Note: Descriptions are shown in the official language in which they were submitted.
W093/04909 . PCT/US92/074~
21~7173
1 S~OCK ABSORBING APPARATUS FOR HYDROFOIL WATERCRAFT
3 FIELD OF THE INVENTION
:~ 4
The present invention relates to watercraft
6 generally and more particularly to hydrofoil
7 watercraft.
:` 8
9 BACKGR0UND OF THE INVENTION
11 There exists a variety of watercraft
12 including hydrofoils. A preferred embodiment of
~'i 13 watercraft including a retractable hydrofoil is
; 14 described in applicant's U.S. Patent 4,715,3~4 and in
~`. 15 the references cited therein.
16 There exists a general problem of shock
17 absorption in watercraft, which has long ago been
18 solved for land vehicles. In watercraft the hull is
19 directly impacted by surface variations in the water
2~ and the impact affects passengers and vehicle
21 oPerators in the bridge and on the decks of the craft.
,"2 22 High speed operation of watercraft of a size and weight -~
23 which is sensitive to such impacts often results in
24 discomfort and even injury to operators and often
.j 25 requires limitations in operating speeds of watercraft,
~j 26 which would otherwise not be required.
27
2 28
~, 29 :~
``' 31
'J, 32
.i~ 33
.i 34
^~ 35
f~ 36
. .
`` 37
.. 38
.
"
W093/04909 PCT/Us92/0?4~
~ 2 2117173
1 SUMMARY OF THE INVENTION
2 The present invention seeks to provide
3 improved watercraft which provides shock absorption
4 between 8 water engaging surface and at least a portion
~, 5 of the hull.
" 6 There is thus provided in accordance with a
7 preferred embodiment of the present invention,
8 watercraft including a hull, a plurality of foils
9 mounted in the hull for engaging a water surface and
1~ shock absorbing means associated with the plurality of
11 foils for coupling the plurality of foils to at least a
12 portion of the hull and providing at least partial
13 absorption of shocks received from waves.
14 The term "foil" is to be understood in a
15 broad sense to include any hydrodynamic surface which
16 is separate from the hull of the watercraft.
17 In accordance with a preferred embodiment of
18 the invention, the plurality o~ foils may be
~' 19 retractable.
2~ Preferably the shock absorbing apparatus
21 includes pivotably mounted shock absorbers engaging the
22 plurality of foils on opposite surfaces thereof.
23 In accordance with a preferred embodiment of
24 the present invention, the shock absorbing apparatus
25 includes apparatus for accommodating variations in the
~ 26 position of the plurality of foils.
`~ 27 Additionally in accordance with a preferred
`` 28 embodiment of the invention, the foils include shock
* 29 absorber engagement grooves formed in opposite surfaces
- 3~ thereof and the shock absorbing apparatus includes
31 apparatus for engaging the grooves at different
32 locations therealong depending on the positions of the
33 foils.
34 Further in accordance with a preferred
35 embodiment of the invention there is provided shock
-. 36 absorber mounted apparatus for selectably retracting
37 the plurality of foils.
38 Additionally in accordance with a preferred
~' .
: ~.,;.- ~ - , . -
- W093/04909 PCT/US92/07~
-' 3 21~7173
1 embodiment of the invention the shock absorber mounted
2 apparatus ~or selectably retracting the plurality of
3 foils includes a motor driven worm gear assembly
~ 4 operatively engaging a threaded groove formed on a
.~ 5 surface of each of the plurality of foils.
~, - 6 Further in accordance with a 'preferred
` 7 embodiment of the presènt invention, each of the
,~ 8 plurality of foils includes a main portion and a tip
9 portion which is selectably positionable relative to
the main portion.
~; 11 Additionally in accordance with a preferred
12 embodiment of the present invention there is provided
13 automatically operable hydraulic apparatus for
14 positioning the tip portion relative to the main
15 portion 85 a function of the angular orientation of the
~, 16 foil.
17 In all of the following operational ~odes,
18 the system comprises a hull including hydrofoils, the
;`1 19 hull being affected by waves all of the time or part of
2~ the time.
21 The foils may operate as full hydrofoils
22 supporting the entire weight of the craft or as partial
23 hydrofoils supporting only part of the weight of the
~i 24 craft, while the rest of the weight is supported by
25 buoyancy or dynamically by a planing bottom having a
~, 26 sufficient plPning surface to create required lift.
27 The foils may operate not only as hydrofoils but also
28 as planing surfaces extending the natural hull planing
~ 29 surface, enabling a craft to maintain planing at a
;- 3~ higher displacement. In this mode, part of the foil
31 surface may act as a planing surface, while the part
32 submerged in water acts as a foil element. The foils
33 may further operate as stabilizers designed to prevent
34 excessive craft motion in rough water operation. For
~` 35 certain sizes of water craft the shock absorber system
- 36 may contribute to overall improved craft motion.
37 Generally speaking, one of the essential
38 features of the present invention is the provision of
., ,
~ ,
....
;.~ ~, . -. :
/i W093/04909 PCT/US92/074~
2117173
1 shock absorbing apparatus associated with a plurality
2 of hydrodynamic surfaces, which may serve several
3 functions.
4 When the relative hydrodynamically developed
5 lift forces of the hydrodynamic surfaces are high in
6 relation to the weight of the water craft, ~he shock
7 absorbing apparatus wi`ll dampen hull vertical
8 acceleration and improve the comfort of operators and
9 passengers. Hydrodynamic surfaces may be hydrofoils or
1~ planing surfaces, retractable or non-retractable, as
'1 described hereinbelow.
12 For large water craft, the shock absorbing
13 apparatus will dampen vertical acceleration of the
14 hydrodynamic surfaces, as opposed to the hull, in
15 violent storm conditions or in the presence of
16 underwster explosions creating great impacts on the
17 hydrodynamic surfaces. This serves to protect the
18 hydrodynamic surfaces and to prevent tearing out of
19 hinges and anchoring. After the acceleration has
2~ subsided, the hydrodynamic surfaces will continue to
21 operate in a more or less fixed position relative to
22 the hull or may even operate while in damped motion
23 relative to the hull.
24 In large water craft equipped with shock
25 absorbing apparatus associated with a plurality of
26 hydrodynamic surfaces, the hydrodynamic surfaces may
27 serve as stabilizers designed to decrease rolling in
28 rough conditions. In submarines, hydrodynamic surfaces
29 may be control surfaces such as diving fins.
3~ Wherever hydrodynamic surfaces are required,
31 and especially where retractability is needed,
32 attachment of hydrodynamic surfaces associated with
33 shock absorbing apparatus to watercraft improves the
34 reliability and protects the attachment thereof to the
35 hull by absorbing forces and moments exerted on the
36 hydrodynamic surfaces.
37 Additionally in accordance with a preferred
38 embodiment of the present invention, the shock
. . .
:
W093/04909 P~T/US92/074~
21~7173
1 absorbing apparatus comprise fluid filled pillows.
2 Preferably, the fluid filled pillows are
3 arranged on opposite sides of each foil and are
; 4 arranged to permit fluid flow between at least one
~;
` 5 pillow on one side of each foil to at least one pillow
6 on the other side of the foil.
7 In accordance with a preferred embodiment of
` 8 the present invention. a valve is interposed between at
;. 9 least one pillow on one side of each foil and at least
, 1~ one pillow on the other side of the foil to control the
11 fluid flow therebetween.
12 Additionally in accordance with a preferred
13 embodiment of the invention, apparatus may be provided
~ 14 from the fluid filled pillows to the hydraulic
-~ 15 apparatus.
16
17
18
19
: 2
21
22
`~ 23
24
~` 26
~ 27
> r 28
~ 29
i . 3
.
r ` 32
33
34
36
37
38
''
~-~ W093/0490~ 2 1 ~ 7 ~ 7 3 PcTJUs92/o74~
-~ 1 BRIEF DESCRIPTION OF THE DRAWIN~S
3 The present invention will be understood and
4 appreciated more fully from the following detaiIed
5 description, taken in conjunction with the drawings in
6 which: ~
7 Fig. 1 is a par~ially schematic, partially
8 pictorial illustration of watercraft including shock
9 absorbers in accordance with a preferred embodiment of
the present invention;
11 Figs. 2A, 2B and 2C are illustrations of the
12 operation of the watercraft of Fig. 1 wherein the foils
13 and the shock absorbers are in three different
14 operative orientations;
Figs. 3A and 3B are respective side view and
16 bottom view illustrations of the watercraft of Fig. 1,
17 each of which illustrates the orientations of the foils
18 in the three different operative orientations shown
19 respectively in Figs. 2A, 2B and 2C;
2~ Fig. 4 illustrates part of shock absorber
21 equipped apparatus for retracting foils which is useful
22 in the embodiment of Figs. l - 3B;
23 Figs. 5A and 5B are illustrations of the
24 apparatus of Fig. 4 in engagement with foils in two
25 alternative foil orientations; Fig. 5C is an
26 illustration of part of the underside of a foil in the
27 configuration of Figs. 5A and 5B;
28 Figs. 6A and 6B are illustrations of part of
29 the apparatus of Fig. 4 in engagement with foils in
3~ respective extended and retracted orientations;
31 Fig. 7 is a simplified illustration of
32 apparatus for mounting a foil and for governing the
33 orien~ation of the tip thereof;
34 Fig. 8 is a simplified illustration of part
35 of the apparatus of Fig. 7;
36 Figs. 9A and 9B are illustrations of part of
37 the foil of Fig. 7 in respective bent and straight
38 orientations;
'''`.. ` ~
;. .
;~ :
.. , '
:: ' ': ' :'' :: ' ~ : :
''' ' ' ~ ' '~
. ' ,
`' W093/04909 . PCTtUS92/074~
2117173
.
1 Fig. 10 is a simplified pictorial
, 2 illustration of a portion of the apparatus of Fig. 7;
-, 3 Figs. llA and llB are respective general and
, 4 detailed illustrations of the use of an alternative
5 embodiment of shock absorbers in accordance with a
6 preferred embodiment of the invention;
7 Figs. 12A, 12B and 12C are illustrations of
8 the operation of the apparatus of Figs. llA and llB
9 wherein the foils and the shock absorbers are in three
different operative orientations;
11 Figs. 13A and 13B are respective side
12 sectional view illustrations of the apparatus of Figs.
13 llA and llB, each of which illustrates the orientations
14 of the foils in a different operative orientation;
Fig. 14 illustrates part of shock absorber
16 equipped apparatus for foils which is useful ln the
17 embodiment of Figs. llA - 13B; and
18 Fig. 15 is a simplified illustration of
i~ 19 apparatus for mounting a foil and for governing the
2~ orientation of the tip thereof in accordance with
;- 21 another preferred embodiment of the present invention.
22
23
24
- 25
26
27
28
29
.
31
32
33
34
.~
`,', 37
38
. j
' i", . ~ ~ ' .' , '
' '~ . " , ' '' ' ~ ' ' ~'
: r,,
W093/04909 2 ~ i 7 1 7 3 PCTJUS92tO74~
1 DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
3 Reference is now made to Figs. 1, 2A, 2B, 2C,
4 3A and 3B, which illustrate watercraft constructed and
5 operative in accordance with a preferred embodiment of
6 the present invention. The watercraft compris~es a hull
7 10 and at least one pair`of hydrofoils 12 associated
8 with the hull for engagement with water. In accordance
9 with a preferred embodiment of the present invention,
shock sbsorbing apparatus is provided for absorbing
11 mechanical shocks received from the waves and
12 preventing them from being fully transferred to at
13 least a portion of the hull.
14 In accordance with a preferred embodiment of
the present invention, the shock absorbing apparatus
16 comprises at least one shock absorber 16 associated
17 with each foil 12 to absorb upwardly directed forces
18 imparted thereto as a result of upward wave motion, and
19 at least one shock absorber 18 associated with each
20 foil to absorb downwardly directed forces imparted
21 thereto as a result of the post-wave descending motion
22 of the craft.
It is noted that the shock absorbers 16 and
24 18 are preferably pivotably mounted with respect to the
25 foils 12 and are mounted onto the hull by means of
26 brackets 20 engaging a pivotably mountable base 22.
27 The shock absorbers may be of any suitable construction
28 and may be commercially available mechanical, hydraulic
29 or pneumatic shock absorbers, such as Catalog No. R1~61
3~ of Monroe, Inc. of the V.S.A .
31 The extension and retraction of the shock
32 absorbers ~6 and 18 with different relative
33 orientations of the foils 12 can readily be seen from a
34 consideration of Figs. 2A - 2c and 3A - 3B which
35 illustrate two extreme orientations and an intermediate
36 orientation of the foils 12 relative to the hull 1~.
37 In accordance with the teachings of
38 applicant's U.S. Patent 4,715,3~4, the foils may be
:
~::
, ' ,'' ' ~"' ~' : .,
:
;
:
- ~ ..
. ~ :
' :: : : -. ::: ~:
W093/~909 PCT/US92/07444
2117173
1 retractable.
2 Reference is now made to Figs. 4 - 6B, which
3 illustrate an embodiment of the invention employing
4 retractable foils. In this embodiment, there is
5 provided foil retraction and shock absorbing apparatus
6 3~. typically comprising a pivotably mountable base 32
7 srranged along a pivot mounting axis 34, mounted by
8 means of brackets 28 onto the hull, and onto which are
9 mounted a pair of shock absorbers 36, of any suitable
1~ type. Shock absorbers 36 preferably extend generally
11 perpendicular to axis 34 and support a foil retraction
12 subassembly 38. Subassembly 38 includes a frame 4~ onto
13 which are mounted a motor 42 of any suitable type,
14 which drives, via suitable gearing 44, a worm gear 46.
15 Worm gear 46 operatively engages gearing grooves 48
16 formed in or otherwise associated with a retractable
17 hydrofoil 12, as illustrated in Figs. 6A and 5B.
18 Rotation of the worm gear 46 in engagement with gearing
19 grooves 48 provides extension or retraction of the
2~ hydrofoil 12 relative ~o the hull.
21 It is a particular feature of the embodiment
22 of Figs. 4 - 6B, thst irrespective of the orientation
23 of ~he hydrofoil 12, which may be at any suitable
24 orientation at or between its extreme positions
25 illustrated in Figs. 6A and 6B, shock absorption is
26 provided by the shock absorbers 36 (Fig. 4) operating
27 in cooperation with additional shock absorbers 5
28 ar~anged at an opposite surface of the foil 12.
29 Foil 12 is supported in the hull in any
3~ orientation by means of a ball pivot and pin assembly
31 49 and an edge of an opening 52 and is positioned by
32 shock absorbers 36 having associated therewith worm
33 gear 46, which engages groove 48 on the upper surface
34 of the foil, paired with shock absorber 5~, having
associated therewith a ball pivot end 51 which engages
36 a correspondingly located groove 53 on the underneath
37 surface of the foil (Fig. 5C).
Reference is now made to Figs. 7 - 9s, which
~,
;
., ,.-~ .
,`'1:, ~ '
W093/04909 PCT/US92/074~
, 10 2117173
1 illustrate hydraulic apparatus for governing the
2 orientation of the tip 6~ of a hydrofoil 62 relative to
3 the main portion 64 of the hydrofoil.
4 A foil mounting pin Z~1 has integrally formed
therein a hydraulic valve 2~2. The pin 2~1 is
6 pivotably seated in a socket 2~7 integrally ~ormed in a
7 wall 2~8 of the hull. Also integrally formed in wall
8 2~8 is a cavity 211 for seating a ball pivot protrusion
9 2~5, integrally formed in hydrofoil 62. Formed in wall
1~ of ball pivot protrusion 2~5 is elongated groove 2~6
11 (Fig. 1~).
12 As the hydrofoil 62 changes its angle in the
13 plane of Fig. 7 and the shock absorbers are operative,
14 pivot protrusion 2~5 moves relative to pin 201 causing
15 pin 2~1 to be in different relative positions along
16 groove 2~6. This hydrofoil motion forces a valve
17 control handle 2~3 to change its position relative to
18 valve 2~2, thus effecting opening and closing of the
19 valve. Valve 2~2 is connected via hydraulic conduits
2~ 2~4 to a power supply 2~9 which activates pistons 21~.
21 Pistons 21~ activate cables 214 which effect a pivotal
22 change in position of the tip 6~ of hydrofoil 62
23 relative to main portion 64 thereof about a generally
24 cylindrically shaped pivot 212, which may be made of
25 any flexible substance such as flexible polyurethane.
26 Reference is now made to Figs. llA, llB, 12A,
27 12B, 12C, 13A, 13B, 14 and 15 which illustrate
28 watercraft constructed and operative in accordance with
29 another preferred embodinent of the present invention.
30 The watercraft comprises a hull 31~ and at least one
31 pair of hydrofoils 312 associated with the hull for
32 engagement with water. In accordance with a preferred
33 embodiment of the present invention, fluid filled
34 resilient shock absorbing apparatus is provided for
35 absorbing mechanical shocks received from the waves and
36 preventing them from being fully transferred to at
37 least a portion of the hull.
38 In accordance with a preferred embodiment of
.
:
:. : . ' : -, ': . '
W093/04909 PCT~US92/074~
~ ` 2117173
1 1
1 the present invention, the shock absorbing apparatus
2 comprises a pair of fluid filled pillow assemblies 316
3 associated with each foil 312 to absorb upwardly
- 4 directed forces imparted thereto as a result of upward
~ 5 wave motion, and downwardly directed forces imparted
i 6 thereto as a result of the post-wave descendi'ng motion
- 7 of the craft.
~` 8 It is noted that the fluid filled pillow
9 assemblies 316 are relatively flexible and thus can
1~ accommodate some pivotal motion of the foils 312 about
~` 11 ball pivots 317 in response to actuation of a piston
12 and cylinder combination 318 operatively connected
13 thereto and to hull 31~.
-. 14 Pillow assemblies 316 each typically comprise
15 a plurality of fluid filled pillows 319, typically
16 formed of suitable conventional rubber or plastic
17 materials and filled with gas or a liquid. Normally the
18 interiors of the fluid filled pillows of each assembly
19 319 are not interconnected, but rather the corre-
2~ sponding individual pillows 319 of a pair of pillow
21 assemblies 316 lying on opposite sides of a foil 312
22 are interconnected by suitable conduit 32~ and valves
~;~ 23 324, which govern the rate of fluid flow therebetween
24 and thus the amount and rate of damping produced by the
~25 assemblies. Valves 324 may be manually or automatically
26 controlled to vary the operating parameters of the
27 shock absorbing apparatus for optimum performance under
28 various conditions.
29 Pillow assemblies 316 are mounted onto the
30 hull 31~ by means of brackets 325 and onto the foils
31 312 by means of a mounting assembly 326, which is
: 32 illustrated in Fig. llB. It is seen from Fig. llB that
; 33 an elongate curved recess 327 extending along the
34 peripheral edge of foil 312 is slidably engaged by low
friction solidified filling material 328, which forms
36 part of a bracket 329 to which both of the pair of
37 pillow assemblies 316 are mounted.
38 The slidable engagement between material 328
,
,. !
.``. ` .
,` ,`' , ~
~ W093/04909 2 1 ~ 7 ~ 7 3 PCT/US92/074~
12
1 and foil 312 is designed to accommodate pivotal motion
2 of the foils 312 about ball pivots 317 in response to
3 actuation of a piston and cylinder combination 318
4 operatively connected thereto.
The extension and retraction of the pillow
6 assemblies 316 with different relative orientations of
7 the foils 312 can readily be seen from a consideration
8 of Figs. 12A - 12C, 13A and 13B which illustrate two
9 extreme orientations and an intermediate orientation of
1~ the foils 312 relative to the hull 31~.
11 In accordance with the teachings of
12 applicant's U.S. Patent 4,715,3~4, the foils may be
13 retractable as by piston and cylinder assembly 318.
14 They are preferably fully retractable into the hull 31
15 via a slot 33~.
16 Reference is now made to Figs. 15, which
17 illustrates an alternative embodiment of hydraulic
18 apparatus for governing the orientation of the tip 36~
19 of a hydrofoil 362 relative to the main portion 364 of
2~ the hydrofoil.
21 A foil mounting pin 4~1 has integrally formed
22 therein a hydraulic valve 4~2. The pin 4~1 is
23 pivotably seated in a socket 4~7 integrally formed in a
24 wall 4~8 of the hull. Also integrally formed in wall
25 4~8 is a cavity 411 for seating a ball pivot protrusion
26 4~5, integrally formed in hydrofoil 362, similarly to
27 the embodiment of Figs. 7 and 1~. As the
28 hydrofoil 362 changes its angle in the plane of Fig. 15
29 and the shock absorbing apparatus is operative, hydro-
30 foil motion forces a valve control handle 4~3 to change
31 its position relative to valve 4~2, thus effecting
32 opening and closing of the valve. Valve 4~2 is
33 connected via hydraulic conduits 4~4 to a power supply
34 4~9 which activates pistons 41~.
~istons 41~ activate cables 414 which effect
36 a pivotal change in position of the tip 36G of
37 hydrofoil 362 relative to main portion 364 thereof
38 about a generally cylindrically shaped pivot 412, which
,~ .
,..
~ W093/04909 PCT/US92/074~
; 13 2117~73
1 may be made of any flexible substance such as flexible
2 polyurethane. Alternatively the mounting of tip 36~
- 3 relative to main portion 364 may be by means Or an
4 ordinary hinge or a ball mounting.
In accordance with a preferred embodiment of
`. 6 the invention, pistons 410 each receive a fluidic input
,~ 7 from a respective one of the pillow assemblies 316 via
8 a respective conduit 430.
9 The apparatus of Fig. 15 enables the angular
; 1~ orientation of the tip 36~ relative to the water
11 surface to be maintained notwithstanding changes of the
12 orientation of the main portion 364.
13 It will be appreciated by persons skilled in
14 the art that the present invention is not limited by
15 what has been particularly shown and described
` 16 hereinabove. Rather the scope of the present invention
~ 17 is defined only by the claims which follow:
`. 18
.' 19
:.
`~ 21
22
23
24
:;
. 25
26
27
~`~ 28
`~
, 29
~ 3
`~ 31
`;" 32
. ~
. 33
.. ~ 4
. 35
., 36
. 37
38
. .
, ~
