Anti-backlash Devices

Anti-backlash devices are internal jack components used to minimize backlash (free movement between the lifting screw and nut) in machine screw jacks. They are typically used in reversing load applications where the lifting screw position is critical. Joyce/Dayton offers three unique anti-backlash designs; each uses the same concept of clamping two independent nut halves against the lifting screw threads.

Finishes

Choose from an extensive list of special materials and finishes to meet environmental and wear requirements.

Encoders

Joyce can equip machine screw jack models between 2-ton and 150-ton capacity and electric cylinders with an encoder to allow accurate position sensing within increments of 0.001 inches.

Counters

Joyce offers mechanical counters for screw jacks and actuators. These allow position tracking for manual operations.

These convert the rotational movement of the input shaft into a numeric readout at the counter. It is important to know the size of increments to be measured ( for instance inches or millimeters) and the number of decimal places to be measured and displayed (for instance 0.000" or 000.0").

Hand Wheels

Joyce offers hand wheels in a variety of diameters. They are recommended for self-locking jacks and actuators and can be mounted directly to the jack input shaft.

Potentiometers

Joyce geared potentiometers are ideal for precise positioning applications.

Using a 10-turn potentiometer, a signal is provided as either a change in resistance or current (when supplied with a 4-20mA instrument transformer), which is proportional to the actual position of the screw. Geared potentiometers are commonly needed when PLCs or computers control jacks.

Limit Switches

Joyce limit switches allow you to set precise travel limits and stops on Joyce jacks and actuators. They are also ideal in any application where rotary motion of a machine component can be used to indicate linear motion of another part. They are compatible with 2-ton through 150-ton jacks, actuators, electric cylinders, and integrated actuators.

Trunnion Mounts

Joyce trunnion adapter plates bolt to the base of 2-ton through 20-ton machine screw or ball screw jacks and ComDRIVEs. They include precision bores for trunnion pins. These are frequently used in installations where a single jack moves through an arc during operation. This jack is often configured with a motor mount or as a ComDRIVE.

Protective Boots for Translating and Keyed Design Machine Screw Jacks

Joyce boots protect the lifting screw from dust, dirt, and help maintain lubrication. Standard boots, fabricated from neoprene-coated nylon also guard against moisture and corrosive contaminants. Adding protective boots may increase the closed height of jacks. For specific dimensional information based on jack design, refer to the information below.