US3015531A - Book box desk - Google Patents

Description

Jan. 2, 1962 R. G. MoHR ETAL BOOK BOX DESK 2 Sheets-Sheet 1 Filed June 5, 1959 INVENTORS.

Jan. 2, 1962 R. G. MOHR x-.TAL 3,015,531

BooK Box' DESK Filed June 5, 1959 f1 2 Sheets-Sheet 2 ZZ H-/ 16 r11/uw l /fww Eil/VW] 2 5am; JWM

United States Patent C 3,015,531 BGOK BOX DESK e Robert G. Mohr and Richard J. Lappin, Kalamazoo,

Mich., assignors to Brunswick Corporation, a corporation of Delaware Filed June 5, 1959, Ser. No. 818,345 2 Claims. (Cl. S12-316) This invention relates to furniture, and more particularly to a book box desk intended principally for use in school rooms, though its utility is not so limited.

lt is a general object of the invention to provide a new and improved book box desk.

A more specific object is to provide a new and improved desk of the type described including a book box having a top opening, a book box cover pivotable on the box over the opening and providing a desk top, and a yieldable torque means urging the cover toward open position with less force the closing force of the cover when closed and with greater force than the closing force of the cover when open to thereby hold the cover in open position.

Another object is to provide a new and improved book box desk of the type described in the preceding paragraph including a friction device exerting a retarding effect on the cover which is greater than the closing force of the cover to prevent the cover slamming closed.

Other objects and advantages will become readily apparent from the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is a top plan view of a book box desk embodying the principles of the present invention;

FIG. 2 is a fragmentary side elevational view of the desk illustrated in FIG. l;

FlG. 3 is a fragmentary enlarged plan view, with the cover removed, taken at about the line 3-3 of FlG. 2;

FIG. 4 is a fragmentary sectional view, taken at about the line 4 4 of FIG. 3;

PEG. 5 is a fragmentary sectional view taken at about the line 5-5 of FlG. 4;

HG. 6 is a fragmentary sectional view takcn at about the line 6-6 of FIG. 5;

FIG. 7 is a fragmentary sectional view, partly broken away, taken at about the line 7-'7 of FlG. 3;

FIG. 8 is a fragmentary sectional View taken at about the line 8-8 of FlG. 7; and

FG. 9 is a graph including a straight line curve illustra ing the varying force of the yieldable torque device and another curve illustrating the varying closing force of the cover.

While an illustrative embodiment of the invention is shown in the drawings and will be described in detail herein, the invention is susceptible of embodiment in many different forms, and it should be understood that the present disclosure is to be considered as an exempliiication of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed'out in the appended claims.

Referring now to the drawings in more detail, a desk constructed according to the principles of the present invention preferably includes a book box 1li having a bottom Wall 11 (PIG, 3), side walls 12, a front Wall 13 and a rear wall 14. The box 1li is open at the top, and a movable book box cover 16 overlies the top opening when the cover is in closed position. The cover 16 is hinged to the rear wall 14 of the book box by conventional hinge means such as that illustrated at 17 and 1S, so that the cover is movable from a closed position illustrated in the drawings to a forwardly and upwardly inclined fully open position (not shown) which exposes the interior of the book box for ready access.

Patented Jan. 2, 1962 ice Usually, the book box 10 with the cover 16 is supported at a suitable elevation by a suitable leg structure such as that illustrated in part at 2l) in FIG. 2.

In order to control movement of the book box cover, and particularly the closing movement of the cover to prevent its weight and resultant closing force from slamming the cover shut, a friction device is provided which exerts a minimum, substantially insignificant effect on opening movement but which exerts a substantial retarding eect on closing movement, and which preferably is greater than the closing force of the cover to thereby hold the cover in partially open positions and requiring but a light manual pressure to close the cover.

The friction device, generally designated 22 is best illustrated in FIGS. 3-6, and includes a rst supporting bracket including a central portion 23, an end portion 24 welded or otherwise suitably secured to the adjacent side wall 12, and an opposite end portion 25 which terminates in a laterally turned ange 26 which is welded or otherwise suitably secured to the rear wall 14. This bracket may be referred to as an inner support, and its central portion 23 is formed with acircular depression as at 2S which receives a circular friction element 29, preferably comprising a disc of leather, one surface of which is adapted Vto continuously engage a depending arm 31 secured to the underside of the cover 17 as by means of a laterally turned flange portion 32 secured by screws or the like as at 33.

As seen best in FlGS. 3, 4 and 5, a second supporting bracket 35 is provided and this may be referred to as an outer bracket as it substantially encloses the inner bracket as well as the arm 31 depending from the cover 16. The outer, covering bracket 35 may be supported as by means of bolts or screws as at 37 and 38 attaching the outer bracket respectively to the portions 25 and 23 of the inner bracket. rlhe outer bracket is formed with a generally rectangularly shaped depression as at 40 which has a bottom wall 41 inclined relative to the path of the depending arm 31. The bracket 40 is adapted to receive a second friction element in the form of a block 43 of powdered iron or the like which carries a friction insert in the form of a generally rectangular piece of leather 44 adapted to oppose the leather element 29 and engage the opposite surface of the depending arm 31.

As will be readily understood, particularly on viewing FlG. 5, when the book box cover 16 is pivoted upwardly from a closed position toward an open position, the depending plate-like arm 31 moves upwardly with the cover, and due to its engagement with the leather element 44 causes the block 43 to tend to rise in the pocket 40. Due to the inclination of the bottom wall 41 relative to the path of the arm 3l, such upward movement of the block 43 reduces the frictional drag on the arm 31 to a nominal value which exerts little or no signicant retarding effect on the movement of the cover.

On the other hand, when the book box cover is moved from an open position toward the closed position the downward movement of the arm 3l, frictionally engaging the leather disc 29 andthe leather element 44, induces movement of the block 43 downwardly. At this time, due to the inclination of the wall 41 the leather element 44 is crowded against the arm 31 and exerts a substantially increased retarding effect on the movement of the cover which is sufficient to hold the cover in an open position. That is, the retarding effect of the friction device exceeds the closing force of the cover due to its mounting.

The retarding effect of the friction device may be adjusted by adjusting the bolt means 3S which has the effect of drawing the outer bracket 35 closer to the inner bracket portion 23 thereby crowding the leather elements 28 and 44 more closely together.

The amount that the cover may be opened is limited by means of a hook-shaped end portion 46 (FIG. 4) on the lower end of arm 41 which functions as a stop engageable with the shaft of the bolt means 33, as best seen at 47 in FIG. 3, which functions-as a stationary stop limiting movement of the movable abutment 46. ln a preferred embodiment, the cover member is pivotable through an angle of about 50 from the closed portion shown, whereupon the abutment d6 engages the stop 47.

AS best seen in FIGS. 3, 7 and 8, according tothe present invention the desk is provided with a yieldable torque means acting on the book box cover and exerting a force tending to open the cover but which force is less than the closing force of the cover when closed and which exceeds the closing force of the cover when open. Thus, the cover remains closed when closed and remains open when open. Intermediate these two extremes, the opening force of the torsion device equals the closing force of the door, so that the cover may be manually moved from 'the closed position illustrated to `an intermediate position whereupon the torsion device will cause continued movement of the cover from the intermediate position to the fully open position.

The torsion device, generaly designated 50, includes an elongate torsion bar having a yieldably twistable intermediate portion 51 of a length somewhat less than the Width of the book box, and having at one end an arm 52 adapted for attachment to the book box, and having at the other end an arm S3 engageable with the underside of the book Vbox cover 16, preferably through the medium of the laterally turned dlange 32 of the depending friction `arm 31 (FIGS. 4 and 5).

The torsion bar is disposed primarily in the book box and is mounted thereon by means of a forwardly and downwardly turned integral flange 55 at the upper edge of the rear wall 14, a somewhat similar forwardly and downwardly turned flange as at 56 at the upper edge of the rear wall 14 adjacent the torque arm 52, and a forwardly and upwardly turned flange 57 at the upper edge of the rear wall 14 adjacent the torque arm 53. These flange means, engaging Vthe intermediate portion l of the torque bar centrally of its length and adjacent its opposite ends, hold the same captive in an operative position. This independent mounting of the torque bar enables independent design of the bar to meet its operational requirements, and holds the torsion bar free to function in the proper manner.

The torque arm 52 is adjustably secured to the book vbox by means of a mounting bracket best illustrated in FIGS. 7 and 8, and including a ange portion 60 welded 'or otherwise suitably secured to the adjacent side wall V12 of the book box, a central plate portion 61 and spaced ange-like lugs 62. The central plate portion 61 is formed with a plurality of laterally and upwardly extending and opening notches or slots as at 64, six as illusv'trated, and each of these is adapted to receive the torque larm 52 so that the latter may be positioned in any of the notches to thereby vary the force exerted by the torsion bar.

.It will be understood that with the oppositevtorque varm 53 urging the cover upwardly, the torque arm 52 reacts downwardly in the notches 64, and the higher the torque arm 52 is positioned on the plate 61 the greater 4the-force exerted by the torsion bar. This construction 'enables use of the same torsion bar with covers of dif- `ferent weights. The torque arm 52 and the mounting bracket securing same to the book box are substantially enclosed by a Vcover 66 which is secured in position by bolt or screw means as at 67 attached to the lugs 62.

Referring to FIG. 9, the graph illustrates the varying closing force of the book box cover in a curve designated A and the varying force of the torsion bar in the straight line B, in inch-pounds on the ordinate versus the angular position of the door on the abscissa. It is obvious, of course, that the closing force of the cover varies from a maximum value when the cover is near a horizontal closed position to a minimum value when the cover would be manually raised, with only a light lifting pressure necessary, from the closed position to about a 45 position whereupon the torsion oar would lift the cover to thetfully open position and maintain the same open. In the range from 6 to 45, where the closing force of the cover exceeds the opening force of the torsion device, the cover will be held in open positions by the friction'device 22.

We claim:

l. A book box desk, comprising a book box having a top opening, a book box cover on the book box, hinge means mounting the cover on the rear of the book box for pivotal movement between a rst position closing the book box and a second inclined position exposing the interior of the book box, an arm depending from the cover, a friction device mounted on the book box engageable with said arm, movable to a first position in response to arm movement in an opening direction to exert a minimum substantially insignicant frictional drag on the arm during opening movement of the cover, and movable to a second position in response to arm movement in a closing direction to exert an increased frictional drag on the arm on closing movement of the cover to reduce the tendency of the cover to slam closed, and a resiliently yieldable means acting between the book box and the cover urging the cover toward open position with less forceV than the combined closing force of the cover and retarding eiect of the friction device, in the opening direction, when the cover is in any position between the iirst, closed position and a third position intermediate the first and second positions, the retarding effect of the friction device, in the closing direction, being at least equal to the net closing force of the cover when the cover is in any position between the first' position and the third position, whereby the cover may be manually opened to any position between the trst position and the third position and remain there, said yieldable means urging the cover toward open position with greater force than the closing torce of the cover and the retarding edect of the friction device, in the opening direction, when the cover is in any position between said second, open position and said third position, whereby the cover may be opened by said yieldable means from the third position to the second position.

2. A book box desk, comprising a book box having a rear wall and a top opening, a movable cover on the top of said book box, hinge means mounting the cover at the upper edge of the rear wall for pivotal movement between a first position closing the book box and a second inclined position exposing the interior of the book box, an arm depending from the cover, a friction device mounted on the book Abox, engageable with said arm, movable to a rst position in response to arm movement in an opening direction to exert a minimum substantially insignificant frictional drag on the arm during opening movement of the cover, and movable to a second position in response to arm movement in a closing direction to exert an increased frictional drag on the arm on closing movement of the cover to reduce the tendency of the cover to slam closed, a torsion bar having an intermediate yieldably twistable portion mounted on the book box at the rear edge thereof, an arm at one end secured to the book boxand an arm at the other end engaging the underside of the cover, urging the cover toward open position with less force than the combined closing force of the cover and retarding eiect of the friction device when the cover is in any position between the first, closed second positions, the retarding etlect of the friction device being at least equal to the net closing force of the cover when the cover is at any position between the rst, closed position and said third position, whereby the cover may be manually opened to any position between the iirst position and the third position and remain there, said torsion bar urging the cover toward open position with greater force than the closing force of the cover and the retarding eiect of the friction device when the cover is in any position between said second, open position and said third position whereby the cover may be opened by said torsion bar from the third position to the second position, and means mounting said torsion bar intermediate portion on the book box comprising, forwardly and downwardly turned ange means at the upper edge of the rear wall of the book box centrally of the length of said intermediate portion and adjacent said iirst mentioned torsion bar arm, and forwardly and upwardly turned flange means at the upper edge of said rear wall adjacent the second mentioned torsion bar arm, said ange means holding said intermediate portion captive in operative position.

References Cited in the iile of this patent UNITED STATES PATENTS 822,555 Rogers June 5, 1906 2,213,319 Lickteig Sept. 3, 1940 2,602,957 Anderson July 15, 1952 2,831,238 Mohr Apr. 22, 1958 2,871,505 Clark Feb. 3, 1959 2,894,277 Bogater July 14, 1959

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