Drafting table

Claim 2

In combination a locking mechanism for a drafting board, said drafting board being mounted on a support, a means to adjust said board for tilting on said support and means to adjust said board vertically on said support, said means to adjust said board for tilting comprising first lock means to lock said drafting board on said support in selected position against tilting, second lock means to lock said drafting board in selected vertical position, and a single handle connected to both said locking means for actuating both said locking means by movement of said handle, said first lock means and said second lock means being locked when said handle is in a first position, said first lock means being unlocked and said second lock means being locked when said handle is moved to a second position, said first lock means being relocked and said second lock means being unlocked when said handle is in a third position.

Claim 3

The combination recited in claim 1 wherein said drafting board is supported on a first leg and a second leg, transverse means fixing said legs together at their upper ends, and counterbalance means for counterbalancing said drafting board in vertical position.

Claim 4

The combination recited in claim 1 wherein said counterbalance means comprises an energy cell at one side of said drafting board, said energy cell having an outer drum, a shaft and a spring connecting said shaft to said drum, and cable means connected to said legs and to said drum.

Claim 5

A drafting table comprising a support structure, a drafting board, first means attaching said drafting board to said support structure for tilting, second means connecting said drafting board to said support structure for vertical movement whereby said drafting board can be moved up and down, first locking means to lock said drafting board against tilting and second locking means to lock said drafting board against vertical movement, and an actuating member connected to said first locking means and to said second lockIng means for actuating both said locking means locking said drafting board against tilting and against vertical movement, said actuating member is movable to a first position to lock said drafting board against both tilting and vertical movement, said actuating member is movable to a second position to unlock said tilting movement and to lock said vertical movement and to a third position to lock said drafting board against tilting and unlock said board for vertical movement.

Claim 6

A drafting table comprising a support structure, a drafting board, first means attaching said drafting board to said support structure for tilting, second means connecting said drafting board to said support structure for vertical movement whereby said drafting board can be moved up and down, first locking means to lock said drafting board against tilting and second locking means to lock said drafting board against vertical movement, and an actuating member connected to said first locking means and to said second lockIng means for actuating both said locking means locking said drafting board against tilting and against vertical movement, said actuating member is movable to a first position to lock said drafting board against both tilting and vertical movement, said actuating member is movable to a second position to unlock said tilting movement and to lock said vertical movement and to a third position to lock said drafting board against tilting and unlock said board for vertical movement.

Claim 7

A drafting table comprising a supporting structure, a pair of spaced legs comprising a yoke mounted for vertical movement on said supporting structure, a drafting board, pivot means on each said leg supporting said drafting board on said yoke, said first lock means comprising two interleaved groups of brake plates, means securing the plates of one of said groups of said plates to said drafting board, means securing the other plates of said group of said plates to the upper end of one of said legs, a pivot tube extending through said groups of brake plates, and actuating means for pressing said brake plates of both said groups together in tight frictional engagement to hold said drafting board in selected pivotal position relative to said leg, said actuating means comprising a toggle linkage, including a first link and a second link, a third link attached to said toggle linkage, said third link having means thereon connected to an elevation lock to actuate a second lock means to lock said legs against vertical movement, a torsion rod extending through said pivot tube, one end of said torsion rod being fixed to said base, the other end of said torsion rod being fixed to said drafting board, said first lock means and said second lock means being locked when said actuating means is in a first position, said first lock being unlocked and said second lock being locked when said actuating means is in a second position, said first lock being relocked and said second lock being unlocked when said actuating means is in a third position.

Claim 8

A drafting table comprising a supporting structure, a pair of spaced legs comprising a yoke mounted for vertical movement on said supporting structure, a drafting board, pivot means on each said leg supporting said drafting board on said yoke, said first lock means comprising two interleaved groups of brake plates, means securing the plates of one of said groups of said plates to said drafting board, means securing the other plates of said group of said plates to the upper end of one of said legs, a pivot tube extending through said groups of brake plates, and actuating means for pressing said brake plates of both said groups together in tight frictional engagement to hold said drafting board in selected pivotal position relative to said leg, said actuating means comprising a toggle linkage, including a first link and a second link, a third link attached to said toggle linkage, said third link having means thereon connected to an elevation lock to actuate a second lock means to lock said legs against vertical movement, a torsion rod extending through said pivot tube, one end of said torsion rod being fixed to said base, the other end of said torsion rod being fixed to said drafting board, said first lock means and said second lock means being locked when said actuating means is in a first position, said first lock being unlocked and said second lock being locked when said actuating means is in a second position, said first lock being relocked and said second lock being unlocked when said actuating means is in a third position.

Claim 9

The drafting board recited in claim 5 wherein said yoke comprises a transverse member, a first leg and a second fixed to said transverse member, said legs being telescopically and slidably received in said base to raise and lower said board, an elevation lock means to lock said legs in selected elevated position, said actuating means comprising an angle bar in said transverse member of said yoke, the outer ends of said transverse member being attached to said locking means, a pickup arm fixed to said bar, and means connected to said links to engage said pickup arm to actuate said elevation lock.

Claim 10

A drafting board comprising a support member, a first leg and a second leg spaced from each other, said spaced legs slidably supported on said support for vertical movement thereon, a drafting board, said drafting board being attached to an upper portion of said legs for tilting movement thereon, two spaced support angle members attached to the lower side of said drafting board, one flange of each said support angle extending generally perpendicular to said drafting board, two groups of plates made up of a plurality of first brake plates and second brake plates disposed in parallel planes, one said group being disposed adjacent each said support angle, first spaced pins fixed to said vertical flanges and extending through holes in said first brake plates, two second groups of brake plates made up of first brake plates and second brake plates, second pins fixed to said legs, said second pins extending through holes in said second brake plates, a first bracket fixed to said first leg and a second bracket fixed to said second leg, a tube extending through said brackets through said support angles and through both said first brake plates and through said second brake plates whereby said drafting board is tiltably supported on said legs, said tube extending through said first plates and said second plates, a first brake engaging member slidably supported on said tube and engaging said first brake plates, a second brake engaging member slidably supported on said tube and engaging said second brake plates, a lever, a first link having its first end pivoted to said lever at a first pivot point and having its second end pivoted to said first brake engaging member, said lever being swingably attached at a third pivot point to said second brake engaging member, said first pivot point and said second pivot point being spaced from each other, said lever being adapted to be swung from a first position to a second position whereby said first brake engaging means and said second brake engaging means are forced away from each other and said first brake plates and said second brake plates are squeezed together locking said drafting board against tilting, said lever being swingable to a second position where said first pivot moves between said second pivot and said third pivot to a second position on the opposite side of said line through said second pivot and said third pivot whereby said first brake engaging member and said second brake engaging member are moved toward each other and said brake plates are allowed to move away from each other, said lever being movable to a third position, second locking means for locking said columns in adjusted vertical positions, said second locking means having a member engagable by second lock actuating means on said lever whereby said second locking means is actuated when said lever is moved to said third position.

Claim 11

A drafting board comprising a support member, a first leg and a second leg spaced from each other, said spaced legs slidably supported on said support for vertical movement thereon, a drafting board, said drafting board being attached to an upper portion of said legs for tilting movement thereon, two spaced support angle members attached to the lower side of said drafting board, one flange of each said support angle extending generally perpendicular to said drafting board, two groups of plates made up of a plurality of first brake plates and second brake plates disposed in parallel planes, one said group being disposed adjacent each said support angle, first spaced pins fixed to said vertical flanges and extending through holes in said first brake plates, two second groups of brake plates made up of first brake plates and second brake plates, second pins fixed to said legs, said second pins extending through holes in said second brake plates, a first bracket fixed to said first leg and a second bracket fixed to said second leg, a tube extending through said brackets through said support angles and through both said first brake plates and through said second brake plates whereby said drafting board is tiltably supported on said legs, said tube extending through said first plates and said second plates, a first brake engaging member slidably supported on said tube and engaging said first brake plates, a second brake engaging member slidably supported on said tube and engaging said second brake plates, a lever, a first link having its first end pivoted to said lever at a first pivot point and having its second end pivoted to said first brake engaging member, said lever being swingably attached at a third pivot point to said second brake engaging member, said first pivot point and said second pivot point being spaced from each other, said lever being adapted to be swung from a first position to a second position whereby said first brake engaging means and said second brake engaging means are forced away from each other and said first brake plates and said second brake plates are squeezed together locking said drafting board against tilting, said lever being swingable to a second position where said first pivot moves between said second pivot and said third pivot to a second position on the opposite side of said line through said second pivot and said third pivot whereby said first brake engaging member and said second brake engaging member are moved toward each other and said brake plates are allowed to move away from each other, said lever being movable to a third position, second locking means for locking said columns in adjusted vertical positions, said second locking means having a member engagable by second lock actuating means on said lever whereby said second locking means is actuated when said lever is moved to said third position.

Claim 12

In combination, a drafting board and a support, first means supporting said drafting board for tilting on said support, second means supporting said drafting board for movement in elevation, first lock means for locking said drafting board against tilting on said support, second locking means for locking said drafting board against movement in elevation, actuating means for said first lock means comprising a first link, a second link pivotally connected to said first link forming a toggle linkage, said first link and said second link being connected to said first lock means at their distal ends, a handle attached to said first link, a third link, having a first end and a second end, said third link being connected to said first link at its said first end and connecting means connecting the said second end of said third link to said second lock means, said third link being connected to said first link at a position between the connection of said second link to said first link and said handle.

Claim 13

In combination, a drafting board and a support, first means supporting said drafting board for tilting on said support, second means supporting said drafting board for movement in elevation, first lock means for locking said drafting board against tilting on said support, second locking means for locking said drafting board against movement in elevation, actuating means for said first lock means comprising a first link, a second link pivotally connected to said first link forming a toggle linkage, said first link and said second link being connected to said first lock means at their distal ends, a handle attached to said first link, a third link, having a first end and a second end, said third link being connected to said first link at its said first end and connecting means connecting the said second end of said third link to said second lock means, said third link being connected to said first link at a position between the connection of said second link to said first link and said handle.

Claim 14

The combination recited in claim 8 wherein said first locking means comprises interleaved plates at each side of said drafting board, and said first link and said second link are adapted to force said plates together in frictional engagement with each other.

Claim 15

The combination recited in claim 8 wherein said second locking means comprises two spaced vertical extending rods fixed to said support, two helical springs, one said helical spring disposed around each said rod, two rock plates rotatably supported on said means supporting said drafting board for tilting, each said helical spring having two ends, said two ends of each said spring being fixed to one of said rock plates, said rock plates being connected to said connecting means.

Claim 16

The combination recited in claim 9 wherein said second locking means comprises two spaced vertical extending rods fixed to said support, two helical springs, one said helical spring disposed around each said rod, two rock plates rotatably supported on said means supporting said drafting board for tilting, each said helical spring having two ends, said two ends of each said spring being fixed to one of said rock plates, said rock plates being connected To said connecting means.

Claim 17

The combination recited in claim 10 wherein said connecting means comprises two bell cranks fixed to said support, vertically extending means connecting said bell cranks to said rock plates, a pickup member connected to said bell cranks, and means connected to said third link adapted to engage said pickup member to move said bell cranks and thereby move said rock levers to move said helical springs out of binding engagement with said rods.

Claim 18

The combination recited in claim 12 wherein said means supporting said drafting board on said support comprises a tubular member supported on said support, said first lock means comprising a first tubular member and a second tubular member telescopically supported on said tubular member, said first and second tubular members comprising said first lock means and said second lock means, and a third tubular member slidably supported on said second tubular member, said third tubular member engaging said pickup member.

Claim 19

The combination recited in claim 13 wherein a compression spring is disposed in engagement with said rock levers urging said rock levers to urge said helical springs to bind on each said rod, said compression spring being adapted to exert a force on said third link when said lever is moved to a position to move said first locking means toward each other whereby said first link and said third link co-act to lock said first locking means.

Claim 20

In combination, a drafting board and a support with a locking mechanism for locking two relatively swingable members together comprising two spaced first members and two spaced second members, said first members being fixed to a drafting board, said second members being fixed to said support, a first tubular member extending through said first members and said second members swingably connecting said first members and said second members together, a first group of brake leaves and a second group of brake leaves, said groups of brake leaves each being made up of a plurality of first brake leaves and second brake leaves, said first brake leaves being loosely received on spaced first pins on said first members, said second brake leaves being loosely received on second pins on said second members, said tubular member extending through a hole in each of said brake leaves thereby connecting said first brake leaves to said second brake leaves, a first square tube telescopically received on said first tubular member and disposed adjacent said first group of brake leaves, a second square tube telescopically received on said first tubular member and disposed adjacent said second group of brake leaves, means on said first square tube engaging said first brake leaves, means on said second square tube engaging said second brake leaves, a crank link pivoted at one end to means on said first square tube, a first link pivoted at one end to said second square tube and to said crank link, said crank link being swingable to urge said brake leaves together to hold said first brake leaves in frictional engagement with each other, a third square tube slidably supported on said second square tube, a second link pivotably connected to said crank link at its first end and to said third square tube at its second end, said first link being pivoted to said crank link between the pivotal connection of said crank link to said second tube and the pivotal connection of said second link, said third square tube having means thereon adapted to engage a pickup member, a handle fixed to said crank link, said handle being swingable to a first position urging said first square tube and said second square tube from each other whereby said brake leaves of said first group and said brake leaves of said second group are each urged into frictional engagement with each other, said handle being swingable to a second position whereby said leaves of said first group and said brake leAves of said second group can each swing relative to the other, said handle being swingable to a third position whereby said second link forces said third square tube into engagement with said pickup member and a force is thereby exerted between said third tubular member and said first tubular member forcing said brake leaves of said first tubular member into frictional engagement.

Claim 21

In combination, a drafting board and a support with a locking mechanism for locking two relatively swingable members together comprising two spaced first members and two spaced second members, said first members being fixed to a drafting board, said second members being fixed to said support, a first tubular member extending through said first members and said second members swingably connecting said first members and said second members together, a first group of brake leaves and a second group of brake leaves, said groups of brake leaves each being made up of a plurality of first brake leaves and second brake leaves, said first brake leaves being loosely received on spaced first pins on said first members, said second brake leaves being loosely received on second pins on said second members, said tubular member extending through a hole in each of said brake leaves thereby connecting said first brake leaves to said second brake leaves, a first square tube telescopically received on said first tubular member and disposed adjacent said first group of brake leaves, a second square tube telescopically received on said first tubular member and disposed adjacent said second group of brake leaves, means on said first square tube engaging said first brake leaves, means on said second square tube engaging said second brake leaves, a crank link pivoted at one end to means on said first square tube, a first link pivoted at one end to said second square tube and to said crank link, said crank link being swingable to urge said brake leaves together to hold said first brake leaves in frictional engagement with each other, a third square tube slidably supported on said second square tube, a second link pivotably connected to said crank link at its first end and to said third square tube at its second end, said first link being pivoted to said crank link between the pivotal connection of said crank link to said second tube and the pivotal connection of said second link, said third square tube having means thereon adapted to engage a pickup member, a handle fixed to said crank link, said handle being swingable to a first position urging said first square tube and said second square tube from each other whereby said brake leaves of said first group and said brake leaves of said second group are each urged into frictional engagement with each other, said handle being swingable to a second position whereby said leaves of said first group and said brake leAves of said second group can each swing relative to the other, said handle being swingable to a third position whereby said second link forces said third square tube into engagement with said pickup member and a force is thereby exerted between said third tubular member and said first tubular member forcing said brake leaves of said first tubular member into frictional engagement.

Claim 22

The combination recited in claim 15 wherein a torsion bar is telescopically received in said first tubular member, said torsion bar has a first end and a second end, said first end of said torsion bar is fixed to said support, said second end of said torsion bar is fixed to said drafting board.

Claim 23

The combination recited in claim 16 wherein said second end of said torsion bar has adjusting means connecting it to said drafting board whereby the torsional force counterbalancing said drafting board may be adjusted.

Claim 24

The combination recited in claim 17 wherein said support comprises a yoke having a transverse member and two spaced vertically extending legs, a disk member slidably supporting said legs, a locking means for holding said yoke in predetermined vertical position, a laterally extending bar on said transverse member, a first bell crank and a second bell crank attached to each end of said transverse member, a locking member on each said leg and attached to each said bell crank, said pickup member being attached to said transverse bar.

Claim 25

The drafting table recited in claim 1 wherein said drafting board is attached to a yoke having a pair of spaced legs mounted on said supporting structure, pivot means on each said leg supporting said drafting board on said yoke, said means to adjust said board for tilting comprising a first group of brake plates and a second group of brake plates interleaved with said first group of brake plates, means securing the plates of said first group of said plates to said drafting board, means securing the plates of said second group of said plates to the upper end of one of said legs, a pivot tube extending through said groups of brake plates, said handle comprising actuating means for pressing said brake plates of both said groups together in tight frictional engagement with each other to hold said drafting board in selected pivotal position relative to said leg, said actuating means further comprising a toggle linkage, including a first link swingably connected to means engaging said first group of plates and a second link swingably connected to means engaging said second group of plates, and said first and said second links being swingably connected together and an actuating handle fixed to said first link, and means supporting said links to said pivot tube.

Claim 26

The drafting board recited in claim 19 wherein a torsion rod extending through said pivot tube, one end of said torsion rod being fixed to said yoke, the other end of said torsion rod being fixed to said drafting board.

Claim 27

The drafting board recited in claim 19 wherein said pivot means further comprises spaced platelike brackets on said yoke, one at each side thereof, a first flange and a second flange spaced from each other and fixed to said board and disposed in planes generally parallel to said brackets, said first group of brake plates disposed ad-jacent said first flange, said second group of brakes plates disposed adjacent said second flange, said tube having a first end and a second end extending through said brackets and through said flanges and through said first group of brake plates and through said second group of brake plates, said first end of said tube having a nut thereon abutting the outside surface of said first flange, the said second end of said tube being fixed to said second flange.

Claim 28

The drafting board recited in claim 21 wherein said first flange has a first horizontal flange fixed thereto and said second flange has A second horizontal flange fixed thereto, said horizontal flanges each having two laterally extending slots therein, fastening means in said slots engaging said board holding said board to said horizontal flanges whereby said first and said second flanges may be adjusted toward and away from each other to adjust the outward movement of said brake leaves.

Claim 29

The drafting board recited in claim 22 wherein said actuating means further comprises a first outside sleeve telescopically supported on said tube adjacent said first group of brake leaves, a second outside sleeve telescopically supported on said tube adjacent said second group of brake leaves, said means supporting said first link and said second link on said pivot tube comprises said first link pivotally attached to said first outside sleeve, said second link pivotally attached to said second outside sleeve, said links being swingably connected together and handle means fixed to one said link.

Claim 30

The drafting board recited in claim 21 wherein a torsion bar extends through said first tube, said torsion bar having a first end and a second end, means fixing a first end of said torsion bar against rotation relative to said first flange, means fixing said second end of said torsion bar against rotation relative to said second bracket whereby said torsion bar is twisted when said board is tilted from a horizontal position.

Claim 31

The combination recited in claim 1 wherein said means to adjust said board comprises a first leg and a second leg spaced from each other, said spaced legs slidably supported on said support for vertical movement thereon, said drafting board being attached to an upper portion of said legs for tilting movement thereon, a first support angle and a second support angle spaced from each other and attached to the lower side of said drafting board, one flange of each said support angle extending generally perpendicular to said drafting board, a first group of plates made up of a plurality of first brake plates and a plurality of second brake plates, a second group of brake plates made up of a plurality of third brake plates and a plurality of fourth brake plates disposed in parallel planes, one said group being disposed adjacent each said support angle, first spaced pins fixed to said vertical flanges and extending through holes in said first brake leaves, a first bracket fixed to said first leg and a second bracket fixed to said second leg, second pins fixed to said brackets, said second pins extending through holes in said second brake leaves, a tube extending through said brackets through said support angles and through both said first brake leaves and through said second brake leaves whereby said drafting board is tiltably supported on said legs, a first brake engaging member slidably supported on said tube and engaging said first group of brake leaves, a second brake engaging member slidably supported on said tube and engaging said second group of brake leaves, a lever, a first link having its first end pivoted to said lever at a first pivot point and having its second end pivoted to said first brake engaging member at a second pivot point, said lever being swingably attached at a third pivot point to said second brake engaging member, said first pivot point and said second pivot point being spaced from each other, said lever being adapted to be swung from a first position to a second position whereby said first brake engaging means and said second brake engaging means are forced away from each other and said first brake leaves and said second brake leaves are squeezed together locking said drafting board against tilting, said lever being swingable to a second position where said first pivot moves between said second pivot and said third pivot to a second position on the opposite side of said line through said second pivot and said third pivot whereby said first brake engaging member and said second brake engaging member are moved toward each other and said brake leaves are allowed to move away from each other, said lever being movable to a third position whereby said brakes are locked.

Claim 32

The actuating mechanism recited in claim 25 wherein said support comprises a table structure, a first anchor plate secured to a first end of said torsion rod and also being secured to said drafting board and a lever secured to a second end of said torsion rod and to one of said legs whereby when said lock means is released and said drafting board is moved toward a predetermined position, said torsion rod is rotatively twisted to counterbalance the weight of said drafting board.