US 2897889 A
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Aug. 4, 1959 G. KESSLER 2,897,889
SCREEN SPLINE WITH DIRECT FRICTIONAL ENGAGEMENT MEANS Filed May 27, 1957 GERALD KESSLER INVENTOR ATTORNEY United States Patent SCREEN SPLINE WITH DIRECT FRICTIONAL ENGAGEMENT NIEANS Gerald Kessler, Youngstown, Ohio Application May 27, 1957, Serial No. 661,671
5 Claims. (Cl. 160-392) This invention relates to an improved screen spline of plastic or similar resilient material, of the type which is forced into a groove in a metal, plastic or wood screen frame in order to retain and attach screen material by frictional engagement in said groove.
It is known practice to fasten screening such as insect screening for windows to the screen frame by providing a groove around the frame into which the screening is forced by means of a resilient elongated spline member which frictionally retains the screening in the groove. The resilient spline member is, according to known practice, a rod or tube usually of plastic or similarly resilient material, sometimes provided with axially extending radial I with such an arrangement to provide sufficient friction to satisfactorily retain the screen material in place in the frame, particularly with the increasingly popular use of metal framing such as extruded aluminum, and metal or plastic screen material, which provides a rather low coefiicient of friction in contact with the aluminum.
According to the invention, a spline member is provided in an arrangement such as is described above, wherein there are a number of protuberances on. the surface of the spline in the form of spurs or knobs, these being of sulficiently small dimensions to pass through the apertures in the screen which is being retained into direct engagement with the walls of the groove. This spline is preferably made of a resilient plastic material having a much higher coeflicient of friction in engagement with the walls of the groove than does the screen material. Furthermore, the small spurs or knobs protruding through the screening material into contact with the frame provide a Wedging action which also tends to maintain the screen material firmly positioned in the groove.
It is accordingly a primary object of the invention to provide an improved spline construction for retaining screen material by means of a groove formed in a rigid supporting member to which the screening is to be attached.
The specific nature of my invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings, in which:
Fig. 1 is a partly sectional perspective view of a portion of an ordinary window screen showing the manner of attaching the screen material to the frame;
Fig. 2 is a sectional view of a screen similar to Fig. l and on an enlarged scale, showing the use of a screen spline according to the invention;
Fig. 3 is a schematic perspective view of a strip of conventional plastic spline material;
2,897,889 Patented Aug. 4, 1959 Fig. 4 is a sectional view taken on line 4-4 of Fig. 5 of one form of spline made according to the invention;
Fig. 5 is a sectional view taken on line 55 of Fig. 4;
Fig. 6 is a sectional view taken on line 66 of Fig. 7, showing another form of spline according to the invention;
Fig. 7 is a sectional view taken on line 77 of Fig. 6;
Fig. 8 is a sectional view showing a corrugated groove; and
Fig. 9 is a sectional view showing another form of groove.
A typical application of the invention would be to a conventional window screen, as indicated in Fig. 1, wherein the frame 2 is provided with a groove 3 for receiving the screen material 4, which is held in place by a spline 6. In this type of known construction, considerable difficulty has been experienced, particularly since the advent of aluminum framing, in securing sufficient frictional contact between the screen 4 and the walls of groove 3 to retain the screen firmly in place. The screen material may be made of aluminum or copper wire mesh, or of suitable plastic material, but in all cases, the commercially available screening has a relatively hard glossy surface which has a rather low coeflicient of friction in contact with the hard surface walls of the aluminum framing. One way of improving this situation is to provide extruded parallel corrugations in the walls of the channel as shown at 13 in Fig. 8. This may be helpful in some cases, but if the corrugations are made too sharp, they tend to tear the screen material, while if they are not made very sharp, the frictional engagement between the relatively hard surfaces of the framing and the screening materials will still not be sutlicient for the purpose.
One form of spline material now widely used is shown at 6a in Fig. 3, wherein the spline consists of a tubular extrusion plastic material, the exterior surface of which is axially serrated. In practice, these serrations tend to engage the adjacent surface of the screening as shown in Fig. l, but the basic frictional engagement of the screen material 4 with the walls of the groove 3 is not thereby improved, and the ditficnlty still exists.
Figs. 4 and 5 show at 6b one modification of splining according to the invention, wherein the spline member, of extruded plastic material, is provided with a plurality of knobs or protuberances 7 extending outwardly from its surface for a suflicient distance to penetrate through the pores 01 apertures of the screen material as shown in Fig. 2 and engage directly the walls of groove 3. The physical characteristics of the plastic material of which the spline is made can, of course, be controlled to a considerable extent in production, and are deliberately selected so as to provide a much greater coefiicient of friction than is provided by the screen material. In this Way, the use of the improved spline construction and material shown provides the necessary frictional engagement to insure that the screen material will not be easily displaced from the groove. In addition to the frictional effect, the tiny fingers 7 protruding through the screen mesh also tend to lock by wedging action between the screen material and the wall of the frame, thus providing further assurance against displacement of the screen material. It will be understood that the average diameter of the knobs 7 is sutficiently small to pass through the apertures in the screen material with which it is to be used.
A typical form of construction is shown in Figs. 2 and 9 at 5 and 5 respectively, wherein an overhanging lip is formed in the channel interlocking with the screen material due to the pressure of the relatively elastic spline material forcing the screening under the lip 5. However, with the use of my improved spline, the knobs 3 7 pass through the screen apertures and some of them will lock under the lip as shown at 7' so that it is difficult to remove the screen by pulling on it without shearing offthe knobs 7 which are thus locked. Similarly, one or more ribs may be provided in the sides of the channel as shown at 13 in Fig. 8, and at 15 in Fig. 9, to provide still more locking action of the same type. It will thus be apparent that an actual mechanical locking action is provided which resists pulling out of the screen to a much greater degree than is otherwise possible. In addition to the overhanging lip 5 or 5', there may also be provided, as shown at in Fig. 9, one or more ridges in the side wall of the channel, with which the protuberances 7 will still further engage to provide locking action very similar to that previously described. 1
Figs. 6 and 7 show another and preferred manner of making the spline. In this case the spline 6c is extruded with a plurality of radially outwardly extending fins 8, each of which provides a continuous longitudinally extending fin, and which 'is therefore not suited for applicants purpose in this form. However, each fin 8 can be cut into a plurality of individual small knobs suitable for applicants purpose, it being necessary only to make the individual protruding pieces of the fin small enough to pass through the holes in the screen. This can be done in any suitable manner, by cutting each fin into a number of small pieces, each attached only at its base to the spline member. For example, a spiral cut can be made in the fins, similar to the cutting of a thread in a machine screw, the adjacent turns of the spiral being spaced sufliciently close together so that each fin 8 is cut into a series of individual protuberances 8a as shown in Fig. 7, each of which is sufficiently small to pass through the apertures of the screen material with which it is to be used. In this way, a spline is simply and economically formed which has a very large number of small projections and which insures that a sufiicient number of projections will pass through the apertures of the screen to provide the frictional engagement and locking action above described.
It will be apparent that the protuberances on the spline may be provided in any of a large number of different ways, the essential feature being that a multiplicity of protuberances is provided sufiiciently small in diameter to pass through the apertures of the screen material, of sufficient length to engage the Walls of the channel in which the screen material is retained, and having a sufficiently great rigidity and high coefficient of friction in contact with the screen material for the intended purpose.
It will be apparent that the embodiments shown are only exemplary and that various modifications can be made in construction and arrangement within the scope of my invention as defined in the appended claims.
1. In combination, a screen having apertures, a frame member having a longitudinal channel in the face thereof, and means for fastening said screen in said channel comprising an elongated resilient plastic spline member of uniform composition, said spline member being slightly thicker in cross-section than the Width of said channel and having a plurality of plastic spike-like protuberances of the same uniform composition as the rest of the spline member extending outwardly from its surface, the crosssection of each said protuberance being sufficiently small to pass freely through the apertures of the screen into frictional contact with the Walls of said channel.
2. The invention according to claim 1, said protuberances extending longitudinally in a series of rows, each said row constituting a fin extending from the surface of said spline, each said fin comprising a number of adjacent aligned protuberances substantially contiguous to each other at a surface of contacts, the surfaces of contact of adjacent rows being slightly displaced to form a helical pattern on said spline.
3. The invention according to claim 1, said channel having a lip on an upper edge thereof extending into the channel, whereby some protuberances on said spline member extend through said screen against the underside of said lip to provide a positive locking action against displacement of said screen.
4. The invention according to claim 1, said channel having at least one longitudinal groove in a side wall thereof, whereby protuberances on said spline member extend through said screen into said groove to provide a positive locking action.
5. The invention according to claim 1, said spline member being made of a material having a relatively high coefficient of surface friction with the material of said longitudinal channel, whereby said protuberances act to retain said screen in said channel by frictional engagement.
References Cited in the file of this patent UNITED STATES PATENTS 1,135,352 Bunger Apr. 13, 1915 1,697,768 King .Tan. 1, 1929 2,335,361 Schiller Nov. 30, 1943 2,639,769 Krantz May 26, 1953 2,797,750 Van Dette July 2, 1957 2,835,325 Gilbert et al May 20, 1958