Abstract:
An improved sight holder for an archery bow including an accurate and rapidly adjustable vertical adjustment, an improved adjustment with axial direction to the arrow. The holder is easily used. The vertical adjustment uses a novel double-threaded screw device so as to achieve both a rapid adjustment by a coarse screw and a delicate adjustment by a fine screw with both threads cut into the same screw shaft and separately engageable nut devices. The adjustment on the line of flight is improved by use of a bar which is tapered to allow a forced tight fit to be accomplished by use of a finger-operated set screw.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     This invention pertains to bow sights particularly useful for archers who desire the best accuracy in placement of the arrow being shot. This may include both contestants in archery contests and hunters for whom accurate shooting is important. Many of the sights include scopes and all such sights, whether with or without scopes, should be adjustable for distance where such may be variable. Adjustments should be provided for dimensions vertically, and laterally of the bow as well as for line-of-sight directions. It is therefore important that the adjustments should be both easy and quick. 
     Vertical adjustment of the sight may be more used than lateral adjustment, and is apt to be required frequently and in the field. It may also be useful to replicate the setting with some frequency so that the ability to make and mark an accurate setting becomes desirable. It may also be desirable to be able to remove the sight from the bow easily and quickly. 
     In the line-of-flight adjustment, it is important that the setting remain constant relative to the vertical setting. Therefore it is important that the bar holding the sight laterally away from the bow not be loose or uncertainly placed. 
     By this invention, the adjustments are greatly improved in the respects noted. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top plan view of a bow sight holder embodying the improved adjustment devices, 
     FIG. 2 is a front elevational view of the holder shown in FIG. 1, 
     FIG. 3 is a detailed side elevational view of the novel collet for fastening the holder to a bow, apart from the holder, 
     FIG. 4 is an end elevational view of the collet shown in FIG. 3, 
     FIG. 5 is a detailed view from line  5 — 5  of FIG.  3 . 
     FIG. 6 is a partial sectional view of the holder shown in FIG. 1, taken from line  3 — 3  of FIG. 1, 
     FIG. 7 is a sectional view from line  7 — 7  of FIG. 6, 
     FIG. 8 is an elevational view of the holder shown in FIG. 1 taken from the left hand side of that Figure, 
     FIG. 9 is a detailed elevational view to an enlarged scale of the screw means with dual threads, 
     FIG. 10 is a detailed plan view of the dual nut to an enlarged scale and isolated from other parts, 
     FIG. 11 is an elevational view from line  11 — 11  of FIG. 10, 
     FIG. 12 is an elevational view from line  12 — 12  of FIG. 10, 
     FIG. 13 is a sectional view from  13 — 13  of FIG. 2, and 
     FIG. 14 is a sectional view from line  14 — 14  of FIG.  2 . 
    
    
     DESCRIPTION 
     Briefly, this invention comprises an improved carrier or mount for a bow sight useful to archers who demand accuracy and convenience in setting the bow sight to achieve their need. More specifically, this invention comprises a carrier for a sight which can be quickly and very accurately adjusted to meet the requirements of the most demanding situations. 
     More specifically, the usual carrier includes a section to fasten the device to the bow; a section for vertical adjustment; a part for adjustment in the horizontal direction of the arrow flight and a holder for the sight device which may be laterally displaced from the bow. This carrier includes each of those parts, several of which have been improved. 
     In the fastening section the present device uses a first plate  10  having a flange  11  by which the vertical adjustment section (described later herein) is held in place. A second plate  8  is adapted to fit opposite the plate  10  and is provided with a pair of aligning posts  12  and a screw threaded attachment stem  9 . These aligning posts  12  fit into aligning holes  7  in the first plate  10  to hold the two plates in proper alignment. It is envisioned the holes  7  may be in alternate places (preferably at opposite corners) to provide that the plates may be turned 90° from a first position to an alternate second position. 
     A hole  6  of relatively enlarged size is provided in the plate  10 . This hole is large enough so that the knurled nut  5  which is threaded onto the stem  9  can pass through the hole  6 . The nut  5  may be formed with flat sides  5 ′ to provide added force surfaces for tightening the nut  5 . 
     A centering and holding device is located within a slot  4  formed in the stem  9 . A pair of dogs  3  is located there to form that centering device. These dogs  3  are of identical shape but are placed in opposite directions within slot  4 . In this position they each include a tapered surface  2  on a dog  3  to engage the edges of the hole  6  and an added tapered surface  1  on the other end of each dog  3  to be engaged by the nut  5  as it is screwed down tightly. A ring  73  formed of an elastic material such as rubber is engaged in hooks  64  formed in the dogs  3  serves to hold the dogs  3  radially within the slot. 
     In use, the plate  8  is fastened to the bow (not shown). The nut  5  is loosened, and as a result the surfaces  2  on the dogs  3  are retracted by the ring  73  enough to clear the edges of the hole  6  so that the plate  10  can be placed over the nut  5  and the dogs  3 . After that the nut  5  can be run down on the stem  9  until it engages the sloped surface  1  on each dog. Because the individual surface  1  on each dog  3  is opposite the surface  2 , the pressure of the nut  5  will cause the dogs  3  to spread resulting in engagement of the surfaces  2  with the edges of the hole  6 , and therefore the holding of the plate  8  to the plate  10 . Further tightening of the nut  5  will cause the further spreading of the surface  2  so that the hole is perfectly centered on the plate  8 . Thus, there is an aligning of the plate by this means as well as substantial control from the posts  12  on the plate  8 . 
     The vertical adjustment section is fastened to a flange  11  of the plate  10  and includes a bracket  13  to which is fastened a square, hollow post  14 . It will be obvious that the post  14  can be fastened to the bracket  13  for adjustment. For example, a T-shaped slot  15  (FIG. 7) can be formed in the post  14  in which the head  16  of a screw  17  may be slidably disposed. A nut  18  can then be used to tighten this screw  17  to hold the two posts in position. For best results, applicant prefers that serrated transverses and matching ridges be formed on the matching face of the bracket  13  and post  14  to assure positive location between the two posts. Such serrations are common in the art. 
     The post  14  is formed with a longitudinal channel  20  (FIGS. 6 and 7) having an open side  21 . A carrier  22  is slidably mounted in the channel  20  and is designed to be adjusted vertically with that channel. Control of the position of the carrier is accomplished by the interplay of a threaded shaft  25  and a novel arrangement of a divided nut  26 . The shaft  25  is rotatably journalled in both the top cover  26 A and bottom cover  27  of the post  14 , and is turned by a knob  28 . Because it may be desired to replicate the setting of the shaft  25 , a series of members or other indicia  29  may be printed on the knob adjacent to an index line  30  on the top cover  26 A. In order to maintain smooth operation and the best possible alignment, a V-groove  31  forming a sliding keyway may be used as a guide. 
     The threaded shaft  25  and its engaged nut  26  are important to the proper operation of the device because they allow, in a single device, for both a quick and coarse adjustment, and alternatively, a fine adjustment. To do this, the shaft  25  is formed with a relatively coarse-pitched thread  35  (FIG.  9 ). The pitch of this thread may be of the order of 0.30 inches so that if there are 10 indicia on the circumference of the knob  28 , the carrier  22  would be moved about 0.03 inches with each interval between indicia. This spacing is, however, much too great for proper adjustment of the sights. Therefore, in order to provide proper adjustment, a second thread is also formed on the shaft  25 . 
     To provide the second thread, the first thread  35  is formed with a smooth cylindrical exterior instead of a sharp edge. A very fine thread  36  is cut into that cylindrical exterior. Thus, there is a coarse thread  35  having a relatively coarse pitch and a thread  36  having very fine pitch superimposed onto the coarse pitch and all on the same shaft. 
     In order to take advantage of the combination of a coarse, quick adjustment and the fine, accurate adjustment thus available on the same shaft, applicant provides a divided nut  26 . This nut is slidably located on a slide member  37  above the carrier  22  and beneath a yoke  38  attached to the carrier  22 . Thus, the nut member  26  can be slid axially of the shaft  25  for a slight distance. 
     The nut  26  itself is formed with an elongated opening  40  adapted to embrace the shaft  25  as is shown in FIG.  7 . One side of the opening  40  has coarse grooves  41  formed in it to engage the coarse threads  35 . The opposite side of the opening has fine grooves  42  which are engageable with the fine threads  36  on the shaft. Thus, the nut can be slid from engagement with one set of threads into engagement with the other. 
     The sliding necessary to change the threadable engagement is accomplished by an eccentric or flattened disc  45 . This disc is journalled on a pin  46 . The disc  45  is pressed into engagement with the yoke  38  by a compression spring  47  engaged between the yoke  38  and the nut  26 , thus biasing the nut in the direction toward the column on post  14 . Preferably, this bias will move the fine threads  36  and grooves  42  into engagement with each other although it will be obvious that a reversal of engagement might also be used. 
     The pin  46  is shown as threaded into an opening in the slide member  37 . It will be obvious that the threaded engagement may not be necessary, so long as the pin is fixed onto that slide. By this arrangement, a turning of the disc  45  away from the position with its flat side engaging the yoke  38  will cause the slide member  37  to be pulled (to the left in FIGS. 3 and 4) so as to slide the nut member  26  in that same direction and thus to change the threaded engagement from the coarse to the fine threads or the reverse. The device illustrated to allow such turning is a threaded peg  48  having a knurled head  49  although many other convenient devices may be conceived of for such a purpose. 
     Because replication of the vertical setting of the sight may often be desirable, a numbered scale  50  may be removably placed in a groove  51  formed in the post  14 . A magnifying device  52  may be carried by the carrier  22  over the scale for ease in reading that scale. 
     Lateral adjustment of the sight is accomplished by a device which may be similar to the vertical adjustment mechanism. A lateral channel member  60  which may be similar in cross section to the post  14  is carried by the carrier unit. Thus, the slotted opening  61  also includes the V-shaped keyway  62 . The opening  61  is capped at each end by caps  63  and  63 ′. An arm holder  65  is slidably journalled in the opening  61  and is moved within that spacing by reason of a threadable engagement with a screw  66  journalled at both ends in the caps  63  and  63 ′. A knob  67  may be used to control the screw  66  and therefore to control the position of the arm holder  65  within the opening  61  in the channel member  60 . 
     The arm holder  65  is designed to hold an arm  70  which in turn carries a mounting  71  for the actual sight. This arm  70  must be firmly set so that there is no play or movement relative to the assembly. To accomplish that goal, the device embodying the present invention includes the particular arm  70  which has a lateral cross section in the shape of a trapezoid having tapered sides fitting the taper of a socket  73  in the holder  65 . A screw device  74  threaded into the top  75  of the socket  73  may be used to press the arm  70  into the socket so as to provide a tight fit with no space for any movement. Any type of device such as a knob  76  or a wing nut arrangement may be used to give the user of the sight an easy way of tightening the screw device  74 . 
     At the end of the arm  70  remote from the adjustment mechanism thus far described, an adjustable mounting  71  for the actual sight is carried. In the figures this mounting  71  is affixed to the arm  70  by a slightly different means. The arm  70  with its tapered cross section is still fitted into a tapered slot  78  in the mounting bracket  79  of the mounting  71 . A simple screw  80  extending through the arm  70  and threaded into the bracket  79  is then used to pull the arm  70  into tight fit with the bracket. 
     The sight  81  itself is carried on a threaded member  82  extending through an opening in a cylindrical part  83 . A bushing  84  formed of nylon or similar plastic material which may be slightly flexible is fitted into one end of the opening in the post  83 . The threaded member  82  extends through the bushing  84  in a snug but not a tight fit. Four substantially equally spaced set screws  85  are threaded into the part  83  in position to press readily onto the bushing  84 . By alternately tightening or loosening diametrically opposite screws  85  some slight adjustment of the threaded member  82  relative to the part  83  is possible. This adjustment may be only of the order of thousandths of an inch, but that may still be significant in the position of the sight  81 . 
     At the end of the cylindrical part  83  opposite the sight, a cup shaped socket (not shown) is formed. A hemispherical shape  87  on a threaded nut  88  fits into the socket so that the threaded member  82  can be tilted slightly by use of the set screws  85 . In use, the threaded member  82  is moved to approximately the position needed for the sight  81 . This is possible either by threading the member  82  through the bushing  84  or pushing it through that bushing. Because the bushing  84  is relatively soft and is not formed with threads, either method is possible. When that position is reached, the nut  88  is threaded onto the member  82  until it fits into the socket in the cylindrical post  83 . The screws  85  can then be used to tighten and adjust the member  82  into the bushing  84 . Further and firmer lateral adjustment of the sight is accomplished by use of the adjustment screw  66  so that accurate adjustment is not completely dependent on the position of the nut  88 . However, in order to maintain the position of that nut, a set screw  90  is provided to hold the nut  88  in a set position on the member  82 . 
     Applicant has by his invention provided a bow sight mounting device which allows for full adjustment by both quick and easily used adjustment devices, but also by a unique double threaded screw makes possible both quick adjustment and finely accurate adjustment in the same mechanism. From the previous description the operation of the device should be apparent to anyone reasonably skilled in the art.