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AssigneeSiemens Aktiengesellschaft
InventorsBengt Skafvenstedt, Sture Ahlgren, Eberhard Tschuertz
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A pump mechanism for pumping ink or similar writing fluid from a fluid reservoir to a writing device. A piston is moved in a cylinder in one direction to draw ink into the cylinder from a reservoir through a capillary tube, and is moved in an opposite direction to discharge the ink to a writing device while at the same time, in cooperation with a flexible membrane located in the cylinder and connected to the piston, to discharge any air in the capillary tube back into the reservoir.
A pump mechanism for delivering ink or the like writing fluid from a fluid reservoir to a writing device comprising pump housing means, means forming a cylinder in said housing comprising a suction chamber and a pumping chamber, a piston carried within said cylinder and movable in a forward direction to block communication between said suction and pumping chambers, and in a backward direction to open communication between said suction and pumping chambers, means including a capillary tube for communicating said suction chamber and the reservoir, and flexible membrane means in said cylinder having a portion connected to said pump housing means and another portion connected to said piston for joint movement therewith, whereby said flexible membrane means forces air bubbles from said capillary tube to the reservoir as the piston moves in said forward direction.
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Ink supply systems ; Circuit parts therefor: ink pumps, ink valves
Piston machines or pumps characterised by having positively-driven valving: in which the valving is performed by pistons and cylinders coacting to…
The means being cams, eccentrics or pin-and-slot mechanisms: the means being pin-and-slot mechanisms
Having reservoirs: the pump being located directly adjacent the reservoir
Term ended 11 Oct 1994 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
This invention relates generally to pump mechanisms and particularly to a pump mechanism for delivering ink or similar writing fluid from a reservoir to a writing device. The pump mechanism includes a piston slidably carried within a cylinder for reciprocatory movement to alternately draw ink from the reservoir into the cylinder and then to discharge the ink from the cylinder to the writing device.
In known pumping mechanisms of this general type and for this general purpose, a control mechanism such as a photo cell is provided to deenergize the pump when the ink in the reservoir is almost exhausted, thereby preventing entry of air bubbles into the inking system. Then, for drawing fresh ink into the inking system after the reservoir has been filled, manual suction and pressure pumps are provided.
These control mechanisms and manually operated pumps are complicated in design, expensive to manufacture and space consuming. In addition, the operation of the manual pumps is difficult and the entire pump mechanism is inoperative if air has become entrained therein.
The drawing is a vertical sectional view of a pump mechanism constructed in accordance with the principles of the present invention.
Referring to the drawing, there is disclosed a pump mechanism indicated generally at reference numeral 1 constructed in accordance with the present invention for delivering a writing or a printing fluid such as ink or the like from a reservoir 2 to a writing device 3. The writing system may be of the type disclosed, for example, in U.S. Pat. No. 2,566,443.
The pump mechanism 1 comprises a pump housing 4 having an upwardly extending mounting collar 7 for supporting the reservoir 2. The collar 7 comprises a thin elongated protuberance 9 which is apertured as at 8 to receive a capillary tube 23. The capillary tube 23 is preferably made of glass.
Formed within the housing 4 is a cylinder 5 in which is disposed for slidable reciprocatory movement a one-piece plastic piston 6.