PNEUMATIC ABRASIVE CUTTING APPARATUS

• US 3,815,286 A
• Filed: 11/01/1971
• Issued: 06/11/1974
• Est. Priority Date: 11/01/1971
• Status: Expired due to Term

• Current Assignee: Meyer Piet
• Original Assignee: Meyer Piet
• Inventors: Piet, Meyer
• Primary Examiner(s): Kelly, Donald G.
• Assistant Examiner(s): Goldberg, Howard N.
• Application Number:
  US05/194,194
• Time in Patent Office: 953 Days
• Field of Search: 51/8,12,11 137/597 138/137
• US Class Current: 451/90
• CPC Class Codes: A61C 3/025 Instruments acting like a sandblast machine, e.g. for cleaning, polishing or cutting teeth
• CPC Class Codes: B24C 7/0046 the abrasive material being fed in a gaseous carrier
• CPC Class Codes: B24C 7/0069 with means for preventing clogging of the equipment or for preventing abrasive entering the airway
• CPC Class Codes: B24C 9/00 Appurtenances of abrasive blasting machines or devices, e.g. working chambers, arrangements for handling used abrasive material

Abstract

Abrasive cutting apparatus in which a mixture of abrasive particles and a fluid, such as air, under pressure, are expelled at high speed from a nozzle, a compartmented housing being utilized to provide a working compartment connecting directly with a suction compartment, and an isolated control compartment for the abrasive reservoir or reservoirs and associated control components which are supported for removal as a unitary assembly. Means are provided for utilizing the pressurized fluid for fluffing up the abrasive powder in the reservoir to facilitate feeding to the nozzle, and to prevent clogging or packing in the reservoir. A pneumatically actuated pinch valve controls flow of air and the carried abrasive powder to the nozzle through a tubing of a material, such as latex, which prevents tunneling, and manually operable valve means provides for reservoir selection and venting.

Claims

1. Abrasive cutting apparatus, comprising:

a. a source of pressurized fluid;

b. an assembly comprising a reservoir containing an abrasive substance, said reservoir having an inlet connectible with said source and being positioned to discharge fluid into said abrasive substance in a bottom portion of said reservoir, and outlet means including a fluid flow passage in a tubular member, a portion of which is positioned in a top space of said reservoir, and an inlet opening in said tubular member for admission of the abrasive substance into said fluid flow passage;

c. discharge nozzle means connected with said outlet means;

d. pneumatic actuated valve means for controlling flow to said discharge nozzle; and

e. a foot valve for controlling the actuation of said valve means including;

a casing having an internal cavity communicating with a vent opening;

a pressurized fluid inlet connected with an inlet-outlet connection operatively connected with said valve means;

a valve structure in said cavity normally urged to one position closing said vent opening and establishing flow between said inlet and said inlet-outlet connection, and upon manual actuation to another position interrupting flow between said inlet and said inlet-outlet connection and connecting said inlet-outlet connection with said vent opening.

2. Abrasive cutting apparatus, comprising:

a. a source of pressurized fluid;

b. an assembly comprising a reservoir containing an abrasive substance, said reservoir having an inlet connectible with said source and being positioned to discharge fluid into said abrasive substance in a bottom portion of said reservoir, and outlet means including a fluid flow passage in a tubular member, a portion of which is positioned in a top space of said reservoir, and an inlet opening in said tubular member for admission of the abrasive substance into said fluid flow passage;

c. discharge nozzle means connected with said outlet means by a flexible tubing structure;

d. valve means for controlling flow to said discharge nozzle including a block member reciprocably movable into pinching and non-pinching relation with respect to said flexible tubing structure; and

e. a pneumatic actuator comprising;

a cylinder and a piston reciprocable in said cylinder, said piston having a stem with an outer end positioned within a receiving socket of said block member;

spring means for moving said piston in a direction enabling movement of said block member into said non-pinching relation; and

a connection with said cylinder for supplying pressurized fluid to move said piston in a direction to carry said block member into said pinching relation.

3. Abrasive cutting apparatus, comprising:

a. a source of pressurized fluid;

b. an assembly comprising a reservoir containing an abrasive substance, said reservoir having an inlet connectable with said source and being positioned in a bottom portion of said reservoir, and outlet means including a fluid flow passage in a horizontally extending tubular member positioned in a top space at the upper end of said reservoir above the abrasive and with an input end connecting the fluid Flow passage with said source of pressurized fluid, and an inlet opening in said tubular member for admission of the abrasive substance into said fluid flow passage, said reservoir inlet having a fluid discharge axis directed generally into the abrasive substance below the inlet opening in said tubular member;

c. a reverse flow check-valve between said source, the reservoir inlet, and said input end of said fluid flow passage;

d. discharge nozzle means connected with said outlet means; and

e. valve means for controlling the flow to said discharge nozzle.

4. Abrasive cutting apparatus according to claim 3, including a flow adjusting needle valve between said check valve and said reservoir inlet.

5. Abrasive cutting apparatus, comprising:

a. a source of pressurized fluid;

b. an assembly comprising a reservoir containing an abrasive substance, a removable cap closure member, a reservoir inlet connectable with said source and being positioned in a bottom portion of said reservoir, and outlet means including a fluid flow passage in a tubular member, a portion of which is positioned in a top space of said reservoir, and an inlet opening in said tubular member for admission of the abrasive substance into said fluid flow passage, said reservoir inlet having a fluid discharge axis directed generally into the abrasive substance surrounding the inlet opening in said tubular member;

c. desiccant means within said reservoir carried by and being removable with said cap member;

d. discharge nozzle means connected with said outlet means; and

e. valve means for controlling flow to said discharge nozzle.

6. Abrasive cutting apparatus according to claim 5, wherein the cap closure has a vent opening normally closed by valve means having an exteriorly manually operable actuator for moving the valve means to open position with respect to said vent opening.

7. Abrasive cutting apparatus according to claim 5, wherein the tubular member of the outlet means extends vertically of the reservoir and has an opening at its upper end for receiving fluid discharged from said reservoir inlet after it has passed through the abrasive substance, and the inlet in said tubular member is positioned at the bottom portion of said reservoir.