Two arms system

Details Two arms system Two arms system

1999-05-05

2001-02-27

Brahan, Thomas J. (Department: 3652)

Traversing hoists

Adjustable to transport or nonuse position

Collapsible or foldable boom

C212S232000, C212S238000

Reexamination Certificate

active

06193087

ABSTRACT:

There is a considerable call for a two-armed system for unit cranes, for instance. Such a crane consists of one rigid arm and thereafter an arm composed of a number of part-arms joined together, which can be influenced hydraulically in such a manner that the part-arms form a polygon. This arm is in turn attached to a stand or to said stand via a supporting arm. The two arms in the system, together with a supporting arm if used, can thus be arranged to be situated one above the other and also so that all the arms are extended. Various units can be attached at the tip of the rigid arm, for use in clearing trees and bushes, for instance. Units functioning as excavators or loaders can also be attached, or even a concrete pump or concrete hose. In existing systems with tow arms, the arm able to form a polygon is influenced by a hydraulic unit arranged between the arm parts so that, when the polygon is extended, the unit is located substantially in the middle of the polygon. Certain problems have been encountered when operating such two-armed systems, with regard to speed control of the tip of the rigid arm, and problems also occur with regard to the force exerted at said tip. Such a unit crane is suitably fitted on a caterpillar vehicle and this involves the problem of how to fold up the unit crane when it is not in operation. The arms will usually have a substantially vertical position, or they will be situated on the roof of the vehicle. There is also the problem of the actual joints of the unit arms being as stable as possible.
The object of the present invention is to solve the above-mentioned drawbacks and this is achieved, since both the arms in the system can be caused to lie one above the other, and possibly also above a supporting arm so that, when the arm system is not in use the free end of the arm with several parts is attached either to a stand or to one end of a supporting arm, the other end of which is journalled in the stand. When folded, therefore, the actual working tip or crane tip of the journalled package will be situated at the opposite part of the stand. To achieve suitable lifting power and suitable speed the crane tip is moved from a packaged position to the position it assumes when the tip is furthest away from the stand. The hydraulic mechanism influencing the arm with the many parts is arranged so that it influences two points situated outside two adjacent arm parts. Such a unit crane with its stand is suitably arranged on a platform provided with cab, in such a way that the arm system in the form of a package does not come into contact with the cab in any way. The vehicle carrying the crane package may be part of a centrally controlled vehicle in which the engine is jointed to the supporting part for the crane package. By arranging the hydraulic unit outside the arm with the many part-arms, the advantage is gained that the crane can be brought to a substantially horizontal position with the various arms arranged one after the other, and that it can be caused to assume a substantially downwardly-directed vertical position and upwardly-directed vertical position. The may joints in the arm system are subjected to considerable strain and it is therefore suitable for two arms to be combined so that one arm has two parallel shafts between which a stud located on the other arm is passed. The stud and the two arms together form a through-opening for a shaft journal. Each end of the shaft journal is provided with a tensioning ring having a conical surface and a tensioning cone, also having a conical surface, cooperating therewith. These two units with conical surfaces are brought into rigid contact with each other since the end cone is provided with a tightening bolt that can be screwed into each end of the shaft journal. Reliable functioning of the shaft journal located at a point about which the two arms can be oscillated is thus obtained.
Additional characteristics of the present invention are revealed in the appended claims.


REFERENCES:
patent: 3828939 (1974-08-01), Tranchero
patent: 4770271 (1988-09-01), Tranchero
patent: 5197615 (1993-03-01), Gunnarson
patent: 5507107 (1996-04-01), Pinomake
patent: 2508872 (1976-09-01), None
patent: 318382 (1969-12-01), None
patent: 382039 (1976-01-01), None
patent: 7411568 (1976-04-01), None
patent: 8603660 (1988-04-01), None
patent: 463668 (1991-01-01), None
patent: 93/00286 (1993-01-01), None

Affiliated with

Also associated with

Rating

Two arms system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Two arms system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two arms system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2577879