Elevator – industrial lift truck – or stationary lift for vehicle – Having specific load support drive-means or its control – Includes linking support cable in drive-means
Patent
1997-02-19
1998-08-18
Noland, Kenneth
Elevator, industrial lift truck, or stationary lift for vehicle
Having specific load support drive-means or its control
Includes linking support cable in drive-means
187350, B66B 1108
Patent
active
057947376
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a traction driving device for hoisting machine and electric elevator, more specifically relates to an antislip traction machine for driving device of hoisting machine and electric elevator during driving to prevent traction rope from slipping and cage from dropping.
TECHNICAL BACKGROUND
The superiority of frictional drive over forced drive has been generally acknowledged and the frictional drive has replaced the forced drive in an all round way. However, an existing frictional driving device for use in electric elevators has rather high requirement to environmental condition, for instance, it must have s speed limiter--safety clamp system and guideways to meet demand for the braking of this system, the pit tunnel must be closed, machine room must be set up, etc. These requirements confine its use within the indoor pit tunnels. In construction work where a machine room is difficult to be set up, the lifting elevators of gear and rack transmission type, hydraulic type and linear electric motor actuation type will undertake the vertical transportation of persons and materials. While the low-cost, easy-to-handle wire rope transmission type lifting machines can only carry materials.
The frictional drive has made the possibility of rope breakage to a negligible degree. The statistical result derived from 200,000 electric elevators during 15 years of service in Germany was: one traction rope breakage occurred only to two electric elevators. According to these basic data together with an assumption that each elevator makes 20 times of lifting daily, a probability calculation shows that the period or cycle for the four traction ropes of an elevator to break in one lifting (resulting in a cage dropping) is 1.57.times.10.sup.37 years.
The function of a speed limiter--safety clamp system is to prevent cage from dropping. The dropping accident almost never happens with modern electric elevators, however not all of this is to be attributed to the action of this system. Tests of preventing cage from dropping with rope breakage conducted by a transportation organization in London to the speed limiter--safety clamp system approved by the European Community Standard Organization showed that in 33 tests, the results of 31 tests were positive and 2 negative. The rate of success was 94%. It suggested the main reason for occurring no cage dropping was the rational use of wire rope in frictional drive which almost results in no breakage of wire. Of course the braking of speed limiter--safety clamp system under the condition of having counterweight in overspeed slipping is reliable.
The present applicant has noticed the condition of almost no breakage of the above-mentioned wire rope in frictional drive, and adopted the wire rope as safety rope to prevent cage from dropping, while making use of frictional drive principle and ratchet pawl braking mechanism as well as centrifugal speed limiter control mechanism to constitute a kind of dropping prevention system and obtained a Patent(CN86100436), and later on, through combining system with the forced drive several kinds of elevating machines for both person and cargo have been produced by making use of wire rope for lifting and dropping prevention, with cost reduced by one half in comparison with existing elevating machines and with distinct economic effect and social effect. However, all these elevating machines have the drawback of forced drive--a larger possibility of lifting rope breakage.
The structure of the frictional drive device of existing electric elevators is rather loose, it is installed horizontally in a machine room, with the drawback of lack of flexibility and in need of a speed limiter--safety clamp system to prevent cage from dropping. Hence the scope of use is limited. The frictional drive can not be popularized. For instance, presently in Japan, elevators for residence all basically adopt oldfashioned forced drive. The reason is that the current frictional drive device is not applicable and the construction of
Zhong Jianyuan
Zhong Lei
LandOfFree
Antislip traction machine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Antislip traction machine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Antislip traction machine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1107260