Buckles – buttons – clasps – etc. – Cord and rope holders – Screw clamp
Reexamination Certificate
1999-12-16
2001-12-11
Brittain, James R. (Department: 3626)
Buckles, buttons, clasps, etc.
Cord and rope holders
Screw clamp
C024S525000
Reexamination Certificate
active
06327753
ABSTRACT:
TECHNICAL FIELD
This invention relates in general to a clamp used in the fields of construction, transportation, building trades and the like for securing flexible cord, such as wire rope, and in particular, relates to a clamp for securing wire rope in an axially aligned position without causing wire rope segments to be deformed by clamping pressure applied by the clamp.
BACKGROUND OF THE INVENTION
In the fields of construction, transportation, building trades and the like its is often desirable to grip or secure one or more segments of wire rope or other flexible cord. For example, wire rope or other flexible cord is often secured at one end by means of a turn back loop formed from a single piece of wire rope or other flexible cord is drawn at one end through an eyelet or chain plate and brought back to form two segments, which are then gripped with a clamp or wire rope clip. In other applications, two or more pieces of wire rope or other flexible cord are joined or spliced together by one or more clamps placed near the ends of the wire rope or other flexible cord.
Previously existing devices used to secure segments of wire rope in the longitudinal axis include the common saddle-type wire rope clip and later variants of the saddle gripping surface. Examples include the Fist Grip (R) wire rope clip manufactured by the Crosby Group, Inc., and the device described and claimed by U.S. Pat. No. 5,802,680 to Postelwait.
These prior art devices generally employ a saddle configuration gripping surface. Using the saddle configuration, these previous devices grip the wire rope by compressing the segments of wire rope between the saddle at one end, and at the opposing end, either a U-bolt or another saddle portion. In these devices, gripping force is applied by rotation of threaded nuts arranged generally perpendicular to the saddle surface and the longitudinal axis of the wire rope, which forcibly draws or pinches the two segments of wire rope together and places them in gripping contact with the saddle surface and U-bolt, or between the two opposing saddle surfaces.
These prior clamps are generally simple in design, often comprising few parts. Therefore, in cases where components of these prior wire rope clamps fail, for example, stripping of threads or bolts due to the large torques applied to the nuts that cause compression of the wire rope with a high retention force, components such as saddles, U-bolts, or nuts may be interchanged or replaced.
However, certain drawbacks are encountered with the use of saddle-type wire rope clips. First, the shape of the gripping surface, which is either the interior surface of two opposing saddles or the interior surface of a saddle and a U-bolt, generally compresses the two cable segments together at the center, thereby undesirably deforming both the cable surface and the longitudinal axis of the cable segments.
Additionally, in the case of the common single-saddle wire rope clip, the gripping surface of the U-bolt is small in comparison with the gripping surface of the saddle, thereby creating a differential in gripping pressure which tends to alter the longitudinal axis of the wire rope segment gripped by the interior portion of the U-bolt. This differential in gripping pressure of ten times causes the wire rope segment gripped by the U-bolt gripping surface to be pinched in relation to the wire rope gripped by the surface of the saddle. The resulting deformed axis of at least one segment of wire rope thus clamped may create difficulties in maintaining the proper position and axial alignment of the wire rope clamped thereby.
Accordingly, it would be desirable to have a clamp for gripping wire rope or flexible cord with a high retention force, provide for significant control over axial alignment of the gripped wire rope or other flexible cord, avoid pinching wire rope segments in relation to one another, and still have the clamp be simple in design and operation, rugged, and easily repaired.
GENERAL DESCRIPTION
The present invention is generally directed to a clamp for wire rope or other flexible cord having an outer housing forming an inner cavity, a traveling block that is operationally movable with in the outer housing, and a threaded member for causing movement of the traveling block with respect to a gripping surface formed on the lower portion of the inner cavity.
The descriptions which follow are non-limiting embodiments of the invention. The exterior of the outer housing may be formed in many shapes, such as the rectangular cross section shape shown in the preferred embodiment described herein below, or, alternatively, circular, semi-circular, or oval.
The gripping surface formed on the lower portion of the inner cavity and an opposing gripping surface formed on the lower portion of the traveling block are preferably disposed with a plurality of gripping channels or gripping teeth for securely gripping and axially aligning the wire rope or flexible cord gripped thereby. Wire rope or flexible cord segments gripped by the present invention may thus be aligned in the longitudinal axis with respect to each other and, unlike prior clamps, the gripped segments of wire rope or flexible cord are not pinched together and potentially deformed.
The traveling block, which is located substantially within an inner cavity formed by the outer housing, is partially constrained to move in a gripping direction by parallel walls formed in the inner cavity, which interact with similar parallel walls formed on the exterior of the traveling block. The traveling block is further constrained to move substantially within the inner cavity by extending a lower portion of the threaded member at least partly within a hole formed in the traveling block axially aligned with the threaded member.
Gripping movement of the traveling block is caused by rotation of the threaded member placed in threaded engagement with the outer housing along an upper portion thereof. The threaded member is rotatable by means of a common bolt end or has an alternative rotatable fixture common to the art, such as a T-handle, allen-head fixture, knurled knob, etc.
A bearing surface is formed between the upper and lower portions of the threaded member. By rotation of the threaded member, the bearing surface contacts the traveling block and forcibly directs gripping movement of the traveling block in relation to the gripping surface of the inner cavity.
A threaded nut or other fastener, such as a headed screw, allen bolt, or C-clip is fastened to the lowermost end of the threaded member. The threaded nut or other fastener is larger than the diameter of the axially aligned hole within the traveling block. Thus, the threaded member with the threaded nut or other fastener attached thereto rotates freely within the axially aligned hole of the traveling block, yet movement of the traveling block is substantially constrained along the axis of the threaded member.
Optionally, a countersink is formed within the lower portion of the traveling block in axial alignment with the threaded member for the purpose of countersinking the threaded nut or other fastener. The use of the countersink reduces the potential for contact between the threaded nut or other fastener and a surface of the gripped wire rope, thus preventing potential damage to both the wire rope and the threaded nut or other fastener. Further, a release hole may be formed in the lower portion of the outer housing in axial alignment with the threaded member to facilitate removal of the threaded nut or other fastener with the appropriate tool. In the case where a countersink is not employed, the release hole also serves to prevent damage to the threaded nut or other fastener when the traveling block is fully compressed against the gripping surface of the inner cavity.
The threaded nut or other fastener facilitates easy repair or replacement of components of the present invention. The repair or replacement of components is accomplished by removal of the threaded nut or other fastener and counter-rotation of the threaded member to raise the thread
Akin Gump Strauss Hauer & Feld & LLP
Brittain James R.
Mason Dwayne L.
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