"he conventional JSTD20 two-hand device utilizes a welded steel housing. Two operating push buttons are protected by over hand flanges. Between these push buttons there is space for a emergency push button and two extra controls or indication lamps. Below each of the operating push buttons is one normally open and one normally closed contact. To start and run the machine both push buttons must be activated within 0.5 seconds. If one or both push buttons are released a stop signal is given to the machine, and all contacts must return to their deactivated positions before a new start is allowed.","The design is robust and can withstand harsh environments and long use. The push buttons and contact blocks are easy to assemble for quick and easy installation. The device can be mounted directly on the machine, on the Jokab Safety fencing system or on the JSTS30 floor mount. For use with movable Two hand devices the JSTS31 floor mount, which is provided with a distance ring to fulfill the requirements of EN 574, is recommended. The JSTD20 is available with or without emergency stop push button.","Why use a two-hand device?","A two hand device can be used when it is necessary to ensure that the operator is outside and must be prevented from reaching into the hazardous area. If the operator decides, after the start signal has been given to the machine, to make an ’after grasp’ i.e. try to adjust the part that has been placed inside the machine, then a dual stop signal is given to the machine. The new JSTD20 is equipped with a new type of large over hand flange according to EN 574.","These prevent unintended activation by a knee or elbow. A two-hand device only protects the operator using it. Large machines operated by several operators can be equipped with one control for each operator. To calculate the correct safety distance, which depends on the machine’s stopping time including the relay’s reaction time, the use of the Jokab Safety SMART Stop Time Monitor is recommended.","Highest Safety Level","Correct connection to a JSBR4 Jokab Safety safety relay ensures the highest level of safety with dual and supervised safety function and requires input activation of both operating push buttons within 0.5 seconds (two hand device type III C according to EN 574 and category 4 according to EN 954-1\/EN ISO 13849-1). If the emergency push button is installed it should be provided with two normally closed contacts and be connected to a separate safety relay, e.g. from the RT series or Pluto."

"With a JSTD25 you have a prepared two-hand station that is easy to install, while utilizing the good ergonomics of the Safeball. There are several variants to meet differing needs. All versions meet EN 574, EN954-1 and EN13849-1 and are supplied with the internal connections made to simplify installation.","JSTD25A\/B\/D\/E for Fixed Installation","JSTD25A, B, D and E are supplied with two Safeballs mounted on steel housing and replaces a traditional two-hand device. It is available with an emergency stop button and ball joint fixtures for the Safeballs. Three 22mm openings are prepared on the top for buttons or signal lamps. A hatch is supplied for wire routing in the base and securing holes for mounting on the rear. The Safeballs are connected to terminal blocks for the user to connect the external wiring through one of the two inlet alternatives (underneath or at the rear)."

"Safeball is a completely new approach to the design of one and two-hand safety devices. Instead of the conventional approach using ordinary push buttons and non-ergonomic protection for unintentional activation, a ‘hands on’ approach has been developed. Safeball consists of a spherical ball containing two embedded push button switches, one on each side of the ball. By using this push button configuration, the risk of unintentional activation is minimized and the device is simple and ergonomic to use.","Safeball can be utilized for either one-hand (one Safeball) or two-hand (two Safeballs) applications. In either application, and in order to meet the required level of safety, the Safeball(s) switches are monitored by specified\/certified Jokab Safety safety relays.","In the case where two-hand control is used, both Safeballs i.e. all four push buttons have to be activated within 0.5 seconds. If one or more push buttons are released, a Stop signal is given to the machine. In order to provide the highest level of safety the Safeball design provides the operator with a dual switching function and short circuit supervision in each hand.","Each Safeball is ergonomically designed and has both its cover and actuator made of environmental friendly polypropylene. The design allows for comfort of use for all hand sizes and operation from numerous gripping positions. Mounting of the Safeball is also very flexible allowing the device to be mounted in the most ergonomic position for the operator.","When can a two-hand or one-hand control be used?","A two-hand control can be used when it is necessary to ensure that the operator is outside and must be prevented from reaching into the hazardous area. If the operator decides, after the start signal has been given to the machine, to make an ‘after grasp’ i.e. try to adjust the part that has been placed into the machine, then a dual stop signal is given to the machine. A one-hand control device can be used when the operator cannot reach the hazardous area with his\/her free hand or on less dangerous machines.","Highest Safety Level","The Safeball is certified by DNV (Inspecta) in Sweden for use as a two-hand control device, when used with a JSBR4 Jokab Safety safety relay or Pluto Safety PLC, in accordance with the highest safety level in standard EN 574 (type IIIc) and EN 954-1\/ISO 13849-1 (safety category 4)."