U.S. patent number 3,903,812 [Application Number 05/383,347] was granted by the patent office on 1975-09-09 for drafting table.
Invention is credited to Gary Cowley.
United States Patent |
3,903,812 |
Cowley |
September 9, 1975 |
Drafting table
Abstract
A drafting table having a novel pedestal assembly including a
horizontal V-shaped base, with the spread of the V toward the
front, mounted on three spaced foot pads disposed in the form of a
triangle for exceptional stability and a forwardly inclined single
trunk rising from the apex of the V-shaped base with an extension
column continuing upwardly from the top of said trunk and pivoted
thereto on a horizontal axis disposed transversely of the V-shaped
base to allow the extension column to hinge downwardly towards the
front to a substantially horizontal position. Rotatably mounted in
the upper end of said extension column is a transversely disposed
horizontal cylinder that parallels the pivot axis of the column
with radial brackets on opposite ends that support a drawing board
and allow it to be tilted to the desired inclination. Within the
trunk and extension column that are both hollow are two counter
balancing mechanisms; an adjustable counter balance device for the
extension column and the variously loaded drawing board it carries
being housed in said trunk and an independent counter balance
device unrelated to the first mentioned one to compensate only for
the tilting of the board on its transverse supporting cylinder
being housed, together with a common locking mechanism for both
articulations, in the extension column.
Inventors: |
Cowley; Gary (Vancouver,
British Columbia, CA) |
Family
ID: |
23512702 |
Appl.
No.: |
05/383,347 |
Filed: |
July 27, 1973 |
Current U.S.
Class: |
108/2; 108/150;
108/4; 108/6 |
Current CPC
Class: |
A47B
27/06 (20130101) |
Current International
Class: |
A47B
27/00 (20060101); A47B 27/06 (20060101); A47F
005/12 () |
Field of
Search: |
;108/1-10,136,150
;188/77R |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Frazier; Roy D.
Assistant Examiner: Lyddane; William E.
Attorney, Agent or Firm: Haskett; W. Irwin
Claims
What is claimed is:
1. A drafting table comprising a horizontally disposed V-shaped
base, with the spread of the V to the front; a single, articulated,
forwardly inclined post rising from the apex thereof, said post
consisting of a lower trunk portion and an extension column portion
continuing upwardly from the top of the trunk and hingedly
connected thereto by a horizontal pivot disposed transversely of
the V of said base, whereby said extension column may be swung
forwardly from upright to approximately horizontal position over
the open, spread, front of the V-shaped base; a drawing board
mounted on the top of said column portion and tiltable on an axis
paralleling said pivot; counter balancing mechanisms for said
hinged column portion of said tiltable drawing board respectively;
locking means for releasably securing the mentioned hinged and
tiltable elements in selected adjusted positions, wherein the
counter balancing mechanism for the extension column portion of the
articulated forwardly inclined post includes a wheel rotatable on
said pivot, a flexible member extending part way around the
circumference of the wheel and being secured thereto at one end, a
tension spring stretched between the other end of said member and
the bottom of the post, a radial extension on said wheel and an
abutment on said extension column portion engageable therewith.
2. A drafting table according to claim 1, wherein the radial
extension on said wheel may be selectably positioned on the wheel's
circumference to vary the tension on the spring.
3. A drafting table according to claim 1, wherein said extension
column portion carries a transversely disposed elongated cylinder
rotatably mounted across the top thereof, closure caps in opposite
ends thereof and angle brackets releasably secured by bolts to said
end caps and extending radially therefrom having confronting
triangular bodies lying in parallel planes each with a narrow
flange along one edge attached to said drawing board.
4. A drafting table according to claim 1, having a transversely
disposed elongated cylinder rotatably mounted across the top of
said extension column portion for tiltably carrying said drawing
board, and wherein the counter balancing mechanism for said
tiltable drawing board includes a flexible member extending part
way around the circumference of said transverse cylinder and
secured thereto at one end and a tension spring stretched between
the other end of said member and an anchor bracket attached to said
extension column portion near its lower end, said flexible member,
tensioning spring and anchor bracket being all housed within said
extension column portion.
5. A drafting table according to claim 1, having a horizontal
transversely disposed cylinder rotatably mounted across the top of
said extension column portion for tiltably carrying said drawing
board, and wherein said locking means includes a first drum fixedly
secured on said cylinder, a second drum on said horizontal pivot
secured against rotation relative to said lower trunk portion, a
brake band anchored to said extension column portion and loosely
encircling said first and second drums in normally slipping
engagement, and means to tighten said band into tightly gripping
engagement.
6. A drafting table according to claim 3, having a horizontal
transversely disposed cylinder rotatably mounted across the top of
said extension column portion for tiltably carrying said drawing
board, and a first drum fixedly secured on said cylinder, and
wherein said locking means includes a second drum on said
horizontal pivot secured against rotation relative to said lower
trunk portion, a brake band anchored to said extension column
portion and loosely encircling said first and second drums in
normally slipping engagement, and a lever-actuated cam to tighten
said band into tightly gripping engagement with said drums, said
cam having a horizontal axle extending transversely of the
extension column and projecting through a side wall thereof,
adjustable toward said band and terminally depending at right
angles as a locking lever.
7. A drafting table comprising a horizontally disposed V-shaped
base, with the spread of the V to the front; a single, articulated,
forwardly inclined post rising from the apex thereof, said post
consisting of a lower trunk portion and an extension column portion
continuing upwardly from the top of the trunk and hingedly
connected thereto by a horizontal pivot disposed transversely of
the V of said base, whereby said extension column may be swung
forwardly from upright to approximately horizontal position over
the open, spread, front of the V-shaped base; a drawing board
mounted on the top of said column portion and tiltable on an axis
paralleling said pivot; counter balancing mechanisms for said
hinged column portion and said tiltable drawing board respectively;
locking means for releasably securing the mentioned hinged and
tiltable elements in selected adjusted positions, wherein the lower
trunk portion and the extension column portion of the articulated
forwardly inclined part are both elongated hollow members of
rectangular cross-section and of similar width, pivot-supporting
plates secured on confronting inside faces of opposite sides of
said trunk portion and rising above the top thereof, the end of
said horizontal pivot extending outwardly beyond said plates and
the opposite side walls of said extension column portion, lying
coplanar with the opposite side walls of the trunk portion, being
pivoted on such outwardly extending ends of the pivot, the top of
the trunk side walls being of arcuate contour and the lower end of
the extension column's coplanar side walls being of corresponding
circular contour, concentric with the pivot, to fit the arcuate top
of the side walls of the trunk; the front wall of the extension
column having an arcuate wing on the bottom thereof and the rear
wall of the trunk having an arcuate upward extension to contribute
to the enclosure of said articulated post adjacent said pivot.
Description
BACKGROUND OF THE INVENTION
This invention relates to improvements in a drafting table and
appertains particularly to one having a uniquely stable pedestal
including a single articulated column.
It has been known to produce drafting tables having a drawing board
adjustable for both elevation and tilt and to provide for counter
balancing the adjustment movements and for locking the adjusted
parts in the selected positions. Attempts have also been made to
produce a drafting table with a single vertically slidable or
articulated post. See U.S. Pat. Nos. 2,988,418 - Knudsen; and
3,638,584 - Cisler; and Canadian Pat. Nos. 695,671 - Wenger;
901,056 Sautereau; and 808,519 - Parigi.
Whether incorporated in a conventional table-like unit or utilizing
a single column pedestal, each of the drafting tables disclosed in
the aforementioned patents is deemed deficient in various ways and
the present item constitutes an improvement thereover.
Many conventional table-type units are large and bulky; even some
single column pedestals present a massive weight problem and those
that do not are so designed as to lack the essential stability of a
good drafting table; the over-sized or ill-shaped base interferes
with the position of the user's feet; the column inclines away from
instead of toward the draftsman, the board is pivoted in the wrong
place, the balance spring is not readily adjustable or the drawing
board when locked is less then rigid.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a drafting table
having an improved pedestal including a horizontal V-shaped base
with the spread of the V to the front and a single articulated
forwardly inclined post rising from the apex thereof, the V-shaped
base being mounted on three spaced feet or floor pads arranged in
the form of a triangle for exceptional stability.
A further object of the invention is to provide a single pedestal
drafting table having a forwardly inclined, articulated post rising
from the apex of a forwardly facing V-shaped base, and wherein the
hingedly mounted upper column of the post swings forwardly from
near vertical to approximately horizontal position over the open
spread front of the V-shaped base.
A further object of the invention is to provide a drafting table of
the character described, having an articulated inclined, two part
post consisting of a trunk and a pivotally mounted extension column
on the top thereof that in turn supports a tiltable drawing board,
wherein the pivoted extension column and the tiltable board are
provided with separate and independent counter balancing mechanisms
yet the articulated movements of the column and board are both
releasably locked in selected adjusted positions by a single
locking mechanism.
A still further object of the invention is to provide an improved
single pedestal drafting table of the character described, that is
of neat, simple and compact construction, is easily and quickly
adjusted to the desired elevation and tilt, conveniently locked in
and released from chosen position and affords the maximum comfort
to the user in sitting or standing position.
BRIEF DESCRIPTION OF THE DRAWINGS
To the accomplishment of these and related objects as shall become
apparent as the description proceeds, the invention resides in the
construction, combination and arrangement of parts as shall be
hereinafter more fully described, illustrated in the accompanying
drawings and pointed out in the claims hereunto appended.
In the drawings:
FIG. 1 is a side elevation of a preferred embodiment of the
invention;
FIG. 2 is a rear elevation thereof;
FIG. 3 is a horizontal, transverse section, on line 3--3 of FIG. 1,
showing the V-shaped, three point foot pad base;
FIG. 4 is an enlarged, vertical, transverse section, taken on line
4--4 of FIG. 1;
FIG. 5 is an enlarged vertical, longitudinal section, taken on line
5--5 of FIG. 2;
FIG. 6 is a similarly enlarged, vertical, longitudinal section
taken on line 6--6 of FIG. 2; and
FIG. 7 is a further enlarged, vertical transverse section, similar
to FIG. 4, detailing the pivot area assembly.
DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION
The present single pedestal drafting table provides a neat and
compact unit utilizing a horizontally disposed V-shaped base 1,
having the spread of the arms of the V to the front, here shown as
a hollow metal form of shallow rectangular-in-cross-section forms.
Three spaced feet or foot pads 2 arranged in the form of a triangle
afford stable support for the base, centrally underlying the
general areas of the apex and the spread apart free forward ends of
the arms of the V as seen clearly in FIG. 3. The front end of both
arms are tapped and threaded, as at 3, for the selective attachment
of a side reference (not shown) or other piece of equipment or
accessory.
Rising from the apex of base 1 is a single post that is inclined
forwardly so that it extends out over the open space between the
spread arms of the V. The post is articulated comprising a lower
trunk portion 4, welded to the base at its apex, and an extension
column portion 5 continuing upwardly from the top of the trunk and
hingedly connected thereto by a transversely disposed horizontal
pivot pin 6. Both the trunk and extension column portions 4 and 5
are elongated hollow members of metal or other suitable material,
being rectangular in cross-section and of similar width. The upper
end of the trunk 4 is fashioned to receive the lower end of the
hinged column 5 having an arcuate contour on the top of both sides
with a plate 8 welded on each of the confronting sides and rising
substantially above the arcuate top to support the outer ends of
the pivot pin 6 that is held against rotation by a clamp 7 fixedly
mounted on one of said plates. The side walls of the hollow
extension column, which may be of less depth though of the same
width as the trunk, terminate at their lower end in a circular
contour concentric with the pin 6 on which the column hinges,
fitting the arcuate contour of the top of the trunk and lying
substantially coplanar therewith. An arcuate wing 9 on the lower
edge of the front wall of the column 5 which is open to the bottom
and an arcuate upward extension 10 on the rear wall of the trunk 4
which is open at the top contribute to the neat appearance of the
hinge joint of this articulated post structure. The extension
column 5 may be swung forwardly from upright to approximately
horizontal position where it extends out over the open spread front
of the V-shaped base, the exceptional stability of the unit being
assured by the design of the V-shaped base and the relation of the
forwardly incline post to it.
Across the top or free outer end of the extension column 5 a
horizontal transversely disposed elongated cylinder 11 is rotatably
journalled in the column's spaced side walls, its opposite ends
being closed with welded-in closure caps 12. A triangular bracket
14 is affixed as by bolts on the outer face of each cap extending
radially from the cylinder and having their spaced confronting
bodies lying in parallel planes. Each bracket has a narrow flange
15 along one side by which it attaches to the underside of drawing
board 16 which is thereby free to be tilted to the desired angle on
the axis of the cylinder 11 that parallels the pivot pin 6. It will
be noted that the bracket triangle is so proportioned that the
board's tilting axis is near to its forward or lower edge.
A counter balance mechanism for the tiltable board 16 is housed
entirely within the extension column 5 and includes a flexible
member 17 that extends part way around the circumference of the
rotatable cylinder 11 and is secured by one end to the cylinder
while its opposite end connects with a tension coil spring 18 that
is remotely anchored to a bracket 19 fastened to the column 5 near
its lower pivoted end. The extension of part of the flexible member
around the rotatable cylinder is such that as the drawing board is
tilted between the upright and horizontal positions the tension on
spring 18 is increased to compensate for the increased load.
A completely separate and independent counter balance mechanism is
provided for the hingeable extension column 5. It includes a wheel
20 rotatably mounted on the pivot pin 6 with a flexible member here
shown as a link chain 21 extending part way around its
circumference and secured thereto at one end by a keeper 22 with a
tension spring 23 stretched between the chain's other end and the
base 1. To convey the load of the extension column 5 and its
drawing board 16, an abutment 24 is secured on the front wall of
the column near its lower open end that engages a pin 25 extending
radially from the rotatable wheel 20 into its path so that as the
hinged column is lowered toward horizontal forwardly extending
position, its load is taken by the stretched tension spring 23. As
the load the tension spring or springs 23 may be required to carry
can differ, depending on the type of drafting machine or
attachments mounted on the drawing board, a means for adjusting the
tension is provided by the wheel 20, alongside that part of its
circumference engaged by the chain, having a series of radial
threaded bores 26 in which the pin 25 may be selectably
positioned.
To assure steadiness to the drafting table and a reliable rigidity
to the drawing board at all times irrespective of the elevation or
angle of tilt it is set at, a handy and conveniently positioned
locking mechanism control is available. On the tiltable cylinder 12
inside the column 5 a drum 30 is secured against rotation and on
the non-rotatable pivot pin 6 a similar drum 31 is secured in
non-rotatable relation as by the drum-carried clamp 32 clearly seen
in FIG. 7. The drums 30 and 31 are in line and encircled by a
flexible brake band 33 that is anchored to the extension column 5
as at 34. The belt or band 33 is normally loose permitting slippage
between it and the spaced drums. To tighten the band 33 so that it
grips the drums in non-sliding relation a cam 35 is rotatably
mounted on brackets 36 on the inside of the front wall of column 5
about mid-way between the drums, its horizontal shaft 37 extending
transversely of the column then projecting through the side thereof
being disposed at right angles and depending as a locking lever 38
that lies within case reach of the user at all times. Should any
stretch occur in the belt 33, the unwanted slack can be taken up by
the upward adjustment of the cam shaft 37 within the brackets 36 or
by inserting shims under the base thereof.
In use, it will be seen that this drafting table, with its novel
pedestal consisting of a single articulared post rising at a
forwardly inclined angle from the rearwardly located apex of a
horizontally disposed V-shaped base, the spread of which V is
toward the front and wherein the base is supported on three foot
pads in a triangular arrangement, provides a neat compact unit of
pleasing design and exceptional stability. The separate and
independent counter balancing mechanisms for the articulated upper
column of the post and the tilting drawing board atop the column
are effectively housed in the trunk and extension column portions
respectively, in relative alignment transversely of the table, the
former mechanism having readily available adjustment to compensate
for the added weight of the particular drafting machine attached to
the drawing board. Especially convenient for the user is the
movement locking mechanism, to hold the hinged column and the
tilting board in any chosen position for drawing, whether seated or
standing, with its single lever handle disposed exteriorly of the
column and within easy reach of the user as it depends from the
column in horizontal position or extends horizontally forwards
therefrom when the column is in approximately vertical
position.
From the foregoing description taken in connection with the
accompanying drawings, it will be manifest that a drafting table is
provided that will fulfil all the necessary requirements of such a
device but various changes in the size, shape and arrangement of
parts may be made to the form of invention herein shown and
described without departing from the spirit of the invention or
scope of the claims.
* * * * *