This technical problem can solve by the present invention, its method is the bottom of contact arrangement insert aperture of fusible link seat usefulness in housing, be made for spring contact, and it is compacted near second contact at the on-position fusible link, and the fusible link seat that has cam is cooperated with a guiding profile that is formed in the housing, when making the conversion of fusible link seat like this, fusible link seat and fusible link are deeper drawn in housing, and fusible link is in the holddown spring contact, after compressing the dead point, it flexibly returns and withstands second contact.
Best, an additional spring is set in housing, it compresses at spring contact at on-position on the direction of fusible link and gives an initial stress to the fusible link seat.
With reference to the accompanying drawings a most preferred embodiment of the present invention is being illustrated with the lower part, wherein:
Safety load close switch shown in Figure 1 has the housing made from insulating material 10, and a fixing contact 12 and a spring contact 14 wherein are set.Spring contact 14 is positioned at two stronger helical springs, 16 supportings of lower casing body wall.Contact 12 and 14 no matter all directly is connected with 20 with terminal 18 respectively.Upper housing wall is in the face of the spring contact 14 in the opening 22, and it is with respect to fixed contact 12 lateral shifts.
The bottom 24 of housing 10 and in housing 10, guide as puller by the case cover (not shown) that the guide rail 26 of fusible link seat 28 usefulness stretches out.Guide rail 26 advances perpendicular to the lower casing body wall in lower area, and crooked subsequently making progress near the left hand edge of opening 22.In Fig. 1, fusible link seat 28 is in the pull-out location, and fusible link 30 can insert the fusible link seat therein.Fusible link 30 shown in Figure 1 is in by fusible link seat 28 pull-out location partly.In facing the upper area of fusible link 30 sides, fusible link seat 28 is opened, and grips opening 32 to form, and it is convenient to grip and take off fusible link 30.In the time of in fusible link 30 fully is inserted in the fusible link seat, it is held in place by spring tongue piece 34, and its lower contact 36 is in the face of the lower end of the unlatching of fusible link seat therein.
The bottom 24 of housing 10 becomes semicircular guiding groove 38 with hood-shaped, and one of them electric insulation lid 40 is configured as semicircular arc, can guide versatilely.An opening of lid 40 is occupied by fusible link seat 28, and has little tolerance, thereby makes lid 40 seal the zone that is positioned at fusible link seat 28 outer opening 22, and the passage that ad hoc blocks fixed contact 12.Fusible link seat 28 have a bayonet lock 42 it in position shown in Figure 1 medial surface against lid 40, and thereby restriction fusible link seat 28 pull out motion.
Each outer surface of fusible link seat 28, it can be changed approaching and leave the observer in Fig. 1, forms a cam 44, and it raises with respect to the top of fusible link seat.These cams 44 are cooperated with the guiding profile 46 of formation in the bottom 24 of housing 10 and cover, and the latter forms nose one by one, are stretched out downwards and are moved by the guide rail of fusible link seat to the free end of fixed contact 12.
When fusible link 30 fully inserts fusible link seat 28, the fusible link seat can be pushed in the housing 10 along guide rail 26, as shown in Figure 2, the bottom of fusible link seat 28 grips with fork-shaped subsequently, cross over spring contact 14 and clamping piece spring 48, and the lower contact 36 of fusible link 30 relies on the spring contact 14.Cam 44 is in the height of the adjacent part that directly is lower than guiding profile 46.
The top of fusible link seat 28 is still stretched out by housing 10, forms a handle 50, and fusible link seat 28 can be as shown in Figure 2 with fusible link 30, and the lower contact 36 that centers on fusible link 30 clockwise rotates.Like this, cam 44 slides along guiding profile 46, and causes fusible link seat 28 and fusible link 30 to move down together, advances along the route that continues converting motion.Therefore, the spring contact 14 compacted power of offsetting helical spring 16 of returning, as shown in Figure 3.When fusible link seat 28 during at converting motion, the removed and skew of lid 40 enters guiding groove 38.In addition, as seen from Figure 3, guiding profile 46 extends upward by guiding groove 38, and it is parallel to guide rail 26 and advances therein, thereby makes when it fully pushes housing, and only fusible link seat 28 can be rotated.
Under situation shown in Figure 3, cam 44 is the nose by the guiding profile 46 of stretching out downwards just in time.Light thus, being rotated further of fusible link seat by the elastic bearing of contact 14 and helical spring 16, and fusible link 30 is compacted upwards with the fusible link seat, thus make fusible link seat and the unexpected ground velocity of fusible link allocate on-position shown in Figure 4 into.The upper contact 52 of fusible link relies on the fixed contact 12 subsequently.Spring contact 14 is in the dependence position that does not fully reach under this state on abutment wall 54, thereby remains between the contact 36,52 of contact 12,14 and fusible link by the contact pressure that the elastic reaction of contact 14 needs.Moving upward of flat spring 48 supporting fusible link seats 28 enters quick link position.
Antetheca on fusible link seat 28 (it is by hidden among the figure) is provided with a transparent window 58, can read the indication of arranging on the upper contact 52 of fusible link by it, can often see that therefore fusible link is conduction or burns.Move by the horizontal of the longitudinal axis of handle 50, help reading indication with respect to the fusible link seat.
When safety load close switch was prepared to disconnect, fusible link seat 28 was disconnected by on-position once more by slight downward pressure, thereby made the conduction between contact 12 and 14 connect interruption, and fusible link seat 28 is back to position shown in Figure 2.If desired, fusible link seat 28 can be pushed out once more so that change fusible link.
Above-mentioned safety load close switch can be equipped with different fusible link 30, to adapt to different normal loads.Because the profile of the fusible link of different types has difference, each fusible link seat 28 that uses has corresponding suitable in-profile.The replacing of fusible link seat 28 can be undertaken by the bayonet lock of making on the spring tongue piece 42, and it can be compressed backward by an instrument, so that fully pull out the fusible link seat by housing 10.