QUICK-RELEASE CAPTIVE CLAMPING PIN SYSTEMS AND METHODS

Abstract

A quick-release captive clamping pin that uses a ball-lock pin and an endcap assembly to provide a tooling assembly with both holding and clamping action with a quick-release function. The captive clamping pin may include an adjustable-length ball-lock pin inserted through the tool and workpiece, where the length adjustment is used to apply clamping force.

Claims

1. A method for clamping a workpiece for machining comprising: providing a workpiece comprising a workpiece bore; providing a machine tool comprising a tool bore; providing a captive clamping pin assembly comprising: an adjustable-length ball-lock pin comprising: a tubular shaft having a plurality of ball apertures at a first end thereof, each of said ball apertures having a ball disposed therein; a plunger slidingly received in said tubular shaft; a handle assembly disposed at a second end opposing said first end; and a distance-adjusting means for adjusting a distance between said handle assembly and said first end by rotating said handle assembly; wherein said plunger is operable to a first position in which said plunger causes said balls to project through said plurality of apertures a distance greater than the outer radius of said shaft; and wherein said plunger is operable to a second position in which said balls recede inward of said outer radius; and a generally cylindrical endcap assembly having a first side and an opposing second side, and a bore extending generally coaxially therethrough; positioning said machine tool on a first side of said workpiece such that said tool bore and said workpiece bore are generally coaxially aligned; disposing said endcap assembly such that said tool bore, said workpiece bore, and said endcap assembly bore are generally coaxially aligned; receding said balls by moving said plunger to said second position; after said receding, inserting said first end of said shaft through said aligned tool bore, said workpiece bore, and said endcap assembly bore until said plurality of apertures are disposed beyond said endcap assembly second side; after said inserting, projecting said balls by moving said plunger to said first position; and rotating said handle assembly to cause said distance-adjusting means to shorten said distance between said handle assembly and said first end to a distance effective to cause said captive clamping pin assembly to apply clamping force to said workpiece and said machine tool.

2. The method of claim 1, further comprising: providing a bushing assembly having an axial bore configured to receive said adjustable-length ball-lock pin; before said inserting, seating said bushing assembly in said tool bore such that said tool bore, said workpiece bore, said endcap assembly bore, and said axial bore are generally coaxially aligned; said inserting comprising inserting said first end of said shaft through said axial bore, said tool bore, said workpiece bore, and said endcap assembly bore.

3. The method of claim 2, further comprising: in said providing a bushing assembly, said bushing assembly further comprising a locking means; after said seating said bushing assembly in said tool bore, locking said adjustable-length ball-lock pin to said bushing assembly with said locking means.

4. The method of claim 3, wherein said locking means is a locking pin.

5. The method of claim 3, wherein said locking comprising locking said shaft to said bushing assembly.

6. The method of claim 1, wherein said disposing further comprises disposing said endcap assembly on a second side of said workpiece opposing said workpiece first side such that said endcap assembly first side is adjacent said workpiece second side.

7. The method of claim 1, further comprising: providing a second machine tool comprising a second tool bore; disposing said second machine tool on said second side of said workpiece such that a first side of said second machine tool is adjacent said workpiece second side; and disposing said endcap assembly on a second side of said workpiece such that said endcap assembly first side is adjacent a second side of said second machine tool opposing said first side.

8. The method of claim 1, wherein said endcap assembly further comprises a lanyard pivotably attached to said endcap assembly.

9. The method of claim 8, wherein said lanyard is pivotably attached to said adjustable-length ball-lock pin.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 is a prior art machine tooling assembly.

[0027] FIG. 2 depicts an isometric view of an embodiment of a ball-lock captive pin according to the present disclosure.

[0028] FIG. 3 depicts a side elevation view of an embodiment of a ball-lock captive pin according to the present disclosure with a cutaway view of the ball-lock captive pin installed on a workpiece and tool.

[0029] FIG. 4 depicts a side elevation view of an embodiment of a ball-lock captive pin according to the present disclosure with a cutaway view of the ball-lock captive pin installed on a workpiece and two tooling elements.

[0030] FIG. 5 depicts a side elevation view of an embodiment of a ball-lock captive pin according to the present disclosure with a cutaway view of the ball-lock captive pin installed on a workpiece without an endcap assembly.

[0031] FIG. 6 depicts a side elevation view of an embodiment of a ball-lock captive pin according to the present disclosure with a cutaway view of the ball-lock captive pin installed on a workpiece and two tooling elements and without an endcap assembly.

[0032] FIG. 7 depicts a side elevation view of a captive ball-lock pin according to the present disclosure.

[0033] FIG. 8 depicts an isometric view of the captive ball-lock pin of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0034] The following detailed description and disclosure illustrates by way of example and not by way of limitation. This description will clearly enable one skilled in the art to make and use the disclosed systems and methods, and describes several embodiments, adaptations, variations, alternatives and uses of the disclosed systems and methods. As various changes could be made in the above constructions without departing from the scope of the disclosures, it is intended that all matter contained in the description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

[0035] Described herein, among other things, is a quick-release captive clamping pin that uses a ball-lock pin and a clamping nut to provide a tooling assembly with clamping action and a quick-release captive pin. FIG. 2 provides an isometric view of an embodiment of an assembled quick-release captive pin assembly (201) according to the present disclosure, without a workpiece or tool. FIG. 3 provides a side elevation view of an embodiment of a quick-release captive pin assembly (201) according to the present disclosure installed in a cutaway view of a workpiece (207) and tool (205).

[0036] In the depicted embodiments, a workpiece (207) to be worked upon is disposed beneath a first tooling element (205). The workpiece (207) may be a movable element to be machined, a workbench, machining frame, or other element which an operator desires to hold in place during a machining operation. The workpiece (207) generally has a through bore (221), referred to herein as a workpiece bore (221) or workpiece bore (221). In the depicted embodiment, the workpiece bore (221) is a smooth-surfaced, cylindrical element disposed generally perpendicularly in the workpiece (207) with respect to the major plane of the workpiece (207). The radius of the depicted workpiece bore (221) is about the same, but slightly larger than, that of the ball-lock pin shaft (214). This radius should provide sufficient clearance for the ball-lock pin shaft (214) to pass through the workpiece bore (221) while remaining a snug fit with minimal lateral movement as commonly understood and used in the art.

[0037] In the depicted embodiment, one or more tooling elements (205) are disposed adjacent to the workpiece (207). The depicted tooling element (205) is a top tooling element (205) but in an alternative embodiment, a bottom tooling element (207) may be used in addition to, or instead of, the top tooling element (205). FIG. 4 depicts an embodiment utilizing two tooling elements (205A) and (205B). The tooling element (205) also has a through bore (223), also referred to herein as the tool bore (223). The depicted through bore (223) comprises circumferential threading adapted or configured to receive a threaded element associated with the assembly (201), such as a bushing (235). In the depicted embodiment, the tool bore (223) is a generally cylindrical element disposed generally perpendicularly in the tool (205) with respect to the major plane of the tool (207). The radius of the depicted tool bore (223) is larger than that of the depicted workpiece bore (221) but in any case is sufficient for the ball-lock pin shaft (214) to pass through. When installed, the workpiece bore (223) and tool bore (221) are generally coaxially aligned.

[0038] In the depicted embodiments of FIGS. 1-4, the workpiece (207) and tool (205) are clamped together using an adjustable captive ball-lock pin (209) and a ball-lock retaining element (211). Examples of adjustable ball-lock pins (209) are known in the art, and an exemplary embodiment of such a pin (209) is shown and described in U.S. Pat. No. 3,101,641, granted Aug. 27, 1963, the entire disclosure of which is incorporated herein by reference.

[0039] The depicted captive ball-lock pin (209) comprises a shaft (214) in the configuration of generally cylindrical hollow tube element. An embodiment of the captive ball-lock pin shaft is depicted in FIGS. 7 and 8. At the distal end (216) of the shaft (214), a plurality of apertures are disposed. Each aperture has is sized and shaped to partially retain a small ball (210). The balls (210) are sized and shaped such that they can partially project through the apertures, but cannot fully pass through the apertures. When partially projecting through the apertures on opposing sides of the shaft (214), the distance from the outer edge of one ball (210) to the axial center of the pin (209), referred to herein as the deployed radius of the pin (209), is greater than the radius of the shaft (214). Thus, the ball-lock pin (209) can be held in place by the retaining element (211), which has a through bore with a diameter slightly larger than that of the shaft (214) but smaller than the deployed diameter of the pin (209). To install the captive ball-lock pin (209), the balls (210) are retracted, the distal end (216) is inserted through the retaining element (211) bore, and then the balls are projected on the distal (or bottom, in the depicted embodiment) side of the retaining element (211). Because the balls can be firmly held in place in projected position, the captive pin (209) cannot be retracted back through the retaining element (211). Structures and methods of operation for deploying and retracting the balls are show in, for example, the aforementioned U.S. Pat. No. 3,101,641. In the depicted embodiment, the balls (210) are projected and retracted by use of a plunger element glidingly disposed in the hollow tubular shaft (214). The plunger is operable to a first position in which it cause the balls (210) to project, and to a second position in which the balls (210) recede.

[0040] Thus, as shown in, for example, the depicted embodiment of FIG. 3, the captive ball-lock pin (209) is installed by inserting the distal end (216) of the pin (209) through the tool bore (223), workpiece bore (221), and retaining element (211). The balls (210) are retracted as needed to pass through the bores and then projected once the apertures are disposed on the opposing or distal side of the retaining element (211). This configuration provides retaining force that inhibits the pin (209) from retracting from the assembly.

[0041] However, in some circumstances it may be desirable to apply further clamping force. In an embodiment, this may be done by utilizing the adjustability features of the ball-lock pin (209). By way of example and not limitation, the ball-lock pin (209) may have an adjustable length, which is configurable by the operator manipulating a handle assembly (241) The depicted handle assembly (241) comprises a grip (215) affixed to a body element (242). Applying twisting force shortens or lengthens the pin (209). When shortened, this has the effect of reducing the distance between the bottom (218) or abutting face (218) of the handle assembly (241) and any other elements of the assembly (201). Once the abutting face (218) is adjacent to any other elements disposed between the abutting face (218) and the tool (205), further adjustment of the handle assembly (241) to shorten the pin (209) effectively applies increasing clamping force to the assembly (201). Structures and methods of operation for an adjustable handle assembly (215) as described herein are show in, for example, the aforementioned U.S. Pat. No. 3,101,641.

[0042] In the depicted embodiment, the retaining element (211) may be included in an endcap assembly (222). In the depicted embodiment, the endcap assembly (222) comprises a non-marking or non-marring element (224) disposed above the retaining element (211) (i.e., adjacent to a surface of the workpiece (207)). The depicted non-marking element (224) comprises a through bore of similar radius to that of the retaining element (211), through which the distal end (216) of the shaft (214) passes during installation. The depicted non-marking element (224) is a generally cylindrical element (224) with a flat top surface abutting the workpiece (207). The side abutting the workpiece (207) comprises a non-marking, non-marring surface to prevent damage to or scratching of the workpiece (207) during installation and machining.

[0043] In the depicted embodiment, the endcap assembly (222) further comprises an attaching element (228) for attaching a lanyard (230). The lanyard (230) holds the endcap assembly (222) and pin (209) together so they do not become inadvertently separated or lost. In the depicted embodiment, the attaching element (228) is a hook or loop protruding laterally or radially from the endcap element (222) and is disposed between the retaining element (211) and non-marking element (224). This configuration is preferred so that the connecting element (228) does not interfere with the retention function nor pose a risk of damaging the workpiece (207). In the depicted embodiment, the pin (209) also comprises a pin connecting element (232), and a lanyard (230) is connected to each. The lanyard (230) is preferably pivotably or rotatably connected on at least one of the two attaching elements (228) and (232) for greater installation flexibility and less risk of stress or damage to the lanyard (230). A shown in FIG. 3, the connecting elements (228) and (232) may be part of a flat ring or other annular element installed coaxially in the endcap assembly (222) or pin (209), respectively, as shown.

[0044] In an embodiment, the assembly (201) may further comprise a bushing assembly (235). A bushing assembly (235) is generally a sleeve (usually of metal) inserted into a bore to protect the interior surface of the bore and provide a seating for a pin, dowel, or other object to be inserted therein. The bushing assembly (235) generally comprises a sleeve attached to a bushing head and may further comprise a locking means (236), such as a locking pin (276) for holding the inserted pin or object in place. An exemplary embodiment of a bushing assembly (235) for use with a captive locating screw is shown and described in U.S. Pat. No. 10,393,159, issued Aug. 27, 2019, the entire disclosure of which is incorporated herein by reference, including (but not limited to) with respect to FIG. 3 thereof. This, or a similar, bushing assembly (235) may be used, alone, or with a captive locating screw as shown and described therein.

[0045] Generally, the bushing assembly (235) is received into the tool bore (223) and seated therein, and the ball-lock pin (209) is then inserted through the seated bushing assembly (235). It should be noted that a washer as disclosed in U.S. Pat. No. 10,393,159 may be omitted in this usage, because the washer is a floating element to facilitate rotation of the handle assembly (241), but in this case, the handle assembly (241) is rotated for purposes of shortening the pin (209), not screwing the captive screw assembly to a receiver.

[0046] In an embodiment, the endcap element (222) may be omitted, and the opposing surface of the workpiece (207) or bottom tool element (205) could provide the retaining element (211). In such an embodiment, the workpiece bore (221) or bottom tool bore (223B), as the case may be, has a radius sized and shaped to be slightly larger than that of the shaft (214) but smaller than that of the deployed dimension of the pin (209). In this configuration, the endcap assembly (222) could be omitted entirely. However, this configuration risks scratching or damage of the workpiece (207) or bottom tool (205) by bearing the force of the balls (210). FIG. 5 depicts an embodiment (201) utilizing a single tooling element (205) without an endcap assembly. FIG. 6 depicts an embodiment utilizing two tooling elements (205A) and (205B) without an endcap assembly.

[0047] Throughout this disclosure, geometric terms may be used to characterize, among other things, sizes, shapes, dimensions, angles, distances, and relationships. These terms may be used with qualifiers such as generally, about, and approximately. One of ordinary skill in the art will understand that, in the context of this disclosure, these terms are used to describe a recognizable attempt to conform a device or component to the qualified term. By way of example and not limitation, components described as being generally coplanar will be recognized by one of ordinary skill in the art to not be actually coplanar in a strict geometric sense because a plane is a purely geometric construct that does not actually exist and no component is truly planer, nor are two components ever truly coplanar. Variations from geometric descriptions are unavoidable due to, among other things, manufacturing tolerances resulting in shape variations, defects, imperfections, non-uniform thermal expansion, natural wear, minor variations that are nevertheless recognizable as the qualified term, and other deformations. One of ordinary skill in the art will understand how to apply geometric terms, whether or not qualified by relative terms such as generally, about, and approximately, to describe a reasonable range of variations from the literal geometric term in view of these and other considerations appropriate to the context. Additionally, the use of the conjunctive and disjunctive should not necessarily be construed as limiting, and the conjunctive may include the disjunctive, and vice versa.

[0048] While the invention has been disclosed in conjunction with a description of certain embodiments, including those that are currently believed to be the preferred embodiments, the detailed description is intended to be illustrative and should not be understood to limit the scope of the present disclosure. As would be understood by one of ordinary skill in the art, embodiments other than those described in detail herein are encompassed by the present invention. Modifications and variations of the described embodiments may be made without departing from the spirit and scope of the invention.