US1939250A - Desk - Google Patents

Description

Dec. 12, 1933.

A. G. BLUOMDAHL ET AL 1,939,250

DESK

' Filed March 8, 1932 2 SheetsSheec l ALB/N G. BLOOMDAHL Wf/son J56,

45 head and typewriter shelf.

Patented Dec. 12, 1933 UNITED STA was PATENT omen DESK' Albin 'G. Bloomdahl and WilsonWgSlraw, Jamestown, N. Y., assignors to Jamestown Metal Desk Company, Jamestown; N.Y., a corporation of New York Application March 8, 1932. Serial No. 597,512

2 Claims.

13 That isQwhen the head'is raised flush with'the top of the desk,.the shelf is lowered into concealed position, whereas, When the head is lowered the shelf and typewriter mounted thereon is in raised position.

Prior to the present invention, several types of supporting mechanisms for typewriter shelves have been developed and installed in a typewriter desk. These'shelvesoperate through a linkage connected with'a drop head; Linkage heretofore developed, although producing an operativearrangement of shelf and drop head, rec'iuired the operator of thedesk to exert considerable strength in manipulating the drop head and shelf, largely because these elements were not balanced. In years past, it was believed expedient'tohave balance occur, if at all, at approximately the middle of the travel of the'shelf and drop head, thus the weight of the shelf plus typewriter and that of the drophead would prevent inadvertent dis location of the typewriter shelf whenin raised position. While this arrangement had certain advantagesat the time of development, is now found more practical to provide proper counter-- balancing as between shelf and typewriter and drop head.

Furthermore, it is believed the number of links heretofore'einployed was unnecessarily great and by reducing thenurriber of these links to ammimum, the ease of operation-may be greatly increased.

The principal object'of the invention lies in the provision of a deskof this class-in which the moving parts are so proportioned and arranged as to facilitate free and easy manipulation of drop Another object of the invention lies in the provision of a typewriter desk, having a drop head and typewritensupporting' shelf which are sub stantially ii -balance with each other at all times,

thus requiring verylittle eifort in the manipulat tion of the parts from one position to another.

A further object of the invention lies in the provision of a latching means by which to secure the typewriter shelf in raised position.

Other and further objects of the invention will be more clearly ,understoodfrom: a' consideration of the following specification which is taken in conjunction with the accompanying drawings,

and in which Fig. 1 is a front elevationof a desk embodying one form of this invention;

Fig. 2 is an enlarged vertical transverse sectional view through the center of the desk; show-, ing the retracted position of a typewriter shelf and its relation to'the desk drop head,being taken substantially on the line 2-2'of Figure l;

Fig. 3 is a view similar to Figure 2, showing the typewriter shelf locked in raised position;

Fig. 4 is an enlarged vertical sectional view, showing latch and stop for the desk drop head;. Fig. 5 is'a fragmentary horizontal sectional view, taken substantially on the line 5--5' of Figure4;

Fig. 6 is a fragmentary plan view of' the shelf, parts being brokenaway to show a shelf latch release mechanism; and p Fig. '7 is an enlarged view of the latch by which the shelf is held in raised position.

In'thedrawings a desk, generally indicated by the reference numeral 10, is shown equipped with a drop head 11, located between spaced pedestals 12. Alsolocated'between the pedestals 12 is a'typewriter shelf 13. The shelf 13 and head operates'the other. The central portion of the desk top'15is cut away'to provide an opening 16 for the head 11. The inner wall 1'7 of the portion 15 is'undercut to provide clearance for the head 11 when moving from one position to another. Inasmuch as the desk per se forms no part of this invention, further description thereof is unnecessary. v

The head 11 is formed with a work surface 19, similar to the desk top. The sides and rear por-' tion of the head are formed with the usual flanges 20. The forward flange 21 terminates in an inwardly directed flange 22. One or' more brackets 23'are secured'by welding to the underface of the head 11."An apron '25 is joined along'walls 26 and 27 to the flange 22 and bracket 23. The rear wall 2'7 connects with the forward wall 26 through several flanges and a'curved portion 28. Theends of the'apron are closed by end walls 29, tothe inner face of each-of which is secured a channel member 30'. One flange of the channel member-30 is' suitably joined to the wall 26 of the apron for the purpose of rigidifying the structure. Mounted in the end walls. 29 of the apron are plns32 to 11 are suitably linked together, as will hereinafter be described, so that manipulation of one which links 33 are joined. The other end of each of these links is joined to the adjacent walls 34 of each of the pedestals 12 by means of pins 35. Adjacent the rear of the head 11 and joined to the flanges 20 by welding are brackets 37. An opening is formed in that portion ofthe bracketprojecting below the flange 20 for receiving a pin 38. Pivotally engaged with this pin is a rocker arm 39. This arm is pivotally joined to the side wall 34 of the desk.

The arm 39 is supported upon the pin 41, which, it will be noted, is located slightly by a pin 41.

more than half the length of the arm from the pin 38. Considering for the present the link 33 and arm 39, it will be noted that the head 11 may be swung from horizontal to vertical position and in so doing the link 33 travels through an arc of approximately 180 degrees, whereas, the arm 39 rotates about the pin 41 approximately 120 degrees.

The typewriter shelf 13 consists of a table portion 43 which terminates on the sides and for-' ward edge in depending flanges 44. 'The rear edge of the table portion terminates in an upstanding flange46 which is again bent to pro vide a rearwardly projecting horizontal flange 45. Secured to the side flanges 44, are rails 47. Slightly forward of the longitudinal center of the flange 44, a pivot pin 49 is located. One end of link 50 is mounted on this pin, the other end being engaged with the wall '34 of the desk by means of a pin 51. Slightly to the rear of the longitudinal center of the flange 44, another pin 53 is located. -This pin pivotally engages one end of the. rocker arm 39. It will be noted that two links support and control thedirection of travel of the shelf 13, namely, link 50 and rocker.

arm 39. It will further be noted that since. the rocker arm also, supportsthe drop head 11, only three links are necessary to operably both the shelf 13 and head 11.

The operation of lowering the head 11 and raising the shelf 13 is as follows. The forward portion of the head is moved upwardly and inwardly,

' this direction of travel being defined by the length of the arcthrough which the link 33 must travel.

As the forward end of the topmoves'up and rear-. wardly, the rear of. the top, which is connected,

with the rocker arm 39, movesrearwardly and downwardly in an arc defined by the distance be-,

tweenpivot pins 41 and 38. As the upper portion of, the rocker arm moves rearwardly, the short and lower'portion moves forwardly, carrying with it the shelf 13. In order for the shelf and top to exchange'position, however, the'shelf, during its upward travel must assume a more nearly vertical position and this is accomplished by means of link 50 which at first raises and then lowers the forward end of the shelf. By the time the link 50 has moved in a direction to lowertheforward end of the shelf, the head has moved to a nearly vertical position and is clear ,of the shelf. The shelf assumes a positionsuch that the rear flange 45 thereof abuts the rearwall 27 of the apron 25;

- l3 and a typewriter. substantiallybalance the support weight of the head 11. This would not be true, however, if, for example, the linkage, by which these elements are carried, was differently arranged. For instance, the pin 41 constitutes a fulcrum for both head and shelf, thus moving this pin nearer the pin 53 attached to the shelf 13, would greatly increase the weight of the head 11 with respect to a shelf. While it is true that typewriters of different sizes and makes vary somewhat in weight, this variance is so slight as not to constitute a serious consideration, the operator of the desk being capable of exerting a sufiiicent force to overcome any slight difference in balance that may occur from the use of an unusually light or heavy typewriter.

Since it is contemplated that the weight of the shelf 13, plus that of a typewriter, will substantially balance the weight of the drop head 11, it has been found advisable to provide a bracket 48, which is joined to the wall 34 of the desk, and in which is mounted a bullet catch 52. This catch engages the end wall 29 of the apron 25 and prevents the head 11 from being inadvertently tipped. Attached to the wall 29 is a block 54 which, when the drop head is in closed position, rests upon the bracket 48. This structure constitutes the support for the forward end of the drop head when closed. It will be noted that any downward pressure exerted adjacent the rear of the drop head will not cause the head to move out of position by 105 reason of the fact that the rear support is had through rocker arm 39 and pins 38 and 41. Because the rocker arm has assumed a substantially vertical position when the drop head is closed, it will not rotate with any application of force on 110 the rear of the head.

By reason of the above described arrangement, it will be appreciated that any slight upward movement, such as striking the knee against the underfaceofithe shelf, will cause the shelf to 115 start movement toward withdrawn position and at the same time raise the head. To prevent this and also toinsure rigidity of the shelf, when imposition of use, a latching device is provided. Secured to the underface of the table portion 43 of the shelf is an arm 57.- This arm is pivotally supported by means of a pin 58. This pin, it will be noted, is adjacent theend of the arm which is in contact with a rod 59. The rod 59 extends longitudinally of the shelf, being supported for longitudinal reciprocation within brackets 60. A disc 61 is fixed to the rod adjacent the rearmost bracket 60and an expansion spring 63 is mounted between this bracket and the disc. Thus the rod is normally moved forward and into engagement with the short end of the arm 57. To prevent the arm 5'7 from disengagement with the rod, a small spring 64 is provided which tends to counteract the force of the spring 63. However, since spring 64 is of 35 considerably less tension than spring 63, the latter spring is not compressed as a result of this counter directional force." Joined to the underface ofthe free end of the arm 5'? is a finger plate 65. The rear end of the rod 59 projects beyond the rear wall 44 and into a socket formed in a, latch 66. The latch is pivotally mounted on a bracket 67 which is welded or otherwise joined to the wall 46. A latch finger 68 extends upwardly through a slot in the rearwardly di- 4 rected flange 45 and is movable toward the wall 44 by manipulation of the arm 57. A slot 70 is cutinto the rear wall 27 of the apron 25. Adjacent one edge of this slot is provided a contact portion 71 for the finger 68. When the shelf is moved into position of use, the finger passes through the slot 70 and engages the portion 71. It will be thus appreciated that since the rear fiange 45 of the shelf is held against the rear wall 27 of the top apron and the forward portion of the shelf rests upon a rod 55, said shelf is immobile and will not jar or vibrate through the use of a typewriter mounted thereon. When it is desired to lower the shelf, the arm 57,

by means of the grip 65, is drawn forwardly.'

This causes the other end of thearm to depress rod 59 against the tension of the spring 63. Inward movement of the rod causes the latch to swing about the pivot and withdraws the finger from engagement with the portion '71. With the parts in this position, the forward end of the shelf may be raised and the finger 68 withdrawn from the slot 70 of the top apron and head and shelf reverse positions.

Although applicants have shown and described only one modification of this invention, it will be apparent to those skilled in the art that other modifications or adaptations may be made without departing from the spirit and scope of the invention as defined in the hereunto annexed claims.

Having thus set forth our invention what we claim as new and for which we desire protection by Letters Patent is: V

1. In a desk of the class described having a typewriter compartment, a typewriter supporting shelf in said compartment, a drop head closing the. top of said compartment, links supporting said head and shelf for pivotal movement relative to said desk and to each other, a latch mounted adjacent the rear of said shelf and engagement with the forward portion of said head when said shelf is raised into position of use, a rod mounted beneath said shelf and pivotally joined to said latch, an arm pivotally supported on said shelf, one end of said arm engaging said rod, the other end of said arm being accessible for manipulation whereby to release engagement of said latch with said head.

2. In a desk of the class described having a typewriter compartment, a shelf in said compartment, a drop head closing the top of said compartment, links supporting said shelf and said head for pivotal movement relative to said desk and each other, an apron joined to and depending from the forward end of said head, the rear Wall of said apron having a slot therein, a latch mounted adjacent the rear of said shelf, said latch, when said shelf is raised into position of use, being projected into said slot to engage said apron, an arm pivotally joined to said shelf adjacent the forward end thereof, and a rod supported on said shelf, said rod connecting said latch with said arm whereby manipulation of said arm will release engagement of said latch with said apron.

ALBIN G. BLOOMDAHL. WILSON W. SHAW.

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