Abstract: A magnetic system for an electromagnetic relay comprises at least two iron pieces 15, 16 extending in parallel through the entire length of one common coil 18, each iron piece being part of its own magnetic circuit for operating an armature which is disposed in this magnetic circuit to operate ah associated contact system. The spacing between the iron pieces 15, 16 inside the coil 18 is substantially smaller than the largest cross-sectional dimension of each iron piece 15, 16 in order to make maximum use of the magnetic flux produced by the coil 18 with minimum loss and minimum stray flux.

Abstract: For increasing the reliability of contact closure in safety relays, a contact spring (10) is provided with two contact pieces (15, 16) which are disposed at the free end of the contact spring (10), spaced transversely of the longitudinal axis thereof and cooperate with contact pieces (17, 18) disposed on a common fixed contact. The contact spring (10) has a zone (19) in which it is not only flexible but also sufficiently torsional about its longitudinal axis in order to ensure the closure of both contact couples. Disposing the free end of the contact spring (10) carrying the contact pieces (15, 16) at an angle with respect to the fixed contact (12) achieves smooth and low-bounce contact closure and at the same time provides the function of a pre-contact and a main contact.

Abstract: A magnetic system for an electromagnetic relay comprises at least two iron pieces 15, 16 extending in parallel through the entire length of one common coil 18, each iron piece being part of its own magnetic circuit for operating an armature which is disposed in this magnetic circuit to operate an associated contact system. The spacing between the iron pieces 15, 16 inside the coil 18 is substantially smaller than the largest cross-sectional dimension of each iron piece 15, 16 in order to make maximum use of the magnetic flux produced by the coil 18 with minimum loss and minimum stray flux.

Abstract: For increasing the reliability of contact closure in safety relays, a contact spring (10) is provided with two contact pieces (15, 16) which are disposed at the free end of the contact spring (10), spaced transversely of the longitudinal axis thereof and cooperate with contact pieces (17, 18) disposed on a common fixed contact. The contact spring (10) has a zone (19) in which it is not only flexible but also sufficiently torsional about its longitudinal axis in order to ensure the closure of both contact couples. Disposing the free end of the contact spring (10) carrying the contact pieces (15, 16) at an angle with respect to the fixed contact (12) achieves smooth and low-bounce contact closure and at the same time provides the function of a pre-contact and a main contact.

Abstract: For increasing the reliability of contact closure in safety relays, a contact spring (10) is provided with two contact pieces (15, 16) which are disposed at the free end of the contact spring (10), spaced transversely of the longitudinal axis thereof and cooperate with contact pieces (17, 18) disposed on a common fixed contact. The contact spring (10) has a zone (19) in which it is not only flexible but also sufficiently torsional about its longitudinal axis in order to ensure the closure of both contact couples. Disposing the free end of the contact spring (10) carrying the contact pieces (15, 16) at an angle with respect to the fixed contact (12) achieves smooth and low-bounce contact closure and at the same time provides the function of a pre-contact and a main contact.

Abstract: In an electrical circuit arrangement, specifically a sequential blasting system as used in mining, the individual circuit units 12 are contacted by a continuous flat cable 10 in such a way that each wire 16 to 19 of the cable 10 has a bared section 21 which is soldered to a contact pad 22 to 26 of a conductor pattern 15 disposed on a printed circuit board 11 which carries the circuit elements of the circuit unit 12. This not only minimizes the total number of contacts but also prevents the contact points from increasing the line resistance and prevents any faulty contact point from interrupting the line.

Abstract: A casing 14 for a junction included in a flat cable 10, e.g. for a trigger stage of a sequential blasting system, consists of two casing portions 12, 13 adapted to be fixed to each other by screwing within the lead-through regions of the cable. The casing portions 12, 13 constitute cramping areas for fixing the cable 10 to the casing 14 in a direct, non-positive way, wherein the screws 23 which interconnect the two casing portions 12, 13 at the same time create the cramping pressure. An additional positive engagement between the cable 10 and the casing 14 is achieved by engagement between a tube 25 which receives the screw 23 and a hole 29 provided in a center web 28 of the cable. Tensile strain occurring within the cable 10 is thus diverted via the casing 14 around the electrical equipment provided in the casing and soldered to the wires 19 of the cable 10. Even under high tensile forces, the soldering points are thus not exposed to any strain.

Abstract: In an electromagnetic relay including a pivotable armature (11) and contact springs (17) extending substantially in parallel thereto, the actuator (21) for transmitting the armature (11) movement to the contact springs (17) is coupled to the armature (11) with play. Thereby relative displacements between the actuator (21) and the contact spring (17) and the resultant frictional forces are prevented. When the relay is a bistable relay, the coupling between armature (11) and actuator (21) with play furthermore means that in the central position of the armature (11) no spring forces and no frictional forces caused by the actuator (21) are applied thereto but only the magnetic actuating forces will act on the armature (11). Thereby the risk of the armature (11) inadvertently remaining in its neutral central position is practically eliminated.

Abstract: A safety electromagnetic relay includes two pairs of contact sets, each pair including a load-driving contact set and a control contact set, and each contact set including a fixed contact and a movable contact spring. The two load-driving contact sets are normally-open contacts and may be connected in series and included in an external load circuit which requires safe interruption. The contact springs of each of the first and second pairs are ganged by a coupling member which is movable independently of a relay armature. The ganged pairs of contact springs are actuated by the armature in such a manner that when one of the load-driving contact sets should become welded in the closed condition, the other load-driving contact set will still open when the armature moves to the inoperative position, but the control contact set associated with the welded load-driving contact set is prevented from returning to its condition corresponding to the inoperative position of the armature.

Abstract: A modular relay incorporated in a plugable element is disclosed. In accordance with the preferred embodiment, the relay is of the bistable type, and in response to actuation, is caused to switch state for a predetermined period of time, thus acting as a monostable device. Structure is disclosed for insuring that the state of the relay is known prior to actuation. A particularly advantageous mounting structure is incorporated within the relay comprising multi-step mounting feet. The energizing circuit in accordance with the invention is disposed within the plug socket.