Fire escape – ladder – or scaffold – Means maintaining platform level on angularly movable support
Reexamination Certificate
2000-03-10
2001-06-26
Stodola, Daniel P. (Department: 3634)
Fire escape, ladder, or scaffold
Means maintaining platform level on angularly movable support
C182S065100, C182S002300
Reexamination Certificate
active
06250423
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a mobile lifting platform comprising a chassis as well as platform support means on which a first live ring or turntable is mounted. Said live ring has its vertical axis approximately centered on said platform and supports a horizontal boom for pivotal movement about said axis. On said horizontal boom in turn there is mounted a second live ring or turntable whose axis is offset from that of the first live ring. Moreover, a swivel structure is attached to said second live ring for pivotal movement about a vertical axis thereof, which swivel structure terminates in a boom carrying a platform or basket for workmen at its distal end.
Mobile lifting platforms of this type are in keeping with the proposed European standard prEN 280 of April 1994, as drafted by the “Technisches Komitee” (technical committee) CEN/TC 98/AG 1of the “Europäisches Komitee für Normung” (European standards committee). Such mobile lifting platforms may be provided in the form of a trailer or as self-propelled machines.
Attempting to provide mobile lifting platforms which are short in total length and thus pose no maneuvering problems when used in traffic, complex multiple telescope systems as well as a pronounced bend of the swivel structure have been proposed in the prior art in order to make use of the area above the driver's cabin. Owing to the pronounced bend of the swivel structure, said structure—once swivelled—will exceed the overall width of the vehicle, thus projecting into the traffic area. Proximal support means are traditionally provided immediately behind the driver's cabin. As a consequence, the range or radius of the lifting means to the front must be limited in order to ensure steadiness and stability of the overall vehicle in operation.
A further disadvantage of the prior art is the common general necessity to use support means or stabilizers which may be telescopically extended or unfolded over the width of the vehicle since these likewise pose a traffic obstacle in operation, yet are required for operational safety.
German patent application DE 1,960,829 A1 discloses a mobile lifting platform with two live rings. The movement of said live rings is separately controlled via two drive units which are independent of each other. Such an arrangement is said to facilitate the reaching of positions which are outside the vehicle range.
It is the object of the present invention to provide a lifting platform of the aforementioned type in which fewer telescopic means are used with the same overall vehicle length and which facilitates movement of the lifting platform itself, at the same time leaving more space for passing traffic both when the lifting platform is being moved into position and when it is in operation.
SUMMARY OF THE INVENTION
According to the invention this object is accomplished by the features of the main claim.
Advantageous embodiments of the invention are described in the subclaims.
The present invention also makes use of the basically known bent swivel structure which, however, may in this case be of a larger size than with comparable lifting platforms in order to use the free area e.g. above the driver's cabin and reduce the overall length of the machine. A reduction of the machine's overall length also results in a shift of its gravity centre which in turn results in a short wheel base - which enhances the manoeuverability of the lifting platform in traffic. Moreover, due to the shift of the gravity centre, the radius or range of the swivel structure to the front above and beyond the driver's cabin of the carrier vehicle is increased considerably.
The fact that the swivel structure is bent more than in the prior art is compensated in that pivoting occurs about two offset pivot axes which are connected with each other so as to be forced to move in opposed directions. To this end, the swivel structure is connected to the horizontal boom such that the directions of the rotary movements of these two parts are opposed to each other. Advantageously, such opposed movement between said swivel structure and said horizontal boom is effected via a gear acting between the two elements, with the opposite angular velocities between the horizontal boom and the swivel structure being approximately of the same amount. This ensures that the vehicle contours will not exceeded in most cases. Moreover, a uniform load acts on the supports or stabilizers and/or the carrier vehicle. In addition, the fact that the horizontal boom and the swivel structure rotate in opposite directions advantageously results in a reduction by approx.
50
% of the gear driving torques.
Furthermore, the distance between the two rotary axes may advantageously be balanced out using a counterweight. As a consequence, the gravity centre is mostly within the narrow dimensions of support means which should not exceed the size of the vehicle, if possible. Also, the bent part is dimensioned according to the invention such that, when the carrier vehicle is in operation, said part rests above a driver's cabin on the one hand and does not exceed the overall vehicle width, on the other.
The known support means also used in the present invention may be made to extend beyond the area taken up by the platform, if necessary, although in most cases, unilateral support will be sufficient.
Further details, features and advantages of the present invention may be gathered from the description hereinafter of an embodiment example which is also shown in the drawings, in which
REFERENCES:
patent: 1528222 (1925-03-01), Miller
patent: 3085648 (1963-04-01), Benedetto
patent: 3533515 (1970-10-01), Milner, Jr.
patent: 3791484 (1974-02-01), Harrison
patent: 4116304 (1978-09-01), Durnell
patent: 4596508 (1986-06-01), Kiski et al.
patent: 4674638 (1987-06-01), Oliphant
patent: 5518128 (1996-05-01), Kroll et al.
patent: 287971 (1971-02-01), None
patent: 1960829 (1966-12-01), None
patent: 2053570 (1971-05-01), None
patent: 26 53 951 (1983-09-01), None
patent: 41 23 398 (1993-01-01), None
patent: 1278537 (1972-01-01), None
patent: 1544564 (1979-04-01), None
patent: 2079243 (1982-01-01), None
Bison Stematec Maschinenbau- und Hubarbeitsbuhnen Produktiongese
Chernoff Vilhauer & McClung & Stenzel
Stodola Daniel P.
Thompson Hugh B.
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