Abstract: A structure of drone (100) comprises a frame (110) comprising an engagement portion (110?), said engagement portion (110?) being a strip having a predetermined geometry. The structure of drone (100) also comprises a plurality of propulsion elements (120). Each propulsion element (120) is arranged, in use, to be engaged in a removable way to the engagement portion (110?) at a any point of the strip, in such a way to easily change the number and the arrangement of the propulsion elements (120) present on the engagement portion (110?).

Abstract: A structure of drone (100) comprises a frame (110) comprising an engagement portion (110?), said engagement portion (110?) being a strip having a predetermined geometry. The structure of drone (100) also comprises a plurality of propulsion elements (120). Each propulsion element (120) is arranged, in use, to be engaged in a removable way to the engagement portion (110?) at a any point of the strip, in such a way to easily change the number and the arrangement of the propulsion elements (120) present on the engagement portion (110?).

Abstract: A pressostat comprises an operating pressure chamber (4) which is limited by its housing (1) and by an operating membrane (5) or the like including a pressure surface for an output adjustment member (3), at least one spring counteracting the pressure (P) in the operating pressure chamber (4), a switch member (2) which responds when a limit pressure value is exceeded in said working pressure chamber (4), and an enclosed protective chamber (6) arranged concentrically to the working pressure chamber (4) limited by the housing (1), the operating membrane (5) and a protective membrane (7) or the like including pressure surface for the output adjustment member (3).

Abstract: A temperature compensated switching relay with thermally effected switching delay should be of simple and compact construction and reliable in switching with precisely adjustable switching delay. For this purpose, the switching relay comprises a switching member (1) movable between two end positions and bearing a permanent magnet (2), with an inherent snapping action to actuate at least one switching contact (6), on opposite sides of the permanent magnet (2) in its direction of movement a first and a second paramagnetic member (3, 4) is provided, on the first paramagnetic member (3) a PTC resistor (5) feedable by a source of current is mounted, and in the end position of the switching member (1) at the second paramagnetic member (4) the distance (A) of the permanent magnet (2) from the first paramagnetic member (3) is less than its distance (B) from the second paramagnetic member (4). The ratios of the distances of the permanent magnet (2) from the paramagnetic members (3, 4) can expediently be adjusted.

Abstract: A snap-action switch, especially microswitch for alternating current comprises at least one stationary contact (2) on a stationary contact part (1) and at least one movable contact (4) on a movable contact part (3). In order to open the switch in the proximity of the zero crossing of the switch current, on the one contact part (1; 3) there is an electromagnet unit (8) excited by the switch current while on the other contact part (3; 1) is disposed an armature unit (12) made of ferromagnetic material which is located opposite the electromagnet unit (8).

Abstract: A temperature controlled switching device in which a first fluid filled temperature sensor responding to the temperature of heating or cooling means moves a first lever. A second sensor sensing the room temperature moves a second lever. The two levers being interconnected to move a snap action switch for control of the heating or cooling means.

Abstract: A refrigerator or freezer of the type having an electrical defrost heater associated with its evaporator has a control unit including a switch device with a first pair of contacts (16, 17) controlling the cyclic cutting-in and cutting-out of a compressor motor and a second pair of contacts (16, 18), sharing a common movable contact (16) with the first pair, controlling the periodic energization of the defrost heater. Closure of the second pair of contacts is normally obstructed by a stop member (22) which is movable by a ratchet mechanism (24, 26) or other means responsive to a predetermined number of switching cycles of the compressor motor to a defrost position in which a notch (23) in the stop member (22) permits movement of the movable contact to close the second pair of contacts (16, 18) and energize the defrost heater.

Abstract: A thermostatic switch unit for controlling a freezer or, for example, refrigeration apparatus in automotive air conditioning, includes a switch (1) which is acted upon by a thermostat mechanism responsive to the working temperature of the evaporator so as to maintain this temperature within a normal working range which is presettable by means of a control knob (18) in a conventional manner. By depressing manually a push button (26) mounted centrally in the control knob a spring loaded trip lever (29) is rotated to release a spring loaded lever (35) into engagement with a switch operating plunger (2, 3), closing the associated switch contacts (21) and causing the compressor motor of the apparatus to run until a low temperature, below the preset working range of the equipment, is reached, when the latch mechanism (29, 35) is reset automatically by the temperature sensing bellows (8) acting through the operating lever (4) of the thermostat mechanism.

Abstract: In a heating and/or cooling system, two heat transmitting media are blended into a blended medium with adjustable temperature. The motor (M) of a blending member is controlled pulsewise in both directions by comparison pulses from a setpoint/actual value temperature comparison.In order to provide a system which is simple to construct, which is wear-resistant and which permits a quick and accurate adjustment of the blending member, the circuit arrangement for controlling the motor (M) contains a first pulse generator (TB1), which generates pulses of constant width commencing respectively with the end of a comparison pulse and is connected to second and third pulse generators (TB2, TB3). The second and third pulse generators (TB2, TB3) generate pulses of a width proportional to the actual value or the setpoint of the temperature, respectively, which directly control the motor (M) after comparison in a comparator (CO).

Abstract: A snap action switch has a Q-shaped blade having two spring arms terminating in outwardly projecting parallel end portions which are located in a slot in a contact element, these end portions being drawn together upon insertion into the slot, and thereby stressing the blade for snap action. The end portions are retained in the slot by the reaction forces due to the stressing of the blade, and made good electrical contact with the contact element. The blade end portions may be drawn together by a clip to which a contact is rivetted.The contact element may alternatively be carried by a conductive arm separate from the blade and operable by the latter.

Abstract: A snap action switch blade has two resilient legs which project from an integral base portion beyond and on each side of a tongue to which an operating force is applied. The legs are joined together by a contact element which is welded to two inwardly projecting arms at the free ends of the legs, drawing the latter together to prestress the blade with a dish deformation. The two arms may be narrower than the legs, their common centerline being spaced from the contact zone of the contact, so that a twisting action is imparted to arms prior to separation of the contact from a fixed contact, assisting in breaking contact welds.

Abstract: A mechanism for setting a thermostat having a housing wall forming a mounting opening. A rotatable setting shaft projects through the mounting opening and defines a circumferential groove concentric with respect to the shaft axis and a cam is fixed to the shaft for rotation therewith relative to the housing wall. The cam has a bore with at least one slot at a predetermined angular location and the shaft is locked to the cam by expanding the shaft into engagement with the bore and slot.The shaft is journaled in a bearing for rotation relative to the housing wall. The bearing comprises at least a collar-like structure fixed with respect to the housing wall and extending axially relative to the shaft and radially inwardly deformed toward engagement with the shaft groove. The collar-like bearing structure and shaft groove cooperate to enable rotation of the shaft relative to the collar-like structure about the axis and to restrain the shaft against axial movement relative to the housing wall.

Abstract: An electrical snap acting switch is calibrated by deforming an unsupported part of a terminal strip which carries a fixed contact after assembly of the switch device, to predetermine the operating point of the switch contacts. Deformation of the fixed contact support strip is facilitated by apertures in the strip on opposite sides of the fixed contact. These apertures also serve to ventilate the make and break zone of the contacts to assist in ozone dispersal from this zone, minimizing arcing.

Abstract: An electrical snap action switch for use in a temperature regulator has a movable contact assembly consisting of a conductive contact carrying arm movable between fixed stops and cantilevered within the switch housing, the contact arm being parallel to and cooperating with a Q-shaped snap-action spring, so that the arm carries the working current while the snap spring acts on the arm to make the switch monostable in operation between the stops.

Abstract: A control switch unit adaptable for a number of different purposes has a fluid-filled flexible-walled capsule acting within a housing on a pivoted operating lever arranged to operate a switch located in the housing on the other side of the pivot axis of the lever from the capsule, the lever being biased by a cam-adjustable tensioning spring acting on the opposite side of the operating lever from the capsule and the switch. Further components such as a manual switch-off control, a pilot lamp operable by an auxiliary switch, or a capsule heater, can be added without rearrangement of the basic unit.

Abstract: A snap action switch blade has a basic `Q` shape with two arms interconnected and drawn together by a bridge portion, which may be integral with the arms, to form a deformed loop capable of snap movement between two configurations, with respective tongues projecting into and out of the loop to afford anchoring and/or actuating points for the blade.