Miter clamp

[57] ABSTRACT

A comer miter clamp comprises a first member for applying a comer pressure to a frame and a separate second member for engaging the frame. These two members are separate from each other to prevent alignment problems resulting from a cocking of the various clamp parts and frame members.

Claims, 15 Drawing Figures

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PATENTED»υε 8 sb

3.682,467

SHEET 1 Of 2

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CASPER W. HEINRICH

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PATENTEDAllt 8197?

3,682.467

SHEET 2 OF 2

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FIG.II ²¹ FIG.12

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FIG.I5

INVENTOR

CASPER W. HEINRICH

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Al I OF?HE

3,682,467

MITER CLAMP

My invention relates to miter clamps and more particularly to miter clamps especially — although not exclusively — adapted for use while making picture frames, or the like.

Although there are a number of jigs, tools, fixtures and the like for making mitered comers, many construction problems remain. While there are precision tools for making high cost frames, there are virtually no truly satisfactory, low cost tools suitable for making inexpensive frames. To find evidence supporting the truth of this statement, one need look no further than nearby stores selling low cost picture frames. The corners are almost always poorly made, and very often they are ready to come apart. As a result, good picture frames continue to be a high cost item relative to the cost of other and similar items.

In the past, efforts to make low cost mitered comer clamps have generally failed. Among other things, this failure occuned because there was not a smooth sliding action. As a result, parts of the clamp tended to be cocked with respect to other parts, and there was a binding between the parts. Also, there was an insufficiency of rigidity and the clamp parts tended to bend under the clamping pressures. To compensate, the worker often over tightened the clamp with a resulting damage to both the clamp and the frame material.

To those who are familiar with the problems of aligning mitered frame comers, it is apparent that it is very difficult to clamp the frame and retain it in a fixed position. Thus, a prime purpose of my invention is to provide a unit which is positive in performance at all times.

Accordingly, an object of my invention is to provide a device for clamping the angled portions of picture frames, or the like, and for retaining them in position while a dowel or other support means is attached thereto.

Another object of my invention is to provide a device of the character described which is adjustable to accommodate various sizes of framing material, such as picture frames, or the like.

Still another object of the invention is to provide a clamp which may be either mounted permanently or be portable.

The device illustrated, described, and claimed herein is simple in construction, and is is designed to enable anyone to manipulate it without having either special mechanical training or special equipment.

Other and further objects of my invention will become more apparent as the description proceeds, when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a top plan view of an assembled clamping device, showing the mitered frame parts in phantom;

FIG. 2 is a vertical cross-sectional view of the assembled device shown in FIG. 1 and taken at the line 2—2 thereof;

FIG. 3 is a perspective view of a plate portion of the clamp shown in FIG. 1;

FIG. 4 is a perspective view of a slidable block member used with the plate of FIG. 3;

FIG. 5 is a perspective view of a tapered wedge block member which improves the sliding action;

FIG. 6 is a top plan view of a modified assembled device, again showing the mitered frame parts in phantom;

FIG. 7 is a vertical cross-sectional view of the assembled device shown in FIG. 6 and taken along the line 7—7;

FIG. 8 is a perspective view of a plate portion of the clamp shown in FIG. 6;

FIG. 9 is a perspective view of a wedge member used with the clamp as shown in FIGS. 6 and 7;

FIG. 10 is a perspective view of a slidable corner contact member, as shown in FIGS. 6 and 7;

FIG. 11 is a top plan view of a resiliently actuated comer clamp unit equipped with two spring members;

FIG. 12 is a similar top plan view showing a single radially disposed resilient support;

FIG. 13 is a similar top plan view showing the resilient member retained by the support;

FIG. 14 is another plan view, as shown in FIG. 13 with the resilient member supported by a retaining bolt; and

FIG. 15 is yet another modified type of construction with two separate resilient springs.

Similar reference characters indicate corresponding parts throughout the several views. In greater detail, the character 20 identifies a support plate which may be constructed of any rigid material, such as a steel or aluminum casting, for example. This plate is equipped with a pair of raised edge wall sections 21 and a corner section 22. The breaks in the wall sections slots 23 may be of any suitable dimension. These breaks or slots 23 provide an entry for drilling the pair of mitered frame members 24, shown in phantom. Thus, a dowel 25 (see FIGS. 1 and 6) may be inserted into and retained by the members 24, thereby holding the mitered parts in a fixed position.

The plate 20 is also provided with a diagonal slot 26, which is recessed or channeled (see FIGS. 2 and 7), to accommodate the head of a screw or bolt 27, as best seen in FIG. 2. The screw 27 is equipped with a wing nut 28 for retaining an angularly disposed wedge block member 29 used for moving and supporting a slidable block member 30. The sliding block member 30 is equipped with a slot 31 for receiving the screw 27 extending upward through a hole 31 in the block member 29 (see FIG. 5).

The sliding action of FIGS. 1-5 should be apparent from an inspection of the drawing. When a force A is applied against the wedge block 29, as indicated in FIGS. 1 and 2, the sliding block 30 is driven in toward the comer 22. If there is any vertical tipping of the block 30, it is in the same direction in which the side or comer walls 21,22 would give. The vertical freedom of movement afforded by the slot 31 enables the member 30 to follow the frame movement. Normally, this give of the clamp or frame should not be enough to detect. Also, the wedge and block divorces the sliding and cocking, if any, movement, so that there is no binding between the clamped parts.

In FIGS. 6 and 7,1 show a modified structure, employing a sliding block 33 slidably held in position on the plate 20 by means of a screw 34. The head of the screw 34 engages the slot 26 in the plate 20. A second sliding block member 35 is disposed over and vertically retained by the block 33. This two block arrangement is formed to be slidably forced forward by the feed screw 36. This screw is threadedly engaged in the member 33 at hole 37. Thus, the member 33 applies

3,682,467 the driving force while the member 35 is free to align the mitered frame members 24 for engagement with one another at the corner point 22 of the plate 20. The frame members 24 may be drilled through the slot 23 to receive the dowel 25.

In FIGS. 11 to 15 inclusive, I show various embodiments of resiliently actuated devices to accomplish the purpose and function for which the device is intended. In each of these embodiments, there is a slidably supported and retaining member 38, held in engagement with the surface of the plate 20 by means of a screw 27 and wing nut 28 combination. A resilient spring means, such as 39, is attached to the front of the retaining member 38 to engage each of a pair of mitered frame members 24. Again, the resilience of the support ¹⁵divorces the sliding action of the block 38 from the clamping action upon the frame members. Therefore, any cocking action is divorced from the sliding action. Also, the clamp may be supplied with resilient members, such as 39, having a great variety of cross section ²⁰shapes to accommodate the various cross section frame shapes.

As shown in FIG. 11, a pair of supporting spring members 39 are attached to the sliding block member 38 by means of screws 40. In FIG. 12, a single spring 41 ²⁵is shown as fastened to the front of the sliding block member 38 by means of screw 42. In FIG. 13, the sliding block member 38 supports a double clip-in leaf spring 43, at a cavity 44. In FIG. 14, the same type of 30 leaf spring 43 is supported by being fitted over the bolt ^J27 before the wing nut 28 is attached. In FIG. 15, two separate springs 45 are attached to the retaining member 38 by the screws 46. Obviously, the resiliency of the spring action may be varied. Also, the shape and 35 positions of the springs may be changed for the engagement of the frame mitered members 24.

Many changes may be made in the parts and features constituting my invention without effecting its operativeness. Therefore, the appended claims are to be construed to cover all equivalents which do not depart from the spirit of the scope of my invention.