US1717648A - Car truck - Google Patents

Description

June 18, 1929.

ill

D. S. BARROWS CAR TRUCK Filed March 1927- 4 Sheets-Sheet l June 18, 1929. BARROWS 1,717,648

CAR TRUCK Filed March 8, 1927 4 Sheets-Sheet 2 gnvaufoz June 18, 1929. D. s; BARROWS CAR TRUCK 4 Sheets-Sheet 5 Filed March 8, 1927 June 18, 1929. BARROWS 1,717,648

CAR TRUCK Filed March 8, 1927 4 SheetsSheet 4 Patented Jime 18, 1929.

DONALD S. BABBOWS, OF ROCHESTER, NEW YORK.

CAR TRUCK.

Application filed March 8, 1927. Serial No. 173,703.

This invention relates to railway car trucks and, more particularly, to cast frames therefor formed to provide room for an increased number of springs and constructed so as to have correspondingly increased strength.

The principal objectof my invention, generally considered, is the provision of car trucks formed with side frames in which the bolster guide columns, at the intermediate portions thereof, are formed with stop portions extending toward each other and adapted to limit downward movement of the bolster, said stop portions being alternatively formed with girder members connecting the side edges thereof providing room thereabove for the reception of the bolster and room therebeneath for receiving the associated spring plank, that portion of the tension member, beneath the bolster opening, being laterally widened and adapted for supporting six spring units, said units being arranged in two transversely disposed rows of three spring units, the intermediate spring units of each of said rows being positioned along the longitudinal 'center line of the frame and, when the girder portions are employed, being preferably arranged between the same.

An object of my invention is the provision of a cast side frame formed with a compression member, a tension member, bolster guide columns spacing intermediate portions of said members with the intermediate portions of said bolster guide columns joined by a bridge preferably formed as two channels with the flanges inwardly disposed and tied together at their ends, said bridge portion being so positioned that the associated bolster is insertable thereabove and the spring plank therebeneath.

Another object of my invention is the provision of side frame construction adapted for use with an increased number of spring units, said units, however, being so arranged that a standard A. R. A. spring plank may be employed therewith.

A further object of my invention is the provision of a side frame and bolster construction involving the use of removable flanged wear blocks to'lock the bolster in place with respect to the side frame, thereby obviating the necessity of lowering the bolster to a wider portion of the bolster opening for insertion and removal thereof with respect to said frame.

A still further object of my invention is the provision of a side frame and spring plank arrangement involving the use of a lower spring plate which functions, not only to properly position the bolster springs, but also to lock the spring plank in proper relation with respect to the frame.

Other objects and advantages of the invention relating to the particular arrangement and construction of the various parts will become apparent as the description proceeds.

Referring to the drawings illustrating my invention, the scope whereof is defined by the appended claims:

Figure 1 is a partial side elevation of a truck illustrating one embodiment of m invention, a portion of a side frame thereo and associated parts being shown in central longitudinal section. v

Figure 2 is a horizontal sectional view taken on the line 2-2 of Figure 1 looking in the direction of the arrows.

Figure 3 is a vertical sectional view on the line 3-3 of Figure 1 looking in the direction of the arrows.

Figure 4 is a horizontal sectional view on the line 44 of Figure 1 looking in the direction of the arrows.

Figure 5 is a partial side elevation of a side frame illustrating another embodiment of my invention, a portion thereof being shown in central longitudinal section, the associated bolster, spring plank and springs being indicated diagrammatically by dot and dash lines.

Figure 6 is a horizontal sectional view on the line 66 of Figure 5 looking in the direction of the arrows.

Figure 7 is a vertical sectional view on the line 7-7 of Figure 5 looking in the direction of the arrows.

Figures 8 and 9 are vertical sectional views on the correspondingly numbered lines of Figure 5 looking in the direction of the arrows.

Referring to the drawings in detail, like parts being designated by like reference characters, and first considering the embodiment of my invention illustrated in Figures 1 to 4, inclusive, a truck side frame 1 of the cast type is partially illustrated although it will be obvious that some of the advantages of my invention may be secured when using frames of other than cast construction. Said frame 1 comprises a compression member 2, a tension member 3, and bolster guide columns or strut portions 4, spacing intermediate portions of said compression and tension members, leaving a bolster or window opening 5 therebetween. The compression and tension members are joined at their ends (not shown) and may be formed with integral journal boxes (not shown) or be adapted for connection with a desired form of journal box, as will be understood.

For rigidifying the construction of the frame and, at the same time, providing an area for properly supporting an increased number of spring units, the tension member 3, between the bolster guide columns 4, is laterally widened and provided with an upper web 6 serving for the support of the bolster springs 7 which are preferably arranged as two longitudinally spaced rows of transverse] disposed spring units, each row, in the em odiment illustrated, comprising three spring units 8. Each spring unit comprises a main or outer coil 9 with or without an inner or supplemental coil 10. In the embodiment illustrated, the extreme spring units of each row are provided with inner coils 10, whereas the intermediate spring units are not provided with such inner coils. It is obvious, however, that the number of spring units provided with inner coils depends upon the capacity desired under the particular circumstances.

In order to provide for the assembly of the spring units prior to placing the same in proper position with respect to the truck, upper and lower spring plates 11 and 12, respectively, are employed, each of said spring plates being formed with spring positioning collars 13. Those collars, which are to position double coil spring units, are preferably formed of a corresponding relatively small size and those, which are to position single coil spring units, are preferably formed of a corresponding larger size for properly positioning the outer coils 9, whereby there will be no danger of improperly arranging the spring units as it will be impossible to assemble the double coil spring units about the coils intended for the single coil units and, if a single coil unit were arranged about a coil intended for a double coil unit, it would obviously not function in the desired manner.

Each spring plate, in the embodiment illustrated, is formed with a pair of bosses 14, those on the spring plate 11 extending downwardly and those on the lower plate extending upwardly and in vertical alinement with those on the upper plate. Said bosses 14 are centrally apertured and adapted for receiving retaini bolts 15, as illustrated, whereby said spring units may be assembled and arranged under any desired initial tension prior to insertion for supporting the associated bolster 16.

The upper sprin plate 11 may be con, veniently formed 0 pressed metalvand provided with substantially conical positioning bosses 17 adapted for reception in corresponding depressions or pockets 18 in the bolster. The lower spring plate 12, however, is preferably of cast construction and provided with downwardly extending collars or bosses 19 adapted for reception in corresponding pockets 20 formed in the web portion 6 of the tension member. The associated spring plank 21 is provided with. registering apertures 22 adapted for the reception of the collars 19 on the spring plate 12, whereby said spring plank is locked in proper relation with respect to the associated side frame 1. One construction for permitting the reception of the spring plank 21 between the spring plate 12 and the web 6 of the tension member is illustrated particularly in Figure 3 where the web 6 is formed with a downwardly offset portion 23 providing the proper space between the spring plate 12 and the web 6 for receiving the ends of the spring plank 21 and particularly the web 24 thereof. It is obvious that the length of the spring plank may vary within wide limits, the construction of the web 6 being correspondingly modified and, if desired, it may, therefore, be formed of standard length and, inasmuch as the springs supported thereon are only two in line longitudinally of the frame, the width of the spring plank 21 may also be standard, as will be further explained in connection with the following modification.

Extending inwardly from the bolster guide columns and overlying the sides of the spring plank 21 are abutment or stop portions 25, said portions 25 being adapted to limit downward movement of the bolster 16 and save the springs from being compressed solid. Said sto portions 25 also partially divide the b0 ster opening 5 into an upper part especially adapted for receiving the bolster and a lower part adapted for receiving the spring plank. Inasmuch as the lower part of the bolster opening is not wider than the upper part and the bolster is also not adapted for downward moveme'nt beyond the stop portions 25, removable locking means 26 are provided for said bolster. In the present embodiment, the locking means 26 are formed with outwardly extending lugs or guide portions 27 with inner faces correspondingly bevelled to embrace and cooperate with the bevelled sides of the bolster guide columns 4 and inwardly extending flange portions 28 receivable between the cooperating flange portions 29 on the bolster. The lower portions of the locking blocks 26 are preferably flared to provide base portions 30 and thesides of the bolster are correspondingly formed, whereby said blocks may be insertable from beneath to lock the bolster in proper position with respect to the side frame. Of course, these locking blocks 26 are preferably inserted before the application of the spring plate 11 and springs 7 and, after the bolster 16 is locked in place, said spring plate and springs or the whole nest of springs, assembled as before described, may be properly positioned as illustrated.

In order to rigidify the connection between the bolster guide columns 4 and the tension member 3, the lower portions of said. guide columns merge into longitudinally extending webs 31 which form outward continuations of the sides of the abutments or stop portions 25 and continue outwardly to finally merge with the tops of the inclined portions 32 of.

the tension member 3 at substantially the elevation of the top of the stop members. The webs 31 continue downwardly substantially in line or slightly inwardly of the inner edges of the bolster guide columns 4 to meet the top of the tension member 3 substantially at the junctions between the horizontal and inclined portions. The bolster guide columns are preferably braced transversely with res ect to the tension member by downwardly aring gusset or rib portions 33. The top edges of the webs 31 are preferably reinforced by inwardly extending ribs or beading 34 which continue outwardly on a slight curve, as illustrated, to merge with the corresponding beading on the tops of the side flanges 35 of the inclined portions 32 of the tension member.

The inclined portions 32 of the tension member are generally channel-shaped in cross section as shown most clearly in Figure 4. As they extend downwardly and inwardly toward the bolster guide columns, however, the flanges 35 thereof preferably diverge slightly to increase the width of the member to correspond more nearly with the relatively great width of the upper web 6 of said tension member. In order to save weight, the lower or web ortion 36 of the tension member is preferably omitted from a point outwardly of and adjacent to the bolster guide colunms to a point beneath said guide columns where the side flanges or walls 35 are joined by transverse connecting walls 37, rigidified at their lower edges by short web portions 38. From a consideration of Figure 1 particularly, it will be seen that the Webs 37 preferably slope downwardly and outwardly and the webs 38 extend inwardly therefrom and function as cross bracing webs. The omission of the web 36 beneath the bolster opening and guide columns is compensated for, not only by beading the edges of the apertured portions of the web 36 as indicated at 39, but by the upper web or spring supporting portion 6 o the tension member which, at the junction with the bolster guide columns, is deflected upwardly and outwardly in line with the tension member for a short distance as indicated at 40.

On account of the transverse spacing of the six unit nest of sprin s, the spring supporting web .6 is wider t an it is long, thereby web portion 6, thereby forming e ective sup ports for the same. In order to save weight without materially decreasing the strength of said reinforcements and, at the same time, provide for core-removal, an aperture 42 is preferably provided in the outer wall of each reinforcement 41.

For pro erly supporting the web 6 between the anges 35, the webs forming the reinforcements 41 are preferably continued at reduced depth to form connecting webs 43, extending beneath the two rows of s rings 7. For tying the lower edges of the anges 35 together substantially midway between the holster guide columns, a substantially inverted T-shaped connecting portion 44 is preferably provided.

The construction before described is adapted to permit the bolster to be shimmed with straight pieces of wood between the top of the spring plate 11 and the bottom of the bolster. Although the spring plate has been described as provided with locating bosses 17, such bosses may be omitted, thereby giving a flat surface upon which the shims may be ap lied.

n account of-the removable flanged wearing pieces 26 for holding the bolster in place and their special shapes enabling them to be moved around with minimum necessary clearances, said \vearingportions can be readily moved to inoperative positions, whereby the bolster can be removed without taking out any other part of the truck except a portion of the nest of springs. On account of the locking of the spring plank in position by the separate preferably malleable iron spring seat or plate 12 by means of bosses or hollow plugs 19 passing through the spring plank holes 22 and into suitable pockets in the top web of the frame, it is possible to remove the spring plank by simply lifting the spring seat high enough to disengage the plugs depending from its under surface. In addition to the pockets 20 in the top web of the frame for receiving the spring plate plugs 19, said frame is preferabl lightened by the provision of longitudinaliy elongated apertures 45 in the web 6, said apertures being preferably s aced, as illustrated,

construction, thebottom portion of the rein forcement 41 may be provided with an aperture 46 preferably similar in outline to the aperture 45 but inwardly spaced with respect thereto, as illustrated.

Although my invention is not so limited, I preferably employ standard A. R. A. springs spaced a standard distance apart, that is, both the outer coils 9 and the inner coils 10 are preferably of standard A. R. A. dimensions. The side frame illustrated in the present embodiment is dimensioned to correspond with that of fifty-five ton capacity for which the A. R. A. nest of springs comprises four double coil spring units. It will, therefore, be seen that, as the arrangement here disclosed provides for six of said spring units, the normal capacity may be increased fifty percent if desired. Under ordinary circumstances, however, the extreme transversely positioned spring units would be double coil while the intermediate spring units or those positioned on the longitudinal center line of the frame would be single coil spring units as illustrated. It will, therefore, beseen that a large increase in spring capacity is provided While permitting the employment of standard A. springs and a standard A. R. A. spring plank.

Referring now to the embodiment of my invention illustrated in Figures 5 to 9, inclusive, a side frame is there shown which is substantially identical with thatof the first embodiment except that, instead of merely having stop or abutment portions 25 extending inwardly toward each other from the bolster guide columns 4*, there are provided bridge or strut portions 47 extending between the sides of the abutments or stops 25 and spaced a suflicient distance apart to permit the reception of the intermediate or centrally disposed spring units 8. These bridge or strut portions 47 are preferably channel-shaped in cross section with substantially vertical web portions 48 and inwardly extending flanges 49, said flanges being preferably braced to the web portions at a plurality of points by cross bracing webs 50. For strengthening the bridge members transversely of the frame, said flanges 47 preferably flare longitudinally and toward the longitudinal center line of the side frame 1 to merge with the abutments 25 adjacent said longitudinal center line, the outline of the edges of said flanges 47 preferably being concentric with the intermediate spring units 8, as shown most clearly in Figure 6, whereby said sprin units are adapted to be closely embraced between the bridge portions 47 and thus securely held in proper position. As in the preceding embodiment, six spring units of standard A. R. A. dimensions are preferably employed, said spring units being normally spaced longitudinall of the frameand spaced transversel cient amount flat so that the bolster can be shimmed with straight pieces of wood as mentioned in connection with the first embodiment. Although the spring arrangement is as in the first embodiment, that is, two spring units longitudinally and three transversely, it is obvious that certain advantages of my invention may be secured using other spring arrangements.

As in the previous embodiment, the bolster 16, shown only diagrammatically, may be provided with removable flanged wearing pieces which can be taken out without removing all of the springs or the spring plank as heretofore described. The compression member 2 and the tension member 3 may correspond generally with that of the first embodiment except that the tension member is preferably slightly modified to provide for the reception of a longer spring plank as will now be described.

Referring now particularly to Figure 7, it will be seen that there is shown a spring plank 21 of standard A. R. A. dimensions so that, inview of the increased width of the spring supporting web 6, said spring plank stops short of the extreme outer edge thereof. Said plank, however, is not only of standard A. R. A. size but is preferably provided with four squaring apertures 22 adapted to receive the normal A. R. A. squaring lugs which, in the present embodiment, are omitted and, in place thereof, four normally spaced pockets 20 of a size corresponding with the apertures 22 are provided. For locking the spring plank 21 in place with respect to the side frame, the lower spring plate 12 is formed with four hollow plugs or collars 19 depending from the lower surface thereof and spaced to correspond with the spacing of the apertures 22 and the pockets 20 so that the spring plank is locked in place by merely placing it with the apertures therein registering with the'pockets 20 in the frame and the spring plate 12 placed thereover with the plugs fitting through the apertures 22 into the pockets 20 in the frame, thereby locking the plate, plank and frame in squared relation.

In order to compensate for the distance between the bottom of the spring plate 12 and the top of the spring supporting web 6, the top of said web may be offset as in the first embodiment or, alternatively, the spring plate 12 may be formed with ribs 51 depending from the bottom thereof to meet the top of the web 6". The top of the spring plate 12 may be formed with spring locating collars as m the first embodiment. However, as an alternative, the spring locating collars 13 of the present embodiment are desirably adapted to surround the outer coils of the spring units rather than be surrounded by the corresponding coil thereof. Such a construction, therefore, gives a spring plank with upstanding flanges at the edges thereof, as illustrated particularly in Figure 7. On account of the provision of the bridge portions 47, not only are the springs 7 more widely spaced transversely of the frame but the pockets provided by the upstanding flanges 13" are correspondingly spaced as will be understood. Except as specifically described in connection with the present embodiment, the construction thereof may correspond substantially with that of the first embodiment.

From the foregoing disclosure, it will be apparent that I have devised a side frame with associated spring plank, bolster and bolster springs allowing for increased spring capacity while not radically changing the dimensions of any of the parts and permitting the use of a standard A. R. A. spring plank and springs. When employing the connecting bridge or strut 47 between the intermediate portions of the bolster guide columns, the frame is greatly strengthened without materially increasing the weight thereof and, at the same time, the springs are protected from being compressed solid, normal compression thereof, however, being permitted. On account of increasing the width of the tension member adjacent the center while splitting the bottom web thereof, a large increase in transverse strength is provided without material increase in weight. By continuing the web portion 31 outwardly to the inclined portions of the tension member from the abutments and, if used, from the brid portions 47, provision is made for the su stantially direct transmission of stresses between said bridge portions and the corresponding inclined portions of the tension member.

Having now described my invention, I claim:

1. A side frame comprising a compression member, a tension member, struts interposed therebctween and spaced to leave a bolster opening, and connecting means extending between intermediate portions of said struts above said tension member and comprising transversely spaced channel portions.

2. A side frame comprising a compression member, a tension member, bolster guide columns positioned therebetween and spaced to leave a window opening, the intermediate portions of said bolster guide columns being connected by a longitudinally extending bridge portion of less width than and spaced, for its entire length, from the tension member.

3. A side frame comprising a compression member, a tension member spaced at intermediate portions thereof by bolster guide columns leaving a window opening therebetween, that portion of the tension member, beneath the window opening, being laterally widened for supporting bolster springs, and

a bridge portion connecting said bolster guide columns above said laterally widened portion of the tension member and comprising laterally spaced portions permitting the insertion of a plurality of longitudinally disposed bolster springs therebctween.

4. A side frame comprising compression and tension members spaced at intermediate portions by bolster guide columns leaving a window opening therebctween, said window opening being divided into an upper portion adapted for the insertion of a bolster and a lower portion adapted for the reception of a spring plank by a member connecting intermediate portions of said guide columns.

5. A side frame comprising a compression member, a tension member, struts interposed therebetween and spaced to leave a bolster opening, stop portions extending toward each other from intermediate portions of said struts leaving room thereabove for the insertion of the bolster and adapted to limit downward movement thereof, the opening therebeneath being of a size suflicient for receiving an associated spring plank.

6. A side frame comprising acompression member, a tension member, bolster guide columns interposed between said compression and tension members and spaced to leave a window opening therebctween, those portions of the tension member, beyond the bolster guide columns, extending diagonally upward and outward to join the compression member adjacent the ends thereof, and girder means connecting intermediate ortions of said bolster guide columns and ormed as a plurality of channel sections with inwardly extending flanges.

7. A side frame comprising a compression member, a tension member, bolster guide columns positioned therebetween and spaced apart to leave a window opening, said window opening comprising an upper portion adapted to receive an associated bolster and a lower portion for receiving an associated spring plank, said guide columns being provided with projections overlying the opening for receiving the spring plank and underlymg the opening for the bolster for limiting downward movement thereof.

8. A side frame comprising a compression member, a tension member, struts interposed therebetween and spaced to leave a bolster opening, said tension member being formed with a laterally widened upper web beneath the bolster opening for supporting a nest of springs of increased width, the tension member, as a whole, gradually increasing in width from the ends thereof toward that portion beneath the bolster opening, said tension member, at the ends, being generally channel-shaped in cross section, the bottom web of said member, however, being split adjacent the bolster guide columns and continued under the bolster opening with a relatively great separation between the parts of said web, whereby increased transverse strength of the tension member is secured without material increase in the weight thereof.

9. A side frame comprising a compression member, a tension member, bolster guide columns interposed therebetween and spaced to leave a window opening, said tension member, beneath the window opening, being formed with an upper Web laterall widened for supporting a nest of springs 0 increased width, said tension member, adjacent the ends thereof, being generally channel-shaped in cross section, and increasing in width and divided into two spaced sections, angular in cross sect-ion, where it passes beneath the supporting web, said web, beyond the angular portions of the tension member, being braced with respect thereto b hollow extensions between the upright fianges of the tension member and the underside of said we 10. A side frame comprising a compression member, a tension member, bolster guide columns positioned therebetween and spaced .to leave a bolster opening, the intermediate portions of said bolster guide columns being formed with inwardly extending abutment or stop portions adapted to limit downward movement of the bolster and means for rigidifying the connection between the lower portions of the bolster guide columns and the tension member comprising longitudinally extendin webs forming outward continuations of t e sides of the stop portions extending to merge with the tops of inclined end portions of the tension member at substantially the elevation of the tops of the stop members.

11. A side frame comprising a compression member, a tension member, struts interposed therebetween and spaced to leave a bolster opening, a bridge ortion connecting intermediate portions 0 said struts and spaced for its full length from the top and bottom of said bolster and means for transmitting force substantially directl to inclined portions of the tension mem r comprising longitudinally extending webs formmg outward continuations of the bridge portions and extended to merge with the tops of the inclined portions of the tension membar at substantially the same elevation.

12. In a car truck, incombination, a side frame formed with compression and tension members, spaced at intermediate portions .by bolster gu de columns, leavin a window opening therebetween, the tension member, beneath" the windowopening, being laterally widened for supporting a nest of springs of increased width, a spring plank supported on said spring seating portion and formed of standard A. R. A. dimensions with standard A. R. A. squaring lug apertures, a spring plate positioned on said spring plank and provided with means for positioning associated bolster springs, said spring plate being also formed with depending bosses adapted to register with the squaring apertures in the spring plank and pass therethrough into corresponding pockets in the spring plank seat portion of the frame for holding said plank in squared relation with respect thereto.

13. In a car truck, in combination, a side frame formed with a window opening and a spring plank seat portion underlying said opening, a spring plank positioned on said seat portion and formed with squaring apertures therethrough, the spring plank seat portion, beneath said apertures, being provided with registering pockets and a spring plate resting on said plank and formed with upstanding spring-positioning means and depending portions passing through the squaring apertures in the plank and into pockets in the seat portion for holding said plank in squared relation with respect to the frame.

14. In a car truck, in combination, a side frame formed with a compression member, a tension member, struts interposed therebetween and spaced to leave a bolster opening, said tension member being formed with an upper web laterally widened for supporting a nest of springs of increased width, and a six unit nest of springs supported by means of said u per web and arranged as two longitudinal y spaced transversely disposed rows'of spring units.

15. In a car truck in combination, a side frame formed with a compression member, a tension member, bolster guide columns disposed between intermediate portions of said members and spaced to leave a window opening, the tension member, beneath the window opening, being formed with a spring plank seating web laterally widened for supporting a nest of springs of increased width, a spring plank supported on said spring plank seat portion and a spring plate supported on said spring lank, said spring plank being of standard R. A. dimensions and, therefore, stopping short of the sprin plank seating web and spring plate an means for filling the space between the spring ppm;I and seat portion beyond said spring p an 16. In a car truck, in combination, a side frame formed with compression and tension members, s seed at intermediate portions member, beneath the window opening, being formed with a spring seating portion, bolster springs supported by means of said spring seating portion, a bolster associated with said frame and adapted for direct insertion into the bolster opening above said springs, said bolster being formed with guiding flanges extending outwardly toward the bolster guide columns but not engaging said columns and removable flanged wear blocks insertable between said columns and bolster and each formed with outwardly extending flanges engaging the corresponding guide columns to prevent transverse motion therebetween and inwardly extending flanges engaging the flanges of the bolster for preventing transverse motion therebetwecn.

17. In a car truck, in combination, a side frame formed With compression and tension members, spaced at intermediate portions thereof by bolster guide columns, leaving a window opening therebetween, the tension member, beneath the window opening, being formed with a spring seating portion, bolster springs supported by means of said spring seating portion, a bolster associated with said frame and adapted for direct insertion into the bolster opening above said springs, said bolster being formed with guiding portions extending outwardly toward the bolster guide columns but not engaging said columns and removable flanged wear members insertable between said columns and bolster and each formed with outwardly extending portions adapted to engage the corresponding guide columns to prevent transverse motion therebetween and inwardly extending portions adapted to engage the guiding portions of the bolster for preventing transverse motion therebetwcen, the lower portions of said wear blocks being flared downwardly to forn'r base portions of increased area for resting upon the springs, the bolster being correspondingly formed for cooperating therewith.

18. A spring plate for a nest of springs formed with means for spacing said springs and means normally depending from the bottom surface thereof for passing through corresponding apertures in an associated spring plank into corresponding pockets in an associated frame for locking said spring plank in squared relation with respect to said frame.

In testimony whereof I affii my signature.

DONALD S. BARROVVS.

Images