Tank configuration for a small floor scrubber

• US 5,566,422 A
• Filed: 01/13/1995
• Issued: 10/22/1996
• Est. Priority Date: 01/13/1995
• Status: Expired due to Term

• Current Assignee: Tennant Company
• Original Assignee: Tennant Company
• Inventors: Geyer, Robert A.
• Primary Examiner(s): Scherbel, David
• Assistant Examiner(s): Chin, Randall E.
• Application Number:
  US08/372,506
• Time in Patent Office: 648 Days
• Field of Search: 15/320, 15/347, 15/353
• US Class Current: 15/320
• CPC Class Codes: A47L 11/302 having rotary tools
• CPC Class Codes: A47L 11/4016 specially adapted for collecting fluids
• CPC Class Codes: A47L 11/4027 Filtering or separating contaminants or debris
• CPC Class Codes: A47L 11/4044 Vacuuming or pick-up tools; Squeegees

Abstract

A small floor scrubbing machine is powered by a centrally located battery pack, with a recovery tank for used scrubbing solution comprised of connected chambers located on four sides of and beneath the batteries, and a tank for clean solution in a lid over the recovery tank and batteries. A partial partition in the chamber behind the batteries effectively divides it into two chambers. A vacuum fan draws air and used solution into one rear chamber of the recovery tank and exhausts air to atmosphere from the other rear chamber. The extended airflow path from one rear chamber to the other around three sides of the battery pack allows mist and foam to settle out of the air stream before it reaches the vacuum fan inlet. The front and rear chambers provide plenum space to reduce the airflow velocity. Openings in the partition between the rear tanks bypass increasing amounts of air directly from one rear chamber to the other as the recovery tank fills with water, thus compensating for the diminishing airflow space above the water and controlling the velocity of the airflow. The arrangement provides improved foam control in the limited space available in a small scrubber, a constant center of gravity as the solution tank empties and the recovery tank fills during normal operation, and easy access to the recovery tank for cleaning.

Claims

1. In a surface scrubbing machine comprising a body, wheels rotatably affixed to said body, at least one battery centrally located within the body for providing power to operate the machine, a solution tank on the body for containing scrubbing solution, means on the body for conveying said scrubbing solution from said solution tank to a surface to be scrubbed, means on the body for working the solution on the surface, a vacuum squeegee on the body for recovering said solution from the scrubbed surface, a recovery tank located within said body for containing scrubbing solution after it has been recovered from the scrubbed surface, duct means for conveying said recovered solution from said vacuum squeegee to said recovery tank, a vacuum fan for withdrawing air from said recovery tank, the recovery tank having connected chambers in front of, to the rear of and at both sides of said at least one battery, two of said chambers being separated by a partial partition, said vacuum fan and said duct means being located with respect to the two chambers of the recovery tank separated by the partial partition such that air which is withdrawn from said recovery tank by said vacuum fan will be replaced by air which is supplied by said duct means, and at least a portion of said replacement air will move in a path through the connected chambers of the recovery tank around at least three sides of the at least one battery in the course of traveling from the duct means to the vacuum fan.

2. The surface scrubbing machine of claim 1 in which the recovery tank chambers in front of and to the rear of the at least one battery are larger than the recovery tank chambers at the sides of the at least one battery and serve as expansion chambers for assisting in the control of foam on the scrubbing solution recovered from the surface being scrubbed.

3. The surface scrubbing machine of claim 1 in which the partial partition separating the two recovery tank chambers provides a limited air passageway between the two chambers through which at least a portion of the airflow moving from the duct means to the vacuum fan may be bypassed without traveling around the at least one battery.

4. The surface scrubbing machine of claim 1 in which a removable lid is fitted above the recovery tank, said removable lid containing the solution tank such that an essentially constant fore and aft center of gravity is maintained as the solution tank empties and the recovery tank fills during normal operation.

5. The surface scrubbing machine of claim 1 in which a removable lid is fitted above the recovery tank, said removable lid containing the vacuum fan, an inlet of said vacuum fan being in fluid connection with said recovery tank and an outlet of said vacuum fan exhausting to atmosphere.

6. The surface scrubbing machine of claim 5 in which the removable lid is fitted with gaskets in the areas covering the recovery tank chambers in front of and to the rear of the at least one battery.

7. The surface scrubbing machine of claim 6 in which the front and rear recovery tank chambers are open to atmosphere when the removable lid is raised.

8. In a surface scrubbing machine of the walk-behind type comprising a body, a solution tank on the body for containing scrubbing solution, means on the body for conveying the scrubbing solution from the solution tank to a surface to be scrubbed, means on the body for working the solution on the surface, a vacuum squeegee on the body for recovering soiled solution from the scrubbed surface, a recovery tank located within the body for containing scrubbing solution after it has been recovered from the scrubbed surface, duct means for conveying the recovered solution from the vacuum squeegee to the recovery tank, and a vacuum fan for withdrawing air from the recovery tank, the improvement comprising the recovery tank having an inlet chamber in fluid communication with the duct means, an exit chamber in fluid communication with the vacuum fan, and at least one intermediate chamber between the inlet and exit chambers and in fluid communication with each of them, the intermediate chamber being at the front of the body and the inlet and exit chambers being at the rear of the body, with side chambers connecting the intermediate chamber to the inlet and exit chambers, the inlet and exit chambers being partially separated from one another by baffles which provide a bypass connecting the inlet and exit chambers to permit at least a portion of the fluid flow to bypass the intermediate chamber.

9. In a walk-behind surface scrubbing machine of the type having a body including a solution tank for containing scrubbing solution, means on the body for conveying the scrubbing solution from the solution tank to a surface to be scrubbed, means on the body for working the solution on the surface, and a vacuum fan on the body in communication with a vacuum squeegee on the body for recovering soiled solution from the scrubbed surface the improvement comprising a mist and foam controlling solution recovery tank formed in the body, the recovery tank comprising a plurality of chambers including a first expansion chamber at a rear of the body, a second expansion chamber located at a front of the body, and at least one connecting chamber providing fluid communication between the expansion chambers, a lid pivotally attached to the solution recovery tank, the vacuum fan being mounted in the lid and being located so as to circulate fluid from the first expansion chamber through the at least one connecting chamber to the second expansion chamber.

10. The surface scrubbing machine of claim 9 wherein the first expansion chamber is partially divided by baffles into an inlet chamber in communication with the vacuum squeegee and an exit chamber in communication with the vacuum fan.

11. The surface scrubbing machine of claim 10 wherein a first connecting chamber is intermediate the inlet chamber and the second expansion chamber and a second connecting chamber is intermediate the second expansion chamber and the exit chamber.

12. The surface scrubbing machine of claim 10 wherein the baffles define a bypass connecting the inlet chamber to the exit chamber, the bypass being sized such that a minor portion of the fluid flow can go directly to the exit chamber from the inlet chamber.

13. The surface scrubbing machine of claim 9 wherein the first expansion chamber is partially divided by baffles into an inlet chamber in communication with the vacuum squeegee and an exit chamber in communication with the vacuum fan, the inlet and exit chambers being at least partially defined by the lid.