US2473632A - Extensible strut - Google Patents

Description

Junezl, 1949. RG, BODE '2,473,632

EXTENS IBLE STRUT Filed May 5, 1945 Patented `urie Z1, 1949 ED; STA

s vrareri'lf aXrnNsILE s'rnii'r Robert- G. Bode, Chicago, Ill., assigner to The Norwood Company, '(Jhicago, Ill., a corporation of Illinois Application MayS, 1945; SerialNo. 592,205'i a partof, amusic stand or likel article and com- 3.

prises a verticallynextending. tubular lower member, a vertically extending tubular upper member in'telescopicrel'ation with the lower member, and releasable means .on the upper end of the lower member for locking.y the upper memberi-.flo

against downward displacement with respect to the lower member after .it has been shifted or slid relatively to the latter.

One obj-ect of the invention is toprovide an provement upon, andy has` certain advantages over, previously designed struts and is characterized by the fac-t that it effectively and ef- `iiciently fulfills its intended purpose and not onlyisflight in weightbut also is capable .oi beingtr produced at a lowy and reasonable cost.

Anotherv object'oif the invention is to provide an extensible strut in which the releasable locking means at the upper end' of the vertically ext-ending tubular lower member is of simple and'ige novelf design and'v comprises a lever type detent `whichf is so arranged andi constructed that it functions as a one-.way clutch whereby the vertically extendingv tubular upper member may be readily slid upwards without the necessity off: manipulating or releasing the lever type detent and'` is automatically locked against downward metal stock and has an inrolled longitudinally extending rib ofV U-shaped cross section and the;V lever type detent constituting the releasable means at the upper yend of the tubular lower member fory locking they tubular upper member against downward displacement after upward shift thereof is arranged so that one end thereof:

v fits within the rib andi coacts therewith to-hold the tubular upper. member against turningI or rotation with respect to the tubular lower member. t

Aiurther object'. ofthe invention is to provide an extensiblestrut of the aforementioned type and' character in which the lever type detent is constructed and'=V mounted in a novel manner andi'coactsY with a= longitudinal1 series of equi- 'dist'.antlyx spacedholes. inthe bottom of the inextensible strut of' thi-stype whichk is an iin-515 (CLI 248--16U 2 rolled: rib on thetubuian-.upreo member positively to lock thev .upper member against downward displacement `with@ respect. ,to the lower member after upward sluit or sliding. movement thereof.

A still further' object o the invention 1SV fr0 provide an extensible Strut.: Which. generally of new and improved constructionand possesses novel characteristics. and ystru.oztliladg featured other objects ofl the: invention and the various advantages and,characteristicseoi the4 present extensible strut'will loe-apparent from a consideration of the lfolluwing detailed description.

he invention consistsim the-several novel-.features which are hereinaf set forth and are more particularly dened, .by/- the elaine; at. the conclusion hereof..

in the drawing which; accompanies.: andiorms a part of this specification Qr disclosure and, in which like numerals, oi reference denotenorrespending paltslthroughQLll the SBVQIla'l Views;

Figure 1 is, a perspective ofv` ,a music stand having as a part. thereof an., extensible strut embodying the initentio1i-;n

Figure 2 is` a.A fragmentaryarear elevation yof the strut;

Figure 3 is a vertical or longitudinal section taken on theline 3.-3i-0 'EigllrefZ and illustrating the construction. leign; and manner of mounting of the lever type detentg,

Figure 4. is al horizontal.:section taken Qn the line lied of Figure 2.- andshowine in detail the design and arrangement; of thealrlgitudinally extending inrolledl rib ontthestublllar upper member oi the strut;

Figure 5` is a horizontal section: taken onthe line 5 5 off Figure Zand showing` the manner in which; the lever, type-.detent constituting the releasablelmeans attheupper endr ofA the tubular lower member; for locking: the tubular Upper member against downward.. displacement after upward shift thereof, coacts with therib on the upper member tohold the-upper member against turning or rotation with` respect to the lower member; and'y Figure 6 is a perspective. of thelever type detent and the spring f or'urging theflatter into its operative or locking-` position.,

The extensible strut which1 is; shownr in the drawing constitutes the preferred form or embodiment of. the invention. vIt isillustratedA in connection with, andv as: forming; a part of, a

` music stand andcomprisesa vertically: extending tubularV lower; Iriember L: a vertically extending1 tubular .upper member 8,A and. releasable means 9 on the upper end of the lower member for locking the upper member against downward displacement with respect to the lower member after it has been shifted or slid relatively to the latter.

The tubular member 'I is preferably formed of sheet metal stock and is circular in cross section and uniform in diameter throughout its length. The upper end of the lower member 1 is open and the lower end is provided with a plurality of depending eqludistantly spaced legs I whereby the music stand with which the strut is associated is maintained in an upstanding position.

The vertically extending tubular upper member 8, like the lower member l, is preferably formed of sheet metal stock. It is circular in cross section and fits slidably within the lower member. The external diameter of the upper member is but slightly less than the internal diameter of the lower member in order that the upper member is slidable freely with respect to the lower member while at the same time it is not so loose that it is subject to pronounced lateral displacement with respect to the lower I member. The upper end of the upper member 8 is crimped and bent rearwards to form a tting I I for slidably receiving a socket equipped clip I2 on a conventional or standard music rack I3. When the rack is in connected relation with the fitting II it may be raised or lowered to any desired extent within a predetermined range by sliding the tubular upper member 8 upwards .or ldownwards with respect to the tubular lower downwards from the tting II to the lower end of the upper member 8 and has a twofold purpose in that it serves to reenforce the upper member against twisting and transverse bending and coacts with the releasable locking means 9 at the upper end of the tubular lower member I. The upper member 8 is preferably the same in length as the lower member in order that the strut as a whole may be extended to a maximum extent. The inner or bottom portion .of the inrolled rib I4 is provided with a longitudinal series of equidistantly spaced transversely extending circular holes I5. Such holes extend completely through the innerportion of the rib and are preferably spaced but a small distance apart.

The releasable locking means 9 on the upper end of the vertically extending tubular lower member I operates or functions as hereinafter described and comprises a bracket I6, a lever type detent II in pivotally connected relation with the bracket, and a V-shaped wire spring I8 for urging the detent into its locking or operative position. The bracket I6 is in the form of a one-piece sheet metal stamping and consists of a vertically elongated housing part I9 and a pair of attaching parts 2G. The housing part of the bracket is located adjacent the rear portion of the upper end of the tubular lower member 'I and embodies a pair of vertically extending laterally spaced parallel side walls 2l, an outer wall 22, a top wall 23 and a bottom wall 24. The outer wall 22 extends between, and serves to space apart, the side walls 2l and has its side margins joined to the outer side margins of the side walls. The top wall 23 extends across and is. joined to the upper end margins of the side and outer walls of the housing part I9 of the bracket 4 I6. The bottom wall 24 extends across and is joined to the lower end margins of the side and outer walls and defines with the latter and the top wall 23 a compartment 25, the inner portion of which opens onto the rear portion of the upper end of the lower member 1. Said rear portion of the upper end of the lower member 'I is provided with a vertically elongated cutout 26 in order that the compartment 25 is in communication with the interior of the upper end of the lower member 'I. As best shown in Figure 3 the bottom wall 24 is of less depth than the top wall and hence its inner margin is spaced from the lower inner corners of the side walls 2I of the bracket housing part I9 and forms a bottom opening 25 leading to the compartment 25. The attaching parts 20 of the bracket are joined to, and extend forwards from, the inner side margins of the side walls 2I of the housing part I9 and extend around the side portions of the upper end of the tubular lower member l of the strut. They are arcuate in cross section and are spot welded or otherwise xedly secured to the adjacent portions of said upper end of the lower member '1. The lever type detent I'I is positioned in an upstanding manner adjacent the rear portion of the upper end of the tubular lower member '1. It is vertically elongated and is preferably in the form of a one-piece sheet metal stamping. As shown in Figure 6 the sheet metal stock of which the detent is formed is bent centrally and longitudinally in order that the detent is of U-shaped cross section and cmbodies a pair of substantially parallel spaced apart sides 2'I. The upper end of the detent extends into the compartment 25 via the opening 25a as shown in Figure 3. The detent is arranged so that the free side margins of the sides thereof project rearwards. The central portions of the rear side margins of the detent sides 2'I are provided with opposed or horizontally aligned notches 28 which are in intertting relation with the inner margin of the bottom wall 24 of the bracket housing part and form therewith a pivotal connection whereby the detent is permitted to tilt or rock laterally with respect to the upper end of the tubular lower member 1. The upper ends of the detent sides 21 are crimped together to form a pointed tooth 29 which extends through the cutout 26 into the inrolled longitudinally extending rib Id on the tubular upper member 8 and is adapted when the detent is swung in a counterclockwise direction as viewed in Figure 3 when. one of the holes I5 is disposed in alignment therewith, to become seated in the hole and thus lock the upper member against downward displacement with respect to the lower member 'I. The tooth 29 functions in the manner of a one-way clutch in that it permits the upper member 8 to be slid freely upwards with respect to the lower member 'I without interference on the part of the detent. When the upper member 8 of the strut is slid upwards the tooth 29 is cammed out of seated relation with the adjacent hole i5 thus causing the detent I1 to tilt or rock in a clockwise direction as viewed in Figure 3 and into an inoperative position wherein it releases the upper member. However, when the upper member is brought to rest while one of the holes I5 is in alignment with the tooth 29 the tooth, as heretofore pointed out, seats within the hole and thus locks the upper member against downward displacement with respect to the lower member 1. When it is desired to release the lever type detent II in order to lower the upper member 8 the lower end of thedetent is swung inwards towards the lower member 1. Such swinging movement on the part of the lower end of the detent eiects withdrawal of the tooth 29 from the adjacent hole I5 and thus renders the tooth ineffective to prevent downward sliding movement of the upper member 8 with respect to the lower member 1. The lower end of the lever type detent I1 is exteriorly disposed with respect to the housing part I9 of the bracket I6 and serves as a nger piece whereby the detent l1 may be readily gripped in connection with swinging thereof into its inoperative position. By reason of the fact that the tooth 29 is disposed within the rib I4 regardless of whether it is in its operative or inoperative position it coacts with the rib to hold the tubular upper member 8 against turning or rotation with respect to the tubular lower member 'I. The V-shaped wire spring I 8 of the releasable locking means 9 serves to urge the tooth 29 on the upper end of the lever type detent in the direction of the holes I in the bottom of the inrolled rib I4. It is disposed within the housing part I9 of the bracket I6 and has one leg thereof positioned between the upper ends of the detent sides 2'I and its other leg in abutment with the outer wall 22 of said housing part I9, as shown in Figure 3.

When it is desired to extend the strut in order to elevate the rack I3 the tubular upper member 8 is merely slid upwards with respect to the lower member 'I. During upward sliding of the upper member the lever type detent I'I is cammed into its inoperative position as hereinbefore pointed out and the tooth 29 at the upper end of the detent snaps past the holes I5 in the bottom of the inrolled rib I4. As soon as the upper member is brought to rest after upward sliding to the desired extent the spring I8 swings the tooth 29 of the detent into its operative position wherein it is in seated relation with the adjacent hole I5 and serves positively to lock the upper member against downward displacement with respect to the lower member. Should the upper member be brought to rest at a point Where there is no hole I5 opposite the tooth the tooth will, as a result of frictional engagement with the rib I4, yieldingly hold the upper member against downward sliding movement. However, should the upper member be slid downwards to a limited extent until one of the holes is in opposed relation with the tooth 29 the tooth, as a result of the action of the spring I8, will snap into the hole and thus form a lock whereby the upper member is positively held against downward sliding movement with respect to the lower member 'I. When it is desired to lower the upper member 8 the lower end of the lever type detent I1 is swung inwards as herein-before described in order to withdraw the tooth 29 from seated relation with the adjacent hole I5. As soon as the tooth is withdrawn from the adjacent hole the upper member 8 is released and hence may be slid downwards to any desired extent.

The herein described extensible strut eiectively and efficiently fulfills its intended purpose and because of the construction and design of the releasable locking means 9 it may be extended with facility. Because of the construction of its component parts the strut is capable of being produced at a low and reasonable cost.

Whereas the strut has been described in connection with, and as forming a part of, a music stand it is to be understood that it has other capabilities of use. It is also to be understood that the invention is not to be restricted to the details set forth since these may be modied within the scope of the appended claim without departing from the spirit and scope of the in- Vention.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

As a new article of manufacture, an extensible strut comprising a cylindrical vertically extending tubular lower member with a cutout in its upper end, a substantially cylindrical vertically extending upper member slidably mounted within the lower member and provided with a longitudinal groove in alignment with the cutout, a bracket connected to the upper end of the lower member and embodying a housing part shaped to form a compartment with the inner portion thereof open and in communication with said cutout, consisting of top, outer, side and bottom walls, and having an opening in the inner portion of its bottom wall, an upstanding lever type detent of U-shaped cross section having the upper end thereof extending into the compartment via said opening and provided with a ratchet type tooth extending into the groove in the upper member and coacting therewith to hold the two members against relative rotation, said detent having the central portions of its sides notched and in such interfitting relation with the bottom wall of the bracket housing part as to form a pivotal connection whereby the detent may be rocked into and out of an operative position wherein said tooth engages the groove dening portion of the upper member and serves to hold said upper member against downward sliding movement with respect to the lower member, and a V-shaped wire spring disposed wholly within the housing part of the bracket, having one leg thereof fitting against the outer wall of said housing part and its other leg disposed within and abutting against the upper end of the detent, and serving to urge the detent into its said operative position.

ROBERT G. BODE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS

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