Variable flow rate mechanical pump assembly

1. A mechanical pump comprising:

a motor with an output shaft;

a cam coupled to the output shaft for rotating the cam when the motor is energized;

a driver with spaced ledges engaging the cam and driven linearly by the rotating cam;

a piston driven by the driver; and

a cylinder receiving the piston therein including an inlet section for drawing fluid into the cylinder and an outlet section for pumping fluid out of the cylinder as the piston reciprocates in the cylinder; and

an adjuster between the driver and the piston configured to vary the stroke length of the piston within the cylinder, the adjuster including a plurality of stepped portions, wherein each one of the plurality of stepped portions is configured to individually engage the piston depending on a position of the adjuster relative to the piston, and engagement of each one of the plurality of stepped portions with the piston corresponds to a different stroke length, wherein linear movement of the driver causes linear movement of the adjuster, the linear movement of the adjuster being parallel to a longitudinal axis of the driver.

2. The pump of claim 1 in which the motor is a synchronous constant speed motor operable by a line voltage.

3. The pump of claim 1 further including a spring compressed by the piston.

4. The pump of claim 1 in which the piston is directly coupled to the driver.

5. The pump of claim 1 in which the driver includes a race receiving a pin of the piston therein adjustably varying the relationship between the piston and the driver.

6. The pump of claim 1 in which the adjuster resides between a ledge of the driver and the piston.

7. The pump of claim 1 further including an actuator for the adjuster.

8. The pump of claim 7 in which the actuator includes one or more races receiving one or more tabs of the adjuster.

9. The pump of claim 7 in which the actuator includes a handle for sliding the actuator.

10. A variable flow rate mechanical pump comprising:

a motor driving an output shaft;

a cam coupled to the output shaft;

a piston driver linearly driven by the cam;

a piston driven by the driver; and

an adjuster between the piston driver and the piston configured to vary the stroke length of the piston, the adjuster including stepped portions, wherein each one of the plurality of stepped portions is configured to individually engage the piston depending on a position of the adjuster relative to the piston, and engagement of each one of the plurality of stepped portions with the piston corresponds to a different stroke length, wherein linear movement of the piston driver causes linear movement of the adjuster, the linear movement of the adjuster being parallel to a longitudinal axis of the piston driver.

11. A variable flow rate device comprising:

a pump configured with a piston;

a piston driver driven linearly by a motor and driving the piston; and

an adjuster between the driver and the piston configured to vary the stroke length of the piston and the piston driver, the adjuster including stepped portions, wherein each one of the plurality of stepped portions is configured to individually engage the piston depending on a position of the adjuster relative to the piston, and engagement of each one of the plurality of stepped portions with the piston corresponds to a different stroke length, wherein linear movement of the piston driver causes linear movement of the adjuster, the linear movement of the adjuster being parallel to a longitudinal axis of the piston driver.

12. The device of claim 11 in which the motor includes an output shaft with a cam coupled thereto driving the piston driver.

13. A steam mop comprising:

a steam generator providing steam to a mop head; and

the mechanical pump of claim 1 , wherein the mechanical pump is configured to provide liquid to the steam generator.