Clamp pieces for lower frame assembly of blanking tool

BACKGROUND OF THE INVENTION

The present invention relates to die cutting machines for making carton blanks, and more particularly to a frame assembly for a lower blanking tool that supports carton scrap during a blanking operation in a die cutting machine.

In the manufacture of cartons, small sheets of paper material having specific profiles are cut out of larger sheets of paper material. These smaller sheets are known as carton blanks which, in turn, are formed into cartons and/or boxes. The blanks are formed during a process known as a blanking operation in a die cutting machine.

In a die cutting machine, the blanks are cut, but not removed from a large sheet of paper material. After the blanks have been cut, the sheet is moved downstream in the die cutting machine to a blanking station where the sheet is positioned over a frame assembly for support. The frame assembly includes an outer frame and an inner grid having large openings which correspond in size, in shape and in position to the profile of the carton blank previously cut. Below the frame is a mechanism for stacking the carton blanks.

At the blanking station, an upper tool is used in combination with the lower tool or frame assembly to knock the carton blanks from the sheet of paper material while holding the scrap material that surrounds the blanks. The upper tool has a support board that moves vertically up and down in the die cutting machine, and the support board typically has a plurality of stand-offs depending therefrom that hold pushers spaced beneath the board which in turn are used to push the carton blanks from the sheet through the lower tool or frame assembly. A plurality of presser assemblies are also mounted in the support board and depend therefrom to hold the scrap material against the lower tool or frame assembly during the blanking operation so that the blanks may be pushed from the sheet. A presser assembly typically includes a presser rail which is biased downwardly away from the support board by a spring so that the rail is positioned slightly below the pushers. As the upper tool is lowered, the presser rail engages the sheet of paper material first such that a scrap portion of the large sheet of material is secured between the presser rail and the frame. The upper tool then continues to be lowered such that the sheet of material engages the inner grid within the frame while at substantially the same time the pushers engage the carton blanks and knock the blanks out of the sheet of material and through the inner grid. The carton blanks then fall into a stacking mechanism below the frame where the blanks are stacked for further processing.

The lower tool used in the blanking operation is typically comprised of a steel outer frame that supports an inner grid. The inner grid is typically comprised of a plurality of lengthwise and crosswise extending bars. In order to secure the inner grid in place on the outer frame, the end of each bar is typically screwed onto attachment pieces which in turn are mounted on the lengthwise and crosswise rails of the outer frame. Since the frame and grid support a sheet of paper material during the blanking operation, the grid must be configured to match or conform to the die cut in the sheet of paper material. In addition, the grid must be reconfigured whenever a different carton blank needs to be produced. Thus, unscrewing the inner grid from the outer frame oftentimes becomes very cumbersome and time consuming. Thus, it is desirable to provide a quicker manner of attaching and removing the inner grid from the outer frame.

Other types of attachment pieces include wedges which are used to clamp the ends of the bars in place. Although these wedges provide a type of quick-connect and quick-disconnect for the bars of the grid, they also have the disadvantage of oftentimes moving the bars slightly during assembly. Movement of the bars, even slight movements thereof, result in the grid being misaligned with the die cut in the sheet of paper material which in turn may result in an imprecise blanking operation.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved frame assembly for a lower blanking tool of a carton die cutting machine.

It is another object of the present invention to provide a frame assembly for a lower blanking tool that includes an inner grid that may be easily attached and removed from its supporting outer frame, can be precisely positioned during assembly, and yet maintains its rigidity during normal blanking operations.

It is yet another object of the invention to provide a frame assembly for a lower blanking tool which is easy to assemble, compatible with standard blanking operation machinery, and relatively inexpensive.

In order to accomplish the above objects, the present invention provides a frame assembly for a lower blanking tool of a carton die cutting machine. The frame assembly includes a rigid outer frame, and an inner grid comprised of a plurality of lengthwise and crosswise extending bars for supporting a sheet of die cut paper material during a blanking operation. The frame assembly also includes a plurality of clamps attaching the ends of the bars of the inner grid to the outer frame. Each clamp comprises an upright plate member defining a substantially flat vertically extending inner face, a substantially flat opposite vertically extending outer face, and a horizontally extending upper face. A substantially U-shaped upper cavity is formed in the inner face of the plate member and opens at its upper end to the upper face. The upper cavity defines an upper abutment surface, an opposite downwardly sloped surface disposed at an acute angle with respect to the upper abutment surface, and an upper support surface. An upper wedge member is disposed within the upper cavity for sliding movement along the downwardly sloped surface between clamped and released positions. The upper wedge is also substantially U-shaped and defines a clamping surface disposed parallel to and spaced from the upper abutment surface, an opposite downwardly angled surface disposed to engage against and slide along the downwardly sloped surface of the U-shaped upper cavity, and a base surface disposed substantially parallel to and spaced from the upper support surface of the cavity when the wedge member is in its clamped position. A screw extends through the upper wedge member into the upper support surface and is used to move the upper wedge between its clamped and released positions so as to hold or clamp the end of a bar of the inner grid between the abutment surface of the upper cavity and the clamping surface of the wedge member.

In another aspect, the invention includes the clamping device itself for attaching the bars of an inner grid to the outer frame of the lower blanking tool of a carton die cutting machine. The clamping device includes the upright plate member, U-shaped upper cavity and upper wedge member described above. However, in an alternate embodiment, the clamping device may also include a lower U-shaped cavity and a lower wedge member disposed within the lower cavity for sliding movement along an upwardly sloped surface between clamped and released positions. The lower cavity is preferably a mirror image of the upper cavity, and is used to clamp a bar of the inner grid at two points rather than only a single point if only the upper cavity and upper wedge is utilized. This is particularly useful to attach the lengthwise or machine direction bars of the inner grid as these bars may be taller than the crosswise bars.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the best mode presently contemplated of carrying out the invention.

In the drawings:

FIG. 1

is a perspective view of a lower frame assembly for a blanking tool of a carton die cutting machine constructed in accordance with the principles of the present invention;

FIG. 2

is an enlarged perspective view illustrating a clamp device for attaching a bar of the inner grid to the outer frame of the lower frame assembly;

FIG. 3

is a front elevational exploded view of the clamping device of

FIG. 2

;

FIG. 4

is a sectional view taken along the plane of the line

4

—

4

in

FIG. 3

of the clamp device;

FIG. 5

is a perspective view illustrating a second embodiment of the clamp device of the present invention;

FIG. 6

is a front elevational exploded view of the clamp device of

FIG. 5

;

FIG. 7

is a sectional view taken along the plane of the line

7

—

7

in

FIG. 6

of the clamp device illustrated therein;

FIG. 8

is a perspective view illustrating a third embodiment of the clamp device of the present invention;

FIG. 9

is a front elevational view of the clamp device illustrated in

FIG. 8

with the two clamping wedges removed;

FIG. 10

is a sectional view taken along the plane in line

10

—

10

in

FIG. 9

of the clamp device illustrated therein;

FIG. 11

is a perspective view, partially in section, illustrating a stiffening assembly for a side rail of the outer frame;

FIG. 12

is a perspective exploded view illustrating a prior art clamp device for attaching a bar of the inner grid to the outer frame of the lower frame assembly for a blanking tool; and

FIG. 13

is a front elevational exploded view of the prior art clamp device of FIG.

12

.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings,

FIG. 1

illustrates a lower frame assembly generally designated by the numeral

1

which is used in a blanking tool of a die cutting machine for converting or processing a sheet of paper material into a carton blank. These machines are well known in the art and are used to cut one or several blanks into each sheet of paper material which, after folding and gluing, may be formed into cartons or boxes. As is conventional, the sheets of paper material move in a substantially horizontal plane within the machine and are carried through various sequences of printing, cutting, embossing, creasing, waste stripping and/or blanking stations.

The die cutting machine usually is formed by a series of stations with the first station being a starting position or input station in which the sheets, which may be preprinted if desired, are taken one by one from the top of a stack to a feed table where they are placed in position against frontal and side guides. The sheet can then be grasped by a gripper bar and lead downstream or in the machine direction into subsequent processing stations. Typically, the sheet is first conveyed into a cutting station where the carton or box blanks of a desired size and profile are die cut into the sheet. These blanks are held to the sheet by knicks which are arranged along the cut edges of the blanks. This cutting station is usually comprised of upper and lower tools, one of which is provided with a plurality of line-shaped straight and curved die cutting blades. If desired, the cutting station may be proceeded by a printing station, or as noted above, the sheets may be preprinted. After cutting, the sheet is then lead to a stripping station where the waste, i.e. the unused scrap between the various blanks, are grasped by upper and lower pins in order to be lead downward into a waste container. The sheet is then fed to a blanking station where the sheet is positioned horizontally over a lower frame for support. The lower frame includes an inner grid having large openings which correspond in size, in shape and in position to the profile of the blank previously cut. An upper blanking tool having one or more presser assemblies mounted thereto then moves vertically downwardly in the die cutting machine to secure the scrap portions against the grid and frame and then as the tool continues to move downwardly, the fasten points or knicks between the blanks and the sheet are broken by pushers so that each of the blanks are released, pushed through the grid and falls below the frame where the blanks are stacked for further processing. Finally, the residual or remaining portion of the sheet is carried into a delivery or exit station where it is released by the gripper bar as waste material.

Referring now to

FIG. 1

, there is illustrated frame assembly

1

for a lower blanking tool of a carton die cutting machine. The lower frame assembly

1

includes an outer frame comprised of a pair of opposite, spaced apart longitudinally extending side frame members or side rails

2

and

3

, and a pair of opposite, spaced apart cross frame members or cross rails

4

and

5

extending crosswise between side rails

2

and

3

. Arrow

6

illustrates the machine direction, i.e. the direction of movement of a sheet of paper material (not shown) within the die cutting machine. Thus, as illustrated in

FIG. 1

, side rail

2

would be considered the left side rail while side rail

3

would be considered the right side rail. Likewise, cross rail

4

would be considered the front or leading cross rail while cross rail

5

would be considered the rear or trailing cross rail. As illustrated, cross rails

4

and

5

each have a length such that their opposite ends overlap the opposite ends of side rails

2

and

3

. Also, cross rails

4

and

5

are disposed on top of side rails

2

and

3

so that the lower surface of cross rails

4

and

5

abut against the upper surfaces of side rails

2

and

3

, as will hereinafter be described.

Side rails

2

and

3

are rigidly interconnected to cross rails

4

and

5

by means of a plurality of corner pieces

7

-

10

. Corner pieces

7

and

9

are referred to herein as right corner pieces while corner pieces

8

and

10

are referred to herein as left corner pieces. The terms “right” and “left” refer to the location of a tenon on the underside of each corner piece (see

FIG. 7

versus FIG.

11

), but it should be noted that left corner pieces

8

and

10

are essentially mirror images of right corner pieces

7

and

9

. Corner pieces

7

-

10

are used to rigidly interconnect rails

2

-

5

to one another, and function like clamps to tightly hold rails

2

-

5

together in a “square” or 90° relationship, as will hereinafter be described.

The inner grid is composed of a plurality of parallel lengthwise bars

11

extending in the machine direction between front rail

4

and rear rail

5

, and a plurality of substantially parallel crosswise bars

12

extending transversely to the machine direction

6

between left rail

2

and right rail

3

. Bars

11

and

12

of the inner grid can be point welded or glued with adhesive at the points where they intersect to insure rigidity of the inner grid. Bars

11

are attached to cross rails

4

and

5

by means of a plurality of attachment pieces or clamp devices

13

. Likewise, bars

12

are attached to side rails

2

and

3

by a plurality of attachment pieces or clamp devices

14

. It should be noted that the present invention is not limited to the design for the inner grid illustrated in

FIG. 1

as the design illustrated is but one example of an inner grid design. In fact, the profile of the inner grid is typically changed depending upon the type, size and shape of the carton blank to be produced. Thus, the inner grid illustrated in

FIG. 1

is for illustration purposes only.

Referring now to

FIG. 11

, there is illustrated in more detail the interconnection of left side rail

2

to front cross rail

4

by corner piece

7

. More specifically, cross rail

4

includes an upper surface

15

, an opposite lower surface

16

, an outer surface

17

, and an opposite inner surface

18

. Each surface

15

-

18

is substantially planar, and surface

18

is referred to as the “inner” surface since it faces the interior of frame assembly

1

, i.e. towards the inner grid. As shown best in

FIG. 11

, rail

4

includes a bolt receiving T-shaped slot

19

formed therein. Slot

19

is formed throughout the entire elongate length of rail

4

and opens to both of the opposite ends of rail

4

. Slot

19

has a blind end located within the interior of rail

4

and has an open end which opens to inner surface

18

. Slot

19

defines a downwardly extending axis

20

disposed at an acute angle

21

with respect to the plane of inner surface

18

. As shown in

FIG. 11

, acute angle

21

is defined as the angle between axis

20

and the plane of inner surface

18

. Acute angle

21

may be an angle between 1° and 89°, but is preferably an angle of about 30° to about 80°, and most preferably an angle of about 65°.

As shown in

FIG. 11

, rail

4

also includes an inwardly projecting ledge

22

formed in inner surface

18

. Ledge

22

is planar in shape and is disposed at an angle of 90° with respect to inner surface

18

. However, ledge

22

could also be modified to be at an acute angle with respect to inner surface

18

if desired. As shown, ledge

22

is located at the intersection of the upper surface

15

and inner surface

18

of rail

4

such that ledge

22

is located between upper surface

15

and T-shaped slot

19

. Ledge

22

extends along the entire length of rail

4

and opens to both of the opposite ends of rail

4

in a manner similar to slot

19

.

Rail

4

further includes a channel-shaped recess

23

formed in upper surface

15

. Recess

23

is formed and extends along the entire length of rail

4

and opens to both of the opposite ends of rail

4

. Recess

23

is typically utilized to receive a ruler or other measuring device which aids in the proper placement of attachment members or clamp devices

13

and

14

when building the inner grid.

Rail

4

also includes a V-shaped cavity

24

formed in its outer surface

17

. Again, as with slot

19

, ledge

22

and recess

23

, cavity

24

is formed along the entire length of rail

4

and opens to both of the opposite ends of rail

4

. Typically, each face of cavity

24

is formed at a 60° angle to a horizontal line running through the center thereof. The function of cavity

24

is to locate a linear scale for measuring placement of the bars

11

,

12

for the inner grid.

Front cross rail

4

also includes a reinforcement or stiffening member

25

which minimizes the flexing of rail

4

during a blanking operation. Reinforcement member

25

projects outwardly from outer surface

17

and is formed along the entire length of rail

4

. Although illustrated as being integral with rail

4

, reinforcement member

25

could also be a separate piece which could be removably attached with fasteners if desired. Also, although illustrated as having a lower surface

26

contiguous with lower surface

16

of rail

4

and a chamfered surface

27

contiguous with outer surface

17

, reinforcement member

25

could take other shapes and be positioned in a slightly different location than illustrated so long as it functions to stiffen front cross rail

4

.

The cross sectional profile of rear cross rail

5

is identical to front cross rail

4

with the exception that rail

5

does not include the reinforcement or stiffening member

25

. Since rail

5

is identical to rail

4

with the exception of reinforcement member

25

, like numbers, except utilizing the designation “A” therewith, are utilized to refer to like parts or elements.

As illustrated, cross rails

4

and

5

are elongated members having opposite ends and a length greater than either its height or its width. Rail

5

and rail

4

(without reinforcement member

25

) have a height greater than their width, and are formed of aluminum, preferably extruded aluminum. Extrusion techniques provide the most efficient and cost effect method of producing an aluminum rail having the profile illustrated in FIG.

11

.

Referring now to

FIGS. 1 and 11

, there is illustrated the cross sectional profile of side rails

2

and

3

. The profiles of rails

2

and

3

are identical, and therefore only one will be described, i.e. side rail

2

. As illustrated, side rail

2

is an elongate member having a length greater than either its height or its width. However, rail

2

has a width which is slightly greater than its height which enables it to accommodate the additional slot to hereinafter be described. Again, as with rails

4

and

5

, rails

2

and

3

are composed of aluminum, preferably extruded aluminum. As illustrated, rail

2

has an upper surface

28

, an opposite lower surface

29

, an outer surface

30

and an opposite inner surface

31

. Surfaces

28

-

31

are substantially planar in shape and are formed along the entire length of rail

2

and extend completely between opposite ends of rail

2

. As shown best in

FIG. 11

, rail

2

includes a bolt receiving T-shaped slot

32

formed therein throughout the entire length thereof. Slot

32

defines a downwardly extending axis

33

disposed at an acute angle

34

with respect to the plane defined by inner surface

31

. Acute angle

34

may be any angle between 1° and 89°, but is preferably between about 30° to about 80° and is most preferably about 65°. Slot

32

has a blind end located within rail

2

and has an open end which opens to inner surface

31

. Slot

32

is formed along the entire length of rail

2

and is open to both of the opposite ends of rail

2

.

As shown in

FIG. 11

, rail

2

further includes a second bolt receiving T-shaped slot

35

formed therein. Slot

35

is identical to slot

32

in shape and also defines a downwardly extending axis

36

disposed at an acute angle

37

with respect to upper surface

28

. As with angle

34

, acute angle

37

may be any angle between about 1° to about 89°, but is preferably between about 30° to about 80° and most preferably about 65°. Slot

35

is formed along the entire length of rail

2

and opens to both of the opposite ends of rail

2

. As illustrated, slot

35

has a blind end located within rail

2

and an open end which opens to upper surface

28

. The blind end of slot

35

(as well as the blind end of slots

19

and

32

) is configured to conform to the shape of a nut (not shown) captured therein. The nut is utilized to threadedly receive and hold the shank of a bolt extending into slot

35

(as well as slots

19

and

32

), as will hereinafter be described.

As illustrated, rail

2

also includes a channel-shaped recess

38

formed in upper surface

28

. Recess

38

is formed in upper surface

28

between slot

35

and inner surface

31

, and functions to receive a ruler or other measuring device to aid in building the inner grid in a manner similar to recess

23

in rails

4

and

5

. Recess

38

is formed throughout the entire length of rail

2

and opens to both of the opposite ends thereof.

As shown best in

FIG. 11

, rail

2

also includes an angled groove

39

formed in inner surface

31

above slot

32

. Again, groove

39

is formed through the entire length of rail

2

and opens to both of the opposite ends thereof. As illustrated, groove

39

includes an inwardly projecting ledge

40

, and an angled surface

41

. Ledge

40

has a planar surface and is disposed at an angle of about 90° with respect to inner surface

31

. Other acute angles for ledge

40

may be used, but 90° is preferred. Angled surface

41

forms an acute angle with ledge

40

which angle is generally between about 30° to about 80°, but is preferably about 70°. Groove

39

functions to receive a tenon of corner piece

7

as will hereinafter be described.

Corner piece

7

is also illustrated in FIG.

11

. As noted earlier, corner piece

7

is identical to corner piece

9

while corner pieces

8

and

10

are mirror images thereof. More specifically, corner piece

7

interconnects side rail

2

and front cross rail

4

of the lower blanking tool frame assembly, and includes an L-shaped body having a horizontal plate member

43

and an upright or vertical plate member

44

. Horizontal plate member

43

defines a substantially flat upper face, a substantially flat opposite lower face, an inside face, an opposite outside face and an end face. As illustrated, each of these faces are substantially planar in shape. Upright or vertical plate member

44

also defines a substantially flat inner face contiguous with the upper face of plate member

43

, a substantially flat outer face contiguous with the lower face of plate member

43

, an inside face contiguous with the inside face of horizontal plate member

43

, an opposite outside face contiguous with the outside face of horizontal plate member

43

, and a top face. Horizontal plate member

43

has a pair of adjacent, aligned outwardly and downwardly extending bolt receiving bores formed therethrough extending between its upper face and lower face. Each bore defines an axis disposed at an acute angle with respect to the upper face of plate member

43

. The acute angle may be between about 1° and 89°, but preferably between about 30° and about 80°, and most preferably about 65° to match angle

37

of slot

35

.

Upright or vertical plate member

44

also includes a pair of adjacent, aligned outwardly and downwardly extending bolt receiving bores formed therethrough from its inner face to its outer face through which bolts

47

and

48

extend into T-shaped slot

32

. Each bore defines an axis disposed at an acute angle with respect to the inner face of plate member

44

. Again, this acute angle may be anywhere between 1° and 89°, it is preferably between about 30° and about 80°, and is most preferably about 65° to match angle

34

of slot

32

.

Upright plate member

44

has a lip

49

projecting outwardly therefrom. Lip

49

has an upper surface and a lower surface. The upper surface of lip

49

is contiguous with the top face of plate member

44

while its lower surface is contiguous with the outer face of plate member

44

. Lip

49

is disposed substantially 90° with respect to the outer face of plate member

44

, and lip

49

extends completely across the outer face of plate member

44

. Although illustrated as being contiguous with the top face of plate member

44

, lip

49

could also be spaced slightly downwardly therefrom if desired. Also, lip

49

need not necessarily extend completely across the outer face of plate member

44

, but preferably does so to provide the maximum amount of clamp force against ledge

22

, as will hereinafter be described.

Corner piece

7

also includes a tenon

50

projecting downwardly from horizontal plate member

43

. Tenon

50

has an angled surface disposed at an acute angle with respect to the lower face of plate member

43

. This acute angle may be any angle between 1° and 89°, but preferably matches the angle formed by surface

41

of groove

39

in side rail

2

. Again, by matching the angle of surface

41

the maximum amount of friction is provided between tenon

50

and surface

41

to provide the maximum clamping force, as will hereinafter be described. Finally, corner piece

7

includes a pair of reinforcement members or blocks

52

and

53

located at the intersection of upright plate member

44

and horizontal plate member

43

. As shown best in

FIG. 11

, each block

52

,

53

preferably comprises a wedge-shaped or triangular-shaped member.

Left corner pieces

8

and

10

are mirror images of right corner pieces

7

and

9

, and therefore need not be described herein in detail, but identical parts utilize like numerals with the designation “A” therewith. Corner pieces

8

and

10

are referred to as “left” corner pieces since tenon

50

A is located on the left side thereof. In like manner, corner pieces

7

and

9

are referred to as “right” corner pieces since tenon

50

is located along the right side thereof. In all other respects, corner pieces

8

and

10

are identical to corner pieces

7

and

9

.

In order to assemble frame assembly

1

, cross rails

4

and

5

are placed on top of side rails

2

and

3

so that the ends of rails

2

-

5

overlap one another, as illustrated in FIG.

1

. Thereafter, right corner piece

7

is placed as illustrated in

FIG. 11

with lip

49

engaging ledge

22

in cross rail

4

, and tenon

50

engaging groove

39

formed in side rail

2

. Bolts

45

and

46

are then inserted through the bores in plate member

43

into corresponding nuts contained in slot

35

of side rail

2

. As bolts

45

and

46

are tightened, they engage the nuts to pull or clamp cross rail

4

tightly against side rail

2

. At the same time, bolts

47

and

48

extend through the bores of upright plate member

44

into nuts captured within slot

19

of cross rail

4

. As bolts

47

and

48

are tightened, they pull or clamp the upper surface

29

of side rail

2

tightly against the lower surface

16

of cross rail

4

. In this manner, rails

2

and

4

are rigidly interconnected. Thereafter, in a like manner, corner pieces

8

-

10

are utilized to rigidly interconnect the other three corners of frame assembly

1

. As a result, rails

2

-

5

are rigidly interconnected to one another to form frame assembly

1

.

As illustrated best in

FIG. 1

, the second T-shaped slot

32

formed in inner surface

41

of side rails

2

and

3

, is utilized to connect a plurality of attachment pieces or clamp pieces

14

for crosswise bars

12

of the inner grid. In like manner, the T-shaped slots

19

and

19

A formed in cross rails

4

and

5

, are also utilized to connect attachment pieces or clamp devices

13

for mounting lengthwise bars

11

of the inner grid.

Clamp devices

13

of the present invention are illustrated in

FIGS. 2-4

. For comparison, a prior art clamp device

108

is illustrated in

FIGS. 12 and 13

. As illustrated, the prior art clamp device

108

includes an upright plate member

109

, a U-shaped cavity

110

formed completely therethrough at its upper end, a wedge member

111

disposed within cavity

110

for sliding movement between a lower clamped position and an upper released position, and a screw member

112

extending vertically through wedge member

111

into plate member

109

for moving wedge member

111

between its clamped and released positions. Openings

113

and

114

extend transversely through the lower end of plate member

109

at a 90° angle to the faces of plate member

109

to receive bolts (not shown) for attaching the clamp device

108

to the rails of the lower frame assembly.

As illustrated in

FIGS. 2-4

, clamp device

13

of the present invention includes an upright plate member defining a substantially flat vertically extending inner face

54

, a substantially flat opposite vertically extending outer face

55

, a horizontally extending upper face

56

, an opposite horizontally extending lower face

57

, and a pair of opposite end faces

58

and

59

. Together, faces

54

-

59

define a rectangular shape solid plate-like body composed of steel or aluminum. Although illustrated as having a height greater than either its length or width, clamp piece

13

may have other geometric shapes depending upon its end use.

A lip

60

is formed on the outer face

55

of clamp piece

13

. Lip

60

projects substantially 90° with respect to outer face

55

, and extends completely across face

55

to extend between end faces

58

and

59

. Although illustrated as being located approximately two-thirds of the distance between upper face

56

and lower face

57

, lip

60

could also be positioned slightly upwardly or downwardly from the location illustrated in FIG.

2

. Also, lip

60

need not necessarily extend completely across face

55

, but preferably does so to provide the maximum amount of clamp force against ledge

22

formed in cross rails

4

and

5

.

A substantially U-shaped upper cavity or recess

61

is formed in inner face

54

, and opens at its inner end to the inner face

54

and at its upper end to upper face

56

. Cavity

61

defines an upper abutment surface

62

which extends vertically in a plane parallel to end faces

58

and

59

, and is disposed at a 90° angle with respect to inner face

54

. Abutment surface

62

as well as cavity

61

has a depth, i.e. extends into clamp device

13

, approximately two-thirds of the distance between inner face

54

and outer face

55

, and surface

62

includes a plurality of parallel vertically extending score lines

63

formed therein. Score lines

63

aid in providing friction to hold the outer ends of bars

11

of the inner grid, as will hereinafter be described. Cavity

61

also defines a downwardly sloped concave surface

64

disposed opposite of abutment surface

62

and at an acute angle

65

with respect to abutment surface

62

. As illustrated best in

FIG. 3

, sloped surface

64

extends downwardly and away from end face

59

so that the lower end of cavity

61

is narrower than the upper end of cavity

61

. Acute angle

65

is preferably between about 5° and about 45°, and most preferably about 15°. Finally, cavity

61

also defines a horizontally extending upper support surface

66

. Surface

66

is substantially parallel to upper face

56

and extends 90° with respect to inner face

54

. Cavity

61

is also defined by a rear wall

67

. Rear wall

67

includes a rear surface

68

extending vertically in a plane parallel to inner face

54

and outer face

55

.

An upper wedge member

69

is disposed within upper cavity

61

for sliding movement along the downwardly sloped surface

64

between a clamped position (i.e. at or toward the lower or narrower end of cavity

61

) wherein the end of bar

11

is fixed in place, and a released position (i.e. at or toward the upper or wider end of cavity

61

) wherein the bar

11

may be removed from cavity

61

. As illustrated, wedge member

69

is substantially U-shaped in profile to substantially match the U-shaped profile of upper cavity

61

. Wedge member

69

includes a vertically extending clamping surface

70

disposed in a plane parallel to and spaced from abutment surface

62

. Clamping surface

70

also includes a plurality of parallel spaced score lines (not shown) formed therein for aiding in providing friction to hold bar

11

between surfaces

70

and

62

. Wedge member

69

also includes a downwardly angled convex surface

72

disposed opposite clamping surface

70

. Angled surface

72

functions to engage against and slide along downwardly sloped concave surface

64

of cavity

61

so as to move surface

70

of wedge member

69

into a position more closely adjacent to abutment surface

62

as wedge member

69

moves downwardly along surface

64

. This action provides the clamping force necessary for clamping an end of a bar

11

between abutment surface

62

and clamping surface

70

as wedge member

69

moves downwardly into cavity

61

. Concave surface

64

and convex surface

72

also function to capture or contain wedge member

69

and essentially lock it in position within cavity

61

so it does not laterally move therein as wedge member

69

moves downwardly to its clamping position. Wedge member

69

also includes a base surface

73

at its lower end disposed substantially parallel to support surface

63

. Base surface

73

typically remains spaced from support surface

66

when the wedge member

69

is in its clamped position. Wedge member

69

also includes an inner substantially flat surface

74

disposed substantially flush with inner face

54

, and an outer substantially flat surface

75

which bears against and slides along surface

68

of rear wall

67

as wedge member

69

moves between its clamped and released positions. As illustrated, rear wall

67

contains wedge member

69

within cavity

61

, and it aids in properly locating wedge member

69

during assembly. Wall

67

also reinforces or stiffens the sides of clamp device

13

and prevents the upper end of cavity

61

from spreading apart as wedge member

69

moves downwardly to its clamping position.

As a means for moving upper wedge member

69

between its clamped and released positions,

FIG. 2

illustrates a screw member

76

which extends vertically through wedge member

69

into support surface

66

. Wedge

69

includes a bore

77

formed therethrough and opening to base surface

73

together with a counterbore

78

opening to top surface

79

so as to enable the head of screw

76

to be flush with surface

79

when wedge member

69

is in its clamped position. An internally threaded bore

80

is formed through a cross member

81

for receiving the externally threaded shank of screw

76

. In this manner, as screw

76

is turned into threaded bore

80

, wedge member

69

moves downwardly along surface

64

until clamping surface

70

engages one side of bar

11

and forces it against abutment surface

62

. As screw

76

is tightened, additional clamping force is applied against bar

11

so as to rigidly clamp bar

11

between abutment surface

62

and clamping surface

70

. To release bar

11

, screw

76

is merely turned in a counterclockwise direction until wedge

69

moves away from bar

11

to release the clamping pressure applied thereto so that bar

11

can be removed from cavity

61

.

In order to attach clamp device

13

to cross rails

4

and

5

, a rectangular recess

82

is formed in inner face

54

to define a lower wall

83

separated by cross member

81

from upper cavity

61

. A downwardly and outwardly extending bolt receiving bore

84

is formed through lower wall

83

. Bore

84

defines an axis

85

disposed at an acute angle

86

with respect to outer face

55

. The acute angle

86

may be anywhere between 1° and 89°, but is preferably between about 30° and about 80°, and is most preferably about 65° to match the angle

21

defined by slot

19

in cross rail

4

. A bolt

87

extends through bore

84

into a nut (not shown) captured within slot

19

. As bolt

87

is tightened, lip

60

is pulled tightly against ledge

22

of rail

4

while at the same time outer face

55

is forced to bear tightly against inner face

18

of cross rail

4

to rigidly hold clamp piece

13

in position on cross rail

4

.

Referring now to

FIGS. 5-7

, there is illustrated clamp devices

14

for attaching the ends of crosswise bars

12

to side rails

2

and

3

. Clamp pieces

14

are identical to clamp pieces

13

with the exception that clamp pieces

14

are slightly taller than clamp pieces

12

. Since clamp pieces

14

are substantially identical to clamp pieces

13

, like numbers, except utilizing the designation “A” therewith, are utilized to refer to like parts or elements. It should be noted that lip

60

A formed on outer face

55

A of clamp piece

14

is located approximately one-third to one-half the distance between upper face

56

A and lower face

57

A thus enabling crosswise bars

12

to be spaced upwardly from side rails

2

and

3

at substantially the same height as lengthwise bars

11

, as seen best in FIG.

1

. Also, it should be noted that recess

82

A is also substantially taller in clamp piece

14

than recess

82

is in clamp piece

13

. In all other respects, clamp pieces

14

are substantially identical to clamp pieces

13

, and need not be further described herein.

Referring now to

FIGS. 8-10

, there is illustrated a third embodiment of the clamp pieces of the present invention. This third embodiment is generally designated by the numeral

88

, and as best shown in

FIG. 8

, provides a double clamping arrangement whereby the end of a rail or other component utilized with a lower blanking tool may be clamped securely in place on cross rails

4

or

5

. Clamp piece

88

includes an upper wedge member

69

B disposed within a U-shaped upper cavity

61

B together with a lower wedge member

69

C disposed within a lower U-shaped cavity

61

C. Wedge members

69

B and

69

C as well as cavities

61

B and

61

C are identical to wedge member

69

and cavity

61

previously described herein with respect to

FIGS. 2-4

. Since the components of clamp piece

88

are substantially identical to the components of clamp pieces

13

and

14

previously described herein, like numbers, except utilizing the designation “B” for the upper components and “C” for the lower components, are utilized in

FIGS. 8-10

to refer to like parts or elements. The only significant differences between clamp piece

88

and clamp pieces

13

and

14

previously described herein is that abutment surface

89

forms a continuous uninterrupted abutment surface extending between upper face

56

B and lower face

57

B. In addition, cross member

81

B does not extend completely to abutment surface

89

, but instead has an end face

90

which is spaced from abutment surface

89

. Additionally, lip

60

B is formed at upper face

56

B and is contiguous therewith rather than being located between upper face

56

B and lower

57

B as for clamp pieces

13

and

14

. Lastly, this third embodiment includes a single screw

91

which simultaneously moves upper wedge

69

B and lower wedge

69

C to their clamped positions as it is turned down in a clockwise direction. In order to accomplish this, screw

91

extends vertically into upper wedge

69

B, through cross member

81

B and vertically through lower wedge member

69

C. Thus, as screw

91

is turned in a clockwise direction, lower wedge

69

C is pulled upwardly along the upwardly sloped surface

64

C while upper wedge

69

B is pushed downwardly along downwardly sloped surface

64

B until their respective clamping surface

70

C and

70

B engage and hold a component against abutment surface

89

. To release the component, screw

91

is merely turned in a counterclockwise direction so that upper wedge

69

B moves upwardly and lower wedge

69

C moves downwardly away from abutment surface

89

.

Clamp piece

88

also includes a pair of aligned outwardly and downwardly extending bolt-receiving bores

92

and

93

formed therethrough through which bolts

94

and

95

extend into the T-shaped slots of rails

4

or

5

. Each bore

92

,

93

defines an axis

96

disposed at an acute angle

97

with respect to the outer face

55

B of clamp piece

88

, as shown best in FIG.

10

. Acute angle

97

may be anywhere between 1° and 89°, but is preferably about 30° to about 80°, and is most preferably about 65° to match the angles of the T-shaped slots. Thus, as bolts

94

and

95

are turned clockwise, they engage nuts (not shown) contained in the T-shaped slot of rails

4

or

5

. As bolts

94

and

95

are tightened, they engage the nuts to pull clamp piece

88

so that its outer face

55

B tightly engages the inner face of the rail. In this manner, clamp piece

88

is rigidly connected to a rail

4

or

5

so that lip

60

B engages the ledge

22

formed in cross rail

4

or cross rail

5

.

Referring now to

FIG. 11

, there is illustrated a stiffening assembly for one or both of side rails

2

and

3

. As illustrated, the stiffening assembly comprises a longitudinally extending angle member

98

having a length substantially the same as the length of side rail

2

or side rail

3

. Angle member

98

includes a horizontal leg

99

and a vertical leg

100

disposed at 90° to one another. Angle member

98

may be composed of any suitable material, but is preferably steel having sufficient strength to stiffen the aluminum side rails

2

or

3

. As illustrated, vertical leg

100

has a longitudinally extending V-shaped groove

101

formed therein. The opposite side of leg

100

defines a planar face which bears or abuts against the outer face

55

A of clamp pieces

13

, as illustrated. Clamp pieces

13

each include a V-shaped cut

102

formed horizontally across its outer face

55

A. The stiffening assembly also includes a C-shaped jaw

103

having a pair of opposite parallel legs

104

,

105

with leg

105

being slightly longer than leg

104

and the terminal ends of which are rounded for engagement within V-shaped groove

101

and V-shaped cut

102

. To complete the assembly, a screw

106

extends through wall

107

of C-shaped jaw

103

into clamp piece

13

. Thus, as screw

106

is turned down in a clockwise direction, jaw

103

is moved toward clamp piece

13

so that leg

104

engages V-shaped groove

101

and leg

105

engages V-shaped cut

102

until angle member

98

is rigidly in place. As a result, angle member

98

stiffens side rail

2

or

3

to prevent any significant flexing thereof during a blanking operation.

Number	Name	Date	Kind
4131047	Schriber et al.	Dec 1978	A
4187753	Walde	Feb 1980	A
4913016	Frei	Apr 1990	A
4920843	Stromberg et al.	May 1990	A

Clamp pieces for lower frame assembly of blanking tool

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Term Extension

Abstract

Description

Claims

US Referenced Citations (4)

Foreign Referenced Citations (1)