Machine element or mechanism – Control lever and linkage systems – Hand operated
Reexamination Certificate
2000-01-19
2001-07-17
Bucci, David A. (Department: 3682)
Machine element or mechanism
Control lever and linkage systems
Hand operated
C074S492000, C184S105100
Reexamination Certificate
active
06260433
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a lubricating device for telescopic shaft with axial conduits formed in its relatively sliding tubular parts. The telescopic shaft is, in particular, a cardanic shaft for transmitting power from a force outlet of an agricultural tractor to an operating machine or driven tool.
In general, the cardanic shaft comprises an intermediate shaft made of two tubular parts bearing, at the respective free extremities, a fork for cardanic joint or the like. The tubular parts of the intermediate shaft, an outer one and an inner one, have conformal profiles in order to be able to slide relatively one inside the other, but are prevented from rotating relative to one another. The cardanic shaft can adapt itself to the mutual displacements of the tractor and of the operating machine or driven tool thanks to the mutual displacements of the tubular parts which allow it to be lengthened and shortened.
This lengthening and shortening adaptation takes place under a generally high transmission torque and hence generates friction on the contact surfaces of the tubular parts of intermediate shaft. The consequences thereof are heating and wear of the aforesaid parts, with obvious consequences of a reduced working life due to defects and breakages.
Lubricating devices mounted on a cardanic shaft have already been realized, with the aim of avoiding the assembling and re-assembling operations which would be necessary for the periodic lubrication of the inner surface of the outer tubular part or of the outer surface of the inner tubular part.
Among others, Italian patent No. 1,286,359 by the same applicant discloses a lubricating device for telescopic shaft, comprising a ball greaser mounted in the fork of the inner tubular part of the telescopic shaft and connected, internally thereto, with a small connecting tube to an element for the storage and distribution of the grease, positioned inside the inner tubular part and having an inner cavity communicating, through its own openings and corresponding through holes obtained in the inner tubular part, with the inner surface of the outer tubular part of the intermediate shaft.
Thus, such a device is able from the exterior to let the grease arrive between the inner and outer tubular portions of a telescopic tube without disassembling any component of the transmission. However, since the play or inter-space between the two tubular parts of the telescopic shaft is relatively small, generally ranging between 0.5 and 0.9 mm, the grease, due to its viscosity, is not able to flow axially in that inter-space, except for a few centimeters. This is due to the fact that resistance to sliding increases extremely rapidly, so that the operator with a manual injector is no longer able to pump grease into the interior. Thus, the quantity of grease that enters the inter-space between the two tubular parts of the telescopic shaft is so small as to cover a very reduced surface area relative to the area of actual sliding, with the consequence of an insufficient lubrication.
On the other hand, if a motorized lubricating apparatus were to be used, whence grease exits at a sufficiently high pressure for an effective diffusion in that inter-space, such pressure could jeopardize the soundness of the couplings in the connecting tube, which is usually made of plastic material.
Moreover, even if the connecting pipe were made for high pressures, motorized lubricating apparatuses may periodically not be available in place.
SUMMARY OF THE INVENTION
The aim of the present invention therefore is to eliminate the aforementioned drawbacks, in order to obtain an effective lubrication of the surfaces of the two tubular parts in mutual sliding contact.
The invention, as it is characterized by the claims that follow, solves the problem of providing a lubricating device for telescopic shaft with axial conduits formed in the relatively sliding tubular parts, with conformal profile, in particular of a cardanic shaft for the transmission of power from a force outlet of an agricultural tractor to a driven tool; lubricating device comprising a greaser in the inner tubular part connected, internally thereto, to a grease distributor element movable integrally with the same inner tubular part, inside the outer tubular part, which from a general point of view is characterized in that:
said internal and external tubular parts, inserted one inside the other, able relatively to slide but prevent from mutually rotating, comprise, between the outer surface of the inner tubular part and the inner surface of the outer tubular part, axial conduits;
said greaser is contained in a lubricating sleeve, fastened to one extremity of said inner tubular part;
said distributor element comprises two segments, said first segment stably inserted in said inner tubular part at the extremity opposite the one that receives the lubricating sleeve, said second segment able to slide with reduced play in the inner profile of the outer tubular part; in said first distributor element segment being obtained a central passage continuing a pipe connecting with said greasing sleeve, radial passages, internally communicating with said central passage, in continuation of the attachment junction, and externally, through outlet ports with the inlets of said axial conduits not covered by said inner tubular part.
REFERENCES:
patent: 3698259 (1972-10-01), Reeves
patent: 4667530 (1987-05-01), Mettler et al.
patent: 5243874 (1993-09-01), Wolfe et al.
patent: 5383811 (1995-01-01), Campbell et al.
patent: 6149526 (2000-11-01), Boersma et al.
Browdy and Neimark
Bucci David A.
Eurocardan S.p.A.
Kim Chong H.
LandOfFree
Lubricating device for telescopic shaft axial conduits... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Lubricating device for telescopic shaft axial conduits..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lubricating device for telescopic shaft axial conduits... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2520857