Positive engagement clutch for a submersible cleaning device

A drive mechanism for converting a reciprocating angular movement into one directional angular movement is disclosed for driving a shaft in a submersible cleaning device. In particular, a positive engagement clutch converts an alternating pivotal or angular motion of a shaft to a unidirectional circular motion of a driven gear. The shaft is affixed to a collar formation comprising pockets in which pawl elements are movably placed. The pawl elements engage teeth of a periphery ring that encloses the collar. The driven gear is affixed to the ring. The pawl elements operate in a dense medium such as the water of a pool in which the device is operating. The water imparts a high degree of inertia to the pawl elements and cause them to engage in the peripheral ring during the alternating motion of the shaft. Rotational movement of the driven gear to one direction is accomplished using a second pawl engaging a ratchet affixed to the periphery of the ring. With this single rotation of the driven gear, a number of cleaning device functions can be performed including, for example, a dislodgement mechanism.

FIELD OF THE INVENTION 
This invention relates to a drive mechanism adapted for use with a 
submersible cleaning device. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a novel drive mechanism 
for converting reciprocating angular movement into one directional angular 
movement for drive purposes. The term "shaft" herein includes gear, lever 
and the like. 
According to the invention such a device comprises a toothed ring 
associated with a driven shaft and one or more pawl elements on a drive 
shaft each mounted for pivotal movement between a first extreme position 
wherein the pawl is generally radially disposed to engage the teeth on the 
rip and a second extreme position wherein the pawl is angled out of a 
radial direction, wherein it is disengaged from the teeth, the arrangement 
being one wherein the pawl elements art in a dense medium which serves to 
hold the pawl stationary relative to the drive shaft upon angular movement 
of the latter, causing the pawl to move to the first extreme position upon 
rotation of the shaft in one direction and to the second extreme position 
upon rotation of the shaft in the reverse direction. 
In a preferred arrangement the dense medium within which the pawl elements 
operate will be the liquid wherein the surface to be cleaned is submerged. 
Further according to the invention the pawl elements will be pivotally 
movable in a pocket defined towards the outer surface of the drive shaft, 
such pocket defining abutment surfaces limiting the pivotal movement of 
the pawl elements between the first and the second extreme positions. 
Still further according to the invention the toothed ring will be defined 
within a socket, bore or the like of the driven shaft with the drive shaft 
and its pawl elements accommodated within such socket or bore. 
Still further according to the invention the mechanism includes means for 
permitting rotational movement of the driven shaft in one direction and 
for constraining it from movement in a reverse direction comprising a pawl 
and ratchet arrangement. Preferably a toothed rack for such pawl and 
ratchet arrangement will be provided on the outer surface of the driven 
shaft and the pawl therefore mounted on an external support.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring to the drawings a drive mechanism, for use with a submersible 
cleaning device, for translating reciprocating angular movement shown at 
10a of a drive shaft 10 into one directional angular movement shown at 11a 
of a driven gear 11, is illustrated. The driven gear 11 can perform a 
number of functions for the pool cleaner and it is in particular envisaged 
that it will drive a dislodgement mechanism for a pool cleaner through a 
number of reduction gears, such as that shown at 19, FIG. 4. 
The drive mechanism comprises a peripheral ring of teeth 12 secured or 
integrally formed within a drum 13 or alternatively a bore, (not shown), 
defined at the end of the driven gear 11 . The teeth are periodically 
engaged by a plurality of pawl or sprag elements 14 which are pivotally 
mounted on pockets 15 defined in a collar formation 20 at the end of the 
drive shaft 10. The collar 20 of the drive shaft 10 and the sprag elements 
14 are thus disposed within the drum 13 of the driven gear 11 to enable 
the pawl elements 14 periodically to engage the internal teeth 12. 
The pockets 15 which pivotally mount the pawl elements 14 define opposed 
abutment surfaces 15a, 15b, which act to limit pivotal movement of the 
pawl elements 14 between a first extreme position (shown in FIG. 2) 
wherein the pawl elements 14 are substantially radially disposed to engage 
the teeth 12; and a second extreme position (shown in FIG. 3) wherein the 
pawl elements 14 are angled relative to the radial and out of engagement 
with the teeth 12. 
It is a feature of the invention that the pawl elements 14 will operate in 
a dense liquid medium 16, preferably the same liquid in which the surface 
to be cleaned is immersed, and this dense medium 16 will tend to impart a 
high degree inertia to the pawl elements 14. The free ends 14a of the pawl 
elements 14 will thus tend to remain stationary during angular movement of 
the drive shaft 10 in one direction or the other. Thus, with the pawl 
elements 14 in the first extreme position and radially orientated (FIG. 
2), rotational movement of the drive shaft 10 in an anti-clockwise 
direction will cause the pawl elements 14 to move to the second extreme 
position (FIG. 3) and remain in such position during further 
anti-clockwise rotation of the drive shaft 10. Likewise, when the shaft 10 
reverses its direction of rotation to a clockwise direction, the sprag 
elements 14 will immediately straighten out to the first extreme position 
wherein they are radially orientated and engage the teeth 12 of the driven 
shaft 11. 
When the drive, shaft 10 is stationary, one or more lower pawl elements 
will tend to be radially orientated in engagement with the teeth 12 under 
the influence of gravity. 
In order to limit rotational movement of the driven gear 11 to one 
directional movement, the invention further provides a pawl and ratchet 
arrangement comprising peripheral ratchet teeth 17 defined on the outer 
periphery of the drum 13 which are engaged by means of a pawl member 18 
which is mounted independently of the drum 13. 
Doubtless variations in detail of the invention are possible without 
departing from the principles of this disclosure.