US1904217A - Metal fixture for typewriter desks - Google Patents

Description

April 1'8, 1933.

METAL FIXTURE FOR TYPEWRITER DESKS M. FOX

2 Sheets-Sheet 1 Wff/ I gwwnto/o M ar/z'n Er.

April 18, 1933. M. Fox

METAL FIXTURE FOR TYPEWRITER DESKS Filed Apri'l 8, 1951 2 Sheets-Sheet 2 lsatentecl pr. 18, 1933 uNifTED STATES PATENrol-FICE MARTIN YI'1`O.X,*OIE GHIGAGO,l ILLINOIS, ASSIGNOR TO THE SENG- COMIANY, OF

i CHICAGO, ILLINOIS 'l METAL FIXTURE non TYrEWnITEn DEsx's Application iiled April 8,71931. Serial No. 528,689.

My invention is an improvement in typewriterdesks of the well known construction in'which the platform for the typewriter is supported by opposite pairs of link-connected bell crank levers carried by vplates slidable on rails in a compartment so, as to provide for housing the typewriter in its lowermost position and for elevating the same to position for use in front of the desk, the'lifting of the platform and typewriter being assisted by spiralsprings interposed between the rear bell crank lever and an arched bar connecting the plates fand forming a part of the carriage. Y Y

In the operation yof swinging typewriter supportsof this general construction the bell crank levers .are locked by weighted pawls cooperating with the rails inthe horizontal movement Vof the carriage, the forward movementjof the latter to released position of the pawls being stoppedV by engagement of the front rollers and forward ends of the plates with the corner posts of the compartment which are recessed Ito receive said rollers and the forward ends of the plates and the repeated striking of these metal parts against the corner posts results in tearing out the wood as well as causing stress onfthe i roller. Furthermore., the operation ofa gravity pawl in' automatically engaging and releasing the bell crank levers is not reliable to the extent required for the effective manipulation of the platform.

It is the principal object of my invention therefore to improve the construction of the metal fixtures of a typewriter desk of this character to increase the simplicity of construction for economy in production and reliability in operation; all asvhereinafter set forth and more specifically pointedV out in the appended claims.

In the accompanying drawings: Figurel 1 is a vertical longitudinal sectional view through the rear portion of a typewriter desk constructed in accordance with my invention, the plat-form for thev typewriter being in housed position.

Fig. 2 Vis a sideview with the compartment broken .away to show the metal fiX- l tures controlling the operation of the platform, the carriage being near the limit of forward movement from -housedfposi- 1on. i Fig. 3 is a similar view with the carriage at the limit of its forward movement.

Fig. 4 is a kdetail perspective view o-f one of the side plates of the carriage.

5 is an edgeview thereof. Figs. 6 and 7' are like views of the locklng pawl. i The typewriter desk to receive the swingmg platform 1s constructed to provide a comi partment 10 in which the typewriter is housed, said compartment having front cornerposts 11, 1l and rear corner `posts 12v to which the sides 13, 13 and back wall 14 are attached, the front of the compartment beling closed by a door (not shown) if so desired. Attached to the front and rear corner postsare horizontal rails 15, 15 supporting 70 the carriage comprising side plates 16, 16 connected at theirrear ends by an arched crossbar 17, they saidv plates having grooved` rollers. 18, 19' at opposite ends thereof c0- operating with pins 20, 21 at opposite edges of the plates from the rollers respectively for properly supporting the carriage in sliding engagement with the-rails, and to these plates are pivoted'bell crank levers 22, 23 the shorter members of which are connected by a link 24 while the longer members are pivotally connected to a platform 25 on which the typewriter is supported, it being noted by reference to Figs. 1 and 2 that said longer members of the bell crank levers depend from the side plates of the carriage inthe lowered position of the platform for housing the typewriter and swing forwardly and upwardly in elevating the platform and typewriter in position for using the latter, and that the lifting movement of the platform is assisted by means of a pair of spiral springs 26, 26 connected at one end to the arched bar 17 and at the other end to a crossbar 27 extending between the longer members of the bell crank levers at the rear end of the carriage.

For pivotally connecting the outer ends of the longer members of the bell crank levers to the platform metal strips 28 are screwed to the opposite edges of said platform and each plate is provided with an upstanding tongue 29 which is adapted to engage a fixture 30 attached to the front corner posts for holding the platform in elevated position as shown in Fie". 3 of the drawings, said fixture being the conventional form of catch.

For locking the bell crank levers in the lowered position of the platform when it is being moved to and from housed position in the desk compartment pawls 31 are pivoted at 31a; to the outer sides of the plates 16 and the projecting hook of each pawl is adapted to engage a pin 32 on the bell crank lever 22, said pawl being automatically released by the tail-piece 33 entering a recess 84 in the underside of the rail at the limit of the forward movement of the carriage carrying the platform. The pawl is shaped so as to be pivoted at the outer side of the plate 16 with a lateral extension under the same adjoining the hook which engages the pin on the bell crank lever, and in the present instance the pawl is actuated by a short spiral spring 85 attached at its upper end to an apertured ear 36 projecting from the inner side of the plate with the lower end of said spring formed into a hook passed through an aperture 37 (Fig. 7 in the offset portion of the pawl. The pawl is limited in its downward movement by a lug 38 projecting from the plate, and both the aforesaid apertured ear and stop-lug are stamped from the plate. Y

The forward ends of the rails 15 are let into recesses 39 in the front posts 11 of the desk, said recesses being adapted to receive the forward ends of the side plates of the carriage, it being noted thatthe bell crank levers are spaced from said plates by reason of the outwardly stamped bearings 40 which also permit of the connecting link 24 being located between the plate and bell crank levers, and to prevent contact of the rollers 18 with the corner posts a laterally projecting stop member 41 is bent from each plate. This arrangement therefore provides substantial stop members at opposite sides of the platform which abut against the corner posts at one side of the recesses receiving the ends of the plates thus entirely relieving the rollers of any stress and also preventing the ends of the plates of the carriage from injuring the wood. Furthermore, inasmuch as the front rollers 18, 18 are disposed away from the corner posts in the forward position of the carriage and the aforesaid stop members engage the corner posts at one side of the recesses 39 obviating the necessity of providing recesses for the rollers as required when the movement ofthe carriage is limited by said rollers and ends of the plates, it is therefore apparent that but a single recess is required to be cut into each corner post. This improvement in addition to actuating the pawl by means of a spring and limiting its locking movement simplifies the construction and provides for a smooth and reliable operation of the mechanism which will increase the durability of the several cooperating parts. n

The operation is similar to that of typewriter desks of this general construction, that is to say in moving the platform and typewriter carried thereby from housed position within the compartment to elevated position for use in` front of the desk the platform is grasped and moved forward sliding the carriage on the rails until the stops 41 projecting from the side plates strike the corner posts at which time the forward ends of said side plates enter the recesses for the advanced position of the parts and the tailpiece of each pawl entering the recess in the lower edge of the rail and hook members of the pawls Iare thereby released from engagement with the bell crank levers permitting them to swing on their pivots for the lifting of the platform to elevated position where it is held by engagement of the tongue 29 with the catch 30, and in this position the longer members of the bell crank levers are substantially perpendicular to their pivots for firmly supporting the typewriter in position for use. The pawls are yieldingly but positively held in released position by means `of the springs 35 so that in housing the typewriterv the lowering of the platform will cause the pins 32 on the bell crank levers 22 to engage the pawls which swing on their pivots until the rear ends thereof strike the lugs 38 and the tail-piece is on a horizontal plane imme-V diately below the rails so that said pawls will be engaged by the lower edges of the rails,Y

and thereby maintain the bell crank levers locked during the movement of the platform into and out of the compartment of the desk.

I claim Y In combination with a typewriter desk having a compartment with corner posts; at its forward end and recesses at the inner side of said posts, of supporting rails at oppoioc posts at one side of the recesses for limiting the forward movement of the sliding plates,

and bell crank levers pivoted to the plates for,

swinging movement and to which the platform is pivoted; together with a pawl pivoted to the plate and having a tail-piece entering a recess in the rail, a spring for moving the pawl into engagement with the recess, and a lug struck from the plate and with which the paWl engages for limiting the movement of the same in one direction,

saicl pavvl cooperating with a pin lon one of' the bell crank levers in the lowered position of the platform.

MARTIN FOX.

Images