US3603554A

US3603554A - Bookholder

Info

Publication number: US3603554A
Application number: US863549A
Authority: US
Inventors: Henry R Dickinson
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-10-03
Filing date: 1969-10-03
Publication date: 1971-09-07
Anticipated expiration: 1988-09-07

Abstract

An improved bookholder utilizing a novel spring clamp biased against the support surface of the holder, the clamp including a spring separate from the holddown arm so as to utilize a different gauge wire. In one embodiment the spring contains a coiled extension of the arm, tension being developed in the spring by means of a straight extension of the arm pressing against an axially extending arm of the coil spring. In the other embodiment, a core is contained by the spring and has at one end a camming surface for engagement by an extension of the holddown arm, the extension in this case not curving to form a coil but only a portion of a complete circle. In both embodiments, an end cap is centered within the housing containing the spring mechanisms, the cap including a clamping lip to assist in attaching the housing to the support surface of the bookholder.

Description

United States Patent Henry R. Dickinson, 1 11 222 Parkhurst, Spring Lake, Mich. 49%6 [72] Inventor [2i] Appl. No. 863,549 [22] Filed Oct. 3, 1969 [45] Patented Sept. 7, i97l [54] BOUKHOLDER FOREIGN PATENTS 10,209 4/1913 Great Britain AlBS'll'll MCT: An improved booltholder utilizing a novel spring clamp biased against the support surface of the holder, the clamp including a spring separate from the holddown arm so as to utilize a different gauge wire. In one embodiment the spring contains a coiled extension of the arm, tension being developed in the spring by means of a straight extension of the arm pressing against an axially extending arm of the coil spring. In the other embodiment, a core is contained by the spring and has at one end a camming surface for engagement by an extension of the holddown arm, the extension in this case not curving to form a coil but only a portion of a complete circle. In both embodiments, an end cap is centered within the housing containing the spring mechanisms, the cap including a clamping lip to assist in attaching the housing to the support surface of the booltholder.

PATENTED ssh 719m SHEET 1 OF 2 FIG] 5 16. 1

HENRY R. DICKINSON III FIG. .9 BY

ATTORNEYS PATENTEUSEP 119m 7 3,603,554

SHEET 2 0F 2 INVEHTOR HENRY R. DICKINSON ID:

ATTORNEYS BOOKIHIOLDIER BACKGROUND OF THE INVENTION Prior art book holders, such as the type disclosed in my U.S. Pat. No. 2,721,417, issued Oct. 25, 1955, have generally performed satisfactorily, but nevertheless have evidenced the need for some improvement, particularly in connection with the spring clamp. Specifically, the manner in which the spring clamp was mounted in these devices such as in my aforesaid patent resulted in a spring clamp which, in order to provide a thick enough gauge in the holddown portion, also provided too much tension in the spring due to the strength present in the thick diameter wire.

Some very old construction of bookholders have provided springs utilizing a different wire thickness than that utilized in the holddown arm, but they have been characterized by complex and unsightly constructions. Further, such constructions have been almost impossible to repair, or for example, replace the spring, should it wear out. An example of such an old construction is the disclosure of U.S. Pat. No. 816,380.

SUMMARY OF THE INVENTION The invention relates to an improved bookholder utilizing a novel spring biasing of the holddown arm. Specifically, the invention is utilized in a bookholder having a support surface and a spring clamp means for removably clamping an object against the surface, the clamp means including an elongated holddown arm having a free end extending over the support surface, its other end being supported for providing a biasing force for the holddown arm. The improvement constituting the invention comprises the holddown arm including at its supported end at least a portion of a convolution, the center of which is the axis about which the holddown arm is biased. A spring means separate from the convoluted portion of the arm is of a smaller gauge than the holddown arm, and formed into convolutions the center axis of which is coincident with the center of the convolution of the holddown arm. Means operably interconnect the convoluted portion of the arm and the spring means whereby the spring means provides the biasing for the holddown arm.

A support means is provided for the end of the holddown arm opposite from the end extending over the surface, including a tubelike housing having open ends, the opposite end of the holddown arm being located in at least one of the open ends; a cap is fitted over the open end in which the am is located, the cap including a slot for receiving the portion of the arm which extends over the surface and also for permitting movement of the arm against the biasing force; and a flange is provided on the cap for securing the cap to the support so as to aid in securing the housing to the support.

Accordingly, it is an object of the invention to provide an improved bookholder wherein the holddown arm utilizes a sufficiently thick wire for support purposes without making the clamp thereby unduly stiff in its spring action.

It is another object of the invention to provide an improved bookholder of the above character wherein the parts can be readily disassembled so as to remove for replacement or repair the coil spring.

It is a further object to provide an improved bookholder of the above character wherein the ends of the housing of the spring are self-attaching to the support surface so as to allow attaching screws to be moved away from the spring mechanism.

It is a related object of the invention to provide a bookholder of the above character which is simple to manufacture and assemble.

It is still another object of the invention to provide a housing for the spring mechanism which also functions as a supporting ledge.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of a book support constructed in accordance with the invention;

FIG. 2 is an exploded elevational view of a portion of a spring clamp constructed in accordance with the invention;

FIG. 3 is an end elevational view of the device illustrated in FIG. 2, in combination with the housing of the spring and the bookholder;

FIG. 4 is a plan view taken generally along the line IV-IV of FIG. 3, with the housing and bookholder eliminated;

FIG. 5 is a front elevational view, partly in section, taken along the line VV of FIG. 1 and illustrating still another embodiment of the invention;

FIG. 6 is a perspective view of a portion of the spring clamp illustrated in FIG. 5',

FIG. 7 is an end elevational view of the device illustrated in FIG. 6;

FIG. 8 is a fragmentary plan view of the device illustrated in FIG. 7;

FIG. 9 is a fragmentary exploded perspective view of the spring clamp illustrated in FIG. 5;

FIG. 10 is an elevational view of an end cap utilized in either of the two embodiments of the invention; and

FIG. ll is a plan view of the cap shown in FIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention relates to an improved bookholder of the type disclosed in my U.S. Pat. No. 2,721,417. Although the in vention is disclosed with reference to such an improved bookholder, it will be readily appreciated that it is not limited to such a use but can be incorporated in any device requiring a spring clamp, such as a clip board.

As in the case of my aforesaid patent, the bookholder 12 comprises a supporting surface 114! to which is hinged at the top a mounting plate 16 which has boltholes ll7 therein. A support arm (not shown) is utilized to hold the supporting surface M in a desired position with respect to the mounting plate 16. A housing 18 is formed from a tube having a rectangular or square cross section and is attached to the lower edge of the supporting surface 14. By this bookholder, the pages are held open at a desired page location by means of holddown arms 20, spring biasing means being included within the housing 18 for biasing the holddown arms. against the pages of the book (not shown). The holddown arms are conveniently, but not necessarily, formed from wire having a diameter of one-eighth inch.

In accordance with one aspect of the invention, the holddown arms 20 are biased by a coil spring 30 (FIG. 2) formed separately from the holddown arms and of a wire gauge which is smaller in gauge than the gauge of the holddown arms. The smaller diameter of the coil spring 30 means that the biasing force developed by the spring will be less than it would be if the same diameter as the holddown arm was utilized, thus avoiding the undesirable stiffness that has been present in previous devices. To hold the coil spring 30 in position so as to resist flexing in the direction shown as counterclockwise in FIG. 3, the end 32 of the coil spring is extended straight tangentially away from the coil spring, thereby providing a surface which abuts against the inside of the tube housing 18. The biasing force of the coil spring 30 is transmitted to holddown arm 20 in a clockwise direction from end 32 and it projects parallel to the axis of the coil spring so as to be removably contacted by the portion 3d of the holddown arm 20 when the coil spring is positioned in nested relationship to the holddown arm. Specifically, the holddown arm 20 has a straight extension 38 bent away from the holddown arm to interconnect the arm with the coil spring. The arm 20 culminates in convolutions 4,0 which fit into and are contained within the coil spring 39. Thus, when the two parts are assembled, any tendency to" move the holddown arm 20 counterclockwise as shown in FIG. 3 causes the arm portion 3% to press against the ear 34.

To allow the parts of the spring assembly to be readily disassembled and to allow the removal of the coil spring 30, the portion 38 is not physically connected to ear 34 but rather removably contacts and presses against it.

The spring clamp comprising the holddown arm 20, its extension 40, and the coil spring 30 are held in their assembled relationship by an end cap 50 (FIG. placed over the ends of the housing 18 and attached thereto by means ofa screw inserted into the opening 52. The mounting of housing 18 on the support surface 14 is assisted by the end cap 50 which includes a lip 54 extending around to the back side of the support surface 14 in a clamping relationship. To provide clearance for the holddown arm 20, a groove 58 is formed in one side of the end of cap 50 (FIG. 11). Because the car 34 projects outwardly beyond the end of the coil extension 40 of the holddown arm 20, an accommodating cutout 60 is provided in the back 62 of the end cap, the cutout being shaped as a portion of a circular path inasmuch as the ear moves in such a circular path. To center during assembly the end cap 50 in the tube comprising the housing 18, locator pins 64 are formed intcgrally with the front surface 66 of the end of cap 50. The pins are spaced apart at distances less than the interior dimensions of the housing 18.

Because of the support provided by the lip 54 on the end cap 50, the screws 70 providing the main attachment of the housing 18 to the supporting surface 14 can be moved to a position interior of the ends of the housing 18, thus providing clearance by the screw 70 of the spring clamp mechanism (see FIG. 5).

To further simplify manufacturing and thereby reducing the cost, the housing 18 is extruded as a single piece tube with its rectangular cross section which because of its hollowness, easily contains the spring mechanisms for the holddown arms 20.

It will be appreciated that, when assembled, the housing 18 acts as a ledge to support whatever is clamped to the surface 14.

FIGS. 5 through 9 illustrate an alternate embodiment of the invention wherein the coil extension 40 of the holddown arm has been eliminated in lieu of a core 92 which fits within the coil spring 30a and which is engaged by the holddown arm a. Parts similar to those described in connection with the previous embodiment bear the same reference numerals to which the distinguishing suffix a has been added. Thus, as shown in FIG. 5, housing 18a contains a coil spring 30a, one and 32a of which extends straight tangentially away from the coil spring so as to provide a gripping surface when in contact with the surface 90 of the housing 18a preventing the coil spring from freely turning. The opposite end 34a of a coil spring extends as a chord across the coil spring and engages the core 92 on a flat surface 94 provided therein. To retain the spring in proper axial position, a shoulder 95 is formed at the end of the core. Thus, any tendency of the core 92 to rotate counterclockwise as shown in FIG. 9 causes the end 34a to rotate in the same direction, thereby tensioning the spring 30a in view of the locked position of the end 32a. To turn the core 92 in such counterclockwise direction, the core includes means for attaching the holddown arm 20a to the core, the means including an arm support end 98 at one end of the core. The support end 98 comprises a protrusion 100 which is either formed integrally with the core 92 or is attached thereto such as by a screw. The protrusion has a curved surface 104, the radius of curvature of which matches the radius of curvature of a convolution portion 40a of the holddown arm 20a. As in the previous embodiment, the convoluted portion 40a is joined to the actual holddown arm 20a by means of a straight portion 38a bent at an angle to the holddown arm 20a. The portion 40a, unlike the previous embodiment, does not include several convolutions but rather forms a portion ofa convolution ending at point 106. The surface 104 ends in a flat portion 108 against which the straight portion 38a cams when the holddown arm 20a rotates counterclockwise as shown in FIG. 9, thereby causing the core 92 to rotate in the same direction so as to set up the tension in the spring 30a.

The core 92 can be molded as a plastic unit with the shape as shown, or it can be machined to have the desired surfaces.

As in the previous embodiment, an end cap 50a is utilized to enclose the spring mechanism, the end cap utilizing a lip 54a to assist in holding the housing 180 on the support surface of the bookholder. The end cap 501: is firmly attached to the housing 180 by means of a screw 110 which is threaded into the tab 112 bent upwardly from one surface of the tube forming the housing. Thus, the end cap 500 is in all respects identical to the end cap 50 disclosed in the previous embodiment.

It will be readily appreciated that when the parts are assembled as shown in either FIG. 1 or FIG. 5, with the holddown arm pressing against the support surface of the bookholder and, in the case of FIG. 5, the extension 40a surrounding the curved camming surface 104, the holddown arm has been rotated counterclockwise so as to position it on the support surface, thereby setting up tension in the spring so as to hold even the thinnest of books on the support surface. Because of the ability of the

coil spring

30 or 30a to bend perpendicularly to its axis to some extent, the assembly can be accomplished with this preset amount of tension in the spring.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.

1. In a combination of a support having a surface and a spring clamp means for removably clamping an object against said surface, said spring clamp means including an elongated holddown arm having a free end extending over said surface, its other end being supported to provide a biasing force for said holddown arm; the improvement comprising a support means for said other end of said holddown arm including a tubelike housing having open ends, said other end of said holddown arm located in at least one of said open ends; and a cap fitted over the open end in which said arm is located; said cap including a slot for receiving the portion of the arm which extends over said surface and also for permitting movement of said arm against said biasing force; and a flange on said cap for securing said cap to said support thereby providing a means for at least aiding in the securing of said housing to said support.

2. The improved combination as defined in claim 1, wherein said cap includes means for centering said cap with respect to said housing.

3. The improved combination as defined in claim 2, wherein said centering means includes a plurality of locator pins spaced apart at distances less than the interior dimensions of said housing.

4. The improved combination as defined in claim 3, wherein said biasing force is provided by a coil spring contained within said housing.

5. The improved bookholder as defined in claim 4, wherein said cap includes a cutout shaped as a portion of a circular path, said cutout accommodating a portion of said spring.

6. The improved combination as defined in claim 1, wherein said housing is a one-piece extrusion having a rectangular cross section.