Handling: hand and hoist-line implements – Hoist-line slings – Latch release
Patent
1988-12-12
1990-09-25
Focarino, Margaret A.
Handling: hand and hoist-line implements
Hoist-line slings
Latch release
294 8224, B66C 112
Patent
active
049588729
DESCRIPTION:
BRIEF SUMMARY
FIELD OF INVENTION AND PRIOR ART
The invention is related to a tensile force transmitting elongated device, which primarily is intended to be used as a lifting device. The device is suitably intended to have the character of a lifting strop at least in part flexible. This is particularly suitable for timber transportation by means of helicopter but may also be used for other types of load transports.
Since the beginning of the 1960's one has tried to transport timber by means of helicopter. All parties involved realize that such transport involves a very big market if it would be possible to carry out transportation in an economical manner for the forest owner as well as the helicopter company. There are today very large areas with good timber located so inaccessibly that it is difficult to be used in an economical manner with the means normally used for timber transportation. The cost per hour for a helicopter is, however, very high and the attempts until now carried out with helicopter based timber transportation in association with use of ordinary lifting strops have turned out to be economically doubtful, i.e. the transportation has become too expensive for the forest owner and poorly paid for the helicopter owner.
The lifting strops until now used in the attempts mentioned hereinabove with helicopter transportation are steel wire or artificial fibre strops, which all have in common that they are attached around the log by means of a running loop which when the strop is released from the helicopter lifting hook remains around the log at the unloading location and must be released by personnel on that location. Apart from this work being difficult and sometimes dangerous it has turned out to cause a lot of extra work for the helicopter since it must land to take on board the empty strops which must be brought back to the timber felling location. This extra stop in connection with the retransportation of the lifting strops to the loading location cause the average time and accordingly the rental cost when using helicopter transportation to be unacceptably high and the profit correspondingly low. The requirement for personnel at the unloading location influences the overall economy negatively to a high degree.
SUMMARY OF THE INVENTION
The object of the invention is to devise an improved tensile force transmitting device, by means of which release of the load in question may occur without the entire device having to be released When using the device according to the invention as a lifting strop with helicopter transportation, the helicopter need no longer land to bring with it the empty lifting strops, a fact which enables a considerable reduction of the time of use of the helicopter and a corresponding increase of profit; contributory to high profits is also the fact that no personnel is necessary at the unloading location.
This object is according to the invention achieved with the device more closely defined in appended claim 1. Preferable embodiments of the device according to the invention are defined in the other claims.
The main advantage when using the device according to the invention designed as a lifting strop is that the load carried by the strop may be released therefrom with signal from the helicopter without need of assisting personnel at the unloading location and the strop may, after having released the load, directly accompany the helicopter back to the felling location and be released thereon. The expenses for personnel are reduced at the same time as the helicopter gets a considerably improved continuity in work than in previous attempts since it is no longer necessary to land to pick up the strop. Experiments carried out while using a helicopter of the type Bell 205 having a maximum load capacity of about 1900 kg have illustrated that it is possible, when using the lifting strop according to the invention, to carry out about 30 trips with load per flying hour at a distance between loading and unloading location of about 500 m and with about 2 m.sup.3 timber (about 1600 kg) per load
REFERENCES:
patent: 690659 (1902-01-01), Ney
patent: 2385338 (1945-09-01), Allerton
patent: 3163401 (1964-12-01), Johnston et al.
patent: 3239266 (1966-03-01), Elliott
patent: 3709550 (1973-01-01), Mitchell
Focarino Margaret A.
Kramer Dean J.
LandOfFree
Tensile force transmitting device, in particular a lifting devic does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tensile force transmitting device, in particular a lifting devic, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tensile force transmitting device, in particular a lifting devic will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-325429