1. A dispensing assembly for dispensing at least one fluid, the dispensing assembly comprising:
a source of a first fluid;
a valve having opened and closed positions in which the valve permits and inhibits flow of the first fluid, respectively;
a source of a second fluid;
a first chamber in fluid communication with the source of the first fluid via the first valve, and in fluid communication with the source of the second fluid;
a dispenser outlet through which the first and second fluids are dispensed from the dispenser assembly, the dispenser outlet having opened and closed states in which flow of the first and second fluids from the dispenser outlet is permitted and inhibited, respectively; and
a second chamber in fluid communication with the first chamber;
the first valve movable from the opened position to the closed position responsive to a change in fluid pressure within the second chamber, and movable from the closed position to the opened position responsive to an opposite change in fluid pressure within the second chamber.
2. The dispensing assembly of claim 1, wherein the first valve is movable under magnetic force from the closed position to the opened position responsive to the opposite change in fluid pressure.
3. The dispensing assembly of claim 1, wherein the first valve comprises a piston.
4. The dispensing assembly of claim 3, further comprising a magnet coupled to the piston and positioned to attract another part of the first valve in at least one position of the piston.
5. The dispensing assembly of claim 4, wherein the magnet defines at least part of the piston.
6. The dispensing assembly of claim 4, wherein the piston is spring-biased.
7. The dispensing assembly of claim 1, further comprising a second valve having opened and closed positions in which the second valve permits and inhibits flow of the second fluid, respectively, into the first chamber.
8. The dispensing assembly of claim 1, wherein the second chamber is a venturi chamber.
9. The dispensing assembly of claim 1, further comprising a flow sensing valve having opened and closed positions in which the second valve permits and inhibits flow of the second fluid, respectively, into the first chamber.
10. The dispensing assembly of claim 9, wherein the flow sensing valve includes a flexible diaphragm.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An optical filter switching apparatus of a surveillance device comprising:
a housing, the housing comprising a bottom housing and a top housing engaged to the top housing, the bottom housing having a sidewall defining a slot;
a guiding mechanism placed in the bottom housing, the guiding mechanism comprising a rod parallel with the slot;
an optical filter holding bracket attached to the guiding mechanism, wherein the optical filter holding bracket comprises:
a through hole defined a first end thereof for extension of the rod therethrough;
a protrusion located on an opposite second end and inserted into the slot;
a gear rack arranged on the first end;
a driving apparatus located adjacent to the gear rack; and
at least two optical filters placed on the optical filter holding bracket, wherein the rod and the slot are configured to guide movement of the optical filter holding bracket therealong, and the slot is configured to limit the movement of the optical filter holding bracket between extremities thereof.
2. The optical filter holding apparatus of claim 1, wherein the bottom housing comprises:
a first room for placing the optical filter holding bracket; and
a second room positioned next to the first room;
wherein the driving apparatus is placed in the second room.
3. The optical filter holding apparatus of claim 1, wherein the optical filter holding bracket comprises at least two windows for placing the optical filters.
4. The optical filter holding apparatus of claim 3, wherein the top housing comprises a light entrance, and the bottom housing comprises a light exit positioned corresponding to the light entrance.
5. The optical filter holding apparatus of claim 4, wherein one of the windows of the optical filter holding bracket is positioned in the light path between the light entrance and the light exit.
6. The optical filter holding apparatus of claim 1, wherein the driving apparatus further comprises:
a motor;
a worm drive coaxially connected to the motor; and
a stepped gear meshed with the worm drive.
7. The optical filter holding apparatus of claim 6, wherein the stepped gear is a two-step gear, and further comprises a worm gear configured for the worm drive of the driving apparatus and a spur gear stacked on the worn gear.
8. The optical filter holding apparatus of claim 7, wherein the worm is meshed with the worm gear, and the spur gear is meshed with the gear rack of the optical filter holding bracket.
9. The optical filter holding apparatus of claim 7, wherein the worm gear is a helix gear.
10. The optical filter holding apparatus of claim 1, wherein the top housing is fixed to the bottom housing by at least a screw.