Improvements in Adjustable Supports for School Desks and Seats and other Furniture.
Year: 1895

page_text: Date of Application, 25th June, 1895-Accepted, 10th Aug., 1895
COMPLETE SPECIFICATION.
Improvements in Adjustable Supports for School Desks and Seats
and other Furniture.
GABRIEL ALEXANDER BOBRICK, of 50 Bromfield Street, Boston, County of
Suffolk, State of Massachusetts, United States of America, Manufacturer.
I ALFRED GEORGE BROOKES of 55 & 56 Chancery Lane, in the County of
London, Chartered Patent Agent, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This invention relates to simple, durable and readily adjustable supports for
furniture, particularly adapted for school desks and seats, which must be adjustable
in accordance with the height of the pupils, the construction of the supports
being such that during adjustment the movable member thereof will not drop or
slide down by its own weight, nor settle before or after adjustment.
This adjustment can be made by one person, and it can be effected even if the
floor is so imperfect or warped as to throw the fixed portions of the supports out of
plumb.
My invention accordingly consists in a construction and arrangement of parts
which will now be described at length and pointed out with particularity in the
claims.
Fig. 1 of the drawings is a perspective view, partly broken out, of a furniture
support embodying my invention, the base being broken off to save space.
Fig. 2 is a top or plan view of the support, the movable member being shewn in
section.
Fig. 3 is a perspective view, partly broken out, of the base or standard with the
movable member omitted.
Fig. 4 in side elevation, with 'the movable member of one of the supports
broken out, represents another form or embodiment of the invention applied to a
school desk.
Fig. 5 is an enlarged sectional view on the line x-x, of 'Fig. 4, shewing the two
standards or supports.
-al, of Fig. 5.
Fig. 6 is a vertical section on the line
Fig. 7 is a side elevation of a school seat or chair modifiéd as to the form of
support, and
Fig. 8 is an enlarged sectional view on the line y-y, Fig. 7.
In the drawings Figs. 1, 2 and 3 shew the upper part of a base or standard a
forming the fixed member of the support, and adapted to be secured at its lower
end to the floor as usual, the base being conveniently made of cast iron.
The upper end or head a' has an opening a² therethrough, a shoulder a³ projecting
into the opening at one side, while the side walls of the opening a² at each side of
the shoulder a³ form long bearings a², preferably bevelled and converging towards
the end wall as of the opening.
A longitudinal space or clearance ax is left between the wall a' and the inner
edges of the bearings a and below the shoulders a³ for a purpose to be described.
The movable member of the support consists essentially of a straight bar or
shank of cast iron or other suitable material, adapted to loosely enter the
opening a², the upper end of the bar being provided with arms having

page_text: holes 2 therein, to rigidly attach the member b to a desk, chair, etcetera by screws
or bolts.
A series of notches 63 is formed on one side of the bar or shank b, and the plane
opposite side is engaged by a clamping device, shewn as a set screw or bolt
extended through a threaded boss d on the bar, located opposite the interior
bearings a¹.
Faces extending substantially the length of the bar are formed thereon at
each side of the series of notches, bevelled as shewn to fit closely the bearings a*
when the movable member is clamped to the base.
A long and rigid bearing is thus obtained at all times for the movable member,
the bevelled faces being centred by the similarly bevelled bearings a¹ in the
head, the shoulder a³ then engaging one of the notches and positively supporting
the movable member, so that it cannot settle or drop down after clamping, even
if the clamping device become loosened.
The clearance space a below the shoulder a3 allows free movement of the
notched side of the movable member when it is being adjusted, and when clamped
the notched side does not bear against the end wall a of the base opening, and
consequently no strain is put upon the notched side.
To adjust the support the clamp is loosened and the shoulder as disengaged from
one of the notches 3, and the movable member is moved up or down to the desired
height, tightening of the clamp moving the member b into place, seating the faces b*
on the bearings a².
Pressure of the clamping device is thus exerted opposite the long bearings, so
that the bar or shank & cannot be cracked or broken, and the bearings also correctly
position and prevent any lateral play of said member.
If the bar bore at one point against the shoulder a³ and at another point against
the end wall a pressure applied by the clamping device to the bar between such
points would crack or break it with comparative ease.
The opening a² in the base is considerably wider than the thickness of the bar,
so as to allow free play of the movable member when its faces 4 are withdrawn
from the bearings a', and the movable member can be moved in the base without
binding on the side walls.
Imperfections or warping of the floor will throw the supports out of plumb, and
cause great friction by the binding of the parts, and by my construction described
desks or other articles of furniture requiring a plurality of supports can be adjusted
readily.
If the supports remain plumb and the desk is raised or lowered the movable
members pass through the centres of the openings a².
The numbers on the sides of the bars are convenient when used with desks or
seats as scales for readily adapting the furniture to the height of the pupil. In
Figs. 4, 5 and 6 a different form of support is shewn with a modified manner of
adjustment, a desk A in Fig. 4 having secured to its underside brackets or cross
arms of like metal bars e and f, longitudinally slotted at ex, fx, respectively.
These movable or adjustable members of the supports are alike, but for
convenience they have been designated by different reference letters, the bars being
shewn as central webs in which are slots e, f, and enlarged at their longitudinal
edges to form separated but converging faces e', f', respectively, transversely
toothed or notched, Figs. 4 and 6, to engage the inner similarly converged and
transversely notched bearings e, f, in the heads e³, j³, respectively, of the two
like standards or fixed members e, f, of the supports.
Each head has an opening in one side for the shanks of suitable bolts g and h,
which are extended through the slots in the movable members e and f, and then
through large washers wand w', which freely enter suitable holes in the opposite
sides of the heads, see Figs. 5 and 6, set nuts a retaining the bolts or clamping
screws in place.
As shewn in Fig. 5 the toothed converging faces e' and flare on the same

page_text: sides of the barse and f, the bearings e² and ƒ2 being similarly situated in the
heads of the stationary members e* and f*.
The open heads e³ and f³ are wide enough to permit considerable movement
laterally of the movable members when the clamping screws are loosened, the
latter being oppositely arranged, but with the washers and 1 bearing on the
corresponding sides of the movable members.
While the screws are tight the notched or toothed faces of the movable member
of each support will be held in close engagement with the correspondingly notched
bearings in the head of each fixed member, but when the nuts n are loosened the
two bars e and f can be moved into dotted line position Fig. 6, preparatory to
adjustment.
By grasping the desk A the operator, moving it laterally, will cause engagement
or disengagement of the bearings and co-operating converging faces.
A loose washer w* surrounds the screw g between the nut n and the side of the
head, and to make the outer side of the other support present a similar appearance
the washer w is built up at w2, Fig. 5, the clamping nuts being at the outer side
of each head in order to be conveniently reached in adjusting.
To prevent an accidental fall of the desk when unclamped each standard below
the head is provided with a series of teeth, only those on the standard being
shewn, however, at e, Fig. 4, to be engaged by a toe e on the lower end of the
movable member e, the weight of the desk being so distributed as to cause said.
tees to normally enter one of the notches of its co-operating series.
To lower the desk the movable members e and fare unclamped and the desk is
moved laterally and forwards, thus disengaging first the notched converging faces
and bearings, and then the supporting toes from their notches, and then the desk
can be lowered to the desired height and released, the toes catching in their
co-operating series of teeth to support it until clamped.
A modification of the support is shewn in Figs. 7 and 8 to adapt it to a desk or
chair B, to the underside of which is attached the movable member i, longitudinally
slotted, and having converging faces, transversely notched or toothed, to be held
against similar converging bearings in the base k, by a clamping screw k² and
nut n', the nut bearing against the outer side of a washer entering a hole in the
side of the base, tightening of the nut drawing the washer against the member i
and forcing the faces against the bearings k₁ of the base.
The supporting toe and the co-operating series of notches forming a detent, are
in this instance omitted.
The converging bearings in the fixed members or standards are long enough to
give a firm, steady bearing for the movable members when clamped.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. The use, in an adjustable support for furniture, of a fixed member having an
open head, long, separated converging bearings located therein, a longitudinally
adjustable member movable in the open head, elongated converging faces formed
on one side of said member to rest on the converging bearings in the head, a series
of notches on one member, one or another of which is engaged by a projection on
the other member, and a clamping device to press the movable member against
and to seat it in its bearings, a clearance space being left between the inner edges
of the separated bearings in the head, substantially as described.
2. The use, in an adjustable desk, of two depending bars which are longitudinally
slotted and transversely notched, the one on its inner and the other on its outer
side, two fixed standards having transversely notched bearings to co-operate with
the adjacent notched sides of the bars, and clamping screws which extend through
the standards and slotted bars, to draw the notched portions of each into engage-
ment, whereby lateral bodily movement of the desk when the clamping screws are

page_text: loosened will disengage the bars from the bearings, to permit adjustment of the
desk, substantially as described.
3. The use, in an adjustable desk, of two depending longitudinally slotted bars
having each two converging transversely notched separated faces on corresponding
sides. to engage converging transversely notched bearings within the open heads of
two fixed standards, clamping screws extended through the heads and slotted bars
to draw the faces of the bars against the bearings in the heads, and thus clamp the
bars, and a detent to retain each bar from downward movement when unclamped,
lateral movement of the desk disengaging the converging faces and bearings when
the clamping screws are loosened; substantially as described.
4. The use, in an adjustable support for furniture, of a fixed member or standard
having an open head provided with transversely notched converging bearings in
one side, a washer loosely held in the head opposite the bearings, a longitudinally
slotted member movable in the head, having converging and transversely notched
faces on one side to co-operate with the bearings, and a clamping screw in the head
extended through the slotted bar and washer, to draw the faces of the bar against
the bearings in the head when clamped, substantially as described.
Dated the 21st day of June 1895
.
WM. BROOKES & SON,
55 & 56 Chancery Lane, London, Agents for the Applicant.