CA1180166A - Connecting device - Google Patents

Abstract

TITLE OF THE INVENTION: A Connecting Device.

ABSTRACT OF THE DISCLOSURE:
A connecting device for securing loads to a lifting or pulling means. The device consists of a ring, and a toggle dimensioned and proportioned so as to fall through the ring under its own weight, but to engage securely with the ring when a load is applied to the toggle.

Description

V:~66 BACKGXOUND OF T~iE; INV~NTIOI~
(1) FIELD OF T~l~ INV~NrrION
The presen-t invention relates to a connec-ting device f'or securing loads to a lifting or pulling rneans. The device of the present in~ention is especially useful for connecting log strops to a pulling rope, and will be described with especial ref'erence to this application, bu-t it will be apprecia-ted that the device of' the present invention also may be used for connecting any of a wide range of loads to pulling or lif'ting means.

(2) DESCRIPTION OF T~IE PRIOR ART
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Felled logs generally are dragged f'rom their fallen position to a central pick-up or processing place by attaching to each log a pulling rope or chain the other ~5 end of which is secured to a skidder or similar vehicle.
At present, the common method of' a~taching the pulling rope to each log is to secure around the log a strop which tightly encircles and grips the log. The free end of' this strop is fi~ted with a metal ring, and the end of thé
pulling rope is secured to the ring by a shackel. Se~eral rings may be secured to a single shackel.
This arrangement has two main drawbacks: firstt the heavy loading on the shackel tends in time to distort the shackel, making it difficult to fasten and unfasterl the shackel pin; secondly, fastening and unfastening a ,.. ' ~

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shackel pin is a time-cons~ning and f'iddling job, especially if' the shackel is ca~ed with mud and the threads of' the pin or pin socket f'ouled or dis-tor-ted.
U.S.Patent No.11~01503 (Williarn Brarnwell Smith) discloses a fastener consisting of' a bar and link, which is connec-ted by passing the bar through the link, and then turning the bar through 90 so that the sides of -the bar bear on the sides of'-the link and thus prevent the bar from passing back through the link under load. This -type of f`astener has been widely used f'or rnany years, and is still in comrnon use f'or securing tyre chains.
Finnish Patent No.B~69L~1 (Oy Finnlines Ltd.) dis-closes a f`astener or connector consisting of` a toggle and a rectangular slot f'orrned in a U-bearn. The toggle is shaped -to provide a rounded portion to which a tie-down chain is attached, and an elongated end portion which is longer than the slo-t. ln use, the toggle is passed through the slot, and turned through 90 to allow the elongated end portion to bear on the ends of the slot and thus prevent the toggle f'rom passing back through the slot under load.
The designs of' U.S.Patent No.lL~01503 and Finnish Patent No.P469L~1 both have the drawback -that -the toggle or bar must be manoeuvered manually through the slot or link, and then manually turned -to the f'astening position.
Also, the ends of' the -toggle or bar must project a ~ 6 6 considerable distance beyond the ends of -the slot or link, so that they cannot disengage accidentally, and this means that the ends tend -to snag on debris and to pick up dirt.
An object of the present invention is the provision of a connecting device which overcomes these disadvantages and is quick and easy to use even in very dirty conditions.

BRIEF SUMMARY OF THE INVENTION
The present invention provides a connecting device cornprising a ring having an internal diameter (a); and a toggle which includes two legs inclined outwards from each other, the closer ends of said legs being connected and the other ends of said legs being spaced apar-t by a distance (b) between the outer surfaces of said ends, measured in a plane parallel to the plane of the ring when said ring and toggle are engag~d under load in use, said distance (b) being greater than said distance (a); and a cross-bar extending between said legs and secured thereto such that the distance (d) between the top of the -toggle and the lower surface of the cross-bar is less than said distance (a). Preferably, the toggle is substantially A-shaped :in cross-section and the legs are of equal length.

BRIEF DESC~IPTION OF D~AWINGS
Figure 1 is a section through a connecting device in accordance with a first embodiment of the invention;
Figures 2-4 are sectional views of the device of _ ~,, _ Figure 1 showing the -three stages of' linking the toggle to the ring in use; and Figure 5 is a side view of' a second embodimen-t of th invention.

DETAILED DESCRIPTIOr~ OF THE P F'ERHED ~r~BODIMENTS OF TH~
INVENTION
-Referring to Figure 1, a connecting device 2 com-prises a ring 3 having an internal diameter (a), and a toggle 4.
The toggle 4 comprises a length of` steel rod bent to form a V-shape in .cross-section with the outer surfaces of the free ends of the legs 5 being spaced apart by a distance (b) measured in a plane parallel to the plane of the ring 3 when the ring and toggle are engaged under load as shown in F'igure 1. The legs 5 are of substantially equal length (c):- this is not essential, but there is no advantage to be gained f'rom making them dif'ferent lengths, and in f'act the toggle may be less easy to use if' one leg is very much longer than the other. For the toggle -to engage the ring in use, the distance (b) rnust be greater than the internal diameter (a) of the ring 3.
The legs 5 are Joined and braced by a cross-bar 7, which serves two functions:- it prevents the toggle from becoming detached from the supporting link ~ oI' the pulling chain (not shown) and it braces the legs 5 against -the .~.~i compressive f'orces f set up when a pullinrr f'orce ~' is applied to the toggle in use. To allow the toggle 4 to drop through the ring 3 as hereina~'ter described, the distance (d) between the lower surfac- o' the nd o the cross-bar 7 and the top of the toggle must be less than the internal diameter (a) of the ring.
The above-described connecting device is used as follows: -the toggle 4 is secured to the last link g of a pulling chain (or chain secured to a pulling rope), either by welding the cross-bar 7 in place af-ter the legs 5 have been engaged with the link or by using a closea'ble 'blacksmith's link' f'or the last link ~. Another possibi-lity is to form the cross-bar 7 with a central gap through which the link ~ can be passed, after which the gap is closed by weiding. The ring 3 is secured to the strop (not shown) passing around the log to which the pulling rope is to be connected. As shown in Figure 2, the toggle is lowered onto the ring 3, allowing one of the legs 5 of the toggle to fall through the ring, and as it does so, the ring engages the cross-bar 7 or the other leg 5, tending to pivot the toggle into the position shown in Figure 3, allowing the toggle to fall right through the ring, as shown in Figure 4. The weight of' the toggle makes it hang more-or-less vertical, as in Figure 4, although it may hang asymmetrically if one of' the legs 5 is substantially longer or heavier than the other. The 6~

free end of each leg/preferably is thickened (not shown) or clad, to improve the wear resistance of the -toggle and -to weight the ends of the leg and so -to assis-t the legs to hang correc-tly~
When -the log is dragged by the pulling rope, the toggle is drawn back towards the ring, i.e. to the position shown in Figure 1. Once the toggle is completely through the ring, it cannot accidentally be disengaged from -the ring:- the only way in which the toggle can be disen-gaged is for -the pulling force F to be removed, and the toggle manually twisted from the position of Figure 4 to that of Figure 3 and manoevered back through the ring.
If more than one log is to be skidded, the toggle is inserted through the rings secured to the other log strops in the same manner.
~ second embodiment of the invention is shown in Figure 5. In this embodiment, the toggle 4 is formed as a solid casting~ forging or pressing9 but the basic features and proportions remain -the sarne as for the embodiment of Figures 1-4 and are marked with the same reference numerals and letters. The cross-bar 7 is greatly increased in thickness, and the legs 5 may be curved inwards, as shown, to aid the -toggle in seating correctly in the ring in use.
The angle be-tween the legs 5 (-the mean angle, in the case of the curved legs of Figure 5) may be varied if ., ~0~6 desired, but i-t has been found that an optirnum angle is in the region of` ~0. If the angle is rnuch less than this7 the legs 5 must be relatively long to achieve the correct distance (b), and as mentioned above, very long legs make the toggle inconvenient to use. However, if the angle is much greater -than the optimum, it may be found necessary -to increase the strength of -the toggle rnaterial because the strength of the legs is reduced as the angle between them is increased. For exarnple, the strength of legs a-t an angle of 120 is approximately 0.6 of the strength of legs at an angle of 50.

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Claims (5)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A connecting device comprising: a ring having an internal diameter (a); and a toggle which includes two legs inclined outwards from each other, the closer ends of said legs being connected and the other ends of said legs being spaced apart by a distance (b) between the outer surfaces of said ends, measured in a plane parallel to the plane of the ring when said ring and toggle are engaged under load in use, said distance (b) being greater than said distance (a); and a cross-bar extending between said legs and secured thereto such that the distance (d) between the top of the toggle and the lower surface of the cross-bar is less than said distance (a).

2. The connecting device as claimed in Claim 1 wherein said toggle is substantially A-shaped in cross-section and said legs are of equal length.

3. The connecting device as claimed in Claim 1 or Claim 2 wherein said legs are formed integrally with each other.

4. The connecting device as claimed in Claim 1 wherein said legs are curved inwards towards each other over a portion of their length.

5. The connecting device as claimed in Claim 1 or Claim 2 wherein said other ends of said legs are weighted.