Not Applicable.
The present invention relates to the field of wooden frames for painter's canvas and printed canvas, and relates specifically to a device for tensioning a canvas on a frame comprising a plurality of side members mutually affixed at their angled ends.
The solution for tensioning a canvas on a frame that is the easiest in term of tools consist in applying on a frame a piece of canvas of a larger size than the frame, then folding down the canvas along the four bars which forms the frame, while pulling on the canvas, for instance using a stretching plier, securing the canvas along the bars, for instance by stapling, while leaving free the canvas at the corner, and then, at each corner of the frame, folding back on itself the free part of the canvas so as to form folds which overlap, and then stapling the folds to the frame.
The above solution has the drawbacks that it requires the use of a stretching plier and that it is relatively time-consuming to implement if one wishes to correctly tension the canvas, since the user should tension it correctly all along the bars before securing it thereto. This must particularly be the case when the frames are of a larger size.
Furthermore, this solution supposes either that the user already has an assembled frame, or that the user assembles himself the four bars of the frame, which is an additional work which once again requires tools and is not easy for frames of larger sizes.
Some of my previous patents utilize rigid spacers that cooperate with a tensioner element that is fixed with the side members of the frame. The spacer and the side members are pushed away from each other with a screw to effect canvas stretching. However, such prior solutions require excessive parts and as such are costly to manufacture.
Therefore, there is a need for a device that has a minimum of parts, yet that can still effect stretching of the canvas by separation of the side members. Such a needed invention would be relatively inexpensive to manufacture and yet intuitive to use. The present invention accomplishes these objectives.
The present device is a device for stretching a canvas mounted to a frame comprising a plurality of side members each mutually abutting at angled ends. Each angled end has at least an inside surface, an angled end surface that has a groove open to each angled end surface, and an outside surface. The angled end includes a contact surface oriented at a first angle, such as 90-degrees, with respect to the longitudinal axis of the side member.
In a preferred embodiment of the invention, the device comprises a spacer and a screw. A first portion of the spacer includes a central aperture therethrough and two opposing ends. Each end of the first portion is sized to engage contact surface of one of the side members when the aperture is positioned between two of the abutting side members.
The screw has a threaded shaft adapted for rotational engagement with the central aperture of the first portion of the spacer. The threaded shaft is at least partially contained within the groove of each side member when the side members are abutting, and terminates at a first end thereof with a screw head that has, in some embodiments, a frustoconical side wall and an end surface that includes a tool-engaging recess, such as a Phillips slot for engaging a Phillips screwdriver, or the like. The side wall of the screw head is preferably angled with respect to the longitudinal axis of the threaded shaft at a fourth angle, preferably 45-degrees, such that a line of contact is formed between the screw head and the inside surface of the side members.
In use, with the spacer fixed between the abutting side members with each end of the first portion contacting the contact surface of the angled end, and with the screw threaded through the central aperture of the first portion and the side wall of the screw head contacting the inside surface of each side member, rotating the screw to move the screw head closer to the spacer causes the spacer to push the side members mutually away from each other along their respective longitudinal axes to stretch the canvas.
In a preferred embodiment of the invention, the spacer includes adjacent sides that are sized to engage the contact surface of the side member, which is orthogonal to the longitudinal axis of the side member. The screw head of the screw in such an embodiment either has its own angled side wall, or takes the form of a conventional screw having a screw collar having an angled side wall and an axial aperture therethrough to receive the screw. Such a screw collar may be formed of, for example, a plastic or metal material, and is preferably separable from the screw. As such a wide variety of different screws may be utilized as long as they engage the central aperture of the spacer and the axial aperture of the screw collar. Preferably the side members used in the preferred embodiment of the device each include a mortise and a tenon, such that the side members can be made identical and they will interlock when flipped with respect to each other and brought into abutting contact.
Further, in some embodiments, at least one elongated cross bar is included for applying tension between two opposing side members of a frame comprising four (or more) of the side members. Each cross bar includes two opposing ends that each have a channel therein for receiving an expansion screw and a threaded spacer that is fixed with each of the opposing ends of the at least one elongated cross bar. The threaded spacer includes a central aperture adapted for receiving the expansion screw therethrough. As such, with the cross bar fixed between two opposing side members the expansion screws can be rotated to cause the expansion screws to move from a retracted position to extended positions in order to apply tension between the two opposing side members.
The present invention is a device that has a minimum of parts, namely two, and yet can affect sufficient stretching of the canvas by separation of the side members. The present invention is relatively inexpensive to manufacture and yet is also intuitive to use. Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
Illustrative embodiments of the invention are described below. The following explanation provides specific details for a thorough understanding of and enabling description for these embodiments. One skilled in the art will understand that the invention may be practiced without such details. In other instances, well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.
Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” Words using the singular or plural number also include the plural or singular number respectively. Additionally, the words “herein,” “above,” “below” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. When the claims use the word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list and any combination of the items in the list. When the word “each” is used to refer to an element that was previously introduced as being at least one in number, the word “each” does not necessarily imply a plurality of the elements, but can also mean a singular element.
It is understood that most frames will comprise four of the side members 30 and four of the devices 10, all used together to stretch the canvas 20 to form a suitable rectangular painting surface. With such typically frames, each angled end 35 is formed at a 45-degree angle. However, other shapes of frames may be contemplated, such as hexagonal, in which case the frame will have six of the side members 30 and six of the devices 10. Adjacent side members 30 in such a hexagonal frame will have a 120-degree angles between them, and the angled ends 35 of such side members will be angled at a 60-degree angle.
It is understood that the device 10 may be sold individually, in sets of 2, 4, 6, etc., or may also be sold with the side members 30 sufficient in number to assemble the entire frame. For ease of illustration, the balance of this disclosure and the drawings focus on just a single device 10 and two of the side members 30 that are connected to each other via the device 10.
In one embodiment of the invention, the device 10 comprises a spacer 50 and a screw 80. A first portion 60 of the spacer 50 includes a central aperture 70 therethrough and two opposing ends 65. Each end 65 of the first portion 60 is sized to engage the contact surface 48 of one of the side members 30 when the aperture 70 is positioned between two of the abutting side members 30 (
The screw 80 has a threaded shaft 82 adapted for rotational engagement with the central aperture 70 of the first portion 60 of the spacer 50. The threaded shaft 82 terminates at a first end 84 thereof with a screw head 88 that has preferably a frustoconical side wall 89 (
In use, with the spacer 50 fixed between the abutting side members 30 with each end 65 of the first portion 60 contacting the contact surface 48 of each side member 30, and with the screw 80 threaded through the central aperture 70 of the first portion 60 and the side wall 89 of the screw head 88 contacting the inside surface 34 of each side member 30, the threaded shaft 82 of the screw 80 at least partially resting in the groove 40 of each side member 30, rotating the screw 80 to move the screw head 88 closer to the spacer 50 causes the spacer 50 to push the side members 30 mutually away from each other along their respective longitudinal axes L1 to stretch the canvas 20.
In a preferred embodiment of the invention, illustrated in
The side members 30 used in the preferred embodiment of the device 10 each include a mortise 90 and a tenon 91 (
Further, in some embodiments, at least one elongated cross bar 100 (
In some embodiments, the angled ends 35 of the side members 30 do not include the mortise 90 or tenon 91 (
In one method of practicing the invention, at least four of the side members 30 may be assembled into the frame 200 with the spacers 50 fixed between each side member 30. The canvas 20 can then be stretched over each side member 30 and secured thereto, such as with adhesive, staples, sonic welding, or the like. Such an assembly can then be sold to an end user, who acquires the screws 80 separately and, if desiring to further stretch the canvas, threads the screws 80 into the central threaded aperture 70 of the spacers 50 until the frustoconical side walls 89 of each screw 80 contact the inside surfaces 34 of each side member 30 to squeeze each side member 30 apart, further stretching the frame.
Alternately each side member 30, spacer 50, screw 80, cross bar 100, and canvas 20 can be sold in a kit form (not shown), in a pre-assembled form with the screws 80 already threaded through the central threaded apertures 70 of the spacers 50. Alternately, the side members 30, spacers 50, screws 80, cross bars 100, and canvas 20 can be sold separately so that an end user can mix-and-match the parts needed for his desired size and shape of frame 200.
While a particular form of the invention has been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. For example, various types of tool-engaging recesses 86,286 not illustrated herein may be utilized. Accordingly, it is not intended that the invention be limited, except as by the appended claims.
Particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification, unless the above Detailed Description section explicitly defines such terms.
Accordingly, the actual scope of the invention encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the invention.
The above detailed description of the embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above or to the particular field of usage mentioned in this disclosure. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. Also, the teachings of the invention provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments.
All of the above patents and applications and other references, including any that may be listed in accompanying filing papers, are incorporated herein by reference. Aspects of the invention can be modified, if necessary, to employ the systems, functions, and concepts of the various references described above to provide yet further embodiments of the invention.
Changes can be made to the invention in light of the above “Detailed Description.” While the above description details certain embodiments of the invention and describes the best mode contemplated, no matter how detailed the above appears in text, the invention can be practiced in many ways. Therefore, implementation details may vary considerably while still being encompassed by the invention disclosed herein. As noted above, particular terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated.
While certain aspects of the invention are presented below in certain claim forms, the inventor contemplates the various aspects of the invention in any number of claim forms. Accordingly, the inventor reserves the right to add additional claims after filing the application to pursue such additional claim forms for other aspects of the invention.
This application is a national-stage application number 35 USC 371 of PCT Application # PCT/CA2019/050110, filed on Jan. 30, 2019, which claims the benefit of U.S. Provisional Patent Applications 62/638,084, filed on Mar. 3, 2018; 62/681,010, filed on Jun. 5, 2018; and 62/750,793, filed on Oct. 25, 2018, all incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/CA2019/050110 | 1/30/2019 | WO | 00 |
Number | Date | Country | |
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62638084 | Mar 2018 | US | |
62681010 | Jun 2018 | US | |
62750793 | Oct 2018 | US |