AU736864B2 - Support apparatus for motion picture cameras - Google Patents

Description

II

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 6 0 04

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: SUPPORT APPARATUS FOR MOTION PICTURE

CAMERAS

The following statement is a full description of this invention, including the best method of performing it known to us: 2 This invention relates to support apparatus for motion picture cameras.

In the United States of America in the 1970s, Garrett W. Brown designed the first of what was to become the STEADICAM (Trade Mark) range of motion picture and video camera support and stabilization apparatus. US-A-4,017,168 to Brown discloses a brace worn by a camera operator, to which is pivotally attached a pair of interconnected spring-loaded arms, the other end of which is connected to a handle adapted to be gripped by the operator, and on which a hand-held motion picture or video camera could be mounted.

Hand-held cameras became popular in motion picture production in the 1960s, 10 lending an atmosphere of reality to productions, as the camera was freed from '..conventional supports such as camera dollies. However, what was gained in S:authenticity was often lost in picture clarity and stability, as the hand-held camera was inherently unable to be held in a stable orientation as it followed the action. The apparatus of US-A-4,017,168 was capable of producing high quality 15 results, even when the camera operator walked or ran with the camera, because of the attendant increase in stability, particularly in stabilizing quick angular deviations along the axes of pan, tilt and roll, which previously could not be adequately controlled.

Garrett Brown's early rig, generally in accordance with US-A-4,017,168, was first used in feature film production on the late Hal Ashby's "Bound For Glory" in 1975. Brown has described how as a camera operator, using his rig on the set of that motion picture, he started off up in the air on a crane platform. Then, he 'got off and "walked"' with the actor David Carradine 'across the huge camp and most of the way back, dodging kids and crowds and tent-ropes and vehicles'.

The "Bound For Glory" sequence was well received. Brown's rig was able to follow the action, while supporting the camera in a manner in which the operator's motion was not transferred to it. The "Bound For Glory" footage did not suffer from the usual hand-held image instability, but it was not until the Garrett Brown rig was used in the production of the motion picture "Rocky" (released in 1976), that the use of STEADICAM-type camera supports became a regular feature of motion picture production.

Since the 1970s, there has been almost constant development of STEADICAMtype apparatus. Core concerns have been the ability to support and stabilize heavier equipment, to cater for a range of equipment weights, and to provide an isodynamic capability. An isodynamic rig allows for a camera to be moved to a particular position relative to the camera operator, at which position it will stay, rather than returning to a median position. Isodynamic capability is discussed under the name iso-elasticity in US-A-5,360,196.

10 As effective as present-day camera support and stabilization apparatus is, there is no rig currently available which permits a desirably wide range of weights to be accommodated, and which also permits an isodynamic capability.

It is an object of this invention to provide improvements in motion picture or video *eeee.

camera support and stabilization apparatus.

:0 15 The invention provides an arm element for the arm of a motion picture or video camera stabilizing apparatus, said arm element having, generally, a parallelogram configuration formed from a plurality of links pivotally attached to one another, said arm element including spring means connecting opposed links, said spring means being at an angle to one or both of the links to which it is not connected.

Preferably, said angle is approximately Preferably, there is a plurality of spring means.

Preferably, there are three spring means.

Alternatively, there are two said spring means, with a third spring means connecting said links, and being disposed at an angle greater than that of said It h 4 other two springs.

Preferably, said third spring is at an angle of between about 100 and about 150.

More preferably, said third spring is at an angle of about 150.

The invention also provides an arm element for the arm of a motion picture or video camera stabilizing apparatus, said arm element having, generally, a parallelogram configuration formed from a plurality of links pivotally attached to one another, said arm element including first spring means attached to a first one of a pair of opposed links, and second spring means attached to a second one of said pair, said first spring means and said second spring means being connected 10 together by a line which passes over first pulley means and second pulley means located on a first one of a pair of opposed links, and over third pulley means and fourth pulley means located on a second one of said pair.

Alternatively, said third pulley means is located on a link which is not one of said pair.

15 Preferably, said line, between said second pulley and said third pulley, is at an angle to one or both of said pair of links.

Preferably, said angle is about Alternatively, third spring means is located between said second pulley and said third pulley and connected in said line.

The invention further provides an arm element for the arm of a motion picture or video camera stabilizing apparatus, said arm element having, generally, a parallelogram configuration formed from a plurality of links pivotally attached to one another, said arm element including first spring means attached to a first one of a pair of opposed links, and second spring means attached to a second one of said pair, said first spring means being attached to a line which passes over first pulley means and second pulley means located on said first one of said pair, and being connected through third spring means to a link other than one forming part of said pair, a second line being attached to said first one of said pair, and passing over third pulley means and fourth pulley means located on said second one of said pair for connection to said second spring means.

Preferably, all said spring means are of variable strength, and/or are capable of being adjusted.

Preferably, all said spring means are compression springs.

.Alternatively, some or all of said spring means are extension springs.

10 The invention also provides a spring force adjusting arrangement, including an **adjustment element adapted to be located in said spring for movement along said spring, said adjustment element also being engaged with adjustment means for immobilising a predetermined portion of said spring between said adjustment element and the non-active and of said spring.

15 Preferably, said spring is an extension spring.

Preferably, said adjustment element has an external thread adapted to cooperate with the coils of said spring such that said adjustment element may be screwed into and along said spring by rotation of said adjustment element, said adjustment element being constructed to float freely within said spring.

Preferably, said adjustment element has an outer surface which assists manual rotation of said adjustment element.

Preferably, the arrangement of any of the preceding paragraphs, or the combination of any of said paragraphs, may be utilised in the previouslydescribed arm elements, arms and camera support apparatus.

V f 6 In particular, the spring force adjustment arrangement may be utilised in an arm element such that opposing links of an arm element each have a spring and a spring force adjustment arrangement as defined herein.

Preferably, said adjustment element has a threaded bore, and said adjustment means is able to screw through said bore to move said adjustment element relative to a fixed point.

Embodiments of the invention, which may be preferred, will be described in detail hereinafter with reference to the accompanying drawings, in which: Fig. 1 is a side elevation of a first embodiment of an element of an arm for a 10 camera support and stabilizing apparatus in accordance with the present invention; Fig. 2 is a side elevation of a second embodiment of an element of an arm for a camera support and stabilizing apparatus in accordance with the present invention; 15 Fig. 3 is a side elevation of a third embodiment of an element of an arm for a camera support and stabilizing apparatus in accordance with the present S invention; Fig. 4 is a side elevation of a fourth embodiment of an element of an arm for a camera support and stabilizing apparatus in accordance with the present invention; Fig. 5 is a side elevation of a fifth embodiment of an element of an arm for a camera support and stabilizing apparatus in accordance with the present invention; Fig. 6 is a side elevation of a sixth embodiment of an element of an arm for a camera support and stabilizing apparatus in accordance with the present 4 7 invention; Fig. 7 is a side elevation of a seventh embodiment of an element of an arm for a camera support and stabilizing apparatus in accordance with the present invention; Fig. 8 is an exploded perspective view of an arrangement for locating a variable strength compression spring in an arm of the type shown in any one of Figs. 1 to 7; Fig. 9 is an exploded perspective view of an arrangement for adjusting an extension spring for location in an arm of the type shown in Figs. 1 to 7; 10 Fig. 10 is a side elevation of a first embodiment of an arm element incorporating the adjusting means of Fig. 9; Fig. 11 is a side elevation of a second embodiment of an arm element incorporating the adjusting means of Fig. 9; Fig. 12 is a perspective view of a third embodiment of an arm element incorporating the adjusting means of Fig. 9; Fig. 13 is a side elevation of a fourth embodiment of an arm element incorporating the adjusting means of Fig. 9; Fig 14 is a side elevation of a spring force adjustment mechanism, showing the mechanism in a first orientation; Fig. 15 is a side elevation of the adjustment mechanism of Fig. 14, showing the mechanism in a second orientation; and Fig. 16 is a side elevation of the adjustment mechanism of Fig. 14, showing the mechanism in a third orientation.

i r 8 Before commencing a detailed description of the various embodiments of the invention, some aspects require clarification. Firstly, although the invention is concerned with motion picture and video camera support and stabilizing apparatus, it is primarily concerned with the operation of the arms in such apparatus, and is more particularly concerned with the elements which comprise such an arm.

Complete camera support and stabilizing apparatus is shown in the previouslymentioned prior art, such as US-A-4,017,168 and US-A-5,360,196. However, the most important features of such apparatus is the arm connecting the operator's vest and the camera mount. An exemplary prior art arm is shown in US-A-4,208,028 (Fig. 2) and US-A-4,394,075 (Fig. That arm is comprised V of two parallelogram arm elements connected together. In the detailed description to follow, each embodiment (Figs 1 to 7) is one such element.

However, it is to be understood that in practice, each element may be connected to another such element to form an arm, and that arm may be connected to an operator's vest on the one end and to the camera mount at the other end.

Nothing inventive depends on other aspects of any support and stabilizing apparatus; the operation of any such apparatus including one or more of the arm So.. elements of Figs. 1 to 7 is governed by the operation of the element concerned.

Thus, no detail is provided of peripheral aspects of any apparatus which may 0oo include such an arm element.

•o~ Secondly, the figures of the drawings are, with the exception of Figs. 8 and 9, diagrammatic. They illustrate the geometry of each arm element, and represent features such as springs in a diagrammatic manner. The nature of the invention may easily be established from a reading of the present specification together with the figures of the drawings, by a person skilled in the art.

Turning firstly to Fig. 1, arm element 10 has the aforementioned generally parallelogram structure, with upper and lower links 12, 14 respectively, and side links 16, 18 respectively. Links 12 and 18 are pivotally connected at 20, links 18 and 14 are pivotally connected at 22, links 14 and 16 are pivotally connected at 9 24, and links 16 and 12 are pivotally connected at 26.

Also connecting links 12 and 14 are three spring means 28, 30 and 32. The spring means 28, 30, 32 affect the manner in which the arm element 10 moves between extreme positions of the parallelogram. Any number of spring means may be used, and they may be of any type, although preferably they are compression springs. Preferably, they are variable strength springs, and preferably or additionally are adjustable such that the amount each spring means is compressed may be changed. Spring 28 is connected to points 34, 36 on links 12 and 14 respectively, spring 30 is connected to points 38, 40 on links 12 and 14 respectively, and spring 32 is connected to points 42, 44 on links 12 and ~14 respectively.

*The manner of connecting the spring means 28, 30, 32 between links 12 and 14 may be any which is suitable, such as those disclosed in the prior art documents referred to earlier in this specification. The adjustment means may involve a 15 threaded end cap abutting and end of the spring, co-operating with a threaded rod which may be part of the connection means.

Each spring means 28, 30, 32 is oriented so that, with reference to the situation in which arm element 10 is in a rectangular configuration, with a right angle between connected pairs of links 12-18, 18-14, 14-16 and 16-12, its line of 20 connection/line of action is at an angle a (as shown in Fig. 1) to the line of links 16, 18. Preferably, the angle a is about 50. It has been found that with an angle of about 50, an arm element 10 has an isodynamic capability. That is, subject to any adjustment of spring means 28, 30, 32 to cater for the weight of a particular load, the arm element 10 may be moved to adopt any configuration between the extreme positions, and will stay in that configuration. If two arm elements were connected to form the arm of a motion picture camera support and stabilization apparatus, a camera could be moved to a position relative to the operator, and would then stay in that position.

The second embodiment of Fig. 2 is a variant 110 of the arm element 10 of Fig.

1, 11 1. Arm element 110 has the aforementioned generally parallelogram structure, with upper and lower links 112, 114 respectively, and side links 116, 118 respectively. Links 112 and 118 are pivotally connected at 120, links 118 and 114 are pivotally connected at 122, links 114 and 116 are pivotally connected at 124, and links 116 and 112 are pivotally connected at 126.

Also connecting links 112 and 114 are three spring means 128, 130 and 132.

The spring means 128, 130, 132 affect the manner in which the arm element 110 moves between extreme positions of the parallelogram. As discussed in relation to the embodiment of Fig. 1, any number of spring means may be used, and they may be of any type, although preferably they are compression springs.

Preferably, they are variable strength springs, and preferably or additionally are adjustable such that the amount each spring means is compressed may be changed. Spring 128 is connected to points 134, 136 on links 112 and 114 respectively, spring 130 is connected to points 138, 140 on links 112 and 114 respectively, and spring 132 is connected to points 142, 144 on links 112 and 114 respectively.

As discussed in relation to the embodiment of Fig. 1, any manner of connecting the spring means 128, 130, 132 between links 112 and 114 may be used. The adjustment means may involve a threaded end cap abutting and end of the spring, co-operating with a threaded rod which may be part of the connection means.

Each spring means 128, 130, 132 is oriented so that, with reference to the situation in which arm element 110 is in a rectangular configuration, with a right angle between each of connected pairs of links 112-118, 118-114, 114-116 and 116-112, its line of connection/line of action is at an angle to the line of links 116, 118. For spring means 130, 132, the angle a is as described in relation to the embodiment of Fig. 1, and is preferably about 50. For spring means 128, the equivalent angle B is greater, preferably in the range of about 100 to about 150, and more preferably about three times the value of angle a at about 150.

11 With such an arrangement, the isodynamic capability of arm element 110 may be varied. For example, if spring means 128 is wound off, that is, relaxed, the arm 110 will be able to act completely isodynamically. As spring means 128 is wound on, that is, tightened, the arm element will gradually become less and less isodynamic. Thus a variation in the isodynamic properties of the arm element 110 is possible.

Fig. 3 shows a third embodiment of the invention. A variant of arm elements and 110 of Figs. 1 and 2, arm element 210 has the aforementioned generally parallelogram structure, with upper and lower links 212, 214 respectively, and side links 216, 218 respectively. Links 212 and 218 are pivotally connected at 220, links 218 and 214 are pivotally connected at 222, links 214 and 216 are

S

pivotally connected at 224, and links 216 and 212 are pivotally connected at 226.

S

Connecting links 216 and 218 is spring means 246, which is pivotally attached to those links at points 248, 250. The spring means affects the manner in which So•0o the arm element 210 moves between extreme positions of the parallelogram. As discussed in relation to the embodiments of Figs. 1 and 2, the spring means 246 may be of any type, although preferably it is a compression spring. Preferably, it is a variable strength spring, and preferably or additionally is adjustable such that the amount the spring means is compressed may be changed.

20 The spring means 246 is oriented so that, with reference to the situation in which arm element 210 is in a rectangular configuration, with a right angle between each of pairs of connected links 212-218, 218-214, 214-216 and 216-212, its line of connection/line of action is at an angle to the line of links 212, 214.

Angle F is preferably about 50. As a result, arm element 210 has an isodynamic capability. That is, subject to adjustment of spring means 246 to cater for the weight of a particular load, the arm element 210 may be moved to adopt any configuration between the extreme positions, and will stay in that configuration.

If two arm elements 210 were connected to form the arm of a motion picture camera support and stabilization apparatus, a camera could be moved to a position relative to the operator, and would then stay in that position.

1 12 A fourth embodiment of the invention is shown in Fig. 4. The arm element 310 of Fig. 4 differs in appearance from the arm elements 10, 110, 210 of Figs. 1 to 3, but still has the basic general parallelogram configuration of those previous embodiments.

Arm element 310 has upper and lower links 312, 314 respectively, and side links 316, 318 respectively. Links 312 and 318 are pivotally connected at 320, links 318 and 314 are pivotally connected at 322, links 314 and 316 are pivotally connected at 324, and links 316 and 312 are pivotally connected at 326.

Spring means 328, 330 are provided to control the motion of the links 312, 314, 10 316 and 318 of arm 310. Spring 328 is connected at one end 356 to link 312 through an adjusting means 354, which may take the form of a bolt connected to end 356, the bolt being capable of co-operating with a nut welded to a washer at 356, such that by being turned, the compression of spring 328 may be altered between ends 352 and 356. End 352 of spring 328 is connected to a pair of wire ropes or equivalent lines (only one of which is shown as 358). Wire ropes 358 pass over a first pair of pulleys (only one of which is shown at 360) mounted side-by-side on link 312, and a second pair of pulleys (only one of which is shown at 362) also mounted side-by-side on link 312. Preferably, second pair of pulleys 362 are mounted in such a way that they are coaxial with pivot point 320.

Se The wire rope 358 then passes over a third pair of pulleys 364 mounted sideby-side on link 314. Preferably pair of pulleys 364 are mounted coaxially with pivot point 324. Rope 358 then passes over a fourth pair of pulleys 366 mounted on link 314, and is attached to one end 370 of spring means 330. At the other end 368 of spring 330 there is a nut welded to a washer, which nut cooperates with bolt 372 so that spring 330 may be compressed between points 368 and 370.

A prototype arm element in accordance with element 310 of Fig. 4 has been found to support weights from approximately 4.54kg (about 101b) to 13 approximately 31.75kg (about 701b). Adjustment means 354 and/or 372 is/are operated to achieve the spring compression suitable for a predetermined weight.

It has been found that the use of the four pairs of pulleys arrangement of Fig. 4 and the line of action across the element 310 allows for effective two-spring means operation.

Fig. 5 shows a fifth embodiment of the invention, which is a variant on the fourth embodiment. Arm element 410 has upper and lower links 412, 414 respectively, and side links 416, 418 respectively. Links 412 and 418 are pivotally connected at 420, links 418 and 414 are pivotally connected at 422, links 414 and 416 are pivotally connected at 424, and links 416 and 412 are pivotally connected at 426.

i. .Spring means 428, 430 are provided to control the motion of the links 412, 414, 416 and 418 of arm 410. Spring 428 is connected at one end 456 to link 412 through an adjusting means 454, which may take the form of a bolt, adapted to co-operate with a nut welded to a washer at end 456, and being capable of S 15 being turned to adjust the compression of spring 428 between ends 452 and 456. End 452 of spring 428 is connected to a pair of wire ropes or equivalent :lines (only one of which is shown at 458). Wire ropes 458 pass over a first pair of pulleys 460 mounted side-by-side on link 412 and a second pair of pulleys 462 also mounted side-by-side on link 412. Preferably, second pair of pulleys 20 462 are mounted in such a way that they are coaxial with pivot point 420.

The wire ropes 458 then pass over a third pair of pulleys 464 mounted side-byside on link 416. Ropes 458 then pass over a fourth pair of pulleys 466 mounted side-by-side on link 414, and is attached to one end 470 of spring means 430.

The other end 468 of spring 430 has a nut welded to a washer, which nut is adapted to co-operate with a bolt 472 which may be similar to, and operate in a similar way to bolt 454.

It can be seen that the line of action of ropes 458, when the arm element 410 is in a rectangular configuration, is at a shallower angle to links 412, 414, than the corresponding angle of the fourth embodiment of Fig. 4. That angle, which may be approximately 50, is believed to assist the arm element to constantly provide isodynamic characteristics. A prototype arm element in accordance with element 410, has been found capable of carrying weights in the range about 4.54kg (approximately 101b) to about 31.75kg (approximately 701b) subject to the operation of the aforementioned adjustability feature to adapt to a particular weight in the stated range.

The sixth embodiment of the present invention, as illustrated in Fig. 6, is a variant on the fifth embodiment of Fig. 5. Arm element 510 has upper and lower links 512, 514 respectively, and side links 516, 518 respectively. Links 512 and 518 are pivotally connected at 520, links 518 and 514 are pivotally connected at ~522, links 514 and 516 are pivotally connected at 524, and links 516 and 512 are pivotally connected at 526.

so 00 ,•Spring means 528, 530 and 532 are provided to control the motion of the links 512, 514, 516 and 518 of arm 510. Spring 528 is connected at one end 556 to link 512 through an adjusting means 554, which may take the form of a bolt, "adapted to co-operate with a nut welded to a washer located at end 556, and see C capable of being turned in relation to that nut to adjust the compression of spring 528. The other end 552 of spring 528 is connected to a pair of wire ropes or equivalent lines, only one of which is shown at 578. Wire ropes 578 pass over a first pair of pulleys (only one of which is shown at 560) mounted side-by-side on link 512 and a second pair of pulleys (only one of which is shown at 562) also mounted side-by-side on link 512. Preferably, second pair of pulleys 562 is mounted in such a way that each of the pair of pulleys is coaxial with pivot point 520.

The wire ropes 578 are then connected to one end 576 of spring 532. The other end 574 of spring 532 is attached to a second pair of wire ropes, only one of which is shown at 558. Ropes 558 pass over a third pair of pulleys 564 mounted side-by-side on link 516. Ropes 558 then pass over a fourth pair of pulleys 566 mounted side-by-side on link 514, and are attached to one end 570 of spring means 530. At the other end 568 of spring 530 there is a nut welded to a washer, which nut is adapted to co-operate with a bolt forming an adjusting means 572 which may be similar to bolt 554.

The line of action in the sixth embodiment is much the same as in the fifth embodiment, with the addition of third spring means 532 on that line.

The seventh embodiment of the present invention, as illustrated in Fig. 7, is an arm element 610 which is both adjustably isodynamic and capable of adjustment to carry a wide range of weights. A perusal of the prior art discussed earlier in this specification will show that much more than merely a motion picture or video camera is required to be supported and stabilized by apparatus of the general type disclosed in the prior art. Features such a battery packs, monitors, junction boxes, and zoom controls may also be required to be carried. Furthermore, :*large format cameras such as those used in OMNIMAX (Trade Mark) and IMAX (Trade Mark) systems are inherently larger and heavier than more conventional cameras.

15 Arm element 610 has upper and lower links 612, 614 respectively, and side links 616, 618 respectively. Links 612 and 618 are pivotally connected at 682, links 618 and 614 are pivotally connected at 622, links 614 and 616 are pivotally *connected at 624, and links 616 and 612 are pivotally connected at 626.

Spring means 628, 630 and 632 are provided to control the motion of the links 612, 614, 616 and 618 of arm 610. Spring 628 is connected at one end 656 to link 612 through an adjusting means 654, which may take the form of the arrangement to be described in relation to Fig. 8, with a bolt (similar to bolt 672 of Fig. adapted to co-operate with a nut (690 in Fig. 8) welded to a washer or plate (686 in Fig. the bolt 654 being capable of being tightened to adjust the compression of spring 628 between ends 652 and 656. The other end 652 of spring 628 is connected to a pair of wire ropes or equivalent lines (only one of which is shown at 678). Wire ropes 678 pass over a first pair of pulleys 660 mounted side-by-side on link 612 and a second pair of pulleys 662 also mounted side-by-side on link 612. Preferably, second pair of pulleys 662 are 16 mounted in such a way that they are coaxial with pivot point 682.

Wire ropes 678 are then connected to one end 676 of spring 632. The other end 674 of spring 632 is attached to link 616 at point 680. A second pair of wire ropes 658 is attached at one end to link 612 at point 682, which may be colocated with the axis of pulley 662. The attachment point may be located elsewhere. For example, it may be desirable to locate the attachment point as far away from point 622 as possible, provided that it is attached to link 618 and provided it is in line with points 622 and 682; it may be located above point 682 on link 618. The location of the attachment point will provide the angle of the 10 line of action of wire 632 between points 624 and the attachment point.

Desirably, for optimum isodynamic effect, this effect will be adjustable through spring means 630.

Ropes 658 pass over a third pair of pulleys 664 mounted side-by-side on link 616. Preferably, the pair of pulleys 664 are coaxial with pivot point 624. Ropes 658 then pass over a fourth pair of pulleys 666 mounted side-by-side on link 614, and are attached to one end 670 of spring means 630. The other end 668 of spring 630 is attached to link 614 through an adjusting means 672 which may be similar to adjusting means 654, and which is shown in more detail in Fig. 8.

*oo 0 In Fig. 8, there is shown the detail of an adjustment arrangement for spring means of the type discussed in relation to the descriptions of embodiments one to seven of the present invention. Although the arrangement will be described specifically in relation to the eighth embodiment of Fig. 8, it is to be understood that it is applicable to the other embodiments of the invention.

In Fig. 8, spring 630 is capped at ends 668, 670 respectively by plates or washers 686, 688. Washer 686 has an aperture to which a nut 690 is attached by welding or the like. The plate or washer may alternatively just have an internally-threaded aperture. Washer 686 also has apertures 692, 694, through which a pair of wire ropes or the like 658, 684 pass. The wire ropes 658, 684 are connected to plate 688 at points 702, 704. Plate 688 has a central aperture t e 17 696, through which the shaft of bolt 672 may pass.

Bolt 672 has a threaded portion 698 at one end, and a head 700 at the other end. Assembled, threaded portion 698 passes through aperture 696 and the centre of spring 630, to co-operate with nut 690, or the alternative threaded portion. By screwing or unscrewing bolt 672, spring 630 is compressed or relaxed to provide the adjustment discussed in relation to the embodiments of Figs. 1 to 7. Such an arrangement, with modifications to suit the arm element involved, may be utilised in any of those embodiments.

Each of the springs referred to in the embodiments of Figs. 1 to 8 may be a variable force spring. The coils of such a spring are of progressively varying strength, the spring being of one strength at one end and of increasing strengths as one moves towards the other end. As the spring is compressed by turning a bolt arrangement of the type discussed earlier in this specification, the spring is compressed such that the weaker coils abut each other and are rendered inoperative. This leaves the next, stronger, portion of the spring to be relied :upon to provide the arm element with greater strength to support a heavier camera.

A further embodiment of an arrangement for locating and adjusting a spring in arm elements of the type shown in Figs. 1 to 7 is shown in Fig. 9, which in a general sense is similar to Fig. 8. Coil spring 2028, which is preferably an extension spring, is suitable to be utilised in an arm element such as element 2010 of Fig. 10. By way of a particular example, link 2012 part of which is shown in Fig. 9 of element 2010 has an abutment 2116, in which is provided an aperture 2102. The aperture 2102 is adapted to co-operate with a threaded bolt 2054, such that the shaft of the bolt is able to pass through the aperture 2102. The threaded bolt 2054 has a head 2100 and a threaded portion 2098.

Threaded portion 2098 of bolt 2054 is adapted to co-operate with the internal threads 2106 of an axial aperture 2108 of an adjustment element 2104.

Externally, element 2104 is provided with a relatively large-scale spiral or helical 18 thread 2110, which thread 2110 is adapted to co-operate with the coils of spring 2028, in that once element 2104 is located in spring 2028 the element 2104 may be rotated manually to move it along spring 2028. To locate adjusting element 2104 in spring 2028, it may be screwed into the spring from end 2052 or 2056 before the assembly shown in exploded fashion in Fig. 9 is completed. Once the assembly of Fig. 9 is completed, adjusting element 2104 is located permanently within spring 2028. The external surface 2118 of element 2104 is preferably knurled or treated in an equivalent manner, to facilitate the aforementioned manual rotation of the adjusting element 2104.

10 Adjustment element 2104 may be seen as a type of worm gear. As the helical thread 2110 has the same pitch as spring 2028, the element 2104 is able to remain within the spring 2028 in a free-floating orientation. Steel ropes cables 2058, 2084, similar to ropes 658, 684 of Fig. 8. are attached, when the various features of Fig. 9 are assembled, to the other end 2052 of spring 2028. It can 15 be seen that by rotating head 2100 of bolt 2054, adjustment element 2104 may be moved relative to bolt 2054.

Turning now to Fig. 10, arm element 2010 has the generally parallelogramshaped structure of earlier figures, with upper and lower links 2012, 2014 .respectively, and side links 2016, 2018 respectively. Links 2012 and 2018 are pivotally connected at 2020, links 2018 and 2014 are pivotally connected at 2022, links 2014 and 2016 are pivotally connected at 2024, and links 2016 and 2012 are pivotally connected at 2026.

Spring means 2028, 2030, preferably extension springs, are provided to control aspects of the motion of the links 2012, 2014, 2016 and 2018 of arm element 2010. Spring 2028 is connected to link 2012 through an adjusting means of the type described in relation to Fig. 9, with a bolt 2054 connected to link 2012 through an aperture 2102 (not shown), the bolt being capable of co-operating with an adjusting element 2104 located in spring 2028, such that by being turned, the tension of spring 2028 may be altered between end 2052 and element 2104.

End 2052 of spring 2028 is connected to a pair of wire ropes or equivalent lines 2058, 2084 (only one of which is shown as 2058). The wire ropes 2058, 2084 pass over a first pair of pulleys (only one of which is shown at 2060) mounted side-by-side on link 2012, and over a second pair of pulleys (only one of which is shown at 2062) mounted side-by-side on link 2016. Preferably, first pair of pulleys 2060 are mounted in such a way that their axis is not coaxial with pivot point 2026.

The wire ropes 2058, 2084 then pass over a third pair of pulleys 2064 mounted side-by-side on link 2014. Preferably the pair of pulleys 2064 are not mounted coaxially with pivot point 2022. Ropes 2058, 2084 are then attached to one end 10 2070 of spring means 2030, which is arranged in relation to link 2014 in a mirror image of the relationship of spring 2028 to link 2012. Spring 2030 has an adjusting element 2112, substantially identical to adjusting element 2104, which element co-operates with bolt 2072 so that the amount of tension of spring 2030 may be varied. Bolt 2072 is attached to link 2014 in a manner similar to that of 15 bolt 2054 and link 2012; head 2114 is used to make the adjustments necessary.

It should be noted that the angle 6 of ropes 2058, 2084 between pulley pairs S° 2062 and 2064 is, relative to links 2012, 2014 when the arm element 2010 is in a rectangular orientation, approximately 50. The angle 6 provides the arm element S. 2010 with isodynamic characteristics, and slows the rate of usage of the spring force of springs 2028, 2030 as the arm element 2010 moves from one extreme orientation to the other.

Fig. 11 shows an alternative arm element 3010, which has the generally parallelogram-shaped structure of earlier figures, with upper and lower links 3012, 3014 respectively, and side links 3016, 3018 respectively. Links 3012 and 3018 are pivotally connected at 3020, links 3018 and 3014 are pivotally connected at 3022, links 3014 and 3016 are pivotally connected at 3024, and links 3016 and 3012 are pivotally connected at 3026.

Spring means 3028, 3030 are provided to control the motion of the links 3012, 3014, 3016 and 3018 of arm 3010. Spring 3028 is connected to link 3012 through an adjusting means of the type generally described in relation to Fig. 9, with a bolt 3054 connected to link 3012 through an aperture (not shown), the bolt being capable of co-operating with an adjusting element 3104 located in spring 3028, such that by being turned, the tension of spring 3028 may be altered between end 3052 and element 3104. End 3052 of spring 3028 is connected to a pair of wire ropes or equivalent lines 3058, 3084 (only one of which is shown as 3058). The wire ropes 3058, 3084 pass over a first pair of pulleys (only one of which is shown at 3060) mounted side-by-side on link 3012, and a second pair of pulleys (only one of which is shown at 3064) mounted side-by-side on link 3014. Preferably, first and second pairs of pulleys 3060, 3064 are mounted 2 in such a way that their axes are not coaxial, respectively, with pivot points 3026 and 3022.

Ropes 3058, 3084 are then attached to one end 3070 of spring means 3030, which is arranged in relation to link 3014 in a mirror image of the relationship of 15 spring 3028 to link 3012. Spring 3030 has an adjusting element 3112, substantially identical to adjusting element 3104, which element co-operates with bolt 3072 so that the extension of the spring 3030 may be varied. Bolt 3072 is attached to link 3014 in a manner similar to that of bolt 3054 and link 3012; head 3114 is used to make the adjustments necessary.

It should be noted that the angle E of ropes 3058, 3084 between pulley pairs 3060 and 3064 is, relative to links 3012, 3014 when the arm element 3010 is in a rectangular orientation, greater than 50. The angle E imbues the arm element 3010 with non-isodynamic characteristics.

Turning now to Fig. 12, there is shown an arm element 4010 which is a version of the isodynamic arrangement of Fig. 10. Again, it has the generally parallelogram-shaped structure of earlier figures, with upper and lower links 4012, 4014 respectively, and side links 4016, 4018 respectively. Links 4012 and 4018 are pivotally connected at 4020, links 4018 and 4014 are pivotally connected at 4022, links 4014 and 4016 are pivotally connected at 4024, and links 4016 and 4012 are pivotally connected at 4026.

Spring means 4028, 4030 and 4032 are provided to control the motion of the links 4012, 4014, 4016 and 4018 of arm 4010. Spring 4028 is connected to link 4012 through an adjusting means of the type described in relation to Fig. 9, with a bolt 4054 connected to link 4012 through an aperture (not shown), the bolt 4054 being capable of co-operating with an adjusting element 4104 (similar to element 2104 of Fig. 9) located in spring 4028, such that by being turned, the tension of spring 4028 may be altered between end 4052 and element 4104.

End 4052 of spring 4028 is connected to a pair of wire ropes or equivalent lines 4058, 4084 (only one of which is shown as 4058). The wire ropes 4058, 4084 pass over a first pair of pulleys (only one of which is shown at 4060) mounted side-by-side on link 4012, and over a second pair of pulleys (only one of which is shown at 4062) mounted side-by-side on link 4016. Preferably, first pair of pulleys 4060 are mounted in such a way that their axis is not coaxial with pivot point 4026.

15 The wire ropes 4058, 4084 are then attached to one end 4074 of second spring means 4032. The other end 4076 of spring means 4032 is attached to a pair of :wire ropes or the like (only one of which is shown as 4078). Ropes 4078 pass over a third pair of pulleys 4064 mounted side-by-side on link 4014. Preferably the pair of pulleys 4064 are not mounted coaxially with pivot point 4022. Ropes 20 4078 are then attached to one end 4070 of spring means 4030, which is arranged in relation to link 4014 in a mirror image of the relationship of spring 4028 to link 4012. Spring 4030 has an adjusting element 4112, substantially identical to adjusting element 4104, which element co-operates with bolt 4072 so that the extension of spring 4030 may be varied. Bolt 4072 is attached to link 4014 in a manner similar to that of bolt 4054 and link 4012; head 4114 is used to make the adjustments necessary.

The arm element 4010 of Fig. 12 effectively adds a third spring (4032) to the arrangement of Fig. 10. Preferably, third spring 4032 is a heavy duty spring, to provide the element 4010 with the capacity to support heavier weights. The isodynamic capacity will not be affected, and the angle 6 will again slow the rate of usage of spring force of springs 4028, 4030 as the arm element 4010 moves from one extreme position to the other.

Fig. 13 shows an arm element 5010, which is effectively another version of the arm element 3010 of Fig. 11. It also has the generally parallelogram-shaped structure of earlier figures, with upper and lower links 5012, 5014 respectively, and side links 5016, 5018 respectively. Links 5012 and 5018 are pivotally connected at 5020, links 5018 and 5014 are pivotally connected at 5022, links 5014 and 5016 are pivotally connected at 5024, and links 5016 and 5012 are pivotally connected at 5026.

10Spring means 5028, 5030 are provided to control the motion of the links 5012, 5014, 5016 and 5018 of arm 5010. Spring 5028 is connected to link 5012 through an adjusting means of the type generally described in relation to Fig. 9, with a bolt 5054 connected to link 5012 through an aperture (not shown), the bolt 5054 being capable of co-operating with an adjusting element 5104 located in spring 5028, such that by being turned, the degree of tension of spring 5028 may be altered between end 5052 and adjusting element 5104. End 5052 of spring 5028 is connected to a pair of wire ropes or equivalent lines 5058, 5084 (only one of which is shown as 5058). The wire ropes 5058, 5084 pass over a first pair of pulleys (only one of which is shown at 5060) mounted side-by-side on link 5012, and are attached to one end 5074 of a third spring 5032. The other end 5076 of spring 5032 is attached to a second pair of wire ropes or the like (only one of which is shown as 5078).

Wire ropes 5078 then pass over a second pair of pulleys (only one of which is shown at 5064) mounted side-by-side on link 5014. Preferably, first and second pairs of pulleys 5060, 5064 are mounted in such a way that their axes are not coaxial, respectively, with pivot points 5026 and 5022.

Ropes 5078 are then attached to one end 5070 of spring means 5030, which is arranged in relation to link 5014 in a mirror image of the relationship of spring 5028 to link 5012. Spring 5030 has an adjusting element 5112, substantially identical to adjusting element 5104, which element co-operates with bolt 5072 so that the tension of spring 5030 may be varied. Bolt 5072 is attached to link 5014 in a manner similar to that of bolt 5054 to link 5012; head 5114 is used to make the adjustments necessary.

It should be noted that the angle E of ropes 5058, 5084, 5078 between pulley pairs 5060 and 5064 is, relative to links 5012, 5014 when the arm element 5010 is in a rectangular orientation, greater than 50. The angle E imbues the arm element 5010 with non-isodynamic characteristics.

The arrangement of Fig. 13 is effectively that of Fig. 11 with the addition of an additional spring (5032), which enables arm element 5010, or a support 10 apparatus of which the element 5010 forms a part, to support heavier weights.

Figs. 14, 15 and 16 show how the arrangement of Fig. 9, particularly as part of the arm elements of Figs. 10 to 13, operates.

Fig. 14 is a side elevation of the arrangement of Fig. 9, as in place in the arm element 2010 of Fig. 10, with some further detail. Link 2012 is shown with pulley pair 2060, and portion of wire ropes 2058, 2084 (with only 2058 shown) running over pulleys 2060 to be attached to one end 2052 of spring 2028. In the orientation of Fig. 14, adjustment element 2104 is located hard up against abutment 2116 of link 2012. This represents the situation where the bolt 2054 has been done up tightly, so as to secure end 2056 of spring 2028 to abutment 2116, to make as much of the spring as possible available. With adjustment element 2104 located on spring 2028 in the position shown in Fig. 14, the spring force will support the lightest weights.

It may be preferred that for the orientation of Fig. 14, it may be of assistance to use a spring which has a subtle taper in its wire, being thickest and strongest at end 2052, and thinnest and weakest at end 2056.

Fig. 15 demonstrates the arrangement when spring 2028 is configured for a medium weight load. An operator unscrews bolt 2054 from adjusting element 24 2104 without removing it entirely. This will release all tension in the arrangement. The operator is then able to move element 2104 along spring 2028 using the palm of the hand on the knurled surface 2118. The operator is able to stop at any point of his or her choosing along spring 2028, up to a predetermined limit. Bolt 2054 may then be screwed back through adjusting element 2104 to the point where bolt head 2100 engages abutment 2116 of link 2012 to secure the arrangement.

Fig. 16 shows the arrangement when configured for the heaviest weight load.

Adjusting element 2104 has been moved along spring 2028 as previously 10 described to a desired position. Turning the bolt 2054 clockwise, in this .embodiment, causes adjusting element 2104 to be drawn along link 2012 towards abutment 2116. This action causes the coils of spring 2028 between end 2052 and adjusting element 2104 to be stretched, creating greater force for lifting strength. A by-product of this action is compression of the coils between 15 adjusting element 2104 and spring end 2056, perhaps even to the point of abutting each other.

A thrust bearing 2120 may be located between bolt head 2100 and abutment 2116 to reduce friction between those two elements whilst adjustment is being made.

Of course, the spring force adjusting arrangement shown in Figs. 9 and 14 to 16 may be used, not only for springs 2028 and 2030 of the arm elements of Figs.

to 13, but may be utilised in any other apparatus which utilises a spring.

In the arrangement of Figs. 9 and 14 to 16, it can be seen that there are two modes of adjustment, the location of adjusting element 2104 by rotating it, and the "fine tuning" adjustment obtained by rotating bolt 2054. Those two adjustment modes provide continuous adjustability over a wide range of weights, with an ability to fine tune the apparatus with extreme precision.

It has been found that camera support apparatus incorporating arm elements of the type shown in Figs. 10 to 13, which in turn employ the spring adjusting means of Figs. 9 and 14 to 16, has been able to support weights from 4.54kg (101b) to 29.48kg (651b), a range of 24.95kg (551b). It is felt that with appropriately-designed springs, a range of 31.75kg (701b) is possible.

The approximate 50 angle discussed in this specification is felt to contribute in two ways. Firstly, it provides an arm element, and an arm incorporating such an arm element, with isodynamic characteristics. Secondly, as an arm element travels between extreme positions, the amount of spring used is minimal, thus 1 leaving plenty of spring available to be drawn upon when adjustment is being i: 10 made to cater for heavier weights.

More specifically, it has been discovered that the use of an angle of about So mentioned throughout the specification and claims of this application, has a particularly desirable outcome. At angles above about 50, the movement of an arm will consume more of the spring involved, such that, for example, at about 150 most if not all of the spring will be utilised in such movement. At about 50 the rate of consumption of the spring is reduced, resulting in an acceptable arrangement.

ooo*°* 9 Below about 50, there are additional frictional forces on the arm joints, and there is an exponential loss of strength. Furthermore, as the angle is reduced from, say, 150, the arm is able to cope with weights which decrease not in a linear manner, but exponentially. This is particularly evident below about 50 Thus, as one reduces the angle progressively from about 50, it becomes necessary to increase both the strength of the spring, but also the strength of the arm structure, which leads to increased weight, eventually leading to an arm which could not in practice be used.

Versatility is also provided in the invention described and claimed herein, in that the variable rate compression spring, having a facility for allowing a predetermined number of spring coils to abut each other, thereby immobilising 26 those coils and allowing the remaining coils to carry a load, enables a wide range of such loads to be carried.

On the other hand, the extension spring arrangement described herein provides versatility through an available wide range of tension in the springs.

It can be seen that this invention provides an improved arm element for a motion picture support and stabilizing apparatus, which arm element facilitates adjustable capacity for carrying a wide range of weights, and/or an isodynamic capacity.

The term "lifting triangle" may be used to describe the three-sided or 10 approximate three-sided figure formed by a spring and two links of an arm element, and the effective angle of that triangle, may be referred to as a "lifting angle".

The entire contents of the specification and drawings of Australian provisional patent applications no. P04418 and P06520 are hereby imported into this specification, and form part of the disclosure of this specification.

The claims also form part of the disclosure of this specification. The claims also form part of the disclosure of this specification.

o

Claims (21)

1. An arm element for the arm of a motion picture or video camera stabilizing apparatus, said arm element having, generally, a parallelogram configuration formed from a plurality of links pivotally attached to one another, said arm element including spring means connecting opposed links, said spring means being at an angle to one or both of the links to which it is not connected.

2. An arm element according to claim 1, characterized in that said angle is approximately An arm element according to claim 1 or claim 2, characterized in that 10 there is a plurality of spring means. 00o0

4. An arm element according to any preceding claim, characterized in that g. there are three spring means. 00 0

5. An arm element according to any one of claims 1 to 4, characterized in S' that there are two said spring means, with a third spring means connecting said 15 links, and being disposed at an angle greater than that of said other two springs.

6. An arm element according to claim 5, characterized in that said third spring is at an angle of between about 100 and about 150.

7. An arm element according to claim 6, characterized in that said third spring is at an angle of about 150.

8. An arm element for the arm of a motion picture or video camera stabilizing apparatus, said arm element having, generally, a parallelogram configuration formed from a plurality of links pivotally attached to one another, said arm element including first spring means attached to a first one of a pair of opposed links, and second spring means attached to a second one of said pair, said first spring means and said second spring means being connected together by a line which passes over first pulley means and second pulley means located on a first one of a pair of opposed links, and over third pulley means and fourth pulley means located on a second one of said pair.

9. An arm element according to claim 8, characterized in that said third pulley means is located on a link which is not one of said pair. An arm element according to claim 8 or claim 9, characterized in that said line, between said second pulley and said third pulley, is at an angle to one or both of said pair of links.

11. An arm element according to any one of claims 8 to 10, characterized in 10 that said angle is about 50

12. An arm element according to claim 8, characterized in that third spring means is located between said second pulley and said third pulley and connected in said line. 9

13. An arm element for the arm of a motion picture or video camera stabilizing apparatus, said arm element having, generally, a parallelogram configuration formed from a plurality of links pivotally attached to one another, said arm element including first spring means attached to a first one of a pair of opposed links, and second spring means attached to a second one of said pair, said first spring means being attached to a line which passes over first pulley means and second pulley means located on said first one of said pair, and being connected through third spring means to a link other than one forming part of said pair, a second line being attached to said first one of said pair, and passing over third pulley means and fourth pulley means located on said second one of said pair for connection to said second spring means.

14. An arm element according to claim 13, characterized in that all said spring means are of variable strength, and/or are capable of being adjusted. 29 An arm element according to claim 13 or claim 14, characterized in that all said spring means are compression springs.

16. An arm element according to claim 13 or claim 14, characterized in that some or all of said spring means are extension springs.

17. An arm element according to any one of claims 14 to 16, further including a spring force adjusting arrangement, said arrangement including an adjustment element adapted to be located in said spring for movement along said spring, said adjustment element also being engaged with adjustment means for immobilising a predetermined portion of said spring between said adjustment element and the non-active and of said spring.

18. An arm element according to claim 17, characterized in that said spring is S* an extension spring.

19. An arm element according to claim 17 or claim 18, characterized in that said adjustment element has an external thread adapted to co-operate with the 15 coils of said spring such that said adjustment element may be screwed into and along said spring by rotation of said adjustment element, said adjustment element being constructed to float freely within said spring. ooo.

20. An arm element according to claim 19, characterized in that said adjustment element has an outer surface which assists manual rotation of said adjustment element.

21. An arm element according to any one of claims 17 to 20, when used in the arm element of any one of claims 1 to 16.

22. An arm element according to claim 21, characterized in that said spring force adjustment arrangement may be utilised in an arm element such that opposing links of an arm element each have a spring and a spring force adjustment arrangement as defined herein.

23. An arm element according to claim 22, characterized in that said adjustment element has a threaded bore, and said adjustment means is able to screw through said bore to move said adjustment element relative to a fixed point.

24. An arm element for the arm of a motion picture or video camera stabilizing apparatus, substantially as herein described with reference to the accompanying drawings. DATED this 18th Day of June 2001 JOHN CHRISTIANSEN 10 Member, F6d6ration Internationale des Conseils en Propriet6 Industrielle (International Federation of Industrial Property Attorneys) Patent Attorney for the Applicant: RIG ENGINEERING PTY. LTD. o•*