pendulum dairy gates fitting and maintenance …...addition of solid sight panels – making it...
TRANSCRIPT
Version 1.4 P a g e | 1
Pendulum® Dairy Gates
Fitting and Maintenance Instructions
Kit for one gate shown
Leask Engineering Ltd | 3442 State Highway 26 | Tatuanui | Morrinsville 3374
+64 7 889 7769 www.leask.co.nz
Version 1.4 P a g e | 2
Contents
Introduction ............................................................................................................................................ 3
Kit List ...................................................................................................................................................... 4
Overall Dimensions ................................................................................................................................. 5
Safety Requirements ............................................................................................................................... 6
Other Requirements (not supplied) ........................................................................................................ 7
Tools .................................................................................................................................................... 7
Galvanised Medium Purpose Pipe ...................................................................................................... 7
Gate Installation ...................................................................................................................................... 8
Step 1: Unpack the components ......................................................................................................... 8
Step 2: Cut the lead out rail (if applicable) ......................................................................................... 9
Step 3: Determine the gate angle ..................................................................................................... 10
Step 4: Position the Mounting Frame ............................................................................................... 11
Step 5: Brace the Mounting Frame ................................................................................................... 13
Step 6: Complete the Mounting Frame Welding. ............................................................................. 14
Step 7: Position the Weight Arm ...................................................................................................... 15
Step 8: Hang the Gate ....................................................................................................................... 16
Step 9: Check and adjust the gate closed alignment ........................................................................ 17
Step 10: Check and adjust the gate open alignment ........................................................................ 17
Step 11: Fabricate the closed gate support ...................................................................................... 18
Installation of the opening and closing mechanism ............................................................................. 20
Step 12: Mount the Control Rail ....................................................................................................... 20
Step 13: Attach the Gate Control Rod .............................................................................................. 24
Step 14: Fit the Crank Stopper .......................................................................................................... 25
Step 15: Adjust the Gate ................................................................................................................... 26
Step 16: Completion ......................................................................................................................... 28
Monthly Maintenance .......................................................................................................................... 28
Operation .............................................................................................................................................. 29
Version 1.4 P a g e | 3
Introduction
Pendulum® gates were introduced to New Zealand dairy farmers in 1983 by Leask
Engineering. The Pendulum® exit gate, manufactured for herringbone dairy sheds, offers a
unique design and effective control over cow flow during milking. The gates, which pivot on
sealed ball bearings, are robustly constructed and can be opened from anywhere along the
pit. On opening, the gate swings away from the operator to an overhead position on the
breast rail side of the shed, allowing a clear exit for the cows. Milked and un-milked cows are
easily separated, thus providing rapid exit and entry to the dairy shed (follow through flow).
Individual cows can be stopped, even when they are exiting in close formation. Selected cows
can be drafted from the herd to be attended to after milking.
Pendulum® Gates have always been reowned for providing:
Quick, easy and accurate control
Labour savings
Positive open and closed locking
Large exit area
Since the early days of design, our Pendulum® gate has evolved and developed, and recent
design changes have seen further significant improvements with the following advantages
and features:
Addition of a mounting frame for quicker and easier installaton
Stronger gate frame
Gate quick attach mounting
Heavier control rod ends and bolts
Stonger secondary arm with the weight incorporated inside
Flanged bearing housings
Extra head clearance for personnel
Extra head clearance for the front cows
Addition of solid sight panels – making it easier for the cows to see the moving gate
Better support of the gate frame during opening/closing motion
Ability to use either 15NB or 20NB control rails
Version 1.4 P a g e | 4
Kit List
Item No. Part Number Description Side Qty (2 gates) 1 S004 10 00 00 0 1 Mounting Frame RH 1
S004 10 00 01 0 1 Mounting Frame LH 1
2 S004 20 00 00 0 1 Weight Arm RH 1
S004 20 00 01 0 1 Weight Arm LH 1
3 S004 30 00 00 0 1 Gate (with pin retaining plate) RH 1
S004 30 00 01 0 1 Gate (with pin retaining plate) LH 1
4 S004 40 00 00 0 1 Control Rod (2 piece, 1 rod end) Common 2
5 S004 40 00 02 0 1 Adjuster (with rod end) RH on gate
S004 40 00 03 0 1 Adjuster (with rod end) LH on gate
6 S004 40 30 04 0 1 Crank Lever Common 2
7 S004 40 30 06 0 1 End Bracket Common 2
8 S004 40 65 00 0 1 Handle Common 12
9 S004 40 65 06 0 1 Support Bracket Common 2
10 S004 40 65 08 0 1 15NB Control Rail Ring Common 24
Note: 20NB Control Rail Rings available on request
11 S004 40 65 12 0 1 Crank Stopper with rubber Common 2
12 S004 40 65 14 0 1 Crank Stopper Support Common 2
13 S004 40 65 16 0 1 Front Stopper Common 2
14 S004 40 65 18 0 1 Front Stopper Support Common 2
15 SHAFT COLLAR 28.6 Shaft Collar 1 1/8” Common 2
16 S004 10 65 00 0 1 2070 x 10mm Alignment Rod Common (not shown) 1
Fig.1 Kit for 1 gate shown
2
1
3
4
7
6
5
10
8
9
11
12
15
13
14
Version 1.4 P a g e | 5
Overall Dimensions
Fig 2. Overall Dimensions
Version 1.4 P a g e | 6
Safety Requirements These installation instructions provide guidance for the correct installation of the Pendulum®
gates and are intended to be used by qualified and experienced site engineers, who are
competent and fit to do the job safely. These gates are fitted internationally, therefore local
or site specific health and safety legislative requirements are not detailed within. Installers
must adhere to all local health and safety legislation. It is the responsibility of the personnel
on site to ensure the health and safety of everyone on and around their worksite, including
workers, clients and members of the public. Within New Zealand, the Health and Safety at
Work Act 2015 applies. If you have any queries or concerns regarding safe working practices,
please contact your supervisor, site foreman/manager or local safety advisor before
proceeding.
Leask Engineering is not responsible for the results of any action taken on the basis of
information in this document, or for any errors or omissions. The following safety list is not
exhaustive, but is intended as a quick guide.
Ensure:
The worksite remains safe
You are aware of the site hazards and controls implemented
You report accidents or near misses in the required timeframes
Personal protective equipment is worn in the correct manner (head, eyes, ears, hands,
feet), relative to site hazards and/or other hazards
Tools and equipment
o are right for the job
o have been tested and visually examined by a competent person
o guards are secure and in good repair
o safety devices are operating correctly
All operators are trained and competent
Electrical cables are within test date, and are routed to guarantee safe working
practices
The work area is fenced off from the public
The pit is guarded to prevent accidental falling
Suitable steps or a platform are available (600mm should suffice but depends upon
roof height)
Proper manual lifting techniques are used to avoid injury
Appropriate first aid and fire extinguishing equipment is at hand
Safe work procedures associated with welding or grinding hot works (welding flashes,
fumes, sparks, burns, fire) are followed
Version 1.4 P a g e | 7
Other Requirements (not supplied)
Tools
Marker Grinder with cutting disc for steel
Plumb line or 2m straight edge Spirit Level
Arc welder 2.5, 3 & 4.5mm allen keys
Hammer Measuring Tape
13,15,16,17,18, 19 and 24mm spanners 3.2 (or 2.5) welding rods
Wire Brush G clamp or similar
Paint and painting equipment Grease gun with multipurpose grease
Rope or strap 2 pairs of vice grips
Galvanised Medium Purpose Pipe
15NB – sufficient length for 2 control rails running the full length of the pit or
20NB - for pits longer than 26m, to avoid excess control rail flexing, 20NB control rails are
recommended. If required please contact Leask Engineering for 20NB control rail rings.
32NB – for diagonal bracing to roof rafters and fabrication of closed gate supports, lengths
are site specific.
50NB Breech Rail Front Posts – Minimum height 1940mm from finished floor level,
preferably higher and connected to a roof rafter as shown below. Alternatively connect
the two Breech Rail Front Posts together with a 50NB hoop.
Fig 3. Breech Rail Front Posts connected to the rafter
Version 1.4 P a g e | 8
Gate Installation
The Leask Pendulum® gate has been purposely designed for quick and easy installation.
Please follow these instructions carefully, incorrect installation may shorten the lifespan of
the gate, or make the gate more difficult to operate. Make sure all steps of the installation
process have been completed as instructed.
Instruction steps 2 to 16 are for the LH gate, when viewed with back to exit, looking towards the
cow entrance. Repeat all steps for the opposite side.
Step 1: Unpack the components
Set out the components, dividing the complete kit into left and right kits as shown below
Fig 4. Viewed with back to exit, looking towards cow entrance.
All components are symmetrical (can be used on either side) except for the 6 items shown below.
Fig 5. Close up of handed components (viewed with back to exit, looking towards cow entrance).
1a
1b
3a
2a
2b
3b
Version 1.4 P a g e | 9
Step 2: Cut the lead out rail (if applicable)
If the lead out (A) rail is attached to the breech rail front post (B), cut 250mm off the lead out
rail, measured from the face of the breech rail front post, and scallop the lead out rail an
additional 15mm (to socket over a 50NB post). The gate mounting frame (1) will be inserted
into this space.
Fig 6. Mark the lead out rail
Fig 7. Shortened and scalloped lead out rail.
B
A
Version 1.4 P a g e | 10
Step 3: Mark the floor where the tip of the gate is going to be above
Measure forward from the front face of the breech rail front posts (B). The distance forward
is determined by the cup centres (width allowed for each cow)
Cup centres Distance forward
660mm 1025mm
700mm 1055mm
760mm 1110mm
800mm 1140mm
900mm 1210mm
Place a straight edge (C) across the floor and mark a line on the floor (D). This is the preferred
distance forward for the tip (sweep arc) of the gate.
Fig 8. Place a straight edge the correct distance forward from the front post.
C
B
D
Version 1.4 P a g e | 11
Step 4: Position the Mounting
Frame
Positon and hold the gate mounting
frame (1) against the breech rail front
post.
Note: Gate mount is 21kg and is top heavy, it
is recommended that 2 people position this
item to ensure safe working practices.
The gate height is pre-determined by
placing the base of the mounting
frame on the finished platform
concrete. Contact Leask Engineering
for advice if the roof height is less than
2400mm as the mounting frame may
need to be shortened.
The gate position (relative to the
breech rail front post) is pre-
determined by socketing the 50NB
breech rail front post into the semi-
circular cut out.
Use a strong G clamp or similar to
secure the mount in place. See red
arrows for clamping position.
Also support the mounting frame and
clamp with a rope or strap, to prevent
either from falling if the clamp slips.
Simulate the gate maximum width (tip
of gate sweep arc) by using the
alignment rod as shown Fig 11.
Use a pair of vice grips to clamp the
10mm diameter x 2070mm alignment
rod (16), in the centre of the mounting
frame (see red arrows), and through
the hole/flush with the back of the
frame.
Fig 9. View of mount positioned against the breech rail front post.
Fig 10. View of mount positioned with breech rail front post socketed into the semi-
circular cut out.
Fig 11. Clamp the alignment rod to the mounting frame.
1
D
16
Version 1.4 P a g e | 12
Position the mounting frame at the correct
angle, relative to the pit. Use a spirit level and
straight edge (or plumb line) (E) to ensure the
tip of the alignment rod is directly above the
line drawn on the floor in step 3.
If necessary, loosen the mounting frame G
clamp and rotate the mounting frame (1)
around the breech rail front post (B) to
achieve the correct position above the line.
Retighten the G clamp.
Temporarily hang and swing the gate through
its full motion (if the G clamp allows), to
ensure you have sufficient space for the gate
to operate. It may be necessary to adjust the
mounting frame position relative to existing
obstacles e.g. roof beams.
Note: The gate is 24.5kg, it is recommended that 2
people position this item to ensure safe working
practices.
Important: To ensure the gate shaft is going
to be horizontal, place a spirit level across the
tips of the mounting frame quick attach hooks
and adjust to make it level. When you are
sure the mount is correctly positioned and
level in both directions, tack weld the mount
frame where it is clamped to the breech rail
front post to hold securely in place. To be fully
welded later.
D
Fig 12. Rotate the mounting frame until the tip of the alignment rod is
directly above the line on the floor.
Fig 13. Hang the gate and swing it through its full motion, to ensure there
is sufficient clearance to operate the gate.
Fig 14. Ensure quick attach brackets are level
E
D
1
B
Version 1.4 P a g e | 13
Step 5: Brace the Mounting Frame
Prior to adding any other components to the gate, the mounting frame must be supported by
bracing. Check the mount has remained level (as per step 4) in all directions and tack the
supports in place. Some bracing examples are shown, and a combination of methods may be
required to create a solid support arrangement.
Fig 15. A diagonal support to the rafter Fig 16. Bracing across the pit, connecting the front corner of the LH mounting frame to the front corner
of the RH mounting frame (if head height allows).
Fig 17. Bracing in line with breech rail front post, bolted to the wall. Fig 18. Bracing in line with breech rail front post, concreted into the
floor.
Version 1.4 P a g e | 14
Step 6: Complete the Mounting
Frame Welding.
When you are sure that the mount is
correctly aligned and is level in each
direction (as per step 4), and that the gate
has sufficient space to swing, the
mounting frame can be fully welded to
the supports (fitted in step 5) and then to
the breech rail post at the top (see Fig 20
yellow lines)
Ensure the mount upright is plumb
(parallel to the front post) in each
direction. Weld the mount to the breech
rail post at the bottom (see Fig 21 yellow
lines).
If applicable also weld the mounting
frame to the lead out rail (A).
Clean and paint all welds with a zinc
enriched paint.
Fig 20. Top welding.
Fig 21. Bottom Welding.
Fig 22. Lead out rail.
A
Version 1.4 P a g e | 15
Step 7: Position the Weight Arm
Note: The weight arm is 25kg, it is recommended that 2 people position
this item to ensure safe working practices.
The weight arm (2) can be lifted into position and supported
using a temporary pin placed through the bottom holes of the
weight arm top brackets as shown.
Lift the weight arm and temporary pin up through the middle
of the gate mount.
Rotate the weight arm 90 degrees and feed the guide box
section between the guide rollers.
Allow the temporary pin to carry the weight arm as it rests on
the mounting frame. This keeps the weight arm high enough
to be able to be joined to the gate.
Fig 23. Temporary pin placement
Fig 24. Lift the weight arm up through the mounting frame and rotate 90 degrees
Fig 25. Place the weight arm guide between the
rollers
Fig 26. Weight arm in temporary rest position.
2
Version 1.4 P a g e | 16
Step 8: Hang the Gate
Note: The gate is 24.5kg, it is recommended that
2 people position this item to ensure safe
working practices.
Ensure you have the correct gate - the
adjuster bracket should be on the cow
side of the gate.
Remove the M16 joining bolt from the
gate (3). Place the retaining plate onto
the gate hinge pin.
Hang the gate by placing the gate hinge
pin into the quick attach brackets.
Secure both sides of the hinge pin with
M10 x 35 bolts and nyloc nuts.
Slide the weight arm back towards the
pit, lift the gate up until the pivot holes
are horizontal, slide the weight arm
forward and align the holes. Replace the
M16 joinin bolt and nut taking care not
to damage the plastic bushes. Do not
overtighten the hinge bolt and nut.
Remove the temporary locating pin
from the weight arm.
When fully open there should be a
minimum of 50mm clearance between
the weight arm (1) and the floor. If the
mounting frame has been mounted
lower than normal, the bottom of the
weight arm and the short diagonal box
section will need to be shortened, to
avoid impact and also ensure there is
enough ground clearance to prevent
accidental nips.
Fig 27. Remove the M16 bolt and placement of the hinge pin retaining plate.
Fig 28. Hang the gate and secure the hinge pin.
Fig 29. Join the gate to the weight arm and fasten.
Fig 30. Shorten the weight arm if the ground clearance is less than 50mm
1
3
Version 1.4 P a g e | 17
Step 9: Check and adjust the gate closed alignment
When the gate is closed check if the gate hangs
correctly aligned, central in line with the weight arm
(see fig 31 red arrow).
If not, slacken the 6 bearing bolts and adjust the
gate, retighten the 6 bolts when the gate is vertical,
and resting between the guides.
While moving the gate up and down, make sure the
weight arm is guided between the rollers without
fouling. The gate should be easy to move, without
any tight spots.
Step 10: Check and adjust the gate open alignment
When the gate is fully open, the vertical rails in the gate should be plumb. If not, slacken the
6 bearing bolts and adjust the gate, retighten when the gate rails are vertical. The weight arm
should be sitting central in the mounting frame.
It may be necessary to complete steps 9 and 10 several times to get the gates to sit correctly
in both open and closed positions. Another adjustment option is to loosen the bearing grub
screws, and slide the bearings sideways on the shaft, then retighten the grub screws. In all
cases small adjustments are recommended.
Note: If the gate is adjusted vertical when closed (as per step 9), once the gate is fully opened
the weight arm will also have moved sideways as illustrated in per fig 34.
Fig 32. Check the gate is plumb. Fig 33. Adjust open gate Fig 34. Check the weight arm is central in the mounting frame.
Fig 31. Check gate hangs central to the weight arm.
Version 1.4 P a g e | 18
Step 11: Fabricate the closed gate support
It is critical that the corner of the gate is supported when in the fully closed position, otherwise
cows could force and bend the gate from either side. A closed gate support is required to
both prevent the cows pushing the gate sideways and also to catch and open the gate
extension (F) as the gate pivots closed.
The size and shape of the closed gate support is site specific therefore is not part of the
supplied kit. Catches and catch supports are included in the kit (see fig 37, items 13 & 14).
Tie the gate and weight arm
tightly together in the closed
position (see fig 35 red
arrows).
Pivot the gate extension (F)
out fully until there is 10mm
clearance at its rubber stopper
(G). Clamp the extension in
this position. The closed gate
support can be fabricated to
suit the gate in this position as
shown in figs 36 and 37.
Use 32NB galvanised pipe to
construct a support (H) from
the front headrail post (J).
Tack the closed gate support in
position. The gate must be
able to swing over the
horizontal stopper (13) (with
25mm clearance in all
directions), but the tip of the
gate extension (F) must catch
on the stopper forcing it to
almost fully extend as shown
in fig 37.
Untie the gate and weight arm, swing the gate through its opening and closing motion and
check the clearance between the gate and the stopper.
When you are sure the closed gate support is in the correct position, complete the closed gate
support welding. Clean and paint the welds.
Fig 35. Tie the gate and weight arm together. Gate fully closed and almost fully extended.
Fig 36. Example of a closed gate support Fig 37. Gate extension can’t get past the closed
configured to suit feeding troughs. support.
F
F
H
G
J
13&14
Version 1.4 P a g e | 19
Fig 38. Gate fully closed.
Fig 39. Gate fully open.
Version 1.4 P a g e | 20
Installation of the opening and closing mechanism
Step 12: Mount the Control Rail
It is recommended that initially only one length of control rail is fitted. The remainder can
be fitted upon completion of the gate set up.
Typically 15NB galvanised pipe is used for the pit control rails (K) and is
fitted along the full length and each side of the pit, enabling the gates to
be operated from anywhere along the pit. However for pits longer than
26m, to avoid excess control rail torsional flexing, 20NB control rails are
recommended. If so please contact Leask Engineering and request 20NB
control rail rings.
12 rings (item 10) are supplied for mounting the 15NB control rails on
each side. When fitted, the rail should be straight and easy to rotate.
The position of the control rail rings and brackets will depend upon how
close the breech rail front post is to the edge of the pit. If the post is at
or close to the edge of the pit, (within 125mm from pit edge to post face)
skip option 1 and instead go to option 2, or vice versa.
Option 1 - The breech rail front post is spaced away from the edge of the pit (>125mm from
the edge of the pit to the post face).
Weld two or three control rail rings (10) to the back of the
breech rail, placing the first ring close to the gate as shown in
fig 40 above. Slide a control rail through the rings.
Slide the crank lever (6) over the 15NB control rail (L) as
shown (or butt against the 20NB control rail), with the arm
towards the cow entry. Fully weld ensuring the axis is
straight.
Accurately measure the distance from the centre of the crank
lever pipe (6) to the face of the breech rail front post (B). Mark
and cut the Support Bracket (9) to suit the above
measurement, then slide it over the crank lever. Support the
weight of the components and tack the support bracket to the
breech rail front post. The bracket must be central to the post
and perpendicular to the control rail. The control rail must be
easy to rotate.
Fig 40. Gate Control Rail
K
H
Fig 41. Weld the crank lever to the control rail
Fig 42. Measure from centre to face. Shorten and
weld the support bracket central to the front post
6
L
10
H
B
6
9
Version 1.4 P a g e | 21
Slide the shaft collar (15) over the crank lever pipe.
Measure from the centre of the crank lever (6) to the centre
of the gate mounting frame post (1). Cut the end bracket (7)
to suit this measurement.
Grease the end of the crank lever tube. Slide the shortened
end bracket into the crank lever tube. Weld the end bracket
to the mounting frame post (1). The crank must go forward
towards the cow exit. The control rail must be easy to rotate.
Slide the shaft collar (15) up against the support bracket (9)
and lock in position.
Diagonally brace the support plate (9) and the end bracket
(7) (see red arrows)
Fig 43. Slide the locating shaft collar over the crank
lever pipe
Fig 44. Measure from centre to centre
Fig 45. Shorten and weld the end bracket to the
gate mount post. Clamp the shaft collar in place.
Fig 46. Diagonal braces
7
1
1
15
6
15
9
9
7
Version 1.4 P a g e | 22
Option 2 - The breech rail front post is close to the
edge of the pit (<125mm from the edge of the pit
to the post face).
If the breech rail front post is in line with the breech
rail, it will be necessary to space the control rail rings
off the breech rail a minimum of 30mm towards the
centre of the pit, to enable the control linkage to
crank over centre.
The distance from the centre of the breech rail front
post (B) to the centre of the control rail (L) needs to
be a minimum of 65mm.
Accurately measure the above distance, mark and
cut both the support bracket (9) and the end bracket
(7) to suit this measurement.
The distance from the centre of the control rail (L) to
the top face of the mounting frame flat
crossmember (1) must be a minimum of 75mm.
Using the above dimensions, weld two or three
control rail rings (10) to the back of the breech rail,
placing the first ring close to the gate as shown in fig
40 above. Slide a control rail through the rings.
Slide the shaft collar (15) and then the shortened
support bracket (9) onto the crank lever (6). Fit the
crank lever (6) over the 15NB control rail (L) as
shown (or butt against the 20NB control rail), with
the arm towards the cow exit. Fully weld the crank
lever to the control rail, ensuring the axis is straight.
Support the weight of the components and weld the
support bracket (9) to the breech rail front post (B).
The bracket must be on the side of the post and
perpendicular to the control rail. The control rail
must be easy to rotate.
Fig 48. Measure between centres.
Fig 49. Weld the crank lever to the control rail.
15
L
9
6
L
1
B
B
Version 1.4 P a g e | 23
Grease the end of the crank lever
tube. Slide the shortened end bracket
(7) into the crank lever tube (6). Weld
the end bracket (7) to the breech rail
front post (B). The crank must go
forward towards the cow exit. The
control rail must be easy to rotate.
Slide the shaft collar (15) up against
the support bracket (9) and lock in
position.
Fig 51. View of ‘post close to pit edge’ crank lever arrangement.
Fig 50. Weld the shortened end bracket to the breech rail front post.
15
B
7
6
9
Version 1.4 P a g e | 24
Step 13: Attach the Gate Control Rod
Position the adjuster approximately in the middle of the
gate adjustment slot.
Fit the straight section of the control rod (4) to the adjuster
bracket (5).
Fit the dog leg section of the control rod (4) to crank lever
(6). Use the inner hole if the post is close to the pit edge (as
per step 2, option 2), otherwise use the end hole as shown.
Ensure the ball joint is pinched up tight, therefore
preventing the ball rotating on the bolt.
With the gate (3) held hard closed, pivot the crank lever
(6) to the ‘1 o’clock’ position.
Use 2 pairs of vice grips to clamp the 2 pieces of control
rods (4) together, edge to edge.
Do not weld the control rods together yet – further
adjustment will be necessary. This is completed at the
end of step 16.
Fig 53. Attach the straight section of control rod
Fig 54. Attach the ‘dog leg’ section of control rod
4
4
6
4
3
Fig 55. Close the gate and pivot the crank lever to 1 o’clock
Fig 56. Clamp the two sections
of control rod
together
3
4
6
4
4
5
Version 1.4 P a g e | 25
Step 14: Fit the Crank Stopper
Pull a string line (see blue line) from the top control rod ball
joint to the middle of the crank lever pipe.
Push the crank lever (6) forward towards the breech rail
front post until the axis of the bottom ball joint is 30mm
past the string line as shown (this puts the crank over centre
and locks the gate closed).
While the crank lever remains in this position, weld the
crank stopper (11) with rubber bush against the crank lever,
and weld a diagonal brace using the crank lever support bar
(12).
If the breech rail front post is close to the pit (as per Step
12, option 2), a small crank stopper with rubber bush can
be welded to the side breech rail front post as shown.
Fig 57. Pull a string line as shown and position the
crank
Fig 58. Crank stopper (option 1, post offset from pit)
Fig 59. Crank stopper (option 2, post close to the pit)
6
11
12
Version 1.4 P a g e | 26
Step 15: Adjust the Gate
Various adjustments may be necessary, as illustrated.
It is assumed that the control rod overlap (see fig 61) is not welded but instead is clamped
with vice grips for easy adjustment. If an existing gate is being reset, it may be necessary to
clamp the control rod with vice grips (see fig 56) and cut existing welds (see fig 66).
A very small adjustment movement can make a large difference to the gate placement and
swing. Make only one adjustment at a time, open and close the gate and observe the
consequence.
Altering one adjustment can negatively affect another adjustment, a combination of
movements is often required to achieve a proper setting.
When making adjustments – the aim is to get a small rise in resistance as the crank lever goes
over centre in both directions (gate fully open and gate fully closed). If the adjustments are
set too ‘tight’ and there is too much resistance or the crank can’t go over centre, the gate will
be too difficult to operate at the far end of the pit. If the over centre is too slack, the gate
could accidentally open or close. The over centre resistance should be the same for both open
and closed positions.
The gate should move through its full motion without any components fouling (except for
rubber buffers). Adjust as necessary if any components are not positioned properly.
Fig 60. Adjuster/gate slide Fig 61. Control Rod overlap slide
Fig 62. Ball joint roll and length adjustment Fig 63. Adjust the fully open/rubber stopper bolts.
Version 1.4 P a g e | 27
To prevent the gate from bouncing (and causing premature fatigue), it is important that the
gate sits firmly against the rubber stoppers. An incorrectly positioned crank stopper (see step
14) can also cause problems if the crank travels too far, the gate can bounce off its rubber
stoppers.
When fully open, the gate should be compressing the
top stoppers (see red arrows).
When fully closed, the gate should be compressing the
weight arm stopper (see red arrow).
Adjustment Result Other consequence Move adjuster towards the gate hinge pin Increased gate swing (both directions) Control rod may also need reset
Move adjuster away from the gate hinge pin Decreased gate swing (both directions) Control rod may also need reset
Extend Control Rod (at overlap or ball joint) Gate closes further, Opens less
Contract Control Rod (at overlap or ball joint) Gate opens further, Closes less
Ball joint roll – lock nut at ball joint Determine the sideways position of the control rod
Extend spacer bolts under top stop buffers Gate opens less (useful for low roof height) Control rod and adjuster may also
need reset
Shorten spacer bolts under top stop buffers Gate opens less (useful for low roof height) Control rod and adjuster may also
need reset
Problem Action Insufficient roof height Extend spacer bolts under the top stop buffers (see fig 64)
Gate does not open high enough, and does not close fully Move adjuster closer to the gate hinge pin
Gate does not open high enough, but is ok when closed Move adjuster closer to the gate hinge pin and shorten the control rod
Crank lever will not go over centre when gate is fully open Move adjuster away from gate hinge pin and lengthen the control rod
but is ok when gate is closed or shorten the top buffer adjustment bolts.
Gate does not close enough, but is ok when open Move adjuster away from gate hinge pin and lengthen the control rod
Crank lever will not go over centre when gate is fully closed
but is ok when gate is open Move adjuster away from gate hinge pin and lengthen the control rod
Gate open crank over centre is too tight, gate closed is too slack Lengthen control rod
Gate open crank over centre is too slack, gate closed is too tight Shorten control rod
Fig 64. Top stoppers compressed when the gate is
fully open.
Fig 65. Weight arm stoper compressed when the
gate is fully closed.
Version 1.4 P a g e | 28
When you are satisfied that the gates are operating
correctly, weld the two sections of control rod (4)
together and remove the vice grips which were added in
step 13 (or 15 above).
The gate operational weight can be adjusted by
repositioning the weight block on the gate. Slide the
weight towards the hinge pin to make the gate easier to
open. Slide the weight away from the hinge pin to make
the gate easier to close.
Step 16: Completion
Finish installing the remainder of the control rail rings and control rails, welding the rails end
to end. Grease each point where the control rails pass through a control rail ring.
6 handles (item 8) are provided for each side of the pit, to be placed one to the rear of the
first cow, and the remainder equally spaced. More handles are available upon request. The
handles should be carefully placed so that the cows sitting back hard on the breech rail cannot
unlock the gates. Handles should be near vertical when closed (crank lever over centre), and
in a position where fingers can’t be nipped.
Clean and paint all installation welds with a high zinc content paint.
Check all nuts, bolts and grub screws are tight.
Grease each of the bearings and the control rod rings.
Monthly Maintenance
Check all nuts and bolts are tight.
Grease each of the bearings and the control rod rings.
Check the gate adjustment as per step 15, and adjust as necessary.
If rubber buffers are damaged, replace as soon as possible.
Ensure all the moving parts are not fouling during their movement.
All parts are available from Leask Engineering if required.
Fig 66. Weld the control rod.
Fig 67. Adjust the gate weight.
4
Version 1.4 P a g e | 29
Operation
Beware of low head height when walking under the gate.
Keep clear of moving parts, to avoid contact or nips. A gate moving at speed can create a
serious impact.
To make operation easier the gates have been weighted so they are lighter to close (pushing
the handle upwards) than they are to open, (pulling the handle downwards).
When cows are exiting, do not use the front handles to close the gate and stop the cows. The
cows will be watching you and will not see the gate close. Instead operate the gate from
further down the pit.
Do not operate the gate without visually checking it is safe to do so.
Do not operate the gate if any components become loose or damaged. Get the gates repaired
immediately.
The gate should be opened and closed gently to avoid continuous use heavy impacts.
If gates become difficult to operate, adjust the gate as per Step 15, or contact the installer for
advice.
23May17