EP0018038B1

EP0018038B1 - Apparatus for effecting a relative linear displacement between a number of columns and a body arranged for movement along said columns

Info

Publication number: EP0018038B1
Application number: EP19800200317
Authority: EP
Inventors: Bart Boon
Original assignee: Gusto Engineering BV
Current assignee: Gusto Engineering BV
Priority date: 1979-04-06
Filing date: 1980-04-08
Publication date: 1983-11-30
Also published as: EP0018038A1; DE3065748D1; NL7902748A

Description

The invention relates to an apparatus for effecting a relative linear displacement between a number of columns and a body arranged for movement along said columns, particularly in a self-lifting pontoon, each one of said columns being provided with at least one longitudinally extending teeth rack having a series of regularly spaced apart teeth capable of cooperating with a driving and a locking pawl means each one of which means is mounted in a yoke means for a slidable movement in transverse direction with respect to the longitudinal direction of the respective column so that the pawl means can be shifted into and out of a space between two teeth, while the yoke means of the driving pawl means can be moved slidably up and down in the longituninal direction of the column by means of a piston-cylinder assembly pivotally connected at one end to said yoke means, said piston-cylinder assembly being pivotally connected at the other end thereof to said body. An apparatus of this type is known from the Dutch patent application 7508373.
In the known apparatus each one of said columns is in the shape of a pile having a square cross section on which a pair of spaced apart parallel teeth racks are mounted, between which the yoke of the driving pawl means is slidably received. In order to keep said yoke between the pair of teeth racks the piston-cylinder assembly pivotally connected at one end to said yoke extends obliquely upwardly towards the respective column necessitating to arrange a second similar assembly of a pair of spaced apart parallel teeth racks cooperating with driving and locking pawl means mounted in yoke means and an obliquely extending piston-cylinder assembly at the opposite side of the column to counterbalance the horizontal forces.
The manufacturing costs of this apparatus are high so that for relatively small bodies the costs of the lifting arrangement become disproportionally high.
The object of the invention is to provide an apparatus of the above mentioned type which may be manufactured from cheap parts which are always in supply on the market.
This object is attained in that in the apparatus according to the invention each one of said columns is formed by a circular pipe or pile, that only one teeth rack is provided on each column and that the yoke means of the driving pawl means is fastened to at least two axially spaced apart annular members or a sleeve shaped member, slidably mounted about the respective column.
Pipes and teeth racks are always in supply so that the columns can be manufactured quickly and at a lower price, while due to the circular shape of the column the guiding means for the driving pawl yoke can be simply formed by two axially spaced apart annular members so that only one lifting assembly having one vertically extending piston-cylinder assembly and only one teeth rack for each column will suffice.
To improve the guiding of the yoke of the driving pawl means a guide shoe facing the teeth rack may be mounted in said yoke, while any lateral movement of this yoke can be restricted by guide strips provided in said yoke at both sides of the teeth rack. For guiding the body along the columns, guide strips may be provided in the yokes of the locking pawl means which guide strips are arranged at both side of the teeth rack.
In DE-B-1252393 an apparatus for effecting up and down movements of a self-lifting pontoon is disclosed, in which two opposed bar- shaped driving pawl means are mounted in a housing which surrounds the respective column having a square cross-section, which housing is connected to the pontoon by means of two vertically extending piston-cylinder assemblies so that said housing can be moved up and downwardly in a substantially horizontal position without being in engagement with the column.
The invention will be elucidated in more detail with reference to the drawing in which

Fig. 1 shows a side elevation of a lifting apparatus according to the invention,
Fig. 2 shows a cross section along the line II-II in Fig. 1, and
Fig. 3 shows a cross section along the line III-III in Fig. 1.

As shown in the figures, in the apparatus according to the invention each one of the columns is in the shape of a circular pipe 1 to which a teeth rack 2 is welded.
The pipe 1 extends through an opening 3 provided in the pontoon of which only the top side 4 is shown partially.
On the top or the deck of the pontoon there is mounted a yoke 5 for the locking pawl means 26. The yoke 5 comprises two parallel plates 6 including a cross support 7 as well as guide strips 8 welded to the end of the plates and disposed on either side of the teeth rack 2. To the plates 6 there are fastened section irons 9 to which irons 9 a cross member 10 is welded which serves for fastening a piston-cylinder assembly (not shown) for actuating the pawl means 26 in a similar way as will be described below for the driving pawl means (13).
Between the plates 6 there is pivotally fastened the piston-cylinder assembly 11. The top part of this piston-cylinder assembly 11 is pivotally fastened to the yoke 12 of the driving pawl means 13.
Likewise the yoke 12 comprises two plates 14 including a cross support 15. To these plates there are welded the section irons 16 which are connected to each other at the rear side by the cross member 17. In the section irons 16 openings 18 are cut for guiding the pawl means 13 which openings are bounded at the one end by the plate elements 19 and at the other end by the guide strips 20. Furthermore there is provided a cover plate 21 having a slot 22 for passing the teeth rack 2. The pawl means 13 is connected to a piston-cylinder assembly 23 which is connected at its other end to the cross member 17. Between the plates 14 a guide shoe 24 is additionally provided.
The yoke 12 is connected to two rings 25 capable of a sliding movement along the pipe 1.
When the floating pontoon has to be raised along the columns the pipes 1 are lowered onto the subaqueous bottom whereupon the pawl means 13 is inserted into a space 28 between two teeth by means of the piston-cylinder assembly 23. Thereafter the piston-cylinder assembly 11 performs a retracting stroke whereby the pontoon is raised over this stroke length in such a manner that the locking pawl means 26 may then be inserted in a space 28. The pawl means 13 is subsequently disengaged from the teeth rack whereupon the piston-cylinder assembly 11 moves the yoke 12 upward until the pawl means 13 is facing a higher located space 28 so that the pontoon may again be raised further after the pawl means 26 is again shifted out of engagement with the teeth rack.

Claims

1. An apparatus for effecting a relative linear displacement between a number of columns (1) and a body (4) arranged for movement along said columns, particularly in a self-lifting pontoon, each one of said columns being provided with a longitudinally extending teeth rack (2) having a series of regularly spaced apart teeth capable of cooperating with a driving (13) and a locking pawl means (26), each one of which is mounted in a yoke means (5; 12) for a slidable movement in transverse direction with respect to the longitudinal direction of the respective column so that the pawl means can be shifted into and out of a space (28) between two teeth, while the yoke means (12) of the driving pawl means can be moved slidably up and down in the longitudinal direction of the column by means of a piston-cylinder assembly (11) pivotally connected at one end to said yoke means (12), said piston cylinder assembly being pivotally connected at the other end thereof to said body (4) characterized in, that each one of said columns is formed by a circular pipe or pile, that only one teeth rack (2) is provided on each column (1) and that the yoke means (12) of the driving pawl means is fastened to at least two axially spaced apart annular members (25) or a sleeve shaped member, slidably mounted about the respective column (1).

2. The apparatus of claim 1, characterized in, that in the yoke (12) of the driving pawl means there is provided a guide shoe (24) facing the teeth rack (2).

3. The apparatus of claims 1 or 2, characterized in, that in the yokes (5, 12) of the pawl means there are provided guide strips (8; 20) mounted at both sides of the teeth rack (2).