US2065952A - Adjustable support - Google Patents

Description

Dec. 29, 1936. Q TRAUTMANN 2,065,952

ADJUSTABLE SUPPORT Filed Aug. 20, 1935 Y 2 Sheets-Sheet 1 OTTO E .TRAUTMAN N INVENTOR Patented Dec. 29, 1936 UNITED STATES PATENT OFFICE ADJUSTABLE SUPPORT Application August 20, 1935, Serial No. 37,038

5 Claims.

The present invention relates to supports such as chairs, tables, instrument stands and the like and relates more particularly to electrically driven vertically adjustable supports.

One of the objects of the present invention is to provide a motor driven adjustable support which is durable and rugged in construction yet accurate and eflicient in operation. Another object is to;provide an improved drive means for an adjustable support. A further object is to provide animproved control system for motor driven adjustable supports. Another object is to provide a'motor driven support having means for preventing movement beyond predetermined points. These and other objects and advantages reside in certain novel features of construction, arrangement and combinations of: parts as will-herein- .after he more fully set forth and pointed out in the appended claims.

Referring to the drawings:

Fig. 1 is a perspective view of a ing this invention. 7

Fig. 2 is a vertical section of same.

Fig. 3 is a fragmentary vertical section taken at 90 degrees tothat of Fig. 2 facing away from the switch bracket.

Fig. 4 is a fragmentary vertical section taken at 90 degrees to that of Fig. 2 and facing toward the switch bracket.

Fig. 5 is a horizontal section taken on line 5-5 of Fig. 2.

Fig. 6 is a horizontal section through the motor casing and base.

Fig- 7 is. a wiring cuits.

Fig.8 is a modified form of wiring diagram of the control circuits.

A preferred embodiment of my invention is illustrated. in the drawings as applied to an instrument table having a base Ill upon which is mounted a casting II fixedly carrying a vertical tubular guide I2. A screw I3, rotatably journalled in a bearing I4 in the casting II, extends upwardly through the tubular guide I2, and a table embodydiagram for the control cirthrust bearing I4 is provided between the lower portion of the screw I3 and the casting I I. A motor I5 is mounted on the base III within a housing I6 and serves to rotate the screw I3 through reduction gearing I1 and a flexible cou- I pling I8.

The top I9 of the table is fixed on a support 20 by means of screws 2I and the support 20 is, in turn, fixed to a downwardly extending tubular member 22 by pins or screws 23.. The tubular member 22 is telescopically slidable into the tubular guide and is provided with a longitudinal keyway 24. A key 25, secured to the guide I2 by screws 26, engages in the key way 24 and serves to hold the guide I2 and member 22 against relative rotation. A tubular shield 21 is also fixed to the support 29 and extends downwardly outside. of the guide I2 forming a cover to protect the interior mechanism from dust and dirt.

Secured near the bottom of the tubular member 22 by screws 28 is a nut 29 which is threaded on the vertical screw I3. The nut 29 is split at 30 and a screw 3| permits a take-up for wear. Thus it is apparent that upon rotation of the screw I3 by the motor I5 the nut 29 will travel along the screw and thus raise or lower the top I9 of the instrument table.

Referring now to Fig. 7, one circuit for controlling the motor I5 will be described. The two wires 32 and 33 are connected to a source of power and lead respectively to a double throw switch 34 and one side of the armature 35 of the motor I5. The field of the motor I5 is split into two windings 36 and 31 which are opposed. Thus, when the switch 34 is closed to the left, the current flows through the field winding 36 and the motor I5 rotates in one direction while when the switch 35 is closed to the right, the field winding 31 is energized and the motor I5 rotates in opposit direction. In order to prevent movement of the table top I9'beyond predetermined limits, a switch 38 is placed in the circuit with the field winding 36 and a switch 39 is placed in the circuit withthe field winding 31. As only one of these switches 38 and 39 is in the circuit at any one time, opening of that switch will stop the rotation of the motor. These switches Hand 39 are operated automatically in a manner to be hereinafter described.

If the split field wiring shown in Fig. 7 fails to provide suficient torque to move the table, a four wire system utilizing the entire field can be used as shown in Fig. 8. The two wires 40 and 4| lead from a source of electrical power to one side of the field coils 42 and to the contacts 43 and 44 of a switch 45 respectively. The switch 45 is of the double pole, double throw variety and 2 comprises two tiltable arms 46 and 41 which are fixed together and pivoted to engage selectively the contacts 43 and 48 or the contacts 44 and 49.

The armature 59 of the motor I5 is connected the contacts 43 and 48 and through the connector and when the switch arms 46 and 41 are closed to the right, current flows through the contacts 44 and 49 and through the connector 52. It is obvious from an examination of Fig. 8 thatthe direction of current flow through the armature 50 is in opposite directions for the two positions of the switch 45 and hence the rotation of the motor I5 is reversed. The tiltable mercury safety switches 38 and 39 are placed in series with the conductors 52 and 5| respectively and serve to stop the motor.

A vertical rod 53, fixed to the casting I I, extends upwardly through the nut 29 and a support,- ing plate 54 is secured thereon by a member 53 which carries a cover plate 55.. A b rack'et5 6 is fixedly mounted on the supporting plate 54 and ing position by a spring 58;

has an arm 51 extending outwardly at a right angle. The mercury switch 38 is tiltably carried bythearm 51 and is normally held in circuit clos- 3 8is in the circuit controlling the downward movement of the table top H! and a lug 59 fixed to the tubular member 22; engages the mercury Switch! and tilts it, thus stopping the motor when the table has-reached the position shown in The mercury switch 3!! is tiltably mounted on the body ofthe bracket 56 and is normally held in circuit closing position, by a spring 60. A

. plunger 6| is slidably mounted in the plate 54 andis urgedaway from the mercury switch}!!! by a'spring 62. The switch 39 is in the'circuit controlling the upward movement of the table top i9 and when the nut 29 reaches the top offits travel, it engages the plunger 6|. and tiltsthe switch ,39 stoppingthe motor l5." r

, A switch box 63 is secured to oneside of the top IQ of the'table and the electric cable 64 extends through a conduit 65 toa plug connector 66 inthe base. This plug connector 66 is simply a detachableplug fil and socket 68 connected respectively tothe motor l5 and cable64. Thus thernotor l5 maybe removed by removing the plug .61 and'it isnot necessary otherwise to disturb the wiring; The mechanical details'of the connections of the switches 38' and 39'to the cable 64 have been omitted in the interests of clarity but such connections are obvious to one skilled in the art..

The-switch box 63 has two buttons 69 and HI controlling respectively the upward and down.-

ward movement of the top I!) of the table, As stated above, either of the wiring circuits shown 7 in Figs; '7 and 8'can be used. Pressure on either provide an improved, motor driven, vertically adjustable support. While I have shown anddescribed myiuvention as applied to an instrument table,-it isobvious that, the .invention could be used with equal facility in instrument stands;

chairs or the like. Various modifications can,

of course, .bemade without departing from the spirit of' my invention or the scope. of the appendedclaims,

I claim: 7 r l. A device of the character "described comprising a base having avertic'altubular guide, a screw rotatably journalled in said base and extending This mercury switch I upward within said "guide, a support having a downwardly extending tubular portion in slid able telescoping engagement with said guide, a nut secured to said tubular portion and threaded on said screw, a motor for rotating said screw in either direction, means for energizing said motor,

' a rod fixedto' said base and extending upward through said nut, a bracket'carried'by' said rod above saidscrew, control means mounted on said bracket for stopping the motorat predetermined limits of travel of said support, and means on I,

said support for actuating said controlmeans.

' 2. I-na'device of the character described a base f having an upstanding tubular guide, a support having a downwardly extending tubular member slidably telescoping into said guide, means ior preventing relative rotation between said tubular member and said guide, .a' screw rotatably journall ed in ,1 said base and extending upwardly through said guide, a nut fixed .to said tubular member and threaded on said screwfanelectricmotor carried by said base for rotating saidscrew; a circuit for energizing'said motor tq'i'otfljteSflld? screw in one direction, a switch'insaid circuit; a" second circuit to energize said motor torqme said v screw in the otherdirection, asecondg switch in said second circuit, a rod extending 'upwardgfrom said base through said nut, f8; bracket'icarrled by said rod. above said 'screw,- ,'meansj or mounting said switches on saidbracket, neans iorurging said switches into circuit closing positionpmeans carried byfsaid support to open the first na'm'ed switch to stop the motorfwhn said su'pport h'as' reached a. predetermined limit of travel-1n said one direction, means carriedby saidgsupporttq open, theYse'cond switch when 3 the motor- 1m reached a predetermined jlimitfgo't travel in said other direction, and mean'sflforfiselectively iconf necting said motor in eitherjofsaid f i 3. In a device of'thecharacter de'sc a.

preventing relative rotationflbetween tubular nailed in said basefl and extending'jgupwardly through said guide, a-nut flxed'jto saidtubular member and threaded on" said j screw, anelectric motor carried bysaid base for rotating said screw,

screw in one direction, a switchinsaidciroilit. a second circuit to energize said motor to rotate'said screw in the other directloma s'econdjswitchj in said'seoond circuit, a rod extending'upwa'rdifrom said base through said nut, a -bracke t carried by o be ,1 having an upstanding tub1'1'lar; guit l e, fasupport; i 5 having a downwardly extending tubular i V slidably telescoping into said; guide; means-- '1for member and said guide, a; screwgrotatably floursaid rod above said screwQmeanstorjmounting carried by said support to open thelfirst-named reached a predetermined limit'fof travel 'insaid one direction, means carried by said supportto open the second switch when the motor'has reached a predetermined limit of I travel, in said other direction, switch meanson'said support for selectively connecting said motor in eitherof'said circuits, an electric cable connecting "saidswitlch conduit secured to 'said base and"extending through saidnut, through which the cable passes from said support to said base.: a a r 4. In a device of the character describedii base, a vertical screw rotatably journalled in said base, a support vertically slidably mounted-upon ;s'aid switches on saidbracket, means 'ifoijurging" said switches into circuit ciOsingpo sItio'n meanS means to said fmotor, and-an ,upstandin'ghollow a circuit for energizing said motor to rotatei 's'aid :59

switch to stop the motor when said support has r said base, a nut on said support cooperating with said screw whereby rotation of said screw actuates said support, an electric motor for driving said screw, a circuit for energizing said motor to rotate said screw in one direction, a second circuit for energizing said motor to rotate said screw in the opposite direction, a rod carried by said base and extending upwardly therefrom, a bracket carried by said rod, a mercury switch for each circuit tiltably mounted on said bracket, means normally urging both of said switches into circuit closing position, means fixed to said support for tilting one of said switches at the predeter mined limit of downward travel of said support, means associated with said nut for tiltingthe other of said switches to stop the motor at the predetermined limit of upward travel of said support and manually operated switch means for selectively connecting said motor in one or the other of said circuits.

5. In a device of the character described, a base, a vertical screw rotatably journalled in said base, a support vertically slidably mounted upon said base, a nut on said support cooperating with said screw whereby rotation of said screw actuates said support, an electric motor for driving said screw, a circuit for energizing said motor to rotate said screw in one directioma second circuit for energizing said motor to rotate said screw in the opposite direction, a rod carried by said base and extending upwardly therefrom, a bracket carried by said rod, a mercury switch for each circuit tiltably mounted on said bracket, means normally urging both of said switches into circuit closing position, means fixed to said support for tilting one of said switches at the predetermined limit of downward travel of said support, a plunger slidably mounted in said bracket beneath the other of said switches, means on said nut for engaging said plunger to tilt said other of said switches to stop the motor at the predetermined limit of upward travel of said support and manually operated switch means carried by said support for selectively connecting said motor in one or the other of said circuits.

O'I'IO E. TRAUTMANN.

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