US3478568A

US3478568A - Hardness tester

Info

Publication number: US3478568A
Application number: US531656A
Authority: US
Inventors: Roland D Borgersen
Original assignee: ROLAND D BORGERSEN
Current assignee: ROLAND D BORGERSEN
Priority date: 1966-03-04
Filing date: 1966-03-04
Publication date: 1969-11-18
Anticipated expiration: 1986-11-18

Description

Nov. 18, 1969 R. D. BoRGERsl-:N

HARDNESS TESTER 5 Sheets-Sheet 1 Filed March 4, 1966 .IIVIIVIIII lll FIG.

INV'ENTOR ROLAND D. BORGERSEN ATTORNEYS Nov. 18, 1969 R. D. BoRGERsr-:N

HARDNESS TESTER 5 Sheets-Sheet 2 Filed March 4, 1966 ROLAND D. BORG-ERSEN ATTORN EYS Filed March 4, 1966 R. D. BORGERSEN 3 Sheets-Sheet 5 BY #M ATTORNEYS United States Patent O U.S. Cl. 73--81 1 Claims ABSTRACT OF THE DISCLOSURE A hardness tester comprising a ram housing, a stationary holding frame supporting the ram housing and supporting an anvil in line with the ram housing, a ram positioned in the housing, a ram pressure chamber be`- hind the ram adapted to receive a hydraulic fluid to move the ram forwardly, a iiexible cup-shaped washer positioned in the chamber at the rear of the ram and having an outwardly extending Wall which is expanded against the inner wall of the housing by the force of the hydraulic uid entering the chamber, thereby providing a seal against fluid leaking between the ram and the inner wall of the housing, a return spring connected between the ram and the ram housing for returning the ram to normal position when the fluid is released from the chamber, and mechanism for moving the ram housing toward and away from the anvil including threads formed on the outside of the ram housing, a threaded nut mounted on the ram housing and rotatably supported by the frame, the ram housing having outside walls positioned close enough to the frame so as to prevent rotation of the housing when the nut is turned, with the frame providing a stop against the movement of the nut in a direction away from the anvil when the ram is being forced toward the anvil by the uid pressure in the pressure chamber to indent a work piece.

This invention relates to hardness testers, and more particularly concerns a hardness tester which is portable and has a test head and a pump unit which are separate and which may be supported in a strong, lightweight frame so that all the components of the hardness tester are compactly arranged.

It is an object of this invention to provide a hardness, tester which is portable and which compactly. contains all the elements for hydraulic operation and for exerting the necessary high pressure for testing the Brinell hardness of various metals.

It is another object to provide a hardness tester with seals against leakage of the hydraulic fluid.

It is another object to provide a hardness tester which holds its accuracy within prescribed `limits, and maintains the full pressure for any desired length of time.

It is another object of this invention to provide a hardness tester that may be readily adapted to work pieces of various sizes and shapes.

It is another object to provide a hardness tester which is simple in construction and uses a small number of parts so that the tester may be manufactured economically, and yet be as accurate as more expensive instruments.

It is another object to provide a hardness tester wherein either a mechanically operated pump or an electrically operated pump may be used economically.

It is another object of this invention to provide a hardness tester wherein the pressure in the test head may be actuated from a distance without diminishing the accuracy of the Brinell test.

Other objects and advantages of this invention, including its simplicity and economy, as well as the ease with which it may be adapted to existing equipment, will 3,478,568 Patented Nov. 18, 1969 ICC further become apparent hereinafter and in the drawings, in which:

FIG. 1 is a view in side elevation of a hardness tester constructed in accordance with this invention;

FIG. 2 is a view in horizontal section taken as indicated -by the lines and arrows 2-2 which appear in FIG. 1;

FIG. 3 is a view in Vertical section taken through the ram housing head as indicated by the lines and arrows 3-3 which appear in FIG. 2, and taken through the ram housing base as indicated by the lines and arrows 3a-3a which appear in FIG. 2; and

FIG. 4 is a view in vertical section of the pump unit.

Although specic terms are used in the following description for clarity, these terms are intended to refer only to the structure shown in the drawings and are not intended to define or limit the scope of the invention.

Turning now to the specic embodiment of the invention selected for illustration in the drawings, there is shown a portable hardness tester which includes a test head 11 and a pump unit 13 which are supported in a holding frame 15.

Frame 15 includes a pair of side -plates 17 which are made of an alloy steel having a high coeicient of elasticity. Side plates 17 are held in parallel position by Welded

steel cross plates

19, 21, 23, and 25, and by base plate 26. Steel cross plate 21 is welded in such a position that it supports a nut 27 which is connected to housing base 29 of test head 11. Plate 21 supports nut 27 rmly but not so tightly as to prevent its free rotary motion.

Ram housing base 29 is of square stock and is supported in an upright position by side plates 17 and cross plate 21. The four corners or edges of the square shaped housing base 29 have external threads 31 formed thereon and they receive the internal threads 33 of nut 27. Accordingly, as nut 27 is rotated by hand, ram housing -base 29 is raised or lowered in the vertical direction to provide a simple adjustment as to the distance between Brinell ball 3S and an anvil 37 which is mounted on cross plate 25 of frame 15 in line with ram housing base 29.

The capacity of the hardness tester for testing specimens or work pieces of Various sizes land shapes is limited only by the strength (and therefore the optimum desired weight) of the supporting side plates 17, which bear the full thrust of the ram pressure, since when ram 39 proceeds forwardly toward anvil 37, the side plates 17 provide a stop against rearward movement by nut 27 and the ram housing base 29 connected to it.

Larger specimens or work pieces may be worked upon by providing side plates 17 which have a greater distance Ibetween

cross plates

21 and 25.

For ease of manufacture and assembly, the ram housing includes housing base 29 and housing head 41 which are connected together by a sealed joint 43 that includes threads 45 and a gasket 47.

Housing base 29 is hollow and includes an inner wall 49, ram 39 having a Brinell ball 35 mounted in its forward end and held there by a retainer cap 51, and a ram pressure chamber S3 behind ram 39 and adapted to receive a hydraulic uid to move the ram forwardly, A ilexible cup-shaped washer 55 is positioned in chamber 53 at the rear of ram 39 and has an outwardly extending wall 57 which is expanded against the inner Wal149 of housing base 29 by the force of the hydraulic fluid entering chamber 53, thereby providing a seal against Huid leaking between ram 39 and inner wall 49 of housing lbase 29.

The forward portion of ram 39 is reduced in cross section and a return spring 59 is positioned around it and is held in place by a retaining nut 61 screwed into the forward end of housing base 29. Spring 59 exerts pressure between nut 61 and shoulder 63 of ram 39 and returns the ram 39 to its normal position when the hydraulic fluid is released from chamber 53.

Housing head 41 contains a unitary high pressure valve 65, a pressure release valve 67, a pressure relief valve 69, and a connection socket 71 for a pressure gage 73. High pressure valve 65 is connected to pressure chamber 53 by a duct 75; release valve 67 is connected to chamber 53 by ducts 77, 79, and 81; relief valve 69 is connected to chamber 53 by ducts 83, 79, and 81; and pressure gage connection socket 71 is connected to chamber 53 by a duct 85.

A feed hose 87 is connected through a duct to high pressure valve 65, and an exhaust hose 89 is connected through ducts to release valve 67 and relief valve 69.

Pump unit 13 is mounted in side plates 17 by screws 90, and includes a pump chamber 91, a pump plunger 93, and a pump handle 95 connected to pump plunger 93 by a mechanical link 97 and supported by fulcrum 99.

A sump or oil reservoir 101 is formed in pump unit 13 and may contain any hydraulic fluid. The open end of sump 101 is threaded to receive a retaining nut 103 which clamps the top of a flexible fluid-proof sac 105 against a shoulder 107 formed at the top of sump 101. Elastic sac 105 prevents the hydraulic fluid from escaping from sump 101, and expands and contracts under varying fluid conditions within sump 101, i.e., when the fluid is low the sac expands and when the fluid is high the sac contracts. Sac 105 prevents escape of fluid from sump 101 when the tester is operated in other than an upright position.

Sump 101 is connected to a valve chamber 109 by a duct 111, valve chamber 109 is connected to a valve chamber 113 by a horizontal duct 114 and a vertical duct 115, and valve chamber 113 is connected to feed hose 87.

Sump 101 is also connected to exhaust hose 89 by a duct 1'17.

In operation of the tester, release valve 67 is opened by turning handle 119 and the ram 39 and housing base 29 are raised by revolving or rotating the nut 27. The test head 11 is thus raised a sufllcient distance to admit the test specimen or work piece into the space between Brinell ball 35 and anvil 37. Release valve 67 is closed by turning handle 119, and handle 95 is pumped. When pump plunger 93 is raised, hydraulic fluid is drawn from sump 101 through duct 111 into valve chamber 109 past ball check 121 which is normally held in place by a spring 123. The fluid is sucked into pump chamber 91 through a duct 125.

As plunger 93 is moved downwardly by the cranking of pump handle 95, the fluid trapped in pump cylinder 91 is forced back into valve chamber 109. Since ball check 121 is seated because of the pressure of spring 123 and the pressure of the fluid from pump cylinder 91, the fluid is forced out of chamber 109 through a horizontal duct 114 and upwardly through vertical duct 115 into valve chamber 113 past the ball check 129, and then into flexible feed hose 87.

The fluid in valve chamber 113 cannot reverse its direction of flow because of the action of ball check 129 which is seated by spring 131 when the fluid pressure from duct 115 diminshes.

As a result of the continued pumping of crank or pump handle 95, the fluid in flexible feed hose 87 flows into high pressure valve 65 and is prevented from reversing its direction of flow from the valve by the action of its ball check which seats because of spring pressure when the fluid pressure from feed hose 87 diminshes.

As pumping continues, the fluid flows downwardly from high pressure valve 65 through duct 75 into ram pressure chamber 53. As more fluid is forced into pressure chamber 53 the pressure is gradually built up therein to move hydraulic ram 39 forwardly.

The ram pressure chamber 53 is connected to pressure gage 73 through duct 83, so the gage 73 displays the amount of pressure in chamber 53.

Ram pressure chamber 53 is also connected to pressure relief valve 69 which may be set for any desired pressure by adjusting the position of its nut in the chamber so that the force of its spring against its ball check becomes greater or less as desired. As shown, the ball is normally seated by the action of its spring-actuated plunger,` and the tension of the spring may be adjusted by rotating the nut which is threaded into the bore above the spring. When the fluid pressure is too high in chamber 53, theball in relief valve 69 is forced away from its seat, and the fluid flows through the relief valve chamber into eX- haust hose 89 which empties into sump 101.

When continued operation of the pump handle has caused the pressure in chamber 53 to build up to the desired pressure, that pressure will be indicated on gage 73. When the desired pressure is exceeded, the relief valve 69 opens and then closes when the pressure decreases to the desired value. Pumping of the pump handle 95 is then discontinued, and the desired pressure is held by the system of check valves in the apparatus for the required length of time to complete the test.

Release valve 67 is then opened by turning handle 119, and the pressure in chamber 53 is relieved as the fluid returns through exhaust hose 89 to sump 101. The test head is raised by rotating nut 27 so that the test specimen can be removed. The impression made on the specimen by Brinell ball 35 is a standard Brinell test and is read in the usual manner.

After the fluid pressure in chamber 53 has returned to normal, ram 39 is returned to its normal, at-rest position by return spring 59.

It will be noted that since the test head 11 and pump unit 13 are separate units, and are connected by flexible hoses, the pump unit 13 need not be mounted in frame 15 but may be positioned remotely from the test head.

Housing base 29 is square in cross section and has its outside walls positioned close enough to the frame side plates 17 so as to prevent rotation of the housing when nut 27 is rotated.

When ram 39 is pushed forwardly by the pressure in chamber 53, the edges of side plates 17 form a stop against nut 27 since the nut extends outwardly past the side plates.

It is to be understood that the form of the invention herewith shown and described is to be taken as a presently preferred embodiment. Various changes may be made in the shape, size and arrangement of parts. For example, equivalent elements may be substituted for those illustrated and described herein, parts may be reversed, and certain features of the invention may be utilized independently of the use of other features, all Without departing from the spirit or scope of the invention as deflned in the subjoined claims.

What is claimed is:

1. A hardness tester comprising a movable cylinder ram housing which is hollow and has an inner wall, a stationary holding frame positioned around and supporting the ram housing, an anvil mounted on the frame in line with the ram housing, and means for moving the ram housing relative to the frame toward and away from the anvil to various desired positions and for holding the ram housing in the desired position.

2. The hardness tester of claim 1 including a ram positioned in the housing, a ram pressure chamber behind the ram adapted to receive a hydraulic fluid to move the ram forwardly, and a flexible cup-shaped washer positioned in the chamber at the rear of the ram and having an outwardly extending wall which is expanded against the inner wall of the housing by the force of the hydraulic fluid entering the chamber, thereby providing a seal against fluid leaking between the ram and the inner wall of the housing.

3. The hardness tester of claim 1 including a ram positioned in the housing, a ram pressure chamber behind the ram adapted to receive a hydraulic fluid to move the ram forwardly, and a return spring operatively connected between the ram and the ram housing for returning the ram to normal position when the uid is released from the chamber.

4. The hardness tester of claim 1 wherein the ram housing includes a housing base having a ram positioned therein and a ram pressure chamber, a housing head containing high pressure, relief and release valves which are connected to the ram pressure chamber by duets, and a sealed joint connecting the housing head and base together.

5. The hardness tester of claim 4 including a flexible feed hose connected to the high pressure valve for feeding fluid under high pressure thereto, and a flexible exhaust hose connected to the relief and release valves for exhausting the fluid from the ram housing.

6. The hardness tester of claim 1 wherein said moving means includes threads formed on the outside of the ram housing, and a threaded nut mounted on the ram housing and rotatably supported by the frame.

7. The hardness tester of claim 6 wherein the ram housing is square in cross section and has outside `walls positioned close enough to the frame so as to prevent rotation of the housing when the nut is turned.

8. The hardness tester of claim 6 wherein the frame includes two spaced-apart side plates connected together by cross plates, and said nut extends outwardly past the side plates so that the side plates provide a stop against rearward movement by the nut and the ram housing connected to it when the ram is being forced forwardly by the fluid pressure in the pressure chamber to indent a work piece.

9. The hardness tester of claim 1 including a pump mounted in the holding frame, and feed and exhaust hoses connected between the pump and the ram housing.

10. A test head for a hardness tester comprising a ram housing which is hollow and has an inner wall, a ram positioned in the housing, a ram pressure chamber behind the ram adapted to receive a hydraulic fluid to move the ram forwardly, a flexible cup-shaped washer positioned in the chamber at the rear of the ram and having an outwardly extending wall which is expanded against the inner wall of the housing by the force of the hydraulic fluid entering the chamber, thereby providing a seal against fluid leaking between the ram and the inner wall of the housing, a return spring operatively connected between the ram and the ram housing for returning the ram to normal position when the fluid is released from the chamber, threads formed on the outside of the ram housing, and a threaded nut mounted on the ram housing and adapted to be rotatably supported in a frame.

11. The test head according to claim 10 wherein the ram housing vincludes a housing base having the ram and pressure chamber positioned therein, a housing head containing the high pressure, relief and release valves which are connected to the ram pressure chamber by ducts, and a sealed joint connecting the housing head and base together.

References Cited UNITED STATES PATENTS 2,203,129 6/1940 Campbell et al. 73-83 2,337,573v 12/1943 Schultz 254-93 X 3,370,421 A 2/1968 Piper 254-93 X 2,297,778 y 10/ 1942 Knerr et al. 73-81 2,839,917 6/1958 Webster 73-81 2,956,432 l0/1960 Henrikson 73-81 3,029,631 4/ 1962 Borgersen et al. 73--81 3,247,824 I 4/1966 Rodgers 73-419 3,309,916 3/1967 Pearson 73--81 RICHARD C. QUEISSER, Primary Examiner JERRY W. MYRACLE, Assistant Examiner U.S. C1. X.R. 254-93