Liquid metering device with adjustable stops

Dispensing apparatus for releasable attachment to the mouth of a liquid reservoir comprising a housing defining an inlet aperture, an outlet aperture and a proportioning aperture, said apertures being in communication with one another within said housing, means for securing said housing to said reservoir so that said inlet aperture is directed into said reservoir mouth and said outlet and proportioning apertures are directed away from said reservoir mouth, a non-return inlet valve connected to said inlet aperture, a non-return delivery valve connected to said outlet aperture and syringe means in communication with said proportioning aperture, wherein said syringe means comprise an open-ended stationary barrel connected to said housing over said proportioning aperture, a plunger displaceable in said barrel to draw liquid past said inlet valve through said inlet aperture and through said proportioning aperture into said barrel on a forward stroke and to discharge said liquid through said proportioning aperture and through said outlet aperture past said delivery valve on a return stroke, and control means for limiting displacement of said plunger, said control means comprising co-operating abutments associated with said plunger and barrel, wherein said abutments comprise two adjustable abutments, means for adjusting one of said adjustable abutments to change the length of stroke of the plunger in discrete steps for providing a coarse setting, and means for adjusting the other of said adjustable abutments to change the length of stroke of the plunger in discrete finer steps for providing a fine setting.