US3890869A - Louver cutter - Google Patents

Abstract

An improved louver apparatus including a reciprocating punch, a die having spaced anvil and support members for receiving the punch therebetween, and actuating means for the punch. The actuating means includes a handle, having a limited degree of free travel, and an integral ball and link for transmission of force from the handle to the punch. The handle, ball and link coact so that maximum downward force is applied to the handle when the punch is cutting through metal to form a louver. The punch and die are jointly pivotally indexable to different positions for cutting louvers both longitudinally and transversely of a metal sheet. The anvil has four working edges to provide longer useful life.

Description

United States Patent [1 1 Van Cleave [451 June 24, 1975 [73] Assignee: Van Mark Products Corporation,

Farmington Hills, Mich.

[22] Filed: Nov. 29, 1972 [21] Appl. No.: 310,046

Primary Examiner-Andrew R. Juhasz Assistant Examiner-Leon Gilden Attorney, Agent, or FirmCullen, Settle, Sloman & Cantor [5 7] ABSTRACT An improved louver apparatus including a reciprocating punch, a die having spaced anvil and support members for receiving the punch therebetween, and actuating means for the punch. The actuating means includes a handle, having a limited degree of free travel, and an integral ball and link for transmission of force from the handle to the punch. The handle, ball and link coact so that maximum downward force is applied to the handle when the punch is cutting through metal to form a louver. The punch and die are jointly pivotally indexable to different positions for cutting louvers both longitudinally and transversely of a metal sheet. The anvil has four working edges to provide longer useful life.

6 Claims, 9 Drawing Figures SHEET PATENTEB JUN 2 4 1915 FIG. 7

LOUVER CUTTER BACKGROUND OF THE INVENTION This invention relates generally to apparatus for selective punching of sheet metal or the like and, more particularly, to an improved apparatus for cutting or punching louvers or vanes in sheet metal.

Machines for forming louvers are well known as exemplified by US. Pat. No. 2,728,316 issued to Oberg et al on Dec. 27, 1955. The Oberg et al patent discloses a basic louver cutter including a frame, a punch and die arrangement and a schematic actuating mechanism.

Other prior art louver cutters include actuating means operating on the principle ofa cam and cam follower to force a punch through the sheet metal with resilient means urging the punch and actuating means back to a rest position. One disadvantage with this type of actuating mechanism is binding of the resilient means. A greater disadvantage is the excess force nec essary to operate the cutter to punch through the sheet metal because the force is not being applied to the actuating means in the same direction that the punch is moving while punching through the sheet metal.

Another problem arises in prior art devices which include an indexing feature to permit louvers to be punched both longitudinally and transversely ofa metal sheet. The prior art indexing means do not provide for proper alignment of the upper reciprocating punch and the stationary die. Such alignment, according to the prior art devices, is by eye which may result in one louver being improperly punched each time the punch and die are indexed and in contact between the punch and die causing excess wear and damage to both the punch and die.

Yet another problem in prior art devices of this nature is based on the rapid wearing out of the working edge of the anvil. The anvil is subjected to a repeated shearing stress each time the cutting member punches through the sheet metal against the anvil. After a certain number of punching operations, the working edge of the anvil wears out and a new anvil is required.

SUMMARY OF THE INVENTION It is, therefore, a principal object of the present invention to provide an improved louver cutter.

It is an object of the present invention to provide an improved louver cutter including actuating means which provide positive control of the punch.

It is another object of the present invention to provide an improved louver cutter having actuating means which provides a mechanical advantage over actuating means of the prior art.

It is yet another object of the present invention to provide an improved louver cutting having an actuating means which permits a maximum force to be applied to the actuating means in the same direction that the punch moves while cutting through the work piece.

It is still another object of the present invention to provide an improved indexing means for a louver cutter so that the punch and die will be aligned after indexing.

Yet another object of the present invention is to provide an improved anvil having a plurality of working edges.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing objects of the present invention, together with other objects and advantages which may be attained by its use, will become more apparent upon reading the following detailed description taken in conjunction with the drawings.

In the drawings, wherein like reference numerals identify corresponding parts:

FIG. 1 is a side elevation of the louver cutter of the present invention showing the actuating means in a rest position;

FIG. 2 is a front elevation of the louver cutter of the present invention;

FIG. 3 is a partial front elevation taken along plane 3-3 of FIG. 1 illustrating the punch means and anvil means of the present invention;

FIG. 4 is a partial side elevation of the louver cutter of the present invention illustrating the actuating means in a working position;

FIG. 5 is an illustration of a work piece having a plurality of louvers punched therein;

FIG. 6 is an exploded perspective view of the actuating means of the present invention;

FIG. 7 is a partial side elevation of the louver cutter of the present invention illustrating the punch means and die means indexed to a different working position;

FIG. 8 is a partial plan view taken along plane 8-8 of FIG. 4 illustrating the punch means indexed in a first position; and

FIG. 9 is a partial plan view taken along plane 99 of FIG. 7 illustrating the punch indexed in a second position.

DETAILED DESCRIPTION OF THE INVENTION The louver cutter of the present invention includes a generally C-shaped frame 10 having an upper leg 12 and a lower leg 14, punch means 16 disposed in the upper leg, die means 18 attached to the lower leg and means 20 for actuating the punch means to punch a louver in a work piece W by reciprocating the punch means with respect to the die means.

The die means 18 of the present invention include a base 22 rotatably mounted in the lower leg 14 of the frame. A support member 24 having an aperture 26 is secured to the base 22 by a screw 28 which is threaded into a tapped hole 29 in the base.

An anvil 30 having a hole 32 therethrough is secured to the base opposite from the support member by another screw 28 which is threaded into a second hole in the base member 22. It may be appreciated that if the hole in the base 22 extends completely therethrough and the hole or aperture in either the support member or the anvil is threaded, a single screw may be utilized to fasten the anvil and support member to the base.

One problem with prior art anvils is that the working or shearing edge or surface of the anvil wears out quickly. To overcome this problem, applicant has provided an improved shearing member 34 which may be configured as a rectangular rod. The shearing member 34 has a plurality of apertures 36 therethrough which may be aligned with apertures38 in the anvil 30. A plurality of screws 40 may be utilized to fasten the shearing member to the top of the anvil.

The punch means 16 of the present invention includes a cylindrical ram 50 disposed for vertical reciprocating movement within the upper frame leg 12. The ram which has a plurality of longitudinal peripheral grooves 52, includes a lower portion 54 of reduced diameter. A cutting member 56 having an aperture or hole 58 therethrough is fastened to the ram by a screw 60 inserted in a threaded hole 62 in the reduced diameter portion 54 of the ram.

The upper end of the ram 50 includes a narrow neck portion 68 and a radial flange 70 axially outward of the neck. The flange, neck and ram define a socket 72 for connection to the actuating means of the present invention.

With reference to FIG. 1, the actuating means of the present invention is shown at rest and includes a handle 74 which is substantially flush with the upper frame leg 12. With reference to FIG. 4 the handle 74 is illustrated in a working position at the time that the punch means 16 and more specifically the cutting member 56 is cutting through a work piece W. It will be appreciated, as shown by the arrow, that the force applied to the handle is in the same direction as the movement of the cutting member. If the handle were more vertical rather than horizontal the force being applied to the handle would be lateral rather than downward.

The novel structure to provide this advantage of applying a downward force during the actual punching is illustrated in an exploded view in FIG. 6 including the handle having a transverse sleeve 76 welded thereto. The sleeve has a arcuate peripheral slot 78 including slot ends 80.

A rod 82 of generally circular cross-section is disposed within the sleeve 76 and journalled in the upper frame leg 12 for rotation. The rod includes a tapped hole 84 and the rod provides an axis for rotation of the handle 74.

Means are provided for transmitting force from the handle 74 to the ram 50. Specifically an integral ball and link 86 has the ball portion disposed in the socket 72. The link is threaded as at 87 and is screwed into the hole 84 in the rod 82.

When it is desired to reciprocate the punch means, the handle 74 is rotated with respect to the rod 82. The slot 78 provides a limited amount of free travel of the handle until the slot end 80 bears against the link portion of the ball and link. At that time force is transmitted from the handle through the ball and link combination to the socket 72 forcing the ram downward.

As the handle is further pivoted with respect to the rod 82 the continued force is transmitted to force the ram downward and the cutting member 56 punches through the work piece.

To return the punch to its rest position, the handle 74 is pivoted back towards its rest position and the opposite slot end engages the bottom portion of the ball and link after a limited amount of free travel of the handle. Force is again transmitted by the ball and link into the socket but acts upward against the bottom of the radial flange 70 on the ram to lift the ram upward. Thus there is positive control of the ram in both directions.

With reference to FIG. 1 it may be appreciated that, as the louver cutter is actuated, the punch means 16 cuts through the work piece W and exerts a force against one edge 41 of the shearing member. When this edge becomes sufficiently worn, the screws 40 may be removed and the shearing member 34 rotated or turned about a longitudinal axis to move a different edge into a working position. This provides four working edges from a single shearing member thus extending useful life of one anvil.

One additional advantage gained by using a shearing member 34 secured to an anvil is that the anvil may be made of ordinary metal stock and the shearing member may be manufactured of a high strength material such as nickel or high carbon steel. Since these are more expensive it is desired to use as little as necessary. With the combination of the present invention, the entire die means is not manufactured of high carbon steel, and only a rectangular rod must be replaced when all four working edges are worn. This provides a reduced cost upon the replacement of the shearing member 34 as contrasted to replacing the entire anvil as required in the prior art.

FIG. 5 illustrates a work piece W having a plurality of louvers 42 punched therein. If it is desired to punch the louvers in a different direction, it is necessary to index both the punch means 16 and the die means 18. Thus the die means 18 must be rotated or indexed about a vertical axis from the position of FIG. 4 to the position of FIG. 7. The base 22 of the die means 18 includes a circumferential groove 44 disposed below the surface of the anvil and support member. A threaded aperture 46 is disposed in the lower frame leg 14 and aligned vertically with the groove 44. A threaded detent 48 is inserted into the aperture 46 and tightened to cooperate with the groove 44 to prevent rotation of the base 22.

Means are provided for indexing the punch means 16 for cutting both longitudinal and transverse louvers. Specifically, a spring detent 64 is threaded into a hole 66 in the upper frame leg 12 and is disposed to engage a groove 52 in the ram 50.

To prevent misalignment of the punch relative to the die means when both are indexed, it may be seen with reference to FIG. 4, that as the punch means 16 is lowered to its extreme bottom position, the bottom of the cutting member 56 is below the top plane of the bearing member 34. Given this spatial relationship, if the detent 48 is loosened in the lower leg of the frame and the cutting member 56 is pivoted to index the punch means, the die means 18 will be pivoted therewith. Once the spring detent 64 engages another longitudinal groove, 52 in the ram, the detent 48 associated with the die means may be tightened and the punch and die are properly aligned. This feature of joint pivotal indexing of the punch means and die means prevents even the slightest misalignment.

The foregoing is a description of one embodiment of the present invention and, therefore, should not be read in a restrictive sense but only as describing the underlying concepts of the present invention. The invention may be further developed within the scope of the following claims.

I claim:

1. In an apparatus for punching louvers or the like in workpieces, said apparatus including a frame having upper and and lower legs, a ram mounted for reciprocation in said upper frame leg, said ram having a punch secured thereto, and die means mounted on said lower leg, the improvement of means for jointly indexing said ram and said die means comprising:

a spring detent threaded through said frame for engaging and resiliently holding said ram in an indexed position;

said spring detent of sufficient resiliancy for releasing said ram from an indexed position upon rotation of said ram with sufficient force to override the resilient holding of said ram by said spring detent; and

a fastener in said lower leg for releasably securing said die means in an indexed position;

so that upon releasing said fastener and positioning said ram adjacent said die means, and then indexing said ram to override the resilience of said spring detent, said die is jointly indexed with said ram and said die is properly aligned relative to said ram for subsequent punching operations.

2. The improvement as in claim 1 wherein said ram has longitudinal grooves on its outer surface and said threaded spring detent coacts with said grooves for releasably holding said ram in an indexed position, to locate the index positions for both said ram and said die means.

3. The improvement as in claim 1 wherein said die means includes a base having a circumferential groove therein and said fastener is threaded through said frame to coact with said groove in said base for holding said die in an indexed position.

4. In an apparatus for punching louvers or the like in workpieces, said apparatus including a frame having upper and lower legs, a ram having a punch secured thereto, said ram mounted for reciprocation in said upper frame leg, and die means mounted on said lower leg, the improvement of means for jointly pivotally indexing said punch and said die means for maintaining proper alignment therebetween, comprising:

a plurality of longitudinal surface grooves on said ram;

a spring detent means threaded in said upper frame leg for resiliently selectively engaging said grooves to retain said ram in an indexed position;

said spring detent means being disengagable from a groove by rotation of said ram with sufficient force to overcome the resilience of said spring detent means;

a circumferential groove on said die means; and

a detent threaded in said lower leg in a direction transverse to the axis of reciprocation of said ram to frictionally engage said circumferential groove;

so that upon positioning said ram adjacent to said die means and releasing said lower leg detent, said ram and die means are jointly rotatable with said spring detent engaging the longitudinal surface grooves for locating each indexed position of both said ram and said die means.

5. In an apparatus for cutting louvers in metal or the like including a frame having a reciprocable punch therein and die means having spaced anvil and support members receiving the punch therebetween, the improvement comprising:

means in said frame for resiliently retaining said punch in a rotatably adjusted position relative to said frame and for releasing said punch for rotation in response to a rotational force sufficient to overcome the resilience of said retaining means;

means in said frame for releasably securing said die means in a rotatably adjustable position relative to said frame; and

means for actuating said punch towards and away from said die means;

so that upon positioning said punch adjacent said die means and upon releasing said die securing means, said punch and die means are jointly pivotally indexed by pivotally indexing said punch against the resilience of said resilient retaining means.

6. The improvement of claim 5 wherein said punch includes a ram, said ram having longitudinal grooves on its outer surface and said punch retaining means includes detent means coacting with said grooves for releasably retaining said ram in an indexed position.

Claims (6)

1. In an apparatus for punching louvers or the like in workpieces, said apparatus including a frame having upper and and lower legs, a ram mounted for reciprocation in said upper frame leg, said ram having a punch secured thereto, and die means mounted on said lower leg, the improvement of means for jointly indexing said ram and said die means comprising: a spring detent threaded through said frame for engaging and resiliently holding said ram in an indexed position; said spring detent of sufficient resiliancy for releasing said ram from an indexed position upon rotation of said ram with sufficient force to override the resilient holding of said ram by said spring detent; and a fastener in said lower leg for releasably securing said die means in an indexed position; so that upon releasing said fastener and positioning said ram adjacent said die means, and then indexing said ram to override the resilience of said spring detent, said die is jointly indexed with said ram and said die is properly aligned relative to said ram for subsequent punching operations.

2. The improvement as in claim 1 wherein said ram has longitudinal grooves on its outer surface and said threaded spring detent coacts with said grooves for releasably holding said ram in an indexed position, to locate the index positions for both said ram and said die means.

3. The improvement as in claim 1 wherein said die means includes a base having a circumferential groove therein and said fastener is threaded through said frame to coact with said groove in said base for holding said die in an indexed position.

4. In an apparatus for punching louvers or the like in workpieces, said apparatus including a frame having upper and lower legs, a ram having a punch secured thereto, said ram mounted for reciprocation in said upper frame leg, and die means mounted on said lower leg, the improvement of means for jointly pivotally indexing said punch and said die means for maintaining proper alignment therebetween, comprising: a plurality of longitudinal surface grooves on said ram; a spring detent means threaDed in said upper frame leg for resiliently selectively engaging said grooves to retain said ram in an indexed position; said spring detent means being disengagable from a groove by rotation of said ram with sufficient force to overcome the resilience of said spring detent means; a circumferential groove on said die means; and a detent threaded in said lower leg in a direction transverse to the axis of reciprocation of said ram to frictionally engage said circumferential groove; so that upon positioning said ram adjacent to said die means and releasing said lower leg detent, said ram and die means are jointly rotatable with said spring detent engaging the longitudinal surface grooves for locating each indexed position of both said ram and said die means.

5. In an apparatus for cutting louvers in metal or the like including a frame having a reciprocable punch therein and die means having spaced anvil and support members receiving the punch therebetween, the improvement comprising: means in said frame for resiliently retaining said punch in a rotatably adjusted position relative to said frame and for releasing said punch for rotation in response to a rotational force sufficient to overcome the resilience of said retaining means; means in said frame for releasably securing said die means in a rotatably adjustable position relative to said frame; and means for actuating said punch towards and away from said die means; so that upon positioning said punch adjacent said die means and upon releasing said die securing means, said punch and die means are jointly pivotally indexed by pivotally indexing said punch against the resilience of said resilient retaining means.

6. The improvement of claim 5 wherein said punch includes a ram, said ram having longitudinal grooves on its outer surface and said punch retaining means includes detent means coacting with said grooves for releasably retaining said ram in an indexed position.

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