Blind bolt and tool combination

• US 10,018,212 B1
• Filed: 12/03/2015
• Issued: 07/10/2018
• Est. Priority Date: 05/19/2014
• Status: Active Grant

• Current Assignee: All Fasteners USA LLC
• Original Assignee: All Fasteners USA LLC
• Inventors: Strange, Michael, Carmichael, Bruce A.
• Primary Examiner(s): Cigna, Jacob
• Assistant Examiner(s): Holly, Lee A
• Application Number:
  US14/957,934
• Time in Patent Office: 950 Days
• CPC Class Codes: B25B 13/481 for operating in areas having limited access
• CPC Class Codes: B25B 23/0085 Counterholding devices
• CPC Class Codes: B25B 23/105 the gripping device being an integral part of the driving bit
• CPC Class Codes: F16B 13/063 by the use of an expander
• CPC Class Codes: F16B 13/0808 by a toggle-mechanism
• CPC Class Codes: F16B 2200/95 with markings, colours, indicators or the like
• CPC Class Codes: F16B 33/00 Features common to bolt and nut
• CPC Class Codes: F16B 35/045 for retention or rotation by a tool specially shaped heads of bolts or screws for rotation by a tool F16B23/00
• CPC Class Codes: F16B 37/00 Nuts or like thread-engaging members specially shaped for rotations by a tool F16B23/00

Abstract

A blind bolt and tool is used for fastening a bolt through a hole in a structure when only one side of the structure is accessible. A receiver is formed on the tip end of a bolt shaft opposite from a bolt head. Internal threads are formed within the receiver proximate an outward end, and a hex socket is formed in the inward end of the receiver. External threads and a guide are formed on a tip of the tool, and the external threads mate with the internal threads in the receiver to hold the bolt during installation. A hex key on one end of the tool engages the hex socket in the receiver so that the tool may impose a torque on the bolt when a nut is being tightened on the bolt. In another embodiment, a splined tip is formed on the end of the bolt. The tip is designed to shear off when a sufficient torque is applied. Also, a shim is configured to fit between structures held together by the blind bolt.

Claims

1. A blind bolt for extending through a cylindrical hole, the hole having a diameter and a length, the hole extending through a first metal member and second metal member with a surface formed on the second member adjacent the hole, the blind bolt comprising:

a blind bolt head having a diameter that is smaller than the diameter of the hole;

a threaded blind bolt shaft extending from the blind bolt head and having a length greater than the length of the hole;

a folding washer being foldable along a fold line and being disposed on the bolt shaft between the bolt head and the surface on the second member and contacting the surface along substantially all of a circumference of the hole except along the fold line, the folding washer having a folded configuration with a diameter smaller than the diameter of the hole and configured such that it may pass through the hole and having an unfolded configuration with a diameter greater than the diameter of the hole and configured such that it may not pass through the hole;

a shear sleeve disposed on the blind bolt shaft proximate the folding washer and having a length dimension sufficient to extend from the washer, through the second metal member and into the first metal member;

a spring disposed on the blind bolt shaft adjacent to the shear sleeve;

a washer disposed on the blind bolt shaft adjacent to the spring and adjacent to the first member;

a nut threaded on the blind bolt shaft adjacent to the washer,

the spring and the shear sleeve having a combined length that is greater than the length of the hole so that when the sleeve and spring are positioned within the hole and the nut is tightened, the spring is in compression.

2. A blind bolt comprising:

a blind bolt head having a diameter;

a threaded blind bolt shaft extending from the blind bolt head to a blind bolt tip;

a folding washer having a folded configuration and an unfolded configuration and folding along a fold line, the folding washer having a hole in the unfolded configuration, the hole being sized to fit around the bolt shaft, the folding washer being disposed in an unfolded configuration on the bolt shaft adjacent the bolt head,

a washer disposed on the blind bolt shaft;

a shear sleeve and a spring disposed on the blind bolt shaft between the washer and the folding washer, the shear sleeve having an end engaging an end of the spring such that the spring may be compressed against the shear sleeve by the washer and folding washer to thereby position the shear sleeve on the bolt; and

a nut threaded on the blind bolt shaft adjacent to the washer such that the nut may be tightened to compress the shear sleeve and spring between the washer and folded washer.

3. The blind bolt of claim 2 wherein the shear sleeve is positioned adjacent the folded washer in the unfolded configuration on the blind bolt shaft.

4. A method for reinforcing a tower having a wall with a thickness, comprising:

providing a blind bolt, the blind bolt comprising;

a blind bolt head having a diameter;

a threaded blind bolt shaft extending from the blind bolt head to a blind bolt tip;

a folding washer having a folded configuration and an unfolded configuration,

the folding washer having a hole in the unfolded configuration sized to fit around the bolt shaft, the folding washer being disposed in an unfolded configuration on the bolt shaft adjacent the bolt head,

a washer disposed on the blind bolt shaft;

a shear sleeve and a spring disposed on the blind bolt shaft between the washer and the folding washer, an end of the shear sleeve engaging an end of the spring such that the spring may be compressed against the shear sleeve by the washer and folding washer to thereby position the shear sleeve on the bolt; and

a nut threaded on the blind bolt shaft adjacent to the washer such that the nut may be tightened to compress the shear sleeve and spring between the washer and folded washer;

attaching the blind bolt tip to a tool;

moving the folding washer, shear sleeve, spring, washer and nut from the blind bolt shaft to the tool;

providing a reinforcing plate adjacent a wall of the tower and providing a hole

extending through the reinforcing plate and the wall of the tower;

inserting the blind bolt and the washer through the hole using the tool;

unfolding the washer and positioning the unfolded washer adjacent the wall using the tool;

moving the shear sleeve and spring into the hole;

moving the washer and nut onto the blind bolt shaft and tightening the nut against the washer and the reinforcing member;

providing the spring and the shear sleeve with a combined length greater than the length of the hole through the wall and the reinforcing plate so that the spring is compressed when the nut is tightened and the spring forces the shear sleeve into a position on the blind bolt shaft within the hole;

removing the tool from the tip of the blind bolt shaft.

5. The method of claim 4 wherein the step of tightening the nut comprises tightening the nut while the tool is attached to the tip and further tightening the nut to a desired torque after the tool is removed from the tip.

6. The method of claim 4 wherein the first step of providing the blind bolt further comprises providing the blind bolt with the shear sleeve positioned on the blind bolt shaft adjacent to the folded washer.