OFFSET PULLING HEAD

Abstract

A pulling head that can be used with a wide range of fasteners and power tools having different stroke lengths and/or power ratings. The pulling head has a set of internal jaws which has serrations that are configured to grip a wide range of fastener types and sizes. The effective stroke of the pulling head is determined by the power tool to which it is engaged, rather than by the structure and design of the pulling head. The pulling head preferably has two jaws and a jaw follower with a leading surface which provides two beveled surfaces. As a result, the trailing surface of the jaws need not be conical, thereby providing that the jaws need not be machined after they are cast, thereby providing a very low cost manufacturing solution.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The organization and manner of the structure and operation of the invention, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings, wherein like reference numerals identify like elements in which:

FIG. 1 is a cross-sectional view of a prior art three jaw straight pulling head;

FIG. 2 is a cross-sectional view of a prior art single jaw offset pulling head;

FIG. 3 is an exploded perspective view of the pulling head shown in FIG. 2;

FIG. 4 illustrates an offset pulling head being used in an obstructed area, and a straight pulling head being used in an open access area;

FIG. 5 is a cross-sectional view of a prior art two jaw offset pulling head;

FIG. 6 is a cross-sectional view of an offset pulling head which is in accordance with an embodiment of the present invention;

FIG. 7 is an exploded perspective view of the pulling head shown in FIG. 6;

FIG. 8 shows an enlarged view of a portion of the pulling head shown in FIG. 6;

FIG. 9 is a perspective view of the pulling head shown in FIG. 6, showing the nosepiece removed;

FIG. 10 shows a set of nosepieces that can be engaged with the pulling head;

FIG. 11 shows how the pulling head can be engaged with a range of different power tools, each having a different stroke and/or power rating;

FIG. 12 is a perspective view of one of the jaws of the pulling head;

FIG. 13 is a front view of one of the jaws of the pulling head;

FIG. 14 is an enlarged view of a portion of the jaw;

FIG. 15 is a side view of one of the jaws;

FIGS. 16-20 show the pulling head being used to install a large, “U” type blind bolt, requiring high installation loads and a relatively short stroke; and

FIGS. 21-23 show the pulling head being used to install a much smaller type of fastener, specifically an “A” code Cherrylock® rivet, commercially available from the assignee of the present invention, and requiring lower installation loads and a relatively long stroke.

Claims

1. A pulling head system which comprises a pulling head configured for engagement with a pulling tool for pulling a stein, said pulling head comprising a front end having a threaded bore, said system further comprising a plurality of different nosepieces which are configured to threadably engage the threaded bore of the pulling head, wherein each of the nosepieces is configured to be used in connection with a different fastener or set of fasteners.

2. A pulling head configured for engagement with a pulling tool for pulling a stem, said pulling head comprising a frame; a carrier which is disposed inside the frame; a drawbolt adapter which is disposed in the frame and engaged with the carrier, wherein an end of the drawbolt adapter is configured for engagement with the pulling tool; a pair of jaws which are disposed in a chamber in the carrier, said pulling head being configured such that upon said drawbolt adapter being pulled by the pulling tool, said pair of jaws tend to close, said pulling head further comprising a jaw follower which engages an end of the jaws, wherein the jaw follower comprises a front surface which comprises a pair of beveled surfaces, wherein the end of each of the jaws comprises an angled surface which engages a corresponding beveled surface on the jaw follower.

3. A pulling head as recited in claim 2, further comprising a nosepiece having a threaded portion, wherein said frame comprises a threaded bore configured to receive the threaded portion of the nosepiece, wherein each of the jaws comprises a tapered leading edge which is engageable with a corresponding angled end surface of the nosepiece, such that said nosepiece tends to keep the jaws opened and centered about an axis of a bore in the nosepiece.

4. A pulling head as recited in claim 2, wherein each of the jaws comprises serrations, wherein each of the serrations includes angled end portions, thereby allowing the jaws to grip a range of stems.

5. A pulling head as recited in claim 2, wherein the jaw follower is spring-biased forward in the chamber of the carrier.

6. A pulling head as recited in claim 2, said pulling head further comprising a plug member which is engaged with the carrier, and a spring which is disposed between the jaw follower and the plug member.

7. A pulling head as recited in claim 2, wherein each of the jaws comprises an external surface which provides an angled surface which engages a corresponding angled surface in the chamber of the carrier.

8. A pulling head as recited in claim 2, wherein the chamber of the carrier does not include an undercut for accommodating the jaws when the jaws open.

9. A pulling head as recited in claim 2, wherein the pulling head is part of a pulling head system which comprises a plurality of different nosepieces which are configured to threadably engage a threaded bore of the pulling head, wherein each of the nosepieces is configured to be used in connection with a different fastener or set of fasteners.

10. A pulling head configured for engagement with a pulling tool for pulling a stem, said pulling head comprising a frame; a carrier which is disposed inside the frame; a drawbolt adapter which is disposed in the frame and engaged with the carrier, wherein an end of the drawbolt adapter is configured for engagement with the pulling tool; a pair of jaws which are disposed in a chamber in the carrier, said pulling head being configured such that upon said drawbolt adapter being pulled by the pulling tool, said pair of jaws tend to close, wherein each of the jaws comprises serrations, wherein each of the serrations includes angled end portions, thereby allowing the jaws to grip a range of stems.

11. A pulling head as recited in claim 10, further comprising a nosepiece having a threaded portion, wherein said frame comprises a threaded bore configured to receive the threaded portion of the nosepiece, wherein each of the jaws comprises a tapered leading edge which is engageable with a corresponding angled end surface of the nosepiece, such that said nosepiece tends to keep the jaws opened and centered about an axis of a bore in the nosepiece.

12. A pulling head as recited in claim 10, wherein the jaw follower is spring-biased forward in the chamber of the carrier.

13. A pulling head as recited in claim 10, said pulling head further comprising a plug member which is engaged with the carrier, and a spring which is disposed between the jaw follower and the plug member.

14. A pulling head as recited in claim 10, wherein each of the jaws comprises an external surface which provides an angled surface which engages a corresponding angled surface in the chamber of the carrier.

15. A pulling head as recited in claim 10, wherein the chamber of the carrier does not include an undercut for accommodating the jaws when the jaws open.

16. A pulling head as recited in claim 10, wherein the pulling head is part of a pulling head system which comprises a plurality of different nosepieces which are configured to threadably engage a threaded bore of the pulling head, wherein each of the nosepieces is configured to be used in connection with a different fastener or set of fasteners.