Common Vibratory Terminology

Air Jet

Small diameter tubing used to assist in moving or orienting parts. Air is adjusted by trial and error. Air jets are used sparingly.

Amplitude Control

A controller that uses voltage change to control speed.

Back Pressure

The force of the parts pushing one against the other as they are feed.

Back Pressure Relief Device

A sensor used to detect part levels in the discharge to control a solenoid that blows air too remove parts from the tooling. Used to keep difficult parts from jamming in tooling areas, or to help keep multiple lane systems even.

Back Pressure Relief (Bubble-Off):

A section of tooling just prior to entering the bowl discharge. Used to allow parts to fall from the tooling back into the return pan without jamming a full bowl discharge.

Back Pressure Relief Tooling

The area just prior to the entrance of the confined area where the parts will buckle if the discharge is full, the parts can then re-circulate in the feeder. This will relieve part pressure at any previous are to prevent problems.


A stainless steel deflector placed on the inside of the bowl bottom to guard the return hole thus allowing parts to flow evenly back up the track from the return pan.

Base plates

Enables easy mounting of the drive unit to the machine bed.

Bowl Basic

The cylindrical “vertical” band and its internal tracks. Each bowl basic is custom fabricated per part and feed specifications, band height and diameter, internal track separation (height distance between tracks) angle and width.

Bowl Tuning

A technical/craft to develop maximum spring energy level but to keep the coil assembly cool. Changing spring tension of the drive unit to allow the feeder mass to return to its neutral position before the next magnetic pulse takes over.
The driving force used to drive the bowl feeders is accomplished by using two or three electromagnetic coils which act upon and pulls face plates which are constrained by leaf springs attached to the cross arms, causing a torsion vibration and translating the vibrations in a vertical direction. When the drive base moves the parts at maximum efficiency with minimum current effort the unit is said to be tuned. The mass of the feeder bowl is the determining factor in tuning the unit. The rubber feet placed at each corner of the base drive play an important part in tuning as well as a solid/firm mounting of the feed system.


Bowl feeder coatings which minimize wear and tear, reduces friction, noise and damage to parts.

Cord Section

A straight section of either stainless or tool steel used to select or orient parts. (can be inside or outside of the feeder).


A section of the feeder used to control parts through the selector, or discharge chute. Confinements are provided to allow access to parts by removing a bolted on section.

Counter-Balance Weight

A piece of metal of predetermined size and weight that is added to the exterior of the feeder at a location determined by a counter-balance wheel in effort to off-set the weight of the external tooling.

Dirt Chute / Dirt Relief

Used to discharge small particles of foreign material from the feeder. Must not be larger than the smallest dimension of the parts being used in the feeder.

Discharge Chute

This controls the parts in the orientation achieved in the feeder. It is mounted tangent to the centerline of the feeder.

Down Angle Discharge Chute

Used to assist parts from the vibratory parts feeder into a gravity track section or to meet a customer specification.


A mechanical device placed at the end of the feeder discharge that allows only one part at a time to move into another place, such as a dead nest, to be picked up by a placing device.

External Tooling

Any construction outside of the cylindrical “vertical” band. This tooling selects, separates, orients and relieves pressure build-up on oriented parts. A rule of thumb for a basic tooling area extending from the band/bowl diameter is 1/3 the bowl diameter.


An adjustable gap which allows part to swing or hang and separate.

Feed Rate

The number of parts per minute or hour discharge from the vibratory parts feeder to maintain production requirements set by the manufacturer. It is good practice to require a 20% higher feed rate of the feeder bowl then the equipment it is supplying product too.

Full Track Shut-off

A means of providing a pressure relief when the parts will not efficiently bubble off of their own accord. This device can be either a proximity, photocell, L.E.D. fiber optic, or pneumatic type sensor to signal the feeder to start or stop. Also a sensor can activate an air jet to eject excess parts from the entrance to confinement, in which case the feeder would continue to run (latter is most generally used with multiple tack feeders).

Horizontal Cam

An irregular shaped piece of metal placed inside the feeder above the parts at different points to control level of parts on the track. Used to reduce the amount of product as it is transferred up the internal tracks.

Inline Vibratory Track/Feeder

A vibratory drive unit designed to produce a straight-line motion. Used with a straight track to transport parts from the feeder discharge to a dead nest or a pick up point for removal via the customer. When used with a feeder they are mounted on risers so the inline tooling can be matched to the feeder discharge. A line track is critical to achieve a consistent feed rate and product accumulation.

Alternative Tracks to Vibratory

Gravity tracks and vertical magazines are ways of getting parts from one location to another. Gravity tracks set on an angle great enough that the gravity will pull the part to its proper location. A magazine is a channel in which oriented parts are stacked.

Internal Tooling

Any construction inside of the cylindrical “vertical” band. This tooling selects, separates, orients and relieves pressure build-up on oriented parts. Typically used on simple to orientate product (headless pins, balls, discs). The benefit of internal styled feeder bowls is reduced bowl size, there is very little material extending outside of the bowl diameter, unlike with an externally tooled bowl.


The position of the part as it exits the discharge required by manufacturer specifications.


The amount of straight track tooling that extends beyond either end of the inline drive-mounting bar.


Properly placed tooling to change the attitude of a part to the proper position for final selection. A pre-orientor will generate higher feed rates and minimize recirculation of the parts, thus extending the life of the bowl, especially with the regard to metal or abrasive parts.

Quick Dump Chute

A quick opening “window” to allow a quick part change when multiple styles or sizes of parts are being fed in the same feeder.


The number of parts discharged per minute or hour, as needed to maintain production requirements.

Return Pan

An area attached to the band, so the parts that have rejected due to incorrect orientation can be re-circulated back into the bottom of the bowl.

Running Surface

The portion of the discharge chute that the part makes contact with product. The running surface is the surface specified for discharge height.


The tooling designed specifically to accept only parts that will be used to accomplish proper orientation and feed rate.


Minimum/maximum level control on a linear track.

Sound Enclosure or Cover

A foam-lined structure that absorbs the noise produced by the vibratory feeder and the parts within it. Enclosures and/or covers help to reduce noise and protect against dust and contamination.

Storage Supply Hopper (Hopper)

A large container used to store extra parts to replenish the supply in the feeder. Hoppers operate automatically upon a demand from the feeder eliminating a deficiency or over supply of parts in the feeder which causes the feeder to malfunction. The used of an automated supply hopper is recommended for the feeding of product into a feeder bowl to maintain an optimum level of product in the bowl. Most all feeder bowls can be adversely effected by the quantity of product placed in the feeder bowl (too much or too little product) hindering feed rates, drive coil and spring fatigue.

Sweep or Cam

A strip of metal placed on the inside of the feeder bottom to guard the return hole and allow parts to flow evenly back up the track from the return pan.

Vibratory Parts Feeder Bowl

The vibratory parts feeder is the basic bowl custom designed with the external or in some cases internal tooling to meet the specifications required by the manufacturer such as feed rate and part orientation. Jerhen Industries, Inc. constructs all of it feeders of 304 stainless steel (316 stainless steel when specified). Tool steels are used in tooling areas of the feeder if there are wear issues and when high degrees of precision are required.