US3620066A - Metal bending method and machine therefor - Google Patents

Abstract

A METHOD OF BENDING METAL WHICH CONSISTS IN APPLYING PRESSURE TO THE AREA WHERE BENDING IS TO BE EFFECTED, THE FORCE OF THE PRESSURE HAVING A VALUE WHICH APPROXIMATES THAT AT WHICH THE BENDING OCCURS, THE METHOD ALSO INCLUDING AUGEMENTING SUCH PRESSURE, PREFERABLY MANUAL, TO EFFECT THE ULTIMATE DEGREE OF BENDING OF THE METAL, SUCH METHOD BEING PERFORMED BY A MACHINE INCLUDING A DEVICE FOR APPLYING PRESSURE, PREFERABLY A HYDRAULIC DEVICE, AND ANOTHER DEVICE, PREFERABLY MANUALLY POWERED, FOR AURGMENTING THE FORCE OF THE FIRST MENTIONED DEVICE, BUT AT A LESSER PRESSURE VALUE.

Description

Nov. 16, 1971 N, T, HENKEL ETAL 3,620,066

METAL BENDING METHOD AND yMACHINE `TI'lEREFOR Filed June 25, 1969 2 Sheets-Sheet 1 f lNvr-NTORS NE v/LLE T. `#ENKEL HARRY wR/GHT B HERMA/v w. scHARER Nov. 16, 1971 N. T. HENKEL ET Al. 3,620,066

METAL BENDING METHOD AND MACHINE THEREFOR 2 Sheets-Shoot Filed June 25, 1969 WSU.

L R S E M Y R K E mmmm N .NHGx R ,.r 0 VTRW NEW v 7 N RM MR a NH#h Y m United States Patent Oy "ice U.S. Cl. 72-362 6 Claims ABSTRACT OF THE DISCLOSURE A method of bending metal which consists in applying pressure to the area where bending is to be effected, the force of the pressure having a value which approximates that at which the bending occurs, the method also including augmenting such pressure, preferably manual, to effect the ultimate degree of bending of the metal, such method being performed by a machine including a device for lapplying pressure, preferably a hydraulic device, and another device, preferably manually powered, for augmenting the force of the first mentioned device, but at a lesser pressure value.

BACKGROUND OF THE INVENTION (l) Field of the invention The invention relates to the method of metal bending and machinery therefor.

(2) Description of the prior art To applicants knowledge, metal bending heretofore has been either by manual manipulation or by metal shaping machinery. Bending of metal to accuracy desired, particularly heavy gauge metal, cannot be effected manually and machinery for bending heavy gauge metal to accuracy has never been perfected. Such machinery has the characteristics of either bending the metal beyond that desired or fails to bend the metal to that desired. By applicants method and machine, relatively high pressure is employed at the area where the bending is to be effected, the high pressure having a value which approximates that at which bending can occur, and this pressure is augmented by a pressure of relatively lesser value, but being sufficient by augmentation to effect the desired bending.

SUMMARY OF THE INVENTION i The method is carried out by machinery including a force, preferably by a hydraulic pressure device, which force is applied to the area at which bending is to be effected. The pressure employed has a value approximating that pressure which is necessary to effect bending, whereby a slight augmenting of that pressure will effect bending. The machinery also includes a second pressure device, which is preferably effected by manual force. The second pressure device is applicable to augment that of the powered device to effect the desired bending.

Other features and the advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the invention is ill-ustrated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the machinery for perfecting the bend, together Iwith the hydraulic power plant for operating the power actuated pressure device, the view also showing in phantom a piece of metal to be bent;

FIG. 2 is a view looking in the direction of arrows 2 of FIG. 1;

Patented Nov. 16, 1971 FIG 3 is a fragmentary view, partly in section, the section being taken along line 3 3 of FIG. 1, but on a larger scale;

FIG. 4 is a fragmentary view, partly in section, the section being taken along line 4-4 of FIG. 3;

FIG. 5 is a fragmentary View, partly in section, the section being taken along line 5 5 of FIG. 3;

FIG. 6 is a fragmentary view looking in the direction of arrows 6 of FIG. 4;

FIG. 7 is a fragmentary sectional view taken along lines 7 7 of FIG. 4;

FIG. 8 is a fragmentary View, partly in section, the section being taken along the lines 8 8 of FIG. l, but on a larger scale; and

FIG. 9 is a top plan view looking in the direction of arrows 9 of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring generally to the drawings, the metal bending machine is shown at 20; the metal to be bent is shown in phantom at 22 and is in the form of a ring; and the power generating machine is shown at 24. The machine 24 is of the standard type including a truck 26 which houses a pressure generating device such as a hydraulic pump (not shown) which is driven by an electric motor 28, which is connected to a source of electric current through a controller disposed on truck 26.

The truck 26 also houses a reservoir (not shown) from which the pump draws the hydraulic fluid. The high pressure outlet of the pump is connected to a manually controlled valve 32 (FIGS. l and 2), which is carried by a table 34, by high pressure tube 35 and return tube 36. Suitable valve mechanism 37 is disposed in the high pressure side of the system and is manually adjustable to maintain the desired maximum pressure of fluid. Tubes 38 and 39 connect the valve 32 with a hydraulic motor 40.

The hydraulic motor 40 actuates a shoe 42 which extends upwardly through a slot 44 in the thick steel table top 46. The top of the table carries steel posts 48 and 50 which receive cylinders 52 and 54. The posts are removably carried in holes 56 in the metal table top. The holes selected for the posts depend upon the shape of the metal to be bent. The metal 22 to be bent is disposed between the shoe 42 and the cylinder. The manually controlled valve 32, -having a manipulating handle 58, is carried by the table for controlling the flow of fluid from the pump to the motor.

The force applied by the shoe 42 on the metal 22 is preset by manipulating the valve mechanism 37 to the maximum force desired. Such pressure is preset at a value whereby the shoe force on the metal approximates that force at which bending of the metal can occur. Under a certain condition, the force exerted by the shoe on the metal may place the metal under slight stress. Still under another condition, the degree of force exerted by the shoe on the metal is between the two aforementioned forces. Under .any of the above conditions, auxiliary force must be applied onto the metal in order to effect the desired accurate bending thereof.

`The auxiliary force may be by any desired extraneous force and is herein disclosed, for illustrating the invention, as a manually applied force. The shoe 42 is formed integrally with a reciprocating plate 60 which carries a rack 62, the teeth of which receive the teeth of a ratchet 64 (FIG. 6). The ratchet is carried by a pin -66 which is slidably carried in a slot 68 on a plate 70, which latter is fixed to the underside of the table 34. A handle 72 is formed integrally with the ratchet 64 for manipulating the rack 62 carried 4by the plate 60.

In operating the mechanism to carry out the method,

the valve 32 is opened to supply fluid to the hydraulic motor 40 which in turn moves the plate 60 and shoe 42 toward the metal 22, which metal at that time abuts the cylinder 52 on the posts 48 and S0. The shoe 42, upon engaging the metal 22, applies the predetermined, pre-selected force onto the metal. After that major force is applied and while it is being applied, the auxiliary, relatively less force is applied, which auxiliary force, when added to the major force, is sufficient to bend the metal to the desired accurate shape. The auxiliary force, for illustrative purpose only, is applied manually through the ratchet 64 and rack 62.

It is emphasized that the manual force being applied through the ratchet 64 and rack 62 is by pulling on the handle 72 of the ratchet. It has been found in actual practice that the muscular reaction in pulling is highly sensitive for imparting the desired manual force to thc shoe, and is far more sensitive than pushing force on the handle.

Referring more in detail to the drawings, the table 34 includes angle iron legs 74 which are braced by a horizontal angle iron frame 76 and an angle iron brace 78. An angle iron 79 is welded to two of the legs 74 and supports the manually actuated valve 32. A rectangularly shaped support 80 bridges and is welded to two of the sections of frame 76. An upright pivot support 82 is Welded to the support 80 for a pivot pin 84.

The cylinder 86 of the hydraulic motor 40 is carried by a frame 88 having two downwardly extending arms 90, the lower ends of which straddle the pivot support 82 and are journaled on the pivot pin 84. The upper end of the hydraulic ram is in the form of an arm 92 and this arm carries a pivot pin 94. The pin 94 is connected to two pairs of links 96 and 98, one pair being disposed on one side of the arm 92 and the other pair on the opposite side of the arm. Links 96 are pivotally connected to a pin 100 which is supported by a downwardly extending support 102 which is fixed to the underside of the table top 46 by screws 104. The links 98 are pivotally connected by a pin 106 to the opposite side of the shoe plate 60.

As seen more clearly in FIG. 4, the plate 60 is provided with longitudinally, i.e. horizontally extending grooves 108 on opposite sides thereof, and these grooves receive guide rods 110. The guide rods are fixed to the underside of table top 46 by oppositely disposed rod supports 112 which are L-shaped in cross-section and fastened to the underside of the table by screws 113.

Thus it is apparent that as the ram arm 92 is moved upwardly upon opening the valve 32, the supporting frame 88 for the hydraulic cylinder 86 will be moved clockwise, as viewed in FIG. 3, forcing the links 98, the pin 106, the shoe plate l60 and the shoe 42 to the right. In this manner the desired pre-selected and predetermined degree of force is applied to the shoe 42.

The extent of oscillatory movement that can be imparted to the ratchet 64 is governed by angular disposed strips 114. These strips together with the plate 70, are fixed to the underside of the table top by screws 116. A strip 118 (see FIG. 6) for slida-bly supporting the handle 72 for ratchet 64 is fastened to the underside of the table top 46 by screws 120. The handle 72, carrying the ratchet y64, and the pin 66 are pulled to the right, as viewed in FIG. 6, prior to the application of the major force whereby the ratchet is disconnected from the rack. After completion of the application and maintaining of the major force on the shoe, the handle 72 is moved to the left to reengage the ratchet and rack teeth. Thereafter, the operator pulls the handle in a clockwises direction to augment the major force.

The degree of augmenting force `being applied can be determined by a gauge 122 (see FIGS. 8 and 9). The gauge is suitably fixed to the top side of table top 46 by a plate 124. The gauge is responsive to fluid pressure in an attached cylinder 126, the pressure therein being varied by a piston, the outer rod of which is shown at 128. The exposed end of the piston rod is attached to an arm which is fixed by screws 132 to shoe plate 60.

In practicing the present invention, the operator will employ a gauge to the metal to determine where pressure should be employed. For example, in the embodiment illustrated wherein the metal 22 is a ring or a part of a ring, the gauge would have an arcuate surface, and if the area of the metal does not conform to the shape of the arcuate surface of the gauge, i.e. that area must be forced radially inwardly, he will place that area `between the cylinders 52 and 54 on the posts 48 and 50. Then the major force is applied to that area by the shoe 42. The metal will be confined between the shoe and the abutments provided by the cylinders. As previously explained, the force applied by the shoe approximate that force at which bending can take place.

The skilled operator, having previously evaluated mentally the degree of auxiliary force that is necessary to bend the metal to the desired shape, will pull the handle 72 clockwise, as viewed in FIGS. 1 and 6, and quite often bend the metal to the desired shape by merely one physical act. Usually, when extreme precision is necessary, several pullings are effected, each pulling gradually increasing the degree of bending. These repeated bendings by physical force by the skilled operator can be effected although hysteresis is taking place in the metal. Thus the accuracy can be attained in a speedy manner.

In certain cases, the gauge is quite helpful. The skilled operator will know what degree of movement of the gauge hand or hands is necessary to approach the ultimate degree of augmenting force desired. He will then apply that desirable augmenting force by observing the extent of movement of the hands of the gauge.

It will be understood that if bending of the ring 22 from the inside surface thereof is necessary, it will be turned so that the shoe 42 engages the inside surface and the outer periphery will abut the cylinders 52 and 54. Various size cylinders, such as those shown in FIG. 1 at 136 and 138, can be substituted for cylinders 52 and 54. By selecting the desired holes 56 for the posts 48 and 50 and the desired cylinders to be put on the post, any desired abutting relationship can be established between the shoe 42 and the cylinders.

Having described our invention, we claim:

1. The steps in the method of bending metal, which steps include:

(A) applying pressure to the metal at the area where bending is to be effected;

(B) limiting and maintaining the application of such pressure at a value short of the pressure necessary to bend the metal to the ultimate shape desired;

(C) thereafter bending the metal to the ultimate shape desired by applying an augmenting pressure to the same area at a lesser value than the first mentioned pressure.

2. The steps in the method of bending metal, as defined in claim 1, characterized in that the pressure being applied by the first mentioned step approximates that pressure at which bending or the metal to be bent can occur'.

3. The steps in the method as dened in claim 1, characterized in that the augmenting pressure is by manual pulling force.

4. The steps in the method as defined in claim 2, characterized in that the augmenting pressure is lby manual pulling force.

5. The steps in the method of bending metal as defined in claim 1, characterized in that the metal is of the type which partly rebounds after being bent, and further characterized in that the application of the augmenting pressure effects bending of the metal to that degree beyond the desired bent shape which, due to the rebounding characteristic of the metal, will rebound to the ultimate desired. shape.

5 6 6. The steps in the method as dened in claim 5, char- 3,184,951 5/ 1965 Hilton 72-389 X acterized in that the augmenting pressure is by manual 1,906,854 5/ 1933 Heinrich Y72--389 11' f pu mg om CHARLES W. LANHAM, Primary Examiner 5 M. I. KEENAN, Assistant Examiner References Cited UNITED STATES PATENTS 3,333,445 8/1967 Mergler 72-702 X U.S, C1. X.R. 3,209,577 10/1965 Teplow 72-389 72-389, 432, 702

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