Overhead Trolley Conveyors
SSI Overhead Trolleys are simple and can be utilized to move a wide variety of materials. 3", 4", or 6" trolley systems are available with a wide selection of versatile components and accessories. Installations that follow almost any required horizontal or vertical direction, or turn, are possible, because of the conveyor's exceptional flexibility.
The SSI Overhead Conveyor provides economy by reducing the manual handling of materials to minimums, while it simultaneously increases speed and accuracy. Costly losses due to damage and negligence are considerably decreased. The conveyor can also furnish convenient storage of parts until needed for processing, which is achieved through elevation to the ceiling, or to positions between the roof trusses. Floor space is left uncluttered, and becomes available for other operations.
With its chain and trolleys properly shielded, the SSI Overhead Conveyor can be used for transporting materials through operations such as metal cleaning, painting, dipping, chemical processing, sand blasting, oven drying, etc. Many operations of this kind cannot be done manually without hazard to the operator.
The SSI Overhead Conveyor can be combined with other types of conveyors to provide maximum efficiencies in automatic conveying and assembly systems. It can maintain a constant supply of parts to processing or assembly points, reduce stock room requirements, help keep inventories to a minimum, and remove accident hazards by keeping work areas clear.
The major components of the SSI Overhead Conveyor are standardized. Should the customer prefer to do his own conveyor installation, SSI can ship the components and other parts necessary for the installation.
The SSI Overhead Conveyor is usually simple to lay out, though special attention should be given to the selection of some of the components. SSI's experienced Engineering Staff is always available for consultation and can greatly assist in the installation of a most effective and economic conveyor system.
Conveyor Layout
The first step in planning an overhead trolley conveyor layout is to prepare a scale drawing of the conveyor path. Clearances between the work carriers, on vertical dips and horizontal turns, should be checked. Bulkier loads may necessitate transport on alternate trolleys for maintenance of proper clearances. Loads which are too heavy for single trolleys require a load bar, which is attached to two consecutive trolleys.
SSI Chain
The standard SSI Overhead Conveyor uses drop forged, rivetless chain. The chain features strong side bars and center links, and is flexible on vertical dips and horizontal bends. SSI offers three standard types of chain:
- #348 Chain - For light individual loads and chain pulls not exceeding 2000 lbs., with 1500 lbs. as a recommended maximum per drive unit.
- #458 Chain - For medium individual loads, and chain pulls not exceeding 3500 lbs., with 2500 lbs. as a recommended maximum per drive unit.
- #678 Chain - For heavy individual loads, and chain pulls not exceeding 6000 lbs., with 4500 lbs. as a recommended maximum per drive unit.
Read more about SSI's Drop Forged Rivetless Chain.
Versatility
For many years the SSI overhead trolley conveyor has proved to be one of the most economical methods of moving materials throughout manufacturing plants.
The versatility of overhead conveyors allows for an almost unrestricted layout in path configuration, both in elevation changes and horizontal roller turn changes.
SSI Trolleys
SSI offers a complete line of trolleys, attachments and load bars for 3 inch, 4 inch, and 6 inch systems. All trolley wheels are fully machined and hardened. Bearing raceways are hardened and ground. For special applications, trolleys can be made to order incorporating features such as rubber covered wheels, or special bearings.
SSI's complete line of trolleys is shown in the trolley section.
SSI Track
SSI fabricates 3", 4" and 6" track to accommodate its trolleys. All track is made of high alloy rolled sections and held to close tolerances in cross sections. Read more about SSI's I-Beam Conveyor Track.
SSI Traction Wheels
It is preferable to use traction wheels whenever possible as the traction wheel will guide the chain around the horizontal turn on a continuous surface. This minimizes wear and eliminates a chordal motion of the chain. Furthermore, the traction wheel has only a single set of bearings to maintain. In an application where the ambient temperature of the turn is high, as in ovens, the traction wheel should be used. In areas where lubrication and wear must be held to a minimum, as in foundries or sand blasting areas, the traction wheel is recommended.
As with roller turns, the largest convenient radius of a turn should be used. The recommended minimum radii are given below:
Take-Ups
Take-ups are usually a necessity for proper overhead conveyor operation, especially on long lines and in cases where the conveyor operates through an oven and is subject to constant temperature change. SSI offers take-ups with either traction wheels or roller turns in a wide selection of sizes. These take-up units are screw, spring, counterweight or air cylinder operated.
SSI Drives
SSI offers two standard types of drives; caterpillar and sprocket. The caterpillar is more frequently used, since it can be located on any section of straight track.
The floating caterpillar drive is mounted on an inner floating frame that is guided and supported by ball bearing wheels attached to the outer frame.
Sprocket drives are offered, but must be located at a turn of 90 degrees minimum.
Horizontal Turns
The radius of a horizontal turn, whether roller or traction wheel type, depends on package width and length being conveyed,and centers on which the packages are hung.
If the part size and part centers are fixed, a clearance diagram is required to determine the minimum radius turn to provide satisfactory operation.
If the conveyor is routed through ovens and/or other enclosures, the part "kick-out" should be checked at the same time the clearance diagram is made.
Vertical Curves
Large radius vertical curves should be used whenever possible. If the conveyor layout is such that a minimum tangent to tangent distance of the vertical curve is required, necessitating short radius turns, a clearance diagram is mandatory.
With a known conveyor rail radius, package size, and trolley spacing, clearance can adequately be determined from a study drawing similar to the picture shown above.
Vertical Curve Radii As It Relates To Trolley Spacing
SSI Rivetless Chain
SSI's rivetless chain meets all industry specifications. The chain consists of three (3) basic parts: Center link, two (2) identical side bar links, and a connecting pin.
The chain requires no special tools or wrenches to assemble, and when properly pinned together it will not disengage, under normal operating conditions. All SSI chain is of the "X" variety, allowing for sharper radii vertical curves. All SSI chain is heat-treated for extra strength and durability.
Special alloy steels are used to provide smooth bearing surfaces which permit smoother chain travel, resist shock. The chain is naturally resistant to corrosion and abrasive atmospheres.
All drop-forged steel chains require a certain "wear-in" period after a new conveyor is installed.
The elongation and extra length developed from the "wear-in" is absorbed with an automatic take-up assembly. When special requirements dictate, matched strands of drop-forged steel chain can be supplied, at a slightly higher cost.
The following tables depict the various sizes of "X" drop-forged steel chains available, general dimensional data, and average ultimate strength.
SSI Silver Seal Trolleys
SSI Overhead Conveyor Trolleys are available in three sizes: 3 inch, 4 inch and 6 inch. These three sizes encompass most industrial usages. Because they are carefully engineered and precision built to assure top quality, SSI's Trolleys offer superior performance and long-lived values.
Load Bars
SSI manufactures both standard and special load bar assemblies to meet individual job requirements. For loads varying from 15 lbs. to 2400 lbs. and with special modifications, even heavier loads for steel mill and foundry applications.
348 Malleable Iron Casting SSI Load Bar
Fabricated Load Bars
458 Malleable Iron Casting SSI Load Bar
678 Malleable Iron Casting SSI Load Bar
3”, 4” & 6” Track
The I-beam track must sustain the entire load carried on an overhead trolley conveyor. Also, the lower flange of the I-beam must withstand the wear caused by trolley wheels. Because of these factors (weight and wear), the I-beam generally limits trolley loading. In most instances a trolley will carry heavier loads than the I-beam will withstand without peening or undue wear.
To assure longer wear and better load carrying characteristics, Southern Systems Inc. supplies I-beams of special high alloy steel in standard structural sections.
I-beam track is typically fabricated in 20 foot lengths, though can be cut to any required length.
SSI Roller Turns
Roller turns are the most economical type of horizontal curves available for Overhead Conveyors and Power & Free Systems. The turns may be equipped with conventional rollers, "Sealed-for-Life" rollers, and/or relube rollers with Alemite grease fittings.
The roller segment is precisely matched to the beam radii, providing concentric engagement around the total arc.
When properly lubricated, roller turns can be used in temperatures up to 400°F. For best operation, however, the temperature should be restricted to 300°F.
Roller turns are easy to manufacture in special radii and odd degrees.
The recommended minimum radius of a turn to be used for various load (chain pull) conditions is listed below:
Traction Wheel Turns
Traction Wheel Turns are used to hold the Conveyor Chain under the Vertical Centerline of the I-beam on Horizontal Curves
Traction wheels are available in both plate type and spoke type construction. SSI wheels utilize spoke type construction for all pitch diameters greater than 48". SSI spoke-type wheels are the strongest in the industry; a unique design allows for a common hub assembly to be used on all diameter traction wheels. This minimizes spare parts inventory for the user.
SSI traction wheels offer several application features over roller turns in conveyor systems layouts, including less chain wear because the chain rides the wheel in lieu of segmented rollers, reduced chain pull on the conveyor system due to the precision antifriction bearings in the traction wheel, and lower maintenance costs due to the single point lubrication.
Tapered roller bearings are utilized in all traction wheels outside process equipment; in ovens, washers, and similar equipment, carbon-bushed hubs are utilized and require no lubrication.
Tapered Roller Bearing Traction Wheel Hub
SSI's Tapered Roller Bearing assembly is suitable for all speed ranges. When properly lubricated, this unit will operate efficiently in dry conditions up to 270° F. Because of their large lubricant storage capacity, these bearings extend the time interval between required maintenance lubrications. These roller bearings are also available with a Removable Shaft Block type hub.
Carbon Bushed Traction Wheel Hub
SSI's Carbon Bushed Assembly is suitable for all speed ranges, and has the ability to withstand high temperatures up to and including 550° F. This unit can be used in highly contaminating conditions, such as those found in washers and ovens. It requires no lubricating.
Traction Wheel Hub Assemblies with Timken Tapered Roller Bearings
Traction Wheel Hub Assemblies are furnished complete, factory adjusted, prelubricated, and ready to use. They are constructed to operate with wheels (sprockets) ranging from two to six feet in diameter. Commonly used in overhead chain conveyors, the units bolt directly to the supporting structure and can be adjusted vertically to three different operating positions.
Take-Ups
Almost all conveyor systems require take-ups for assuring the removal of chain slack and the maintenance of correct chain tension. SSI furnishes two basic types of take-ups: Traction Wheel and Roller Turn.
Anti-Backup Devices
To prevent reverse conveyor travel caused by chain breakage, this Anti-Backup device is installed on vertical curves.
Silver Seal Swivels & Hooks
SSI No. 512 & 513 Indexing Swivels
This malleable iron indexing swivel has a 125 lb capacity rating. It is used with SSI 3" and 4" trolley "H" attachments.
SSI No. 513-B Indexing Swivel
Made of malleable iron, this indexing swivel has a 200 lb capacity. It is used with SSI 3" and 4" trolley "H" attachments.
SSI No. 7073 90° Indexing Swivel
This indexing swivel is made of malleable iron and has a 125 lb capacity rating. It is used with 3" and 4" trolley attachments.
SSI Sanitary Hook Assembly No. 514-C
SSI No. 4155 “Smooth Index & Swivel” Automatic Indexing Asssembly
When the automated rotation of units carried by an overhead conveyor is required, such as in electrostatic spray painting booths, etc., this automatic indexing swivel assembly performs admirably.
Made of malleable iron, it has a 150 lb. capacity and is used with 3" and 4" trolley attachments for 90°, 180°, 270°, and 360° rotations. Its design accommodates gradually accelerating or de-accelerating rotation at conveyor speeds in excess of 30 fpm.
SSI No. 4155-C Sanitary “C” Hook
Many Painting Systems require a sanitary pan guard to circumvent dirt from falling on the painted parts.
When a sanitary pan guard is required, SSI Indexing Swivel #4155-C should be utilized. The same automatic, gradual acceleration and de-acceleration features of the basic Indexing Hook #4155 are available with this assembly. The unit is manufactured by adding a flame cut "C" yoke to the basic Swivel Assembly. Further, adjusting nuts are furnished on the swivel to assure proper product alignment. This is especially suitable for automatic electrostatic painting.
A unique SSI feature is the bearing surface plates which rest on the chain pins located on either side of the trolley assembly. This design allows for "C" hook stability without necessitating double trolleys and a load bar arrangement. Variations of SSI standard 4155-C Hook assemblies are available upon request.
Overhead Conveyor Carriers
Usually, products to be processed dictate the type of carrier that should be selected. When small parts are being handled, sometimes a more versatile carrier helps to get the job done better.
Some of the more typical carriers are shown below:
Overhead Conveyor Guards
The most commonly used SSI guarding is the welded wire type due to its low initial installation cost, as well as its ability to be easily relocated with future conveyor layout changes.
This comes from the fact that the side walls of the guarding are attached with steel helixes, as are the adjoining sections. No welding, bolting or special tools are needed for installation.
SSI sheet metal guarding is generally used after cleaning, painting, dipping and chemical processing. It eliminates the hazard of these liquids dripping and accumulating under the conveyor. The elimination of smaller parts falling onto work areas below is another feature of this guard.
SSI expanded metal guarding is available in many sizes and gauges depending on the size and weight of the item conveyed.
Vertical Dips
Dimensions of single and compound vertical curves are standard in the industry for given radii and degree. Most any tangent-to-tangent length, drop (elevation difference) as well as correct conveyor chain length can readily be determined by utilizing these charts and the following sections.
Dimensions of Single Bends
Vertical Curve Combined Bend Dimensions
Example:
- Given 8'-0" radius x 30° curve and 10'-10" total drop,
- Find: L (tan/tan) = 2c + E
- Find: Total rail length (2a + G)
- From Charts on Opposite Page: 8'-0" R. x 30°
- "a" = 4'-2 1/4"
- "b" = 1'-0 7/8"
- "c" = 4'-0"
- Drop (D) = 2b + F
- F = D - 2b
- F = 10'-10"-2(1'-0 7/8") = 8'-8 1/4"
- From Charts on This Page
- Find value of E and G with F = 8'-81/4"
- L(tan/tan)=2c+E
- 2(4'-0") + 15'-0 1/2" = 23'-0 1/2"
- Total length =2A + G
- 2(4'-2 1/2") + 17'-4 1/2" = 25'-9"
Overhead Conveyor Track Compound Vertical Curve Dips
SSI Conveyor Drives
Because of its unique design, the SSI Caterpillar Drive can be located along any straight portion of an Overhead Trolley Conveyor or Power and Free Conveyor system. The forged dogs on the cat chain provide smooth strong engagement for the main conveyor chain.
Due to the small diameter head sprocket on the cat chain, extremely high chain pulls are available for single drive units. SSI Caterpillar Drives are available for floating frames, with preset chain pull limits and an automatic electrical overload device to shut off the conveyor in the event of a jam.
Floating Caterpillar Drive
SSI Sprocket Drives are furnished either in the fixed frame or floating frame design. A sprocket drive must be located at the corner turn at a minimum of 90° and recommended locations are at 180° turns.
Sprocket drives are normally limited to 36" P.D. diameters. SSI sprocket drives are generally limited in application to relatively short conveyors with light chain pull requirements.
Caterpillar Drives
Caterpillar Drive Assembly
Overhead Conveyor Rotary Drives
SSI manufactures a full complement of rotary frame drives for both Overhead Systems and Chain-on-Edge Conveyors. The unit depicted below was specifically designed for an oven drive application, wherein the Caterpillar head assembly was located inside the oven, and the drive machinery was located on top of the oven.
SSI's rotary frame drives provide a simple overload "cut-out", while maintaining a fixed position for the Caterpillar head unit, eliminating chain jams on multiple drive systems.
Rotary Frame drives are available from 1HP thru 25HP units.
