Restraining devices

A bail assembly including bail members moveable between operative engaged positions and a disengaged position; bail actuating structure for quickly moving the bail members between the operative engaged positions and the disengaged position, and holding devices for holding the bail members at any selected operative engaged position. Preferably the holding device is a selectively releasable self locking hydraulic cylinder assembly which includes adjustable holding device, a locking chamber associated with the adjustable holding device which may be filled to lock the adjustable holding device, control structure for controlling flow of fluid to and from the locking chamber, and actuating structure for selectively actuating the control structure.

This invention relates to restraining devices and holding assemblies. 
This invention has particular but not exclusive application to restraining 
devices such as head bails for animals and holding devices therefore and 
for illustrative purposes reference will be made hereinafter to such 
application. However it is to be understood that the restraining devices 
and holding assemblies of the present invention can be used independently 
of one another. 
Presently utilised restraining devices such as head bails for cattle 
typically include moveable bails which are arranged to capture a beast by 
quickly clamping against opposite sides of a beasts neck, behind the ears. 
In this manner the beast is restrained before it can exit rearwardly from 
the bails which are maintained in their clamped position by a suitable 
holding assembly. 
Generally the bails are actuated by a single action lever mechanism which 
affords a sufficiently high speed of operation to capture the beast's neck 
between the bails. The holding assembly is typically a ratchet and pawl 
mechanism which maintains the bails in the captured position against the 
neck of the beast. However, an optimum clamping force on the beast's neck 
cannot always be achieved because the rachet mechanism provides only a 
specific number of discrete holding positions and one of these positions 
must be engaged. Single action lever mechanisms are utilised as the speed 
of reversal of a beast generally does not permit performance of more than 
one operating action by an operator. Beasts which are not captured in the 
initial pass often become very difficult to handle. 
Such rachet type holding assemblies are prone to wear rapidly as the rachet 
must be released whilst under load. Worn ratchet mechanisms can become 
liable to pawl slip and accordingly can be dangerous, allowing unexpected 
release of a secured beast. 
Attempts have been made to overcome this problem, for example by the use of 
larger rachet teeth. However, when the size of the ratchet teeth is 
increased the number of discrete holding positions is reduced so that the 
beast cannot be restrained in the desired position. 
In another attempt at reducing the danger of worn or wearing ratchet type 
holding assemblies the tooth cutback has been increased. However, the 
increased cutback makes the ratchet mechanism more difficult to release 
under load, thereby increasing the likelihood of damage to or loss of the 
beast as well as danger to the operator. 
Ratchet type holding assemblies also create undesirable noise as the rachet 
pawl travels across the ratchet teeth as the head bail is being moved to 
the clamped position. Such noise may frighten the beast being clamped in 
the head bail and also those beasts in the race or holding yard awaiting 
treatment. This may result in greater difficulty in coaxing or encouraging 
the waiting beasts to enter the head bail. 
Head bails are often makeshift as relatively poor bail performance can be 
tolerated provided there are adequate persons to control the beast to be 
bailed. However, many modern farmers have significantly reduced their 
labour forces and as a consequence they require good performance from 
their head bails. As such articles are bulky, their transport costs add 
significantly to the cost of supplying new head bails. Furthermore the 
addition of a modern head bail assembly to an existing race is often a 
practical mismatch leading to premature failure of the head bail assembly. 
SUMMARY OF THE INVENTION 
The present invention aims to alleviate at least one of the above 
disadvantages and to provide beast restraining apparatus which will be 
reliable and efficient in use. 
This invention in one aspect resides broadly in a bail assembly including: 
bail means moveable between operative engaged positions and a disengaged 
position; 
bail actuating means for quickly moving said bail means between said 
operative engaged positions and said disengaged position, and 
holding means for holding said bail means at any selected said operative 
engaged position. The holding means is suitably infinitely variable over 
at least the engaged positions of the bail means. 
The bail means may include one fixed bail and one moveable bail but 
preferably it includes a pair of opposed moveable bails interconnected for 
movement towards and away from each other. The bail means may be arranged 
to move in any manner suitable for engaging a beast. For example the bails 
may be arranged for parallel sliding movement or pivotal movement. 
Preferably the bail means are arranged so that in a disengaged position 
the head of a beast may be passed through the gap between the bails and in 
an engaged position the bail means may clamp against the neck of the 
beast. 
The bail actuating means may be an electrically operated device such as a 
motorised screw or solenoid operative to quickly move the bail means to 
and from the engaged position upon activation of a power supply. 
Preferably, however the bail actuating means is an operating handle 
operatively connected to the bail means so as to move the bail means to 
the engaged position upon movement of the handle in one direction. 
The holding means may include a rod or rope operatively connected to the 
bail means and a clutch adapted to selectively clamp the rod or rope such 
that the bail means is held in a desired position. Alternatively, the 
holding means may include a rotary clutch with a pivotable handle allowing 
movement of the bail means to the engaged position but selectively 
preventing reverse movement of the restraining means to the disengaged 
position. Preferably however, the holding means is a hydraulically 
operated holding assembly which allows passage of hydraulic fluid such as 
water or oil from a fluid supply to a locking chamber as the bail means is 
moved to the engaged position and wherein the fluid is selectively 
prevented from flowing out of the locking chamber so as to hold the bail 
means in the engaged position. 
It is preferred that the bail means includes a pair of bail members 
connected by concertina type hinges to opposed spaced supports. Suitably 
the bail members extend upwardly for engagement with guide means for 
guiding the bail members to and from engagement and wherein the guide 
members restrain only longitudinal movement of the bail members, lateral 
and vertical movement being controlled and restrained by the hinges. 
In a preferred form the bail assembly is demountable for supply in 
knocked-down form and adapted for bolted interconnection of major 
structural components, especially those that provide additional rigidity 
to the race walls. It is also preferred that the members of the bail 
assembly, when disassembled, can be packed into a relatively small 
package. For this purpose it is preferred that the bail assembly include a 
pair of opposed support posts adapted to be rigidly interconnected by 
transverse members providing moment transfer about respective longitudinal 
race axes between support posts and post rotational support about post 
axes through bolted connections, each including bolts spaced from these 
respective axes. Preferably the moment transfer about respective 
longitudinal race axes is provided by a transverse structure at upper ends 
of the posts and the rotational support about post axes is provided by a 
transverse structure at the lower ends of the posts. 
The upper transverse structure is suitably formed by spaced laterally 
extending bars which form guides for upward extension of the bail members. 
The rotational support about post axes fixes the posts against rotational 
movement such that hinge pivots fixed to the posts and spaced from their 
respective longitudinal axes will remain in a fixed orientation to enable 
the concertina type hinge members to hinge across their front faces 
between operative and inoperative attitudes. The support also relieves 
such loads from the other said bolted connections. 
In relation to the bolted connections it is considered that rigid 
all-welded head bail structures assume crush loads imparted by heavy 
beasts to the crush walls because of the relative high rigidity of the 
head bail compared to the crush. This results in overload of the welded 
joints and their premature failure. 
It is also preferred that one of the support posts provide a lower mounting 
for the holding means and an upper pivotal mounting for a translation 
mechanism able to translate pivotal movement of an operating handle 
thereon to lateral motion of the bail members, the translation mechanism 
preferably being connected to the upper ends of the bail members which 
extend between the guide bars. 
In a further aspect this invention resides broadly in a method of 
installing a head bail assembly to an existing race, the method including 
providing the crush in a knock-down form and bolting the crush components 
together such that the bolted joints provide moment transfer about 
respective longitudinal race axes between support posts and post 
rotational support about post axes through bolted connections, each 
including bolts spaced from these respective axes. Servicing of such head 
bail assemblies is also facilitated as parts requiring service may be 
readily dismantled and sent away for repair. 
In another aspect this invention resides in a demountable bail assembly 
generally of the type described above and utilising any suitable form of 
holding means such as a ratchet mechanism or a hydraulic mechanism as 
previously described. 
In yet another aspect this invention resides broadly in a holding assembly 
including: 
adjustable holding means; 
a locking chamber associated with said adjustable holding means which may 
be filled with fluid to lock said adjustable holding means; 
control means for controlling flow of fluid from said locking chamber, and 
actuating means for selectively actuating said control means. 
Preferably, the adjustable holding means is an extendable hydraulic ram 
assembly but it may be a rotary hydraulic actuator or other like device. 
The locking chamber may be separate to the adjustable holding means and 
operatively connected to it. Preferably however, the locking chamber is 
integral with the adjustable holding means. 
The control means may be a solenoid or lever controlled gate valve which is 
closed in the engaged position and is opened to allow movement of the 
adjustable holding means to the disengaged position. Preferably, the 
control means is a non-return valve which may be overridden to permit 
fluid to flow from the locking chamber but which normally operates to 
admit fluid to the locking chamber and prevent reverse flow therefrom. In 
one such embodiment there is suitably provided an actuating shaft passing 
to the non-return valve through the storage chamber. 
Preferably the hydraulic holding assembly includes a fluid supply reservoir 
integral with the adjustable holding means. However, the fluid supply may 
be a continuous supply such as piped water or oil which is operatively 
connected to the locking chamber from an external source. 
In another aspect this invention resides broadly in a beast restraining 
assembly including: 
restraining means moveable between operative engaged positions and a 
disengaged position; 
low noise holding means for holding said restraining means in an operative 
engaged position. 
The restraining means may be a gate, clamp, cradle or the like but 
preferably it is a bail assembly adapted to engage the neck of a beast as 
previously described. 
The low noise holding means may be a ratchet and pawl mechanism, screw 
mechanism or the like suitably housed in a sound attenuation module such 
as an oil bath or insulated chamber. Preferably, however the holding means 
is a hydraulic holding assembly as described herein.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The bail assembly 10 illustrated in FIG. 1 includes a rectangular frame 
assembly 12 having opposed top and bottom members 13 and 14 and opposed 
vertical side members 15 and 16. Head bails 18 and 19 are slideably 
connected between the top and bottom members 13 and 14 so as to be movable 
towards and away from the vertical side members 15 and 16. 
A yoke assembly 25 is pivotally mounted to an extended portion of the frame 
member 15 and includes a yoke member 24 having opposed ends 26 and 27 
which are linked to the respective upper end portions of the head bails 18 
and 19 by link members 21 and 22 such that upon rotation of the yoke 
assembly about its pivot point 28, the link members move the head bails 18 
and 19 inwardly or outwardly so as to be able to clamp on the neck of a 
beast. A holding arm 29 and a sleeve 30 are loosely fitted around the yoke 
member 24 and are connected to pivot point 28 so as to allow pivotal 
movement between the sleeve and the yoke arm. An operating handle 31 is 
rigidly connected to the sleeve 30. 
The bail assembly also includes a hydraulically operated holding assembly 
35 pivotally connected at one end to the holding arm 29 of the yoke 
assembly 25 and at the other end pivotally connected to a mid portion of 
the frame member 16 through holes 36a and 37a respectively. 
The holding assembly 35 includes an outer cylindrical wall 40 having an 
upper end cap 41 and a piston rod 42 slidably and sealably engaged within 
the outer cylindrical wall in a lower portion thereof so as to form a 
fluid chamber between the upper end cap 41 and the piston face of piston 
rod 42. A `J` seal 43 is positioned at the piston rod end of the cylinder 
to prevent the ingress of contaminants such as dust. 
A control means 44 is arranged in a mid portion of the chamber so as to 
divide it into a locking chamber 36 on the piston rod side of the control 
means 44 and a fluid reservoir 46 on the other side. The control means 44 
includes a one-way ball valve 47 arranged to allow fluid flow from the 
fluid reservoir to the locking chamber but to prevent flow in the reverse 
direction unless the ball valve 47 is manually held in the open position. 
For this purpose there is provided a shaft 48 extending at one end through 
the upper end cap 41 and at the other end slidably engaging with the ball 
valve 47 so as to be able to move the ball valve to an open position when 
the shaft 48 is depressed, and wherein fluid may flow from the locking 
chamber to the reservoir. The upper end of the shaft 48 is encapsulated in 
a shaft cap 49 attached to the upper end cap 41 to prevent the shaft 48 
from becoming disengaged from the ball valve 47. The shaft is maintained 
in a non-engaged position by a spring 50 located between the shaft cap 49 
and the end cap 41. 
The shaft 48 may be engaged at its upper end by an engaging portion 31a of 
the operating handle 31 which is arranged to depress the shaft 48 upon 
initial pivotal movement of the operating handle about the pivot point 2 
thereby opening the ball valve 47. 
The fluid reservoir 46 can be charged with fluid through filling cap 51 
positioned at an upper end thereof. The filling cap includes a vent to 
atmosphere which may be closed to prevent ingress of moisture when the 
hydraulic holding assembly is not in use. 
The upper end portion of the outer cylindrical wall 40 is connected to a 
mounting portion 36 suitably adapted for pivotal connection to the yoke 
assembly 25 whilst the lower end of piston 42 includes a mounting portion 
37 adapted for pivotal connection to the frame member 16. 
In use, the head bails 18 and 19 are moved towards the side members 15 and 
16 to enable the neck of a beast to be accommodated therebetween. The 
operating handle 31 is then pivoted to pivot the yoke assembly 25 in a 
direction causing opposing movement of the link members 21 and 22 which 
slide the head bails 18 and 19 towards each other wherein they clamp 
against the neck of the beast. 
While the link members 21 and 22 are moving the head bails towards each 
other the holding arm 29 coincidentally moves the outer cylindrical wall 
40 of the hydraulic assembly 35 upwardly thereby extending the holding 
assembly. As the hydraulic holding assembly 35 begins to extend, the ball 
valve 47 opens and allows fluid to flow into the locking chamber 36 from 
the vented reservoir 46 as the holding assembly extends. 
As rotation of the yoke member 24 ceases the ball valve 47 closes to 
prevent fluid returning from the locking chamber to the reservoir so that 
the yoke assembly cannot be rotated in the reverse direction by movement 
of the head bails 18 and 19 thereby holding them in any desired engaged 
position against the neck of the beast. 
To release the beast from the bail assembly, the operating handle 31 is 
rotated in a reverse direction wherein initially an engaging portion 31a 
of the operating handle contacts the upper end of shaft 48 and forces it 
downwardly to open the ball valve 47 so that fluid may return to the 
reservoir from the locking chamber as illustrated in dashed line in FIG. 
2. As the operating handle is forced further in a reverse direction, the 
yoke 25 pivots and the oil is forced out of the locking chamber by the 
piston rod 42. Coincidentally the head bails 18 and 19 move apart. 
It is preferred that the head bail assembly 60 illustrated in FIGS. 4 and 5 
include head bails 61, 62 connected to opposed support posts 63 by 
concertina type hinge linkages 64. These linkages include respective pairs 
of straight outer links 65 connected to brackets at the front of the 
support posts 63 and cranked inner links 66 connected rigidly at their 
inner ends to the head bails 61, 62. The respective pairs of outer links 
are rigidly connected to upright members 67 so as to maintain the upper 
and lower ends of the head bails parallel. As illustrated the hinge links 
support and guide the head bails for movement between their engaged and 
disengaged positions, the upper guide members 68 only restraining 
longitudinal movement of the bail members. Furthermore in their disengaged 
positions the linkages 65, 66 protrude laterally only a short distance 
from the outer faces of the support posts 63. 
It will be appreciated that the bail assembly 60 is demountable for supply 
in knocked-down form whereby the members of the bail assembly may be 
packaged into a relatively small package. For this purpose the opposed 
support posts 63 are rigidly interconnected at their upper ends to 
longitudinally spaced laterally extending bars 68 which form guides for 
upward extension 70 of the head bails. The bars 68 have upper and lower 
bolt connections 72 providing moment transfer about respective 
longitudinal race axes 71 between the support posts 63. The bottoms 73 of 
the posts 63 are non-rotatably bolted to a lower bail member 74 by 
laterally spaced bolts 75 such that hinge pivots 76 extending from the 
front of the posts 63 remain in a fixed orientation to enable the 
concertina type hinge members to hinge across their front faces. One 
support post 63 is provided with a lower mounting 77 for the holding means 
78 and an upper pivotal mounting 79a for the translation mechanism 79 
which operates the bail link members 80, it being understood that the 
operation of the bail assembly 60 is by the mechanism described in 
relation to FIGS. 1 to 3. 
In order to maintain ruggedness in the assembled bail assembly in use, the 
guide bars 68 are pre-assembled as a rigid parallel frame bolted at its 
outer end to the front face of the posts 63 and the lower bar 74 is a flat 
bar through bolted through widely spaced pairs of bolt apertures formed on 
mounting wings welded to the lower ends of the posts 63. 
It will of course be realised that the above has been given only by way of 
illustrative example of the invention and that all such modifications and 
variations thereto as would be apparent to persons skilled in the art are 
deemed to fall within the broad scope and ambit of the invention as is 
defined in the appended claims.