms, each of the arms comprising a head portion and each of the head portions ending at an end. A second opening in the upper element extends through one of the head portions and the end thereof in a direction toward the other head portion, while a third opening exists in the upper element through the end of the other head portion in an orientation substantially opposite to and in communication with the second opening so that a tightening mechanism received through the second opening can be received into the third opening. Tightening of the tightening mechanism into the third opening causes the ends of the head portions to draw toward each other so that the first opening of the upper element tightens around the at least a portion of the protruding member.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Divisional application of U.S. patent application Ser. No. 13/208,887, filed on Aug. 12, 2011, which has issued as U.S. Pat. No. 8,567,968 on Oct. 29, 2013, and which is a Divisional application of U.S. patent application Ser. No. 11/674,315, filed Feb. 13, 2007, which has issued as U.S. Pat. No. 8,092,030 on Jan. 10, 2012, and which claims priority to, and the benefit of, U.S. Provisional Patent Application Ser. No. 60/791,564, filed Apr. 12, 2006, the entireties of which applications and patents are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to the field of mounts for optical structures, including but not limited to, reflective panels, hollow retroreflectors and solid retroreflectors. 
     Optical structures such as, but not limited to, reflective panels (mirror panels), hollow retroreflectors and solid retroreflectors are old in the art. Solid retroreflectors are solid cubes of glass wherein adjacent sides of the cube are substantially perpendicular to each other and three of the sides that meet at a common corner are polished to have a high degree of flatness. Hollow retroreflectors are made of three mirror panels joined together preferably having optically flat reflective surfaces disposed at right angles to each other, and meeting at what can be described as a common inside corner of an imaginary cube. Both solid and hollow retroreflectors in general have the essential property of causing incident and reflected light rays to travel along substantially parallel paths. 
     When hollow retroreflectors are assembled for high accuracy and precision it is important to maintain the mutual perpendicularity of the reflective surfaces and sometimes essential to ensure that the retroreflector as a whole does not move. The perpendicularity of the reflective surfaces is affected by external stresses. With regard to high accuracy and precise reflective panels, such as mirror panels to be used for high accuracy purposes, it is also important to try and maintain as optically flat as possible the reflective surface of the panel. 
     Examples of external stresses that can affect the optical flatness of a reflective panel and/or the perpendicularity of reflective surfaces of abutting reflective panels of a hollow retroreflector, are thermal expansion or contraction of the substrate material from which the panels are made, deflection caused by curing of the adhesives used to join elements together and/or to join the retroreflector to its mount and/or the mass of the panels themselves. Accordingly, it would be desirable to assemble together the elements of a hollow retroreflector and/or to assemble a reflective panel to a mount, in such a manner as to reduce these stresses. It would also be desirable that the manner of mounting a retroreflector to its mount not add to these stresses, but nevertheless, securely retain the retroreflector on the mount. Examples of hollow retroreflector mounts which have proven successful in maintaining the reflective surfaces in their perpendicular orientations are found in U.S. Pat. No. 3,977,765, to Morton S. Lipkins, U.S. Pat. No. 5,122,901, to Zvi Bleier, and U.S. Pat. No. 5,335,111, also to Bleier. 
     The present mount also achieves secure mounting of the optical structure in a manner designed to help eliminate deflective stresses on the reflective surface(s) of the structure caused by the mounting of the retroreflector to its mount. 
     The mount also allows for easy and secure mounting of the optical structure onto a support structure. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, an improved mount for, and methods of mounting an optical structure are provided. The mount has a protruding member extending from a surface of the optical structure, a base element having a mounting structure for mounting the mount to another structure and an upper element extending from the base element having a first opening extending therethrough for receipt therein of at least a portion of the protruding member. The first opening defines first and second arms, each of the arms comprising a head portion and each of the head portions ending at an end. A second opening in the upper element extends through one of the head portions and the end thereof in a direction toward the other head portion, while a third opening exists in the upper element through the end of the other head portion in an orientation substantially opposite to and in communication with the second opening so that a tightening mechanism received through the second opening can be received into the third opening. Tightening of the tightening mechanism into the third opening causes the ends of the head portions to draw toward each other so that the first opening of the upper element tightens around the at least a portion of the protruding member. 
     The method of mounting the optical structure onto the mount is to form an optical structure having a reflective surface and a portion of the mount comprising a protruding member extending from a back surface of the optical structure, wherein the protruding member is either integrally formed with, or bonded to, the back surface of the optical structure. Forming the remainder of the mount comprising a base element having a construction for allowing the mount to be mounted to another structure, the mount further having an upper element having a first opening extending therethrough, such first opening forming two arms each having a head portion and ending at ends thereof. Sliding the first opening of the mount over at least a portion of the protruding member. Tightening the first opening of the mount around the protruding member by inserting a tightening mechanism into a second opening located through one of the head portions of the mount and by further inserting and tightening the tightening member into a third opening in the other head portion of the mount so that the tightening member draws the two ends of the head portions toward each other thereby contracting the first opening of the mount around the protruding member of the optical structure. 
     Accordingly, it is an object of the invention to provide an improved mount for an optical structure. 
     Another object of the invention is to provide an improved mount for an optical structure which causes minimal external stresses to the reflective surfaces of the optical structure. 
     Still another object of the invention is to provide an improved mount for an optical structure wherein the mount achieves reductions in movement of the optical structure in order to achieve higher-accuracy distance measurements. 
     Yet a further object of the invention is to provide an improved mount for an optical structure wherein the mounting of the mount and optical structure to a support structure is easy and secure. 
     It is even a further object of the invention to provide an improved method of mounting an optical structure using the improved mount. 
     Other objects of the invention will in part be obvious and will in part be apparent from the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the invention, reference is made to the following description taken in connection with the accompanying drawings, in which: 
         FIG. 1  is an exploded perspective view of a mount, optical structure and screw, made in accordance with the invention; 
         FIG. 2  is a perspective view of the structures of  FIG. 1  as joined together; 
         FIG. 3  is a cross-sectional view taken along line  3 - 3  of  FIG. 1 ; 
         FIG. 4A  is a side view of the mount  10  of  FIG. 1  along with another structure having a threaded member extending therefrom; 
         FIG. 4B  is a side view of an alternative embodiment for a mount having a threaded member extending therefrom in accordance with one or more aspects of the instant application along with another structure having a threaded opening  110   a  therethrough; and 
         FIG. 5  is a perspective view of a roof mirror having a pin extending therefrom in accordance with one or more aspects of the instant application. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the figures, a mount for an optical structure made in accordance with the invention is generally designated at  10 . In the particular case of the figures of this application, the optical structure portrayed is that of a hollow retroreflector, which will hereinafter generally be designated in the figures at  20 . It is of course to be understood that other optical structures are anticipated to be compatibly used with mount  10 , including but not limited to, individual mirror panels (not shown) and/or roof mirrors (see e.g., roof mirror  520  having a protruding member  90  with an outer surface  92  of  FIG. 5 ) and/or solid retroreflectors (not shown). 
     Retroreflector  20  is preferably made of fused quartz or fine annealed Pyrex (i.e., any type of borosilicate glass or glasses having a low coefficient of thermal expansion), while mount  10  is preferably made of a metal alloy having a very low coefficient of thermal expansion, such as INVAR (e.g., a nickel iron alloy having a low coefficient of thermal expansion) or aluminum. 
     Hollow retroreflector  20  is comprised of a first panel  30 , a second panel  40 , and a third panel  50 . Each of the panels  30 ,  40  and  50  has a corresponding reflective surface  32 ,  42  and  52 . The higher the degree of optical flatness achieved in surfaces  32 ,  42  and  52  will in part determine the accuracy of the corresponding panels  30 ,  40  and  50 . Panels  30 ,  40  and  50  are disposed substantially at right angles to each other so that reflective surfaces  32 ,  42  and  52  are also disposed substantially at right angles to each other. Each of panels  30 ,  40  and  50  also has non-reflective, back surfaces  34 ,  44  and  54  which are opposite to reflective surfaces  32 ,  42  and  52 . 
     As with all hollow retroreflectors, retroreflector  20  is designed to receive an incoming (incident) light ray (not shown) and reflect the light ray off of the reflective surfaces  32 ,  42  and  52  and out from retroreflector  20  along a path substantially parallel to the incident light ray. Of course, the incident light ray can initially strike any one of the reflective surfaces without bearing upon the accuracy of the parallelism of the reflected light ray. The accuracy tolerances for retroreflector  20  will almost always depend upon the function to be performed by retroreflector  20 . If high degrees of accuracy; i.e., parallelism of the incident and reflected light rays, is a primary purpose of retroreflector  20 , then high degrees of precision must be created and maintained with respect to the flatness of and perpendicularity of reflective surfaces  32 ,  42  and  52 . 
     One construction for a hollow retroreflector is as disclosed in U.S. Pat. No. 3,663,084 to Morton S. Lipkins. If the construction shown in the &#39;084 patent is used herein, then each of panels  30 ,  40  and  50  of hollow retroreflector  20  has at least first and second sides  36  and  38 ,  46  and  48  and  56  and  58 , respectively. The first and second sides of each of the panels are substantially perpendicular to each other and to each of the other sides of the other panels. As is seen in the figures, second side  48  of panel  40  is abutted against and adhered to reflective surface  32  of panel  30 , second side  38  of panel  30  is abutted against and adhered to reflective surface  52  of panel  50 , and second side  58  of panel  50  is abutted against and adhered to reflective surface  42  of panel  40 . Accordingly, each of panels  30 ,  40  and  50  is simultaneously an abutting panel at second sides  38 ,  48  and  58 , and an adjacent panel at first sides  36 ,  46  and  56 . 
     Turning now to a discussion of mount  10 , it is seen from the figures that mount  10  has an upper element  60  and a base element  100 . 
     As seen in the figures, base element  100  has extending therein an opening  110 . Opening  110  preferably extends through a bottom surface  112  of base  100 , but may be placed anywhere on base  100 . Opening  110  (e.g., opening  110  of mount  10  of  FIG. 4A ) is preferably threaded to receive a correspondingly threaded member (see e.g., threaded extending member  123  of  FIG. 4A ) extending from some type of support structure (see e.g., support structure  140  of  FIG. 4A ). However, it is also to be understood that instead of having opening  110 , a mount  10   a  (best seen in  FIG. 4B ) may include a base element  100   a  having a bottom surface  112   a ; the base element (e.g., the base element  100   a  of  FIG. 4B ) may have an outwardly extending member (see e.g., threaded extending member  123   a  of  FIG. 4B ) which would in turn be received into a cooperating opening  110   a  on a support structure (see e.g., support structure  140   a  of  FIG. 4B ). In this instance also it is preferred that the extending member and support opening both be threaded to allow for a more secure connection between the two. Additionally, other mounting constructions are intended to be encompassed in the invention, such as the use of a clamp from the support structure to securely hold base element  100 ,  100   a , as are other constructions. 
     Turning now to a discussion of upper element  60  of mount  10 , it is seen that in a preferred embodiment upper element  60  has an opening  62  extending therethrough. In the embodiment shown herein opening  62  is circular and such a circular opening is preferred, but not mandatory, it being anticipated by the invention herein that opening  62  may be any geometric shape. It is also seen that opening  62  of upper element  60  creates two arms  64  and  65 , each having a respective head portion  67  and  69 . Head portion  67  ends at end  70 , while head portion  69  ends at end  72 . Ends  70  and  72  do not touch and have a gap  68  extending therebetween. Through head  69  extends opening  74 , through which screw/bolt/tightening mechanism  80  (hereinafter “element  80 ”) is received. Opening  74  extends completely through head  69  and end  72  of head  69 . As is best shown in  FIG. 3 , a corresponding and communicating opening  75  extends through end  70  of head  67 , so that element  80  is able to be received therein. Assuming element  80  is threaded and that at least opening  75  is also threaded, then as element  80  is tightened into opening  75 , ends  70  and  72  are drawn together. As ends  70  and  72  draw together, opening  62  of element  60  becomes smaller; i.e., the diameter lessens, thereby creating a clamping force against protruding member  90  of panel  30 , discussed in more detail below. It is also to be understood herein that some, or all of, opening  74  may be correspondingly threaded to receive element  80 . 
     To help secure element  80  within the opening in end  70 , all of, or at least a portion of, opening  74  may also be correspondingly threaded. In the figures shown, element  80  is a threaded bolt having an Alan wrench opening in its head for tightening and loosening element  80 , as is known in the art. Other elements  80  are anticipated herein; such as, but not limited to, screws and/or bolts having Philips or flat head openings. Other manners of tightening the clamping force of opening  62  by bringing ends  70  and  72  together are also anticipated herein, the primary inventive concept being the mounting of mount  10  through opening  62  onto protruding member  90 . As way of a further example, another embodiment of the invention may involve no element  80  and no gap  68  between ends  70  and  72 . Instead, opening  62  may be continuous and sized so that a little adhesive applied between the outer surface  92  of protruding member  90  allows opening  62  to be adhered to surface  92 . 
     Turning now to a more detailed discussion of member  90 , panel  30  may be formed such that member  90  is an integrally extending part of panel  30  or member  90  may be a separate member that is bonded to back surface  34  of panel  30 . In the preferred embodiment, bonding refers to fusing or adhering member  90  to back surface  34  of panel  30 . As seen in the figures, member  90  is circular and/or disk-shaped in cross section to conform to opening  62  of mount  10 . However, as has been previously discussed, if opening  62  takes a different shape, member  90  would take the same shape. By way of example of at least one embodiment shown in  FIGS. 1-2 , the protruding member  90  may include a first surface  91  (e.g., on a first end of the protruding member  90 ) and a second surface  93  (e.g., on a second end of the protruding member  90 ). The protruding member  90  may include a third surface (e.g., the outer surface  92  of the protruding member) extending between the first and second surfaces  91 ,  93 . The protruding member  90  may be substantially circular, circular, disk-shaped and/or substantially disk-shaped in cross section to conform to the opening  62  of the mount  10  when the opening  62  of the mount  10  is substantially circular, circular, disk-shaped and/or substantially disk-shaped. Because the protruding member  90  preferably is sized and shaped to conform to the opening  62 , one surface (e.g., such as the first surface  91 ) may be either integral with the panel  30  or bonded, fused and/or adhered to the back surface  34  of the panel  30 . The one surface (e.g., such as the first surface  91 ) and/or the protruding member  90  may be sized and shaped such that the protruding member  90  extends through the hole  62  so that the tightening mechanism (e.g., in at least one embodiment, the tightening mechanism may be the screw/bolt/tightening mechanism  80 ) may draw the ends  70 ,  72  of the heads  67 ,  69  together such that the opening  62  may be at least one of substantially on, in connection with and contracted around the protruding member  90 . In at least one embodiment, the protruding member  90  may be cylindrical. The first surface  91  of the protruding member  90  may comprise at least one of: a surface bonded, fused and/or adhered to the back surface  34  of the panel  30 ; the back surface  34  of the panel  30  (e.g., by way of an adhesive, adhering material and/or adhering element, a bonding material or element; via an adhering material and/or element, adhesive, bonding material, etc. located between at least one portion of an optical structure, such as the panel  30 , and at least one portion of the first surface  91  of the protruding member  90 ; etc.); a surface of the panel  30  when the member  90  is integrally formed with the panel  30 ; the top surface of a cylinder (e.g., when the protruding member  90  is cylindrical); and any other surface as discussed herein and/or known to those skilled in the art at the time the invention was filed that includes the structural attributes of the first surface  91  discussed herein. The second surface  93  of the protruding member  90  may comprise at least one of: a surface on the opposite side of the protruding member  90  from the first surface  91 ; a surface in contact with the third surface (e.g., the outer surface  92 ) of the protruding member  90  and spaced away from the panel  30  and/or the back surface  34  of the panel  30 ; the bottom surface of a cylinder (e.g., when the protruding member  90  is cylindrical); a surface of the cylinder that is inserted into and/or disposed within the opening  62 ; a surface of the protruding member  90  that is aligned with or substantially aligned with a surface of the arms  64 ,  65  (e.g., the surface of the arms  64 ,  65  that is on the opposite side of the upper element  60  of the mount  10  away from the panel  30 ); and any other surface as discussed herein and/or known to those skilled in the art at the time the invention was filed that includes the structural attributes of the second surface  93  discussed herein. In at least one embodiment where the protruding member  90  does not extend all the way through the opening  62  or where the second surface  93  of the protruding member  90  is aligned with or substantially aligned with a surface of the arms  64 ,  65  (see e.g.,  FIG. 2 ), the opening  62  may be disposed at least one of substantially on, in connection with and around at least one of a third surface (e.g., the outer surface  92  of the protruding member  90 ) and the second surface  93 . Any of the first, second and third surfaces  91 ,  93 ,  92  of the protruding member  90  may be solid (see e.g.,  FIGS. 1-2 ). For example, when the protruding member  90  is cylindrical, the first, second and third surfaces  91 ,  93 ,  92  of the protruding member  90  may define a solid cylinder. The first and second surfaces  91 ,  93  of the protruding member  90  may be substantially parallel or parallel to each other. 
     The method of mounting optical structure  20  onto mount  10  is to form an optical structure having a reflective surface and a protruding member extending from a back surface of the optical structure, wherein the protruding member is either integrally formed from, or bonded to, the back surface of the optical structure. Forming a mounting member having a base element having a construction for allowing the mounting member to be mounted to another structure, the mounting member further having an upper element having a first opening extending therethrough, such first opening forming two arms each having a head portion and ending at ends thereof such that the ends are preferably separated by a gap therebetween at least when the mounting member is not attached to the optical structure. Sliding the first opening of the mounting member over the protruding member of the optical structure. Tightening the first opening of the mounting member around the protruding member by inserting a tightening mechanism into a second opening located through one of the head portions of the mounting member and by further inserting and tightening the tightening member into a third opening in the other head portion of the mounting member so that the tightening member draws the two ends of the head portions together thereby contracting the first opening of the mounting member around the protruding member of the optical structure. The tightening member preferably being a threaded bolt which is received into the third opening and the third opening also being threaded. As previously stated above, the second opening of the mounting member may also be threaded in whole or in part along its length. 
     The manner of mounting described herein is an improvement over prior mounting manners and is equally good, if not better, at preventing distortion of reflective surface  32  (and therefore of reflective surfaces  42  and  52 ) so as to help maintain reflective surfaces  32 ,  42  and  52  in their substantially flat and substantially perpendicular relationship to each other. In particular, with the manner of mounting described herein there are no distortional stresses applied on reflective surface  32  by either the securing forces exerted by the contracting of first opening  62  around protruding member  90  or due to contraction or expansion of the mounting member due to temperature change, or other reasons. For example, as best seen in  FIGS. 1-2 , the upper element  60  and/or the opening  62  of the upper element  60  may be disposed at least one of substantially on, in connection with and around at least one of the third surface (e.g., the outer surface  92 ) of the protruding member  90  and the second surface  93 . In particular, due to the orientation of protruding member  90  to reflective surface  32  and further since any such contracting or distortional forces exerted on member  90  from the mounting member are applied in directions/planes that are parallel to reflective surface  32 , and not perpendicular to it, such forces will only nominally, if at all, effect the optical flatness of surface  32 . 
     It will also be seen that the manner of mounting described herein achieves substantial rigidity between optical structure  20  and mount  10 . Further, as described in the immediate above paragraph, the preferred low coefficient of thermal expansion metal alloy material which makes up mount  10  significantly reduces the effects of thermal expansion/contraction of mount  10  so as to substantially minimize these effects on the accuracy of optical structure  20 . 
     It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and, since certain changes may be made in the above constructions without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall only be interpreted as illustrative and not in a limiting sense. 
     It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.