US2660140A

US2660140A - Vibration isolating means for sewing units

Info

Publication number: US2660140A
Application number: US162783A
Authority: US
Inventors: John G Attwood
Original assignee: Union Special Machine Co
Current assignee: Union Special Machine Co
Priority date: 1950-05-18
Filing date: 1950-05-18
Publication date: 1953-11-24
Anticipated expiration: 1970-11-24
Also published as: NL154734C; FR1023932A; BE502459A; DE869898C; GB688800A

Description

Nov. 24, 1953 Filed May 18, 1950 J. G. ATTWOOD VIBRATION ISOLATING MEANS FOR SEWING UNITS 7 Sheets-Sheet l 1 FEG.I r

IN V EN TOR.

JOHN G. ATTWOOD ATTOR NEY Nov. 24, 1953 J. G. ATTWOOD 2,660,140

VIBRATION ISOLATING MEANS FOR SEWING UNITS Filed May 18, 1950 7 Sheets-Sheet 2 INVEN TOR. JOHN G. ATTWQOD ATTORNEY.

NOV. 24, 1953 T D 2,660,140

VIBRATION ISOLATING MEANS FOR SEWING UNITS Filed May 18, 1950 7 Sheets-Sheet 5 In N o o 9m Q w G g Q m w Q ENTOR.

' JOHN G. ATTWOOD ATTORNEY.

Nov. 24, 1953 J, a A O v 2,660,140

VIBRATION ISOLATING MEANS FOR SEWING UNITS Filed May 18, 1950 7 Sheets-Sheet 4 INVEN TOR. JOHN G. ATTWOOD ATTORNEY.

Noy. 24, 1953 G, ATTWOOD 2,660,140

VIBRATION ISOLATING MEANS FOR SEWING UNITS Filed May 18, 1950 7 Sheets-Sheet 5 INVEN TOR.

JOHN G. ATTWOOD ATTORNEY.

Nov. 24, 1953 .LG. ATTWOOD VIBRATICN ISOLATING MEANS FOR SEWING UNITS Filed May 1'8, 1950 7 Sheets-Sheet 6 INVENTOR. JOHN G. ATTWOOD I BY ATTORNEY.

Nov. 24, 1953 J. G. ATTWOOD 2,660,140

VIBRATION xsouamc MEANS FOR SEWING UNITS Filed May 18, 1950 7 Sheets-Sheet 7 7 lTb FIG. l4 v INVENTOR.

JOHN G. ATTWOOD ATTORNEYv supporting the sewing machine and Patented Nov. 24, 1953 UNITED STATES PATENT OFFICE VIBRATION ISOLATING MEANS FOR SEWING UNITS John G. Attwood, Oak Park, Ill., assignor to Union Special Machine Company, Chicago, 111., a corporation of Illinois Application May 18, 1950, Serial No. 162,783

11 Claims. (Cl.,11.2--258)' This invention relates to a sewing unit involvinvention is, however, applicable also to units 1 having sewing machines of other types.

Units of the character indicated, as heretofore constructed, have been highly satisfactory from most standpoints, but they have had a tendency to set up excessive vibrations when the sewing machines have been operated at high speeds. Such a vibration creates noise and is otherwise objectionable to the operator. At times it interferes .with the proper functioning of the machine. Prior attempts to eliminate such vibration have been only partially successful.

A primary object of this invention has been to provide a sewing unit of the foregoing character which may be operated at high speed without objectionable vibration. Toward this end a novel arrangement has been provided for mounting the sewing machine and the driving motor on the pedestal support.

Other objects, features, and advantages of the invention will appear from the detailed description of an illustrative form of the same which will now be given in conjunction with the accompanying drawings, in which:

Fig. 1 is a side elevational view of a sewing unit embodying the invention, a cover member for the driving motor being indicated in broken lines;

Fig. 2 is an enlarged detail View of certain of the parts in vertical section along the line 22 of Fig. 1;

Fig. 3 is a top plan view of the sewing unit with the cover member removed from the driving motor;

Fig. 4 is an enlarged detail view, in vertical section taken along the line 4-4 of Fig. 1, showing the means for securing the driving motor;

, in section, showing a handwheel associatedmth the motor drive; 7

various con- Fig. 8 is a detail view, in perspective, of a plate member forming part of the supporting structure,

a portion of the plate being broken away;

Fig. 9 is a horizontal sectional view through the cover member for the motor drive, the latter being omitted to disclose the supporting structure beneath the cover;

Fig. 10 is a side elevational view of the supporting structure at the upper end of the vertical column of the pedestal and the cover for the driving motor;

Fig. 11 is a detail view, partly in elevation and partly in section, showing one of the means for retaining the cover for the driving motor;

Fig. 12 is a plan view of a horizontal bracket member forming part of the pedestal support;

Fig. 13 and Fig. 14 are side and end elevational views, respectively, of a modified form of the support plate shown in Fig. 8; and.

Fig. 15 is an enlarged detail view, partly in section of a type of bolt member employed to isolate I vibrations.

,. tions for engaging the floor.

. tending sleeve II adjacent one end of the base member is arranged to receive the lower end of a tubular column I2 which is secured within the sleeve I I by suitable set screws I3. At the upper end of the column I2 there is similarly mounted a bracket member I4, having a collar portion bers I1.

secured to the column by set screws I5 and having a horizontally disposed, relatively flat portion arranged to support the parts to be hereinafter described. The form of the bracket arm I 4 is best illustrated in Fig. 12, in plan, and in Figs. 1 and 10 in elevation. The vertical position of the bracket member in relation to the floor may be varied slightly by adjusting the position of the 1 column I2 both in relation to the sleeve II and to the collar portion of the bracket arm.

On the upper surface of the bracket member I4 there is mounted a plate member I6 which is secured to member I 4 by a plurality of bolt mem- Six such bolt members are shown in Figs. 3 and 8. Each is of the form disclosed in Figs. 6 and 15. g It comprises an upwardly extending element Ila which passes through a suitable opening I8 through the plate and a downwardly of the bracket member I4.

,of any vibrations imparted to the plate l6.

has heen found that the provision of a plurality which projects fro and lid, respectively, which are firmly embedded in and held in assembled but spaced relation by means of an encasing cylindrical element He formed of a suitable vibration absorbin material, which is relatively soft and capable of yielding. It may suitably be formed of compressed felt or rubberorsynthetic resin or the like. Element He is seated in suitable counterbores in the under surface of member [6 and the upper surface of member I4. A nut applied to the upper end of the element Ila retains a washer 2 infirm engagement with the upper surface of the plate [6. A nut 23 applied tothe elementllb similarly retains a washer 24 firmly against the under surface of the horizontal portion of member M to complete the assembly and retain the members is and E6 in firmly united relation; The vibration absorbing elements ll'e serve to absorb and; pre; vent the transmission to the bracket member Hi It of such elements in the manner indicated, be-

tween two relatively fiat plate-like members, is

exceptionally effective for the elimination of noise and vibration.

To assist further in eliminating vibration of the supporting structure an whole the plate I6 is made relatively thick in' the region of the outer en of the bracket member 14. The thickened portion of the plate is indicated at25 inFi'gs. sand 6 If desired, the plate may be thickened to an even greater extent inthis area, as indicated in Fi'gsllO, 13' and r41 Thus a: downward b'ulge may befprovifded on the under; surface of the plate in substantially the same region in which an I the outer end er the tracker member; I4.

At its right end (Figs; 3, 9 and 1 3 the m 7 l6 extends laterally to form a reverse L-shape.

Theouter end of the laterally extendin branch of the L projejcts" downwardly, as shown at 26 in Figs. 6', l3 and 14, to provide a vertically disposed portion spaced slightlyfrom a face 2! of the bracket member It. Against an outer flat surface28 of extension 26 is abutted a correspondmg flat sur ace on the main frame 29 of the sewing machine forming partof the unit. A series of openings 30 extending through the portion- 26 of plate" member It ar ariahged to receive screws 3;} which have threaded engagement with openi n'gs 32 in theadiaeeht wen ofthe sewing machine frame 29'. A firm connection is thus pro 'vided' etween the" sew ng machinetime and the plate I 6 and these'part's mayhave metal to metal contact in yiewef the isolation, by means of the elements He, of any vibrations developed by the sewing machine. t t I As best shown in Figs. land 3, the sewing machine rre ie zsf eel hsesen upper horizontally dispqsedportion 33 adownwardly extending por- 34, and a fi ended work supporting arm 35 end of the work supporting arm 35 terminates beneath a needle head 'tffi which Drdjeots laterally from the es eeeht end of the part as. The onarsena of the sewing machine is generally simil r to that disclosed in the Christensenet a1.

Patent No. 1,741,095, granted an De mber 24,

5 9 s d. p ti I at an afigle to a ve iejal plane einZe'iMmg through the exact the: pa t 33 er the frame. Theouter ALL) details of construction and operation of the sewing machine form no part of the present invention, it is unnecessary to describe them more fully. A main operating shaft extends longitudinally of the portion 33 of the frame, as disclosed in said prior patents, and this carries at its outer end, which projects from the frame, a pulley 3'5.

Mounted on the upper surface of the plate [6 is an electric drive unit 38 comprising a motor 39 and aclutch ill. This power unit may be of the same general construction as the unit disclosed in the patentto Peets et al., No. 2,004,055, granted on June 4, I935. It involves an axially slidable sleeve carrying a shaft on which is mounted one member of a friction clutch and on which is also mounteda pulley 'll connected by a belt 32 with the pulley 31 of the sewing machine. As best in Fig. 7, the pulley 3! is splined to the end of the driven shaft 43 of the clutch. This shaft, however, is provided with a screw threaded portion 4%, extending beyond the outer face of the pulley l'l which carries an internally threaded portion c5 of asle'eve-like extension 46 of a handwheel 41. This h'andwheel is so positioned as to be readily accessible to the operator and eliminates the inconvenience of turning a combined handwheel and pulley, normally provided in the position of the pulley 31, for turning the main drive shaft of the sewing machine by hand.

In order; to permit adjustment of the power unit in relation to the plate member [6, for belt tightening purposes, elongated openings 48 are providedthrehgn the plate member (see Figs. 4, 8' and- 9'). These openings are arranged to receive bolts 49 having enlarged heads 50 cooperati'ng with the under surface of the plate member adjacent the openings. Each bolt has a nut 51, in threaded engagement with its upper end, arranged to be screwed tightly against a sleeve 52 which surrounds the bolt and at its lower end engages the upper surface of the plate member [5. Surrounding the sleeve 52 is a vibration abs'o'rbing sleeve 53 formed in two parts, upper and lower, of rubber or felt or other yielding material. Each of the parts of sleeve 53 has an outwere-1y ex tehcrhg flange arranged to cooperate with one of the faces of a foot 54 formed on the frame of the drivingu'nit. Washers 55 are preferably provided at the outer ends of the sleeve 53. The arrangement is such that when the nut 5| is tightened against the upper end of the sleeve 52, the flanges of the sleeve 53 will be squeezed sufficiently to retain the driving unit firmly inits set position.- It will be understood that when it is desired to adjust the driving unit in relation to plate member IS, the nuts 51 are loosened and the bolts 49 are caused to slide in one direction or the other along the openings 48. Upon tightening of the nuts 5| the power unit is firmly secured to the plate member [6 again. If desired, the vibration isolating elements 53 and the sleeve 52 may be omitted, since it has been found that the elements lle serve quite effectively to isolate any vibration imparted to the supporting plate It, whether derived from the sewing machine or the power unit. It is, however, preferred to eliminate the transmission of vibrations from the driving unit to the plate by the use of the sleeves.

In the base It] a pair of treadles 56 and 5! is provided for controlling various functions of the unit. 'Ireadle 55, for example, is adapted to lift I scribed, with a lubricant pump.

5 described. Treadle 51 is arranged to control the clutch of the power unit to determine at will when 1 the sewing machine is to be driven. Suitable connections from this treadle are also provided for operating a pump arranged to transfer lubricant from certain points to others within the sewing machine frame, as'will be explained hereinafter.

Referring to Fig. 5, the treadle 51 has downwardly extending supporting ears clamped to a rock shaft 58 suitably journaled in the base I0. The left end of this rock shaft is bent at right angles, as indicated at 59, and extends to a point beneath the lower end of the column I2. Here it is connected with a rod 60 which extends upwardly through the column. In a similar manner the treadle 56, which is pivoted on the base member by means of a pin 6|, carries a rod 62 adjacent its opposite end which extends to a point beneath the lower end of the column I2. Here it is connected with a rod 63 extending upwardly through the column.

Rod 60 has its upper end coupled by means of a block 60b with a parallel rod 60a (Fig. 1). The

latter is connected with the free outer end of a yoke 64 (Figs. 1 and 3) having a split collar 65 (Figs. 1 and 6) arranged to be clamped upon the inner end of a sleeve 56 forming part of the clutch of the power unit. As will be seen by reference to the Peets, et a1. patent, above mentioned, rocking of the sleeve 66 by a downward pull on the arm of yoke 64 will cause the sleeve to be shifted axially to engage the clutch and cause the pulley M to be driven. The connection between the yoke 64 and the rod a preferably includes a ring 61 secured to the yoke and extending inwardly therefrom. Rod 60a passes upwardly through this ring and carries a collar 68 cooperating with the under face of the ring. A spring 69 is compressed between the upper face of the ring and a washer I0 carried by the rod 60a and held thereon by an enlargement of the upper end thereof. It will be seen that in this way the arm 64 is normally held against the collar 68 but as the rod 60a is moved downwardly the yoke 64 isyieldingly urged downwardly but is not positively forced in this direction. After the clutch has been engaged the further movement of the treadle and corresponding downward movement of the

rods

60, 60a serves to compress the spring 69 to increase the pressure between the clutch faces. A spring II (Fig. 6), connected at one end with a rearwardly extending arm integral with the split collar 65 and at its other end with a hook or the like carried by the frame of the power unit, serves normally to rock the sleeve 66 and yoke 64 into their inactive positions in which the clutch elements are disengaged.

Another arm I2 (Figs. 1, 3 and 6) of the yoke 64 is connected, through means now to be de- A vertically disposed opening through the arm I2 slidably receives a pin I3 which carries a pair of centering springs I4. These cooperate at their inner ends with the opposite faces of the arm I2 and at their outer ends with collars 13a secured to the pin I3. At its lower end the pin I3 is connected through a universal joint with one arm I of a lever pivotally mounted, by means of a sleeve l6 integral with the lever; on a stud I'I carried by a lug I0 extending upwardly from the plate member I6. The universal joint connecting the pin I3 with the arm I5 comprises a socket element 13b at the lower end of the pin which receives a ball ele-,

ment 13c carried by the arm. The ball element may be positioned in either of a plurality of openings 15d in a bent-over branch of the arm15. This permits the ball element to be mounted in the position best suited for the particular adjustment of the power unit on the member I6. A downwardly extending arm I9 of the lever is connected by means of a rod or link with a piston rod 8| (Fig. 3) of a reciprocating pump 82. The latter may suitably be of the type disclosed in the patent to Smith, No. 2,430,370, granted November 4, 1947, and may be arranged to transfer lubricant from different points within the sewing machine frame to suitable reservoirs for distribution to the various parts requiring lubrication, all as fully set forth in said Smith patent.

Turning now to the rod 63 connected with the treadle 56, this, as best shown in Figs. 1 and 2. is connected at its upper end with an arm 63. Rod 63 passes through an opening in the arm 83 and carries a collar 84 above said arm having a spherical lower end arranged to engage the upper'surface of the arm. A sleeve 85 surrounding the rod 63 engages the under surface of the arm 83 and is held in such position by a collar 86 secured to the rod. A slight clearance is pro-' vided for the arm 83 between the collar 84 and sleeve 85 to permit the necessary relative movement between these parts. A spring 87 connected withthe outer end of the arm 83 and with the collar 86 serves to take up the play between the parts and holds the arm against the upper end of the sleeve 85. I

Arm 83 is integral with, or otherwise connected with, a sleeve 88 secured by a set screw or the like to a rock shaft 89 journaled in bearing lugs 90 and 9| (Figs. 1 and 3) extending upwardly from the upper surface of the support member I4. Another arm 92 (Figs. 2 and 3) extending rearwardly from the sleeve 60 has a spring 93 connected with its outer end, said spring having its opposite end attached to a small bracket 94 secured to the support member I4. This arrangement is such that the shaft 89 is urged in a counterclockwise direction (Fig. 2) and tends to urge the rod 63 upwardly. Upon depression of the treadle 56 and downward movement of the rod 63, shaft 89 is rocked in a clockwise direction (Fig. 2). This causes lifting of the presser bar of the sewing machine through connections of the type disclosed in the application of Norman V. Christensen and George Sauer, Serial No. 704,822, filed October .22, 1946, now Patent No. 2,511,047. dated June 13, 1950. These connections include an arm 95 secured to shaft 69 adjacent bearing lug 9|. Arm 95 is connected by a link 96 with an arm 91? mounted on the frame of the sewing machine and which is, in turn, connected by a link 98 with a presser bar lifting arm 99 mounted on the side of the needle head of the sewing machine.

It will be understood that the lever 91 in the foregoing linkage performs the same function as the bell crank lever 53 in the construction ofthe Smith patent above mentioned and the operation of the linkage is such as to bring about lifting of the presser bar I00, upon the depression of the treadle 56, in opposition to the spring IOI (Figs. 1 and3).

A cover is preferably provided for the power unit, this being best illustrated in Figs. 9, 10 and 11. The cover is indicated generally at I02 and it may comprise three sheet metal sections I03,

I04 and I05. The section Hi3 forms the top and 7 the: two: ends-,, these: three sections; being welded:v togetheii' along thesoverla-pping, edges, indicateddmFigs- Band 10. .Eorretaining the cover it? is; suitably provided with: three footv members formed by 'bracketi elements i l 06' welded or other- Wise'fsecured'to-the inner surfaceof the'cover at the; three; points shown, each bracket element havingsecured to it avertically disposed pin- Hi1. The latter may be welded or otherwise secured to. the side'of the bracket and-projects a suitable distance below the lower edge of the bracket and thelower. edge of the cover. Pins ID! are adapted to enter openings I08 provided in the support I member I4, as shown in Fig. 3. A small rubber sleeve: 109 ispreferably applied tothe projecting en'dwf eachofthe pins I01, asshown in-Fig. 11, to: preventthe transmission of vibrations from the support member to-the cover. These rubber sleeves, moreover, provideadequate friction for firmly retaining the cover, so-that no screws or boltsare required. An opening H0, provided in one wall of the member I03-of thecover and in the adjacent portion of the end. section I05, allows for the passage of the-driving belt 42 and also-portions of the connections from thetreadles to the sewing machine. An opening Ill provided centrally through the end wall of the section I as permits the application and removal of the cover over the hand wheel 41. The lower edge of section. 105 is also cut away sufficiently to accomm'odatethe adjacent portion of the member It.

It will be-understood that the sewing unit may be provided with a portion I I2 extending beyond the' wall of the cover I02 (Fig. 9) and this may carry a post H3 for supporting a thread stand. If desired, needle cooling means of the type disclosed'in the Christensen et-al. application Serial No. 704,822 may be provided and for this purpose the support member 14 is provided with an extension lhl having a horizontally disposed opening H therethrough. For further details as to the construction and mounting of the needle cooling means, reference may be had to the Christensen et a1. application hereinabove mentioned.

While an illustrativeembodiment of the invention has been disclosed in considerable detail, it will be understood that various changes may be made in the construction and'arrangement of the several parts without departing from the general principles and scope of the invention.

What I claim is:

1. In a pedestal mounting for a sewing machine and its driving means which comprises a base, a column extending upwardly from said base, and a laterally extending support member mounted on said column adjacent its upper end, the combination of a rigid plate-like member secured directly to the upper surface of said support member, said plate-like member being rigid throughout, vibration absorbing means interposed between said members, and means for securing the sewing machine and its driving means directly to said plate-like member.

2-. In a pedestal mounting for a sewing machine and its driving means which comprises a base, a

column extending upwardly from said base, and a laterally extending support member mounted on said column adjacent its upper end, the combination of a rigid plate-like member mounted on the upper surface of said support member, said platelike member being of integral construction and rigid throughout, a plurality of bolt means comprising screw threaded elements secured at their opposite ends to said members and having vibration absorbing elements interposed between said members said vibration absorbingelements; comprising small padssurrounding saidscrew threadedi elements: and serving to maintain said mem.- bers in spaced relation, and means. for securin the sewing machine and its driving meansdirectly' to said plate-like member.

3. In a pedestal mounting for a sewingmachine and its driving means which comprises a. base, a column extending upwardly from said base. and a laterally extending support member mounted on said column adjacent its upper end, the combination of a rigid plate-like member secured to the upper surface of said support. member, vibration absorbing means interposed between said members and arranged to prevent transmission. of vibrations there-between, said plate-like member having a portion projecting beyond the edge of said. support. member, means for securing the sewing machine to the projecting portion of said plate-like, member, and means for securing the driving means to the uppersurface of said plate-like member.

4. In a pedestal mounting fora sewing machine and its driving means which comprises a base, a column extending upwardly from said base, and-a laterally extending support member mounted on saidcolumn adjacent its: upper end, the combination of a rigid plate-like member, secured tothe upper surface of said support member, vibration absorbing means interposed between said, members and arranged. toprevent transmission of vibrations there-between, said plate-like member having a portion projecting beyond the. edge of said support member and extending downwardly over the edge thereof, the-plate-like member being substantially thickened at and adjacent said projecting portion, means forsecuring the sewing machine to the downwardly extending part of said portion, and means for securing the driving means to the upper surface of a non-thickened portion of said plate-like member.

5. In a pedestal mounting for a sewing machine and its driving means which comprises a base, a column extending upwardly fromsaidbase, and a laterally extending support member mounted on said column adjacent its upper end, the combination of a rigid plate-like member disposed over the upper surface of said support member, vibration absorbing means interposed between said members, said plate-like member being of substantially uniform thickness in a portion thereof overlying said support member and being thickened in both directions from the median plane thereof in a second portion, a pair of bolts carried by each of said vibration absorbing means in spaced relation for securing said members together said second portion projecting beyond the edge of said support. member and having a part extending downwardly over said edge, means for securing the sewing machine to said part, and

' recess in one member being alined with a recess in the other, vibration absorbing meansv seated in each alined pair of said recesses serving to retain the opposed surfaces of said members in spaced relation, a pair of bolts carried by each of said vibration absorbing means in spaced relation for securing said members together and means for securing the sewing machine and its driving means directly to said plate-like memher.

'7. In a sewing unit comprising a pedestal having a floor engaging base, a column extending upwardly from said base and a horizontally disposed support member at the upper end of said column, the combination of a carrying member extending over said support member and having a portion projecting beyond the edge thereof, vibration absorbing connections for securing said members firmly together, yieldable vibration absorbing means associated with said connections and interposed between said members for maintaining the same in spaced relation, a sewing machine secured to the projecting portion of said carrying member and having a work support below said support member, motor drive means connected with said sewing machine for operating the same, said motor drive means being mounted on said carrying member over said sup port member, and means for securing said motor drive means to said carrying member.

8. In a sewing unit comprising a pedestal having a door engaging base, a column extending upwardly from said base and a horizontally disposed support member at the upper end of said column, the combination of a carrying member extending over said support member and having a portion projecting beyond the edge thereof, vibration absorbing connections for securing said members firmly together, yieldable vibration absorbing means associated with said connections and interposed between said members for maintaining the same in spaced relation, a sewing machine rigidly secured to the projecting portion of said carrying member and having a work support below said support member, motor drive means mounted on said carrying member over said support, said drive means and said sewing machine having pulleys disposed in the same vertical plane, a belt connecting said pulleys, and vibration absorbing means for adjustably securing said drive means to said carrying member and enabling relative adjustment thereof to vary the tension of said belt.

9. In a sewing unit comprising a pedestal having a floor engaging base, a column extending upwardly from said base and a horizontally disposed support member at the upper end of said column, the combination of a carrying member extending over said support member and having a portion projecting beyond the edge thereof, vibration absorbing connections for securing said members firmly together, yieldable vibration absorbing means associated with said connections and interposed between said members for maintaining the same in spaced relation, a sewing machine secured to the projecting portion of said carrying member and having a work support below said support member, motor drive means connected with said sewing machine for operating the same, said motor drive means being mounted on said carrying member over said support member, means for securing said motor drive means to said carrying member, treadle means mounted on said base, and yielding connections from said treadle means to said sewing machine and to said motor drive.

10. In a sewing unit comprising a pedestal having a floor engaging base, a column extending upwardly from said base and a horizontally disposed support member at the upper end of said column, the combination of a carrying member extending over said support member and having a portion projecting .beyond the edge thereof, vibration absorbing connections for securing said members firmly together, yieldable vibration absorbing means associated with said connections and interposed between said members for maintaining the same in spaced relation, a sewing machine secured to the projecting portion of said carrying member and having a work support below said support member, motor drive means mounted on said carrying member over said support, said drive means and said sewing machine having pulleys disposed in the same vertical plane, a belt connecting said ulleys, means for adjustably securing said drive means to said carrying member and enabling relative adjustment thereof to vary the tension of said belt, treadle means mounted on said base, and yielding connections from said treadle means to said motor drive means and said sewing machine including a rock member mounted on said drive means and a rock shaft carried by said support member.

11. In a sewing unit comprising a supporting structure having a horizontally disposed support member, the combination of a carrying member extending over said support member and having a portion projecting beyond the edge thereof, a plurality of bolt members for securing said support member and said carrying member firmly together, each of said bolt members comprising a pair of screw threaded elements having enlarged heads and a coupling element formed of yieldable vibration absorbing material for retaining said screw threaded elements in assembled but spaced relation, said vibration elements absorbing material being positioned between said support member and said carrying member and keeping the same in spaced relation, a sewing machine secured to the projecting portion of said carrying member, a power unit carried by one of said members and connected with said sewing machine for driving the same.

JOHN G. ATTWOOD.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,641,602 Roberts Sept. 6, 1927 2,089,383 Kroener Aug. 10, 1937 2,241,026 Wylie May 6, 1941 2,511,047 Christensen et a1. June 13, 1950