Polishing plate clamp

Abstract

A polishing fixture has a clamp pad having a first rounded surface and a second rounded surface separated by a gap, the first rounded surface engaging the rear face on a multi-fiber ferrule on a first side of the opening in the rear face and the second rounded surface engaging the rear face on a second side of the opening in the rear face, and at least one rounded bottom portion to engage a top side of the multi-fiber ferrule, and a polishing plate having a first polishing datum and a second polishing datum, the first polishing datum engaging a first ferrule datum and a second polishing datum engaging a second ferrule datum, the clamp pad maintaining the multi-fiber ferrule against the polishing plate upon application of force to the clamp pad.

Description

USCO-190POLISHING PLATE CLAMPREFERENCE TO RELATED CASES

[0001] This application claims priority under 35 U.S.C. § 119 (e) to U.S. provisional application no. 63 / 730,521 filed on December 11, 2024, the contents of which are hereby incorporated by reference in their entirety.BACKGROUND OF THE INVENTION

[0002] The polishing of a multi-fiber ferrule is critical to the operation of any system that uses multi-fiber ferrules. The end faces of the multi-fiber ferrule need to have a particular configuration, one that is specified by standards. There are a number of multifiber ferrules that can be used today. Each of the finished (polished) multi-fiber ferrules must conform to the regulations. One multi-fiber ferrule that can be used is the TMT ferrule that is available from the applicant, US Conec Ltd. A large number of multi-fiber ferrules need to be polished at one time. Polishing the multi-fiber ferrules individually is simply not tenable. In order to polish a number of multi-fiber ferrules, the multi-fiber ferrules need to be put in a fixture to hold the multi-fiber ferrules in place during the polishing. However, the fixture has been found to be inexact in holding the multi-fiber ferrules during polishing. Additionally, the multi-fiber ferrules may be subject to vibration in the fixture during polishing. This could lead to the ferrule moving to another position and either rounding the end face or effectively polishing an un-desired angle into the end face. This results in an end face geometry that is less than useable. A new clamp pad for the polishing fixture that addresses the aforementioned challenges and provides that the end faces of the multi-fiber ferrules can now be polished in bulk more accurately than conventional polishing fixtures and processes.SUMMARY OF THE INVENTION

[0003] The present invention is directed to a polishing fixture for a plurality of multifiber ferrules, each of the multi-fiber ferrules in the plurality of multi-fiber ferrules having a first ferrule datum and a second ferrule datum, a rear face, and an opening in the rear face to receive a plurality of optical fibers, the polishing fixture that includes a clamp pad having a first rounded surface and a second rounded surface separated by a gap, the first rounded surface engaging the rear face on a first side of the opening in the rear face and the secondUSCO-190 rounded surface engaging the rear face on a second side of the opening in the rear face, the opening in the rear face being between the first rounded surface and the second rounded surface, and at least one rounded bottom portion to engage a top portion of the multi-fiber ferrule, and a polishing plate having a first polishing datum and a second polishing datum, the first polishing datum engaging the first ferrule datum and the second polishing datum engaging the second ferrule datum, the clamp pad maintaining the multi-fiber ferrule against the polishing plate upon application of force to the clamp pad.

[0004] In some embodiments, the gap between the first rounded surface and the second rounded surface allows the plurality of optical fibers to be received in the opening.

[0005] In some embodiments, the first rounded surface and the second rounded surface contact the rear face substantially midway between a top portion and a bottom portion of the ferrule.

[0006] In some embodiments, the first rounded surface and the second rounded surface contact the rear face closer to one of a top portion and a bottom portion of the ferrule than the other of the top portion and the bottom portion of the ferrule.

[0007] In some embodiments, the first ferrule datum is a top portion of the multi-fiber ferrule.

[0008] In some embodiments, the second ferrule datum is a forward facing surface on a top portion of the multi-fiber ferrule.

[0009] In some embodiments, the first polishing datum is a flat surface on the polishing fixture.

[0010] In some embodiments, the second polishing datum is a ledge on the polishing fixture to engage the forward facing surface on the top portion of the multi-fiber ferrule.

[0011] In some embodiments, the first and second rounded surfaces of the clamp pad engage the rear face along a central portion between the top portion and a bottom portion of the multi-fiber ferrule and exert a force on the multi-fiber ferrule towards an end face of the multi-fiber ferrule.

[0012] In some embodiments, the first rounded surface and the second rounded surface of the clamp pad exert a first force on the multi-fiber ferrule towards an end face of the multi-fiber ferrule, and the at least one bottom rounded surface exerts a second force on the multi-fiber ferrule, the first force and second force intersecting at an intersection point, and wherein the clamp pad is engaged with an actuator, the actuator having an axis that intersects with the first and the second forces at the intersection point.USCO-190

[0013] In another aspect, the invention is directed to a polishing fixture for a plurality of multi-fiber ferrules, each multi-fiber ferrule in the plurality of multi-fiber ferrules having a first ferrule datum and a second ferrule datum, a rear face, and an opening in the rear face to receive a plurality of optical fibers, the polishing fixture that includes a clamp pad having a first rounded surface and a second rounded surface, the first rounded surface and the second rounded surface to engage the rear face, and at least one rounded surface to engage a portion side of the multi-fiber ferrule, wherein the first rounded surface and the second rounded surface are separated by a gap to receive the plurality of optical fibers at the opening, and a polishing plate having a first polishing datum and a second polishing datum, the first polishing datum engaging the first ferrule datum and the second polishing datum engaging the second ferrule datum, the clamp pad maintaining the multi-fiber ferrule against the polishing plate upon application of force to the clamp pad.

[0014] Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings.

[0015] It is to be understood that both the foregoing general description and the following detailed description of the present embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention, and together with the description serve to explain the principles and operations of the invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Fig. 1 is a picture of a polishing fixture that can be used with the present invention;

[0017] Fig. 2 is a rendering of one polishing clamp that can be used with the present invention;

[0018] Fig. 3 is a top perspective view of one embodiment of a multi-fiber ferrule used with the present invention;USCO-190

[0019] Fig. 4 is a bottom perspective view of the multi-fiber ferrule in Fig. 3;

[0020] Fig. 5 is a rear elevational view of the multi-fiber ferrule in Fig. 3;

[0021] Fig. 6 is front elevational view of the multi-fiber ferrule in Fig. 3;

[0022] Fig. 7 is a cross sectional view from the rear of the multi-fiber ferrule in Fig. 3;

[0023] Fig. 8 is a cross sectional view of the multi-fiber ferrule in Fig. 3;

[0024] Fig. 9 is a bottom view of a the multi-fiber ferrule to be used with the clamp pads and polishing fixture showing the ferrule datums;

[0025] Fig. 10 illustrates the multi-fiber ferrule and a polishing plate about to engage one another;

[0026] Fig. 11 shows the ferrule datums engaging the polishing datums;

[0027] Fig. 12 is a side elevational view of one embodiment of a conventional clamp pad;

[0028] Fig. 13 is a rendering of the conventional clamp pad in Fig. 12 engaging the multi-fiber ferrule in the polishing fixture;

[0029] Fig. 14 shows the total deformation of the actuator of the polishing fixture when engaging the conventional clamp pad in Fig. 13;

[0030] Fig. 15 A shows one version of a conventional claim pad as a reference;

[0031] Figs. 15B-15E illustrate four embodiments of new clamp pad according to the present invention and;

[0032] Fig. 16 is a magnified side view of one embodiment of a clamp pad according to the present invention engaging a multi-fiber ferrule at the back and side thereof;

[0033] Fig. 17 shows the actuator engaging one of the clamp pads according to the present invention;

[0034] Fig. 18 illustrates the forces applied to the multi-fiber ferrule as the clamp pad engages the multi-fiber ferrule and polishing plate;

[0035] Fig. 19 shows the total displacement of the actuator of the polishing fixture when engaging a new clamp pad according to the present invention;

[0036] Fig. 20 illustrates a scenario when the intersection of the forces applied to the multi-fiber ferrule do not necessarily align with the axis of the actuator; and

[0037] Figs. 21 - 25 are a series of renderings showing the engagement of the clamp pad with the multi-fiber ferrule.USCO-190DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] Reference will now be made in detail to the present preferred embodiment s) of the invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts.

[0039] A polishing fixture 10 that can be used with the present invention is illustrated in Fig. 1. The polishing fixture is populated with 24 multi-fiber ferrules, but there could also be more or fewer places for polishing the multi-fiber ferrules. Additionally, this polishing fixture 10 is configured to receive the TMT multi-fiber ferrule that is available from the Applicant and described in U.S. Patent Nos. 12,019,278 and 12,379,549, the contents of which are incorporated herein in their entirety. The polishing fixture 10 could be configured to receive other multi-fiber ferrules. More information about the polishing fixture can be found in U.S. Patent Nos. 11,326,630 and 11,493,067, the contents of which are incorporated herein by reference.

[0040] Referring to Figs. 3-8, the multi-fiber ferrule 100 has a main body 102 having a top portion 104 and a bottom portion 106. There is a first side portion 108 that extends between the top portion 104 and the bottom portion 106. There is also a second side portion 110 extending between the top portion 104 and the bottom portion 106 on opposites sides of the main body 102. The main body 102 also has an end face 112 at a front end 114 of the main body 102 and a rear face 116 at a rear end 118 of the main body 102. The multi-fiber ferrule 100 is significantly smaller than the conventional MT ferrule and has typical dimensions of 1.25 mm height, 4 mm length (between the front end 114 and the rear end 118), and a width of 6.4 mm between the first side portion 108 and the second side portion 110

[0041] Applicant notes that the term “front” or “forward” means that direction where the fiber optic ferrule would meet with another fiber optic ferrule or device, while the term “rear” or “rearward” is used to mean the direction from which the optical fibers enter into the fiber-optic ferrule or fiber optic connector. In the present application, the multi-fiber ferrule will therefore have a front and a rear, the front will be inserted into an adapter, sleeve or other receptacle. Thus, in FIG. 3, the “front” of the multi-fiber ferrule is on the left side of the figure and pointing out of the figure. The “rear” or “back” is that part of multi-fiberUSCO-190 ferrule is on the right side of FIG. 3 and “rearward” and “backward” is toward the right and into the page.

[0042] As seen in FIG. 5, the multi-fiber ferrule 100 has a rear central opening 120 extending into the main body 102 from the rear face 116 and configured to receive at least three optical fibers (not shown). The multi-fiber ferrule 100 also has a plurality of fiber support structures 122 to support the optical fibers. See also FIG. 7. The fiber support structures 122 are in communication with the rear central opening 120 and extending through the main body 102 to the end face 112. Along the length of the fiber support structures 122 there may be chamfered portions 124 that assist in insertion of the optical fibers into the multi-fiber ferrule 100 without the skiving of the front ends of the optical fibers. The fiber support structures 122 may be fiber openings or fiber bores, but may alternatively be groove structures, or the combination or both. The main body 102 may also include two guide pin holes 126, which extend between the end face 112 and the rear face 116. The guide pin holes 126 provide a reference point with respect to the main body 102 and other structures to which the multi-fiber ferrule 100 is mated. As noted below, the guide pin holes 126 are outside the area of cutouts to allow for enough material in the main body 102 to allow for the guide pin holes 126. The end face 112 may have a rectangular profile, although a trapezoidal profile (as shown) may also be provided as an alternative.

[0043] The top portion 104 has a top cut-out 130 that forms a first forward facing surface 132. The first forward facing surface 132 is used as a stop surface in conjunction with a housing for a connector, e.g., an SFP / QSFP connector. There may also be a number of other surfaces formed by the top cut-out 130. For example there is a second, slanted surface 134 on both sides of the top cut-out 130 that assist in the location of the multi-fiber ferrule 100 in the housing for a connector. The second, slanted surfaces 134 assist in moving the multi-fiber ferrule 100 in a side-to-side manner relative to the housing. There are also laterally facing surfaces 136 on each side that form the last part of the cut-out 130 and extend to the end face 112 from the second, slanted surfaces 134. As illustrated in the figures, the top cut-out 130 does not extend all of the way to the rear end 118, but stops short at the first forward facing surface 132. However, a portion of the top cut-out 130 could extend all the way to the back of the multi-fiber ferrule 100. For example, a cutout in the shape of a “T” with a thin narrow section going all the way to the back would work as well, as long as there is at least one forward facing surface adjacent to such a variation of the top cut-out 130. This applies to a bottom cut-out 150 as well, described below.USCO-190

[0044] The top portion 104 has a first surface 140 that lies in a first plane A and the cutout 130 forms a second surface 142 that lies in a second plane B. See Fig. 6. Planes A and B are preferably parallel to one another but off set, with plane B being closer to a longitudinal axis E passing through the center of the main body 102 and through the rear central opening 120 between the front end 114 and the rear end 118. See also FIG. 7. It should also be noted that the cut-out portion 130 does not extend into the rear central opening 120 or the fiber support structures 122.

[0045] Similarly, the bottom portion 104 has the bottom cut-out 150 that forms a second forward facing surface 152. The second forward facing surface 152 is also used as a stop surface in conjunction with a housing for a connector. The bottom cut-out 150 also has two laterally facing surfaces 154 that form a portion thereof. The bottom cut-out 150 extends from the end face 112 towards the rear end 118, but does not reach the rear end 118. It may reach the same distance toward the rear end 118 from the end face 112 as does the top cutout 130, but it may stop short of or beyond where the top cut-out 130 stops at forward facing surface 132.

[0046] The bottom portion 106 has a first surface 160 that lies in a third plane C and the bottom cut-out 150 forms a fourth surface 162 that lies in a fourth plane D. See Figs. 6 and 7. The Planes C and D are preferably parallel to one another but off set, with plane D being closer to the longitudinal axis E passing through the center of the main body 102 and through the rear central opening 120 between the front end 114 and the rear end 118. It should also be noted that the bottom cut-out 150 does not extend into the rear central opening 120 or the fiber support structures 122.

[0047] It should be noted that the thickness of the main body 102 varies across a width and a depth. As seen in Figs. 6 and 8, the thickness of the main body 102 is least where the two cut-outs 130, 150 are located. This is seen in Fig. 6 and represented by the distance between planes B and D. The thickness of the main body 102 is greatest where there are no cut-outs, which corresponds to the distance between the planes A and C.

[0048] Returning to the main body 102, there is first side portion 108 that extends between the top portion 104 and the bottom portion 106. There is also a second side portion 110 extending between the top portion 104 and the bottom portion 106 on opposites sides of the main body 102. The first side portion 108 and the second side portion 110 are smooth between the front end 114 and the rear end 118. Additionally, there is no shoulder with multi-fiber ferrule 100 making the profile from the back to the front the same as the front toUSCO-190 the back — and also the same at the end face 112 and the rear face 116. That is, the multifiber ferrule 100 is shoulder-less. The term shoulder-less referring to a lack of any protrusions or other features on the first side portion 108 and the second side portion 110 that may be used to engage the multi-fiber ferrule 100 with a receptacle or an adapter. There are also no sharp edges along the length of the multi-fiber ferrule 100 at the junction of the side portions 108,110 to the top and bottom portions 104,106. See, e.g., Figs. 3 and 4.

[0049] It should also be noted the rear surface 116 may be used as a reference surface for polishing the end face 112 of the main body 102 as noted below. The use of the rear surface 116 is in addition to the first forward facing surface 132 and / or the second forward facing surface 152. Preferably, the wider of the first forward facing surface 132 and the second forward facing surface 152 would be used as a reference datum surface for polishing using polishing machine 10, for example, and interferometry. The end face 112 may be angle-polished at an angle relative to the rear face 116 (generally 8°). Alternatively, the endface 112 may be flat polished.

[0050] Turning to Fig. 2, one of the 24 positions of the polishing fixture 10 is schematically represented. Starting at the bottom, the polishing fixture 10 has a polishing plate 12, the multi-fiber ferrule 100, a clamp pad 14, a clamp base 16, an actuator 18, and a latch 20. The clamp pad 14 may also have an opening 22 to receive a spring (not shown) to bias the clamp pad 14 toward the multi-fiber ferrule 100. See, e.g., Figs. 13 and 18. The present invention is directed to the clamp pads described herein in particular and also to the polishing plate 12 interacting with the multi-fiber ferrule 100.

[0051] Turning to Figs. 9 - 11, the engagement of the multi-fiber ferrule 100 with the polishing plate 12 will be described. The multi-fiber ferrule 100 has a bottom portion 106 that serves as a first ferrule datum and the second forward facing surface 152 serves as the second ferrule datum. The polishing plate 12 has a first polishing datum 156 that engages with the first ferrule datum 106 and a second polishing datum 158 that engages with the second ferrule datum 152. As illustrated, the first ferrule datum 106 and the first polishing datum 156 are generally flat surfaces but may take on other configurations. The second ferrule datum is the forward facing surface 152 that is in the bottom cut-out 150 and the second polishing datum 158 is a projection or ledge upon which the forward facing surface 152 and the multi-fiber ferrule 100 rest. Forces are applied to the multi-fiber ferrule 100 in the direction of the polishing plate 12 in an effort to keep the multi-fiber ferrule 100 engagedUSCO-190 to the polishing plate without moving relative to the polishing fixture 10 during the polishing of the multi-fiber ferrule 100.

[0052] Figs. 12 -14 illustrate the engagement of the multi-fiber ferrule 100 with the conventional clamp pad 14 in a polishing fixture 10. It is clear from Fig. 12 that the first ferrule datum 106 is engaging the first polishing datum 156. Although not visible, the second ferrule datum 152 and the second polishing datum 158 are also engaging each other. The conventional clamp pad 14 has top pad portion 14a that engages the rear surface 116 at the rear end 118 of the multi-fiber ferrule 100. The top pad portion 14a engages the rear surface 116 between the rear central opening 120 and the top portion 104. While not shown, there are optical fibers that extend out of the rear central opening 120, which interfere with the top pad portion 14a engaging the rear surface 116. Thus, the top pad portion 14a has limited places it can engage the rear surface 116. At the same time, there is a lower portion 14b that extends from the conventional clamp pad 14 and runs across the lower portion 14b to engage the top portion 104 of the multi-fiber ferrule 100. The contact of the lower portion 14b with the multi-fiber ferrule 100 is disposed closer to the end face 112. However, the engagement of the multi-fiber ferrule 100 with the clamp pad 14 in this configuration may cause the multi-fiber ferrule 100 to move relative to the clamp pad 14 and the polishing fixture 12. Illustrated in Fig. 14 is a contour plot of the total deformation of the clamp pad 14, the multi-fiber ferrule 100, and actuator 18. The contours on the actuator 18 are curved, indicating that the actuator 18 is bent. The presence of contours on the multi-fiber ferrule 100 indicate that the multi-fiber ferrule 100 has moved off of the first polishing datum 156 or the second polishing datum 158..

[0053] A close inspection of Fig. 13 shows that the multi-fiber ferrule 100 is not completely engaged with the polishing fixture 12. This results in the end face 112 not being correctly polished.

[0054] Fig. 15A illustrates the clamp pad 14 discussed above.

[0055] Figs. 15B-E illustrate a number of clamp pads that can be used as embodiments according to the present invention. One is the clamp pad 214 according to the present invention and is also illustrated in Fig. 15B. The clamp pad 214 has a body portion 216, an upper portion 218 that engages the rear surface 116 of multi-fiber ferrule 100, and a lower portion 220 that engages the top portion 104 of the multi-fiber ferrule 100. The upper portion 218 has two arms 222 that each have a rounded surface 224 toward the end 226 of each of the arms 222. The ends 226 of the arms 222 engage the rear surface 116 at the rearUSCO-190 end 118 of the multi-fiber ferrule 100. The arms 222 keep the multi-fiber ferrule 100 on the second datum 152 during polishing. The arms 222 can engage the rear surface 116 on opposite sides of the rear central opening 120 because there is a gap 230 between the arms 222. See Fig. 16. The gap should be at least as wide as the rear central opening 120 to allow for the optical fibers in the multi-fiber ferrule 100. Indeed, the arms 222 can engage the rear surface 116 nearly anywhere thereon, closer to the top portion 104, in the middle or closer to the bottom portion 106. If placed near the guide pin holes 126, the arms 222 should be large enough that they do not enter into the guide pin holes 126 however.

[0056] The lower portion 220 has at least one rounded surface 232 that engages the top portion 104 of the multi-fiber ferrule 100 and pushes the first ferrule datum against the first polishing datum. The at least one rounded surface 232 preferably extends across the width of the clamp pad 214.

[0057] Another embodiment of a clamp pad 314 according to the present invention is also in Fig. 15C. The clamp pad 314 also has a body portion 316, an upper portion 318 that engages the rear surface 116 of multi-fiber ferrule 100, and a lower portion 320 that engages the top portion 104 of the multi-fiber ferrule 100. The body portion 316 and the upper portion 318 are similar to clamp pad 214. However, the lower portion 320 has a smaller rounded surface 332 to engage the center of the multi-fiber ferrule 100. Since there is only one lower portion 320, it is preferable to have it disposed in the center of the body portion 316

[0058] Another embodiment of a clamp pad 414 according to the present invention is also in Fig. 15D. The clamp pad 414 also has a body portion 416, an upper portion 418 that engages the rear surface 116 of multi-fiber ferrule 100, and a lower portion 420 that engages the top portion 104 of the multi-fiber ferrule 100. The body portion 416 and the upper portion 418 are similar to clamp pad 214. However, in this embodiment, the lower portion 420 has two projections with rounded surfaces.

[0059] Clamp pad 514 is illustrated in Fig. 15E. The clamp pad 514 has a body portion 516, an upper portion 518 that engages the rear surface 116 of multi-fiber ferrule 100. It also has a lower portion 520 that engages the top portion 104 of the multi-fiber ferrule 100. The upper portion 518 has at least one rounded surface 524 to engage and provide a force on the rear surface 116 at the rear end 118 of the multi-fiber ferrule 100. The at least one rounded surface 532 preferably extends across the width of the clamp pad 214. The lower portion 520 has at least one rounded surface 532, (and two in this embodiment) that engages the topUSCO-190 portion 104 of the multi-fiber ferrule 100 and pushes the first ferrule datum with a force against the first polishing datum. The two forces are perpendicular to one another and intersect at an intersection point P. The actuator 18 that engages the clamp pad 514 has an axis that also intersects with the first and the second forces at the intersection point P. See Fig. 18.

[0060] Fig. 16 and 17 show in detail how the clamp pads engage the actuator 18 and position the multi-fiber ferrule 100 against the clamp pads 214,314,414, and 514.

[0061] Fig. 18 explains how to keep the multi-fiber ferrule 100 against the polishing fixture 10 and from moving during the polishing of the multi-fiber ferrule 100. The multifiber ferrule 100 is positioned to engage the first polishing datum 156 with the first ferrule datum 106. The multi-fiber ferrule 100 is also positioned to engage the second polishing datum 158 with the second ferrule datum 152. The arms 222 apply a force Fl on the rear surface 116 of the multi-fiber ferrule 100 pushing the multi-fiber ferrule 100 down on the second polishing datum 158. At the same time, the lower portion 220 with the rounded surface 232 engages the top portion 104 of the multi-fiber ferrule 100 and applies a force F2 to the multi-fiber ferrule 100 to push the first ferrule datum 106 against the first polishing datum 156. The force Fl may be substantially perpendicular to the force F2 (i.e., within a given range of 90° relative to each other). It should be noted here that the diagram in Fig.18 assumes that there are no frictional forces between the components. Generally, the frictional forces are relatively small and can be nearly zero after vibrations are generated during the polishing process.

[0062] The forces Fl and F2 intersect at point P within the multi-fiber ferrule 100 as illustrated in Fig. 18. It should be noted that an axis Al along the actuator 18 also intersects at the intersection point P - making the force on the actuator 18 axial. See Fig. 19. The force Fl opposes the force applied during the polishing and the force F2 opposes moments induced by the friction of the multi-fiber ferrule 100 and the polishing media.

[0063] Illustrated in Fig. 20 is that in a different clamp pad, the forces Fl and F2 may intersect with one another point P2. The point P2 is closer to the bottom portion 106 and to the rear face 116. Also, it should be noted that the actuator 18 is further down and the axial force along axis A2 does not intersect the point P2. However, the multi-fiber ferrule 100 may be just as stable as the multi-fiber ferrule 100 in Fig. 18.

[0064] Figs. 21 - 25 illustrate the operation of engaging the clamp pad 214 (or other variations) with the multi-fiber ferrule 100. In Fig. 21, the clamp pad 214 approaches theUSCO-190 multi-fiber ferrule 100. Fig. 22 has the clamp pad 214 engaging the top portion 104 of the multi-fiber ferrule 100. In Fig. 23, the multi-fiber ferrule 100 is engaging the first and second polishing datums 156 and 158. The clamp pad 214 continues to rotate in Fig. 24 and then in Fig. 25, the arms 222 of the clamp pad have engaged the rear surface 116 of the multi-fiber ferrule 100.

[0065] A clamp pad for a polishing fixture for a plurality of multi-fiber ferrules, each of the multi-fiber ferrules in the plurality of multi-fiber ferrules having a first ferrule datum and a second ferrule datum, a rear face, and an opening in the rear face to receive a plurality of optical fibers, the clamp pad including a first rounded surface and a second rounded surface separated by a gap, the first rounded surface engaging the rear face on a first side of the opening in the rear face and the second rounded surface engaging the rear face on a second side of the opening in the rear face, the opening in the rear face being between the first rounded surface and the second rounded surface, and at least one bottom rounded surface to engage a bottom side of the multi-fiber ferrule.

[0066] A clamp pad for a polishing fixture for a plurality of multi-fiber ferrules includes each of the multi-fiber ferrules in the plurality of multi-fiber ferrules having a first ferrule datum and a second ferrule datum, a rear face, and an opening in the rear face to receive a plurality of optical fibers, the clamp pad having a first rounded surface and a second rounded surface, the first rounded surface and the second rounded surface to engage the rear face, and at least one rounded surface to engage a bottom side of the multi-fiber ferrule, wherein the first rounded surface and the second rounded surface are separated by a gap to receive the plurality of optical fibers at the opening.

[0067] A method for securing a plurality of multi-fiber ferrules in a polishing fixture that includes providing a clamp pad having a first rounded surface and a second rounded surface to engage the rear face, and at least one bottom rounded surface to engage a bottom side of the multi-fiber ferrule; inserting at least one of the plurality of multi-fiber ferrules into the polishing fixture and against a plate; moving the clamp pad against the at least one of the plurality of multi-fiber ferrules so that the first rounded surface and the second rounded surface engage the rear face of at least one of the plurality of multi-fiber ferrules and the at least one bottom rounded surface on the clamp pad engages a bottom side of the at least one of the plurality of multi-fiber ferrules.

[0068] A clamp pad for a polishing fixture for a plurality of multi-fiber ferrules, each of the multi-fiber ferrules in the plurality of multi-fiber ferrules having a first ferrule datum andUSCO-190 a second ferrule datum, a rear face, and an opening in the rear face to receive a plurality of optical fibers, the clamp pad includes at least one rounded surface to engage a rear side of the multi-fiber ferrule; and at least one bottom rounded surface to engage a top side of the multifiber ferrule, wherein the at least one rounded surface of the clamp pad exerts a first force on the multi-fiber ferrule towards an end face of the multi-fiber ferrule, and wherein the at least one bottom rounded surface exerts a second force on the multi-fiber ferrule that is substantially perpendicular to the first force, the first force and second force intersecting at an intersection point, and wherein the clamp pad is engaged with an actuator, the actuator having an axis that intersects with the first and the second forces at the intersection point.

[0069] It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Thus it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

USCO-190What is claimed:

1. A polishing fixture for a plurality of multi-fiber ferrules, each of the multi-fiber ferrules in the plurality of multi-fiber ferrules having a first ferrule datum and a second ferrule datum, a rear face, and an opening in the rear face to receive a plurality of optical fibers, the polishing fixture comprising: a clamp pad having a first rounded surface and a second rounded surface separated by a gap, the first rounded surface engaging the rear face on a first side of the opening in the rear face and the second rounded surface engaging the rear face on a second side of the opening in the rear face, the opening in the rear face being between the first rounded surface and the second rounded surface, and at least one rounded bottom portion to engage a top portion of the multi-fiber ferrule; and a polishing plate having a first polishing datum and a second polishing datum, the first polishing datum engaging the first ferrule datum and the second polishing datum engaging the second ferrule datum, the clamp pad maintaining the multi-fiber ferrule against the polishing plate upon application of force to the clamp pad.

2. The polishing fixture of claim 1, wherein the gap between the first rounded surface and the second rounded surface allows the plurality of optical fibers to be received in the opening.

3. The polishing fixture of claim 1, wherein the first rounded surface and the second rounded surface contact the rear face substantially midway between a top portion and a bottom portion of the ferrule.

4. The polishing fixture of claim 1, wherein the first rounded surface and the second rounded surface contact the rear face closer to one of a top portion and a bottom portion of the ferrule than the other of the top portion and the bottom portion of the ferrule.

5. The polishing fixture according to claim 1, wherein the first ferrule datum is a top portion of the multi-fiber ferrule.USCO-1906. The polishing fixture according to claim 1, wherein the second ferrule datum is a forward facing surface on a top portion of the multi-fiber ferrule.

7. The polishing fixture according to claim 1, wherein the first polishing datum is a flat surface on the polishing fixture.

8. The polishing fixture according to claim 1, wherein the second polishing datum is a ledge on the polishing fixture to engage a forward facing surface on the top portion of the multi-fiber ferrule.

9. The polishing fixture according to claim 1, wherein the first and second rounded surfaces of the clamp pad engage the rear face along a central portion between the top portion and a bottom portion of the multi-fiber ferrule and exert a force on the multi-fiber ferrule towards an end face of the multi-fiber ferrule.

10. The polishing fixture according to claim 9, wherein the at least one rounded bottom portion engages the top portion of the multi-fiber ferrule and exerts a force on the multi-fiber ferrule that intersects perpendicularly with the force exerted from the first and second rounded surfaces.

11. The polishing fixture according to claim 1, wherein the first rounded surface and the second rounded surface of the clamp pad exert a first force on the multi-fiber ferrule towards an end face of the multi-fiber ferrule, and wherein the at least one bottom rounded surface exerts a second force on the multifiber ferrule, the first force and second force intersecting at an intersection point; and wherein the clamp pad is engaged with an actuator, the actuator having an axis that intersects with the first and the second forces at the intersection point.

12. A polishing fixture for a plurality of multi-fiber ferrules, each multi-fiber ferrule in the plurality of multi-fiber ferrules having a first ferrule datum and a second ferrule datum, a rear face, and an opening in the rear face to receive a plurality of optical fibers, the polishing fixture comprising:USCO-190 a clamp pad having a first rounded surface and a second rounded surface, the first rounded surface and the second rounded surface to engage the rear face, and at least one rounded surface to engage a top portion of the multi-fiber ferrule, wherein the first rounded surface and the second rounded surface are separated by a gap to receive the plurality of optical fibers at the opening; and a polishing plate having a first polishing datum and a second polishing datum, the first polishing datum engaging the first ferrule datum and the second polishing datum engaging the second ferrule datum, the clamp pad maintaining the multi-fiber ferrule against the polishing plate upon application of force to the clamp pad.

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