SPECIFICATIONImprovements in or relating to shacklesBackground to the InventionThis invention relates to shackles.
The invention provides a self-locking shackledispensing with the need for seizing (i.e. locking),wires like shackle-pin securing arrangements.
Summary of the InventionAccording to the invention, a shacklecomprising a generally "U"-shaped body ofresilient material with holes for receiving a shacklepin, wherein one of the components is providedwith at least one convexity and the other of thecomponents is provided with at least oneconcavity, whereby the convexity and theconcavity can interengage and resilience of thebody subjects the pin to tension, so as to hold thebody and the pin together.
The invention also comprises the generally"U"-shaped body per se and further comprises theshackle-pin per se.
Brief Description of the DrawingsEmbodiments of the invention will now bedescribed, by way of example only, with referenceto the accompanying drawings, wherein: Figure 1 is a side view, in medial section, of ashackle body according to one embodiment,Figure 2 is an end view of the body of Figure 1,looking in the direction of arrow II thereof,Figure 3 is a sectional view, taken on lines Ill-Ill of Figure 2,Figure 4 is a plan view of the shackle-pin foruse with the body of Figure 1,Figure 5 is a sectional view, taken on the lines V-V of Figure 4,Figure 6 is a side view, in medial section, of ashackle body according to another embodiment, Figure 7 is an end view of the body of Figure 6,looking in the direction of arrow VII thereof,Figure 8 is a plan view of the shackle-pin foruse with the body of Figure 6,Figure 9 is a side view of the shackle-pin ofFigure 8,Figure 10 is a side view, in medial section, of ashackle body according to yet anotherembodiment,Figure 11 is an end view of the body of Figure10, looking in the direction of arrow Xl thereof,Figure 12 is a plan view of the shackle-pin foruse with the body of Figure 10,Figure 1 3 is a side view of the shackle-pin ofFigure 12, andFigure 14 is an end view of the shackle-pin ofFigure 12, looking in the direction of arrow XIVthereof.
In the figures, like reference numerals refer to like components.
As used herein, the term "generally "U"-shapedbody" include shackle bodies with curved limbs,for example, bow-type shackle bodies.
Detailed Description of the PreferredEmbodimentsWith reference to Figures 1 to 5, a shackle comprises a generally "U"-shaped shackle body 1 of resilient material with aligned holes 2, 3 for receiving a shackle-pin 4. In this embodiment the shackle body 1 is provided with a pair of convexities in the form of aligned protuberances 5, disposed one on each side of the hole 2, and the shackle-pin 4 is provided with a pair of cooperating concavities in the form-of aligned grooves 6, disposed one on each side of the pin shank 7 and cut in the pin head 8. As explained hereinafter, the protuberances 5 and grooves 6 interengage so as to hold the body 1 and pin 4 together.
The shackle 1/4 is of drop forced steel which possesses sufficient resilience. (Stainless steel or other suitable material may be used as an alternative.)Hole 3 in body 1 is screw-threaded to receive the screw-threaded end 7a of the pin shank 7.
Hole 2 in body 1 is not screw-threaded. The pin head 8 is provided with a ring 8a defining a hole 9.
In use, the pin 4 is inserted through hole 2 in the body 1 and into the screw-threaded hole 3.
The pin 4 is then tightened, using a key inserted in hole 9 of the ring 8a if necessary, until the head 8 abuts the body 1. The tightening is continued until the protuberances 5 "click" into place as they enter the grooves 6.
For the protuberances 5 to enter the grooves 6, the body 1 has to "bow" slightly whereby the limbs of the body are moved towards each other by the pin 4 as it is tightened. After entry of the protuberances 5 into the grooves 6, natural resilience of the body 1 tends to bias the limbs of the body apart, towards their original positions.
This resilience subjects the pin 4 to tension whereby the body 1 and pin 4 are held firmly together. The threaded end 7a of the pin is of sufficient length to ensure "bowing" of the body as the pin is tightened.
To remove the pin 4 from the body 1, the pin is rotated in the opposite direction, so that the protuberances 5 move out of the grooves 6.
A thief or tamper-proof shackle can be provided by over-tightening the pin 4 whereby the ring 8a is twisted off.
Although the provision of only one protuberance 5 and only one groove 6 may suffice, the use of two protuberances and two grooves is preferred.
With reference now to Figures 6 to 9, a shackle comprises a generally "U"-shaped shackle body 10 of resilient material with aligned holes 12, 13, for receiving s shackle-pin 14. The shackle body 10 is provided with a pair of concavities in the form of aligned grooves 16, disposed one on each side of the hole 1 2, and the shackle-pin 1 4 is provided with a flattened head 1 8 the sides of which define a pair of cooperating convexities 15, disposed one on each side of the pin shank 17. As explained hereinafter, the side 1 5 and grooves 1 6 interengage so as to hold the body 10 and pin 14 together The shackle 10/14 is of drop forged steel.
(Stainless steel or other suitable material may be used as an alternative.) Hole 13 in body 10 is screw-threaded to receive the screw-threaded end1 7a of the pin shank 7. Hole 12 in body 10 is not screw-threaded. A hole 19 is formed in the pinhead 1 8. Threaded end 1 7a of the pin is of sufficient length to ensure "bowing" of the body10 as the pin is tightened.
In use, the pin 14 is inserted through hole 12 in the body 10 and into the screw-threaded hole 13.
The pin 14 is then tightened, using a key inserted in the hole 19 if necessary, until the key-like head18 abuts the body 10. The tightening is continued until the sides 1 5 of the pin head 1 8 "click" into place as they enter the grooves 16.
For the sides 1 5 to enter the grooves 1 6, the body 10 has to "bow" slightly whereby the limbs of the body are moved towards each other by the pin 14 as it is tightened. After entry of the sides1 5 into the grooves 1 6, natural resilience of the body 10 tends to bias the limbs of the body apart, towards their original positions. This resilience subjects the pin 14 to tension whereby the body10 and pin 14 are held firmly together.
To remove the pin 14 from the body 10, the pin is rotated in the opposite direction, so that the sides 15 move out of the grooves 16.
With reference now to Figures 10 to 14, a shackle comprises a generally "U"-shaped shackle body 20 of resilient material with aligned holes 22, 23, for receiving a shackle-pin 24. In this embodiment the shackle body 20 is provided with a ring of substantially equi-spaced concavities in the form of grooves 26, disposed radially about the common axis of the holes 22, 23, and the shackle-pin 24 is provided with a pair of oppositely-disposed and cooperating convexities in the form of ribs 25 extending radially from the longitudinal axis of the pin shank 27 and formed in the pin head 28. As explained hereinafter, the ribs25 and grooves 26 interengage so as to hold the body 20 and pin 24 together.
The shackle 20/24 is of drop forged steel.
(Stainless steel or other suitable material may be used as an alternative.) Hole 23 in body 20 is screw-threaded to receive the screw-threaded end 27a of the pin shank 27. Hole 22 in body 20 is not screw-threaded. The pin head 28 is provided with a ring 28a formed with a hole 29.
In use, the pin 24 is inserted through hole 22 in the body 20 and into the screw-threaded hole 23. The pin 24 is then tightened, using a key inserted in the hole 29 of the ring 28a if necessary, until the head 28 abuts the body 20.
The tightening is continued until the ribs 25 "click" into place as they enter the grooves 26.
For the ribs 25 to enter the grooves 26, the body 20 has to "bow" slightly whereby the limbs of the body are moved towards each other by the pin 24 as it is tightened. After entry of the ribs 25 into the grooves 26, natural resilience of the body 20 tends to bias the limbs of the body apart, towards their original positions. This resilience subjects the pin 24 to tension whereby the body 20 and pin 24 are held firmly together, threaded end 27a being of sufficient length to ensure "bowing" of the body 20 as the pin is tightened.
To remove the pin 24 from the body'20, the ein 24 is rotated in the opposite direction so that the ribs 25 move out of the grooves 26.
As in the case of the embodiment of Figures 5 to 5, a thief or tamper-proof shackle can be provided by over-tightening the pin 24 whereby the ring 28a is twisted off.
In a modification, the body 20 may be formed with a ring of convexities and the pin 24 with a cooperating ring of concavities.
The teachings of the invention may be applied to shackles provided with longer pins which do not screw into shackle bodies but instead employ nuts for tightening purposes.
The invention avoids the need for seizing wires to secure a shackle-pin to a shackle body, but such wires can still be used, if desired.
In the above examples, the positions of concavities and convexities can be reversed. For example, with reference to Figures 1 and 4, concavities 6 can be replaced by convexities and protuberances 5 by concavities.