Overhead Conveyors
Overhead Conveyors
Overhead Conveyors
Drive Specifications
Safety Devices
Screen Guarding
Pitfalls To Avoid
Power and Free with chain, drive(s), trolleys with load bars,
horizontal, and vertical curves, switches, take-ups, stops, etc
Light Duty:
Heavy Duty: For 200 lbs and 1200 lbs per hook loading
The following are some basic considerations to help you layout your system:
- Start with drawing a plan to scale of the building area in which
the conveyor system will be installed, showing all aisles, columns,
obstructions, equipment, and areas to be considered. - Determine
the type of load carried.
Consider the size and type of load to be carried and also the type of carrier
or hook to be used.
- Then consider the total load to be carried on each trolley.
This is an important factor in determining the size of the trolley, chain, track
and drive to be used.
- Plan the material flow which involves the speed at which the
conveyor will operate, and the spacing of trolleys, carriers or
hooks.
The desired conveyor speed is calculated by taking the required number of
parts per hour, multiplying this by the carrier spacing and dividing by 60
multiplied by the parts per carrier. Manual loading and unloading of an
overhead conveyor is considered to be between 10 and 25 FPM.
- Consider the type of conditions under which the conveyor will
operate.
This includes temperature, paint and chemical conditions and the
accessibility for lubrication or other factors which would have important
bearing on the type of components to be used especially the kind of trolleys,
turns and bearings.
- Choose the horizontal and vertical curves based on the size of
load and desired carrier spacing.
See tables A and B below for radii and trolley spacing minimums
- Be sure that the loads do not interfere with each other in curves
by laying out the horizontal and vertical curves and then laying in
the loads. - Allow for one trolley spacing of straight track between
horizontal and vertical changes to ensure proper chain alignment. Try to place the drive in the high point in the system with the takeup in front of the drive preferably in the low point in the system,
but close to the drive as possible.
This will ensure that slack chain is pulled away from the drive chain.
- Figure the total chain pull by first calculating the weight of the
product, carrier, chain and attachments on the entire system.
The most practical thing to do is to provide an ample margin of safety in
planning the chain and drive size.
- One means of figuring the total chain pull, particularly on simple
systems involving only one drive is the Total Moving Load
Method as described below:
The quick chain pull method for simple systems with one drive andno more
than 18 changes in direction is:
Calculate the total moving load and multiple this number by the friction
factor from Table C. This will give you a quick chain pull to help choose a
drive, system size, and type. To this figure you must add the vertical loads
by adding and subtracting the up and down loads. Multiply the vertical drop
or rise by the number of pounds per foot and consider the worst conditions
of loading. Many times a load going up will be cancelled by a load going
down.
Sc
Sp
Air
*Note*
Take-Up travel is normally 8, 12 or 16 and amount of chain that can be
taken up isdouble the travel.
*Note*
The X number designation of I-beam conveyors is a combination of the
chain pitch (3,4 or 6) and the diameter of the chain pin (.48, .58, or .
68)
Retainer Type: These are typically used in light or moderate load and
low contaminate conditions such as transportation, parts delivery or
assembly operations. The advantage is low friction, minimum ball
wear, and the least drive energy.
Full Ball Type: These are used for heavier loads and
contaminant conditions. Also, they are use in high temperature
conditions up to 500 degree Fretainer types have a maximum range
of 325 degrees F.
They come in pairs and are bolted together between the trolley
brackets.
2. B Attachments:
Normally used to support the load bar from a pair of trolleys but can
be used for other applications.
3. C Attachments:
Can also be used with a bent rod hook to carry light loads.
4. I or Dummy attachments:
5. Indexing Swivels:
6. Rotary Rack Swivel hooks have a gear rack which provides positive
turning action when engaged by a corresponding gear.
The sides and floor panels are joined with a steel helix.
It is not easy to do, but the new chain needs to be dispersed evenly in
20 to 30 sections evenly through out the system in order to
minimize the pitch difference.
The problem comes when the wrong drop trolley comes to the
drive.it will not go through.
The wrong length bolts or thicker nuts may not engage the drive and
turns properly.