US3032092A - Propeller straightening apparatus - Google Patents

Description

y 1, 1952 R. w. ERLBACHER 3,032,092

PROPELLER STRAIGHTENING APPARATUS Filed April 8, 1957 3 Sheets-Sheet l V5 /\/TO 1?: KQBERT W. ERL sac HER,

HTTQRN y 1962 R. w. ERLBACHER 3,032,092

d A l 8, 1957 3 Sheets-Sheet 2 File prl m.

y R. w. ERLBACHER 3,032,092

PROPELLER'STRAIGHTENING APPARATUS Filed April 8, 1957 3 Sheets-Sheet 5 WINK:

/A/l/EA/TO 05527 MERLE/QC R,

United States Patent 3,632,092 PROPELLER STRAIGHTENING APPARATUS Robert W. Erlbacher, 920 N. Fountain, Cape Girardeau, Mo. Filed Apr. 8, 1957, Ser. No. 651,332 16 Claims. (Cl. 153-32) This invention relates to improvements in marine propeller straightening apparatus and in particular relates to supporting means for tilting a propeller so that its blades may be disposed for straightening by ram devices.

It has been a major problem in the marine industry in the past to straighten the blades of damaged propellers. Damage to these blades may be through a number of conditions such as striking underwater obstructions and the like. When the blades are dented or otherwise distorted out of their proper relationship, loss in efliciency and propulsion results. The alignment of the blades is quite important in the marine industry for obtaining the proper propulsion and any dents or bending of the propeller blade seriously detracts from the performance of the propeller.

By means of the instant invention, there has been devised an operative apparatus for handling marine propellers of up to several feet in diameter and of great weight where such handling has been quite difficult in the past. The apparatus includes special tilting filler blocks which are used to support the hub of the propeller and tilt the blade at the area desired to be Worked upon to a proper horizontal position. When in the horizontal position, an underlying supporting ram or jack is placed under the blade and a movable hydraulically operated ram carried by a supporting track is used to bend the blade back to the desired shape. The special tiltable filler blocks are designed so that the hub of the propeller can be tilted from the vertical to a desired position for working application by the hydraulic rams. In spite of the great weight of the marine propellers by the use of the tiltable filler blocks, the propellers can be simply adjusted to the desired position and the rams may be then easily moved into place for the bending and truing operation.

This invention, because of the simple adjustment of the tiltable filler blocks, provides for simple and expeditous application of the apparatus. Further, the tiltable filler blocks are so designed that a great pressure in the order of thousands of pounds per square inch may be exerted upon the propeller blade while the propeller is held firmly in position against these great stresses by the tiltable filler blocks and no undue strain is incurred in this application. The apparatus is comparatively simple in the nature of its operation and may be used by relatively unskilled workmen which is of advantage in shop use.

Accordingly, it is an object of this invention to provide an apparatus for supporting a propeller in tiltable relation and means for exerting pressure upon the blades to change their shape.

Another object of this invention is to provide an apparatus for supporting a propeller in tiltable relation by a shaft supported by rotatable filler blocks having a cam surface which provides a tilting of the marine propeller when the blocks are moved with respect to one another.

Yet another object of this invention is to provide an apparatus for working upon propellers in which the pro peller may be supported in various tiltable positions from the vertical position and in which a propeller blade desired to be worked upon may be bent by the movement of an adjustable overhead ram which can be moved into desired positions for the propeller blade working operation.

Still another object of this invention is to provide a propeller straightening apparatus comprising a table upon which the propeller may be supported in various tiltable ice relations and upon which there is supported a movable overhead ram which is adjustable with respect to the propeller blade to be worked upon and which table has provisions for supporting a bottom rarn underneath the propeller blade to be worked upon and in various positions of support.

Still a further object of this invention is to provide a device for supporting a propeller blade in various positions of tiltable adjustment upon a base by means of tiltable filler blocks which support a work shaft passing through the propeller and the filler blocks and which rotation of the filler blocks with respect to one another causes the desired tiltable adjustment of the propeller.

Yet a further object of this invention is to provide a propeller straightening apparatus comprising a work table, a propeller supporting device, which provides for tiltable support of the propeller, and hydraulic rams for working upon the propeller blade, which apparatus is simple in design and rugged in construction and easy to use.

Further objects of this invention will appear in the detailed description which follows and will be further apparent to those skilled in the art.

For the purpose of illustration, there is shown in the accompanying drawings a preferred embodiment of this invention. It is to be understood that these drawings are for the purpose of example only, and that the invention is not limited thereto.

In the drawings:

FIGURE 1 is a top plan view of the apparatus with a propeller shown in dotted lines;

FIGURE 2 is a view in front elevation of the apparatus with a propeller shown in section and a bottom jack shown in dotted lines;

FIGURE 3 is a view in elevation taken from the left I end of FIGURE 2;

FIGURE 4 is an enlarged view in section taken on the line 4--4 of FIGURE 1 showing the structure of the movable ram carrying device;

FIGURE 5 is a view taken similar to FIGURE 2 but showing the apparatus in use with a portion of the top ram carrying device broken away for clarity in showing the bottom ram or jack in position;

FIGURE 6 is an enlarged view in section taken through the axis of the filler blocks used for the tilting of the propeller showing the blocks arranged in the vertical propeller shaft position;

FIGURE 7 is a view in elevation of the filler blocks shown in altered position to obtain the tilting of the propeller shaft;

FIGURE 8 is a view in section taken through the diametrical axis of the filler blocks of FIGURE 7 showing the internal construction of the filler block tilting device;

FIGURE 9 is a view taken partly in elevation and partly in section of a modified filler block tilting device;

FIGURE 10 is a view in elevation of the anchoring element employed in the modification of FIGURE 9;

FIGURE 11 is a view taken similarly to FIGURE 9 showing a further modified anchoring element;

FIGURE 12 is another view taken similarly to FIG URE 9 showing a still further modified anchoring element;

FIGURE 13 is a view taken in section through an other modification of the filler block tilting device employing the anchoring element of FIGURE 11; and

FIGURE 14 is a top plan view of the base tilting block of FIGURE 13.

The propeller straightening apparatus of this invention is generally indicated by the reference numeral 10 in FIGURES l, 2, 3 and 5. It includes as: its major components a work table 11 which has a generally T shaped configuration, a tiltable propeller supporting device 12,

3 an adjustable overhead ram carriage 13, and a bottom ram or jack 14.

The table 11 has a strong steel top so that the pressures exerted by the ram upon it will not cause breakage or distortion. The enlarged portion shown at the right of FIGURE 1 and comprising the head of the T provides a base for workmen working upon the propeller blades. The shank of the T has fiat parallel sides to provide for a rail structure for the adjustable carriage, as best shown in FIGURES 1 and 3, in positioning the rams for the straightening of the propeller blade to be Worked upon.

The supporting and adjustable carriage 13 for the overhead ram has a generally G-shaped frame or arbor 16 which has two underlying legs 17 and 13 and to provide for retention upon the table when the hydraulic ram is operated and to give firm support to the carriage. Side rollers 21 and 22 are provided adjacent the bottom of the frame in order that the carriage may be rolled along the bed to desired positions of adjustment. At the top of the carriage and as best shown in FIGURES 3 and 4, flanged tracks 23 and 24 are provided for transverse movement of a hydraulic ram 25. The ram is fitted with wheels 26 and 27 which are adapted to rest upon tracks in order to provide the desired transverse adjustment of the ram across the table.

The hydraulic ram 25 is connected by fluid pressure line 28 to a control box 29 situated upon the side of the frame in order that proper control of the ram may be exercised. At the bottom of the ram is an adjustable ram head 31 which is adapted to be extended in the operation of the ram by application of the control box 29. The ram is confined within the enclosed top structure of the frame in order that great pressures may be exerted through the extension of the ram and head31.

The ram or jack 14 shown in FIGURES 2 and may be positioned in any desired position upon the table 11. by manually moving the same. It is of conventional structure and has an adjustable top ram head 33 which is adapted to be operated to various positions by the use of the operating handle 34. It is to be understood that this manually movable ram may be made in other modifications such as by movably supporting it upon a track on the base as will be well understood in the art.

The tiltable filler block device for supporting the propeller and, generally indicated by the reference numeral 12, is best shown in construction in FIGURES 2, 3, 5, 6, 7 and 8. The device comprises top side filler blocks 41 and 42 and bottom side filler blocks 43 and 44 which are supported on the top and the underneath side of the table respectively. These filler blocks are somewhat in the form of a capstan and are each provided with holes 45 around their periphery for the insertion of a capstan bar for rotating the filler blocks to provide the desired tiltable adjustment.

The propeller tilting device 12 further includes a propeller supporting shaft 46 which passes through each of the filler blocks and which has a tightening nut 47 at the bottom which is also provided with a capstan hole 45 for secure tightening. In FIGURE 2, a propeller generally indicated by the reference numeral 48 is shown supported upon the top filler block 41 and is secured in place by a top nut 49, likewise provided with capstan holes.

As particularly shown in FIGURES 6 and 8, all of the filler blocks 41, 42, 43 and 44 are of a hillside washer configuration. Thus, each one of the four blocks has a general configuration of a Washer with one side being provided of a plane surface perpendicular to the axis of the washer and the other side having a slanting relation to the axis. This is best shown in FIGURE 6 where it it seen that the filler blocks when completely assembled to support the supporting shaft 46 in the vertical position have the configuration of a cylinder with the interfaces between the filler blocks 41 and 42 being parallel to the interfaces between the bottom side mating blocks 43 and 4 44. In general, these interfaces may be termed as cammed surfaces since the rotation of the filler blocks 41 and 42 with respect to one another will cause the shifting of the propeller supporting shaft and also the shifting of the filler blocks 43 and 44, as will be more particularly described.

The top filler block 41 is secured against rotational relation with the propeller supporting shaft 46 by a connecting key 51. This same relationship holds true for the bottom filler block 44 which is held against rotatable relation with the propeller supporting shaft 46 by a key 52. It will be noted that the intermediate filler blocks 42 and 43 both have enlarged central openings and may both be rotated with respect to the propeller shaft and also the top filler blocks 41 and 44. The filler blocks are maintained in mating relation by annular drive tracks 53 for the top filler blocks and drive tracks 54 for the bottom filler blocks.

A slightly modified form of tilting device is shown in FIGURES 9 and 10. In this modification, use is made of the tilting blocks 41 and 42 supported on the top of the base 11. However, the table or base 11 has an opening 70 of a generally conical configuration. This is desirable to form a rest surface since the bottom tilting blocks 43 and 44 are not employed. An anchoring device generally indicated by the reference numeral 71 is utilized in the place of the bottom filler blocks. The anchoring device as shown in FIGURE 10 comprises an anchoring plate 72 which is locked to the propeller supporting shaft 46 by a bolt 73, with provision being made for the support of the anchoring plate within the shaft 46 through bifurcated construction. The top of the anchoring plate is beveled to provide line contact for rocking movement.

This type of modified construction of the tiltable filler blocks may be employed in handling propellers which are not of the great mass of those employed with the tiltable filler blocks of the construction of FIGURES 6 through 8. It will be observed that through the deletion of the bottom filler blocks the apparatus may be employed obviously without the required movement of the bottom filler blocks which reduces the amount of work involved.

Further modified anchoring devices are shown in FIG- URES 11 and 12. The modified anchoring devices are indicated by the numeral in FIGURE 11 and 81 in FIGURE 12, and it will be observed that there is a difference in the bottom construction, as will further appear.

The modified form of anchoring device 80, shown in FIGURE 11, employs the same top filler blocks 41 and 42 shown in the construction of FIGURES 6 through 8, and in FIGURES 9 and 10. However, it will be observed that the opening 82 in the base 11 through which the propeller supporting shaft 46 passes is of a modified construction. Thus at its top it comprises a frusto-conical surface 83 and at the bottom it has a partially spherical configuration, as designated at 84. The anchoring device itself comprises a hemispherical element 85, which nests within the surface 84 of the opening in the base. The anchoring element is tightened on the shaft by a stop nut 86.

In the slightly modified construction of FIGURE 12, the anchoring device 81 uses the same type of opening as above-described in FIGURE 11, and identical reference numerals are employed. However, the anchoring element 91 is comprised of a spherical configuration and may be firmly secured to the propeller supporting shaft 46 by means of threads or other types of affixation. A hearing support 92 is secured to the bottom of the base 11 and with the cooperation of the surface 84 of the base opening provides a firm and secure bearing for the anchoring element 91. For the construction of the anchoring device of FIGURE 11, friction and wear are reduced by the provision of the spherical form of the bearing, and the engagement with the mating surface of the base 11 of the anchoring element. Adjustment is provided by a top propeller shaft nut 49 as in earlier described embodiments.

In FIGURE 13, there is shown a modified form of the tiltable filler block construction. This modification provides for tilting of the propeller shaft and the supported propeller without the requirement of adjusting the lock nuts upon the propeller supporting shaft. This is achieved through the hemispherical mating relation of the filler blocks and also a hemispherical construction of the anchoring bearing which is identical with the anchoring device of FIGURE 11, and for which similar reference numerals will be employed. A top filler block 101 is employed which is provided with capstan holes 45. This block has an opening to receive the propeller supporting shaft 46, and a flat top surface upon which the propeller 48 is supported. The bottom surface 102 of the top block is of a generally spherical configuration, so that it may be positioned upon and mate with the bottom block 103.

The bottom block 103 is substantially of a hemispherical configuration in which the radius is the same as that of the top block 101. This block is also provided with the usual capstan holes 45. It is further provided with a frusto-conical opening 104- which mates with the top frusto-conical surface 83 and the opening within the base 11.

In the construction shown in FIGURE 13, the top filler block 101 may be turned and rotated in any desired direction upon the top surface of the bottom filler block 103. It will be observed that the width of the block 101 must be slightly greater than the width of a chord drawn across the top opening 104 to prevent the block falling down within the opening in the vertical position. However, a substantial amount of rotation and tilting may be effected through this construction.

A further modified form of tiltable filler block construction is shown in FIGURE 14. In this construction, the identical type of top filler block 101 and anchoring device 80 or 3 1 may be employed as previously described in FIGURE 13. However, the bottom filler block 106 is of a slightly modified construction from the filler block 103. Thus, in FIGURE 13, the filler block was prowided with a frusto-conical opening 104. The frustoconical opening makes possble the movement of the top filler block without movement of the bottom filler block where such type of operation is desired. However in FIG- URE 14, a greater amount of tilt is effected through the employment of a slotted opening 107. In this type of slotted opening, the side walls of the opening designated 108 and 109 may form a wider angle than the side walls of the opening 104 and the walls forming the opening 83 in the base 11 may also be of a wider divergence to mate with the opening 107. Through this construction, the filler block 101 may be employed without being limited by the size of the opening 104 of the construction shown in FIGURE 13. It will be observed, however, that in the modified construction of FIGURE 14 for the bottom filler block 103 a compound movement comprising tilting of the top filler block 101 or radial movement upon the bottom filler block must be employed, while the bottom filler block 103 is rotated in a horizontal plane.

Use

The apparatus of this invention is shown ready for use in FIGURE 5. In this showing, the propeller 48 has a damaged blade 60 positioned underneath the ram carriage for the straightening operation.

In this straightening operation, it is desired to straighten the propeller blade 60 to the original trued surface. It is a very important consideration in most propeller designs that the radial surfaces of the propeller blade be true in order to provide the maximum propulsion efficiency. Thus the propeller blade 60, as shown in FIG- URE 1, in the truing operation may have radial lines 62 and 63 drawn in chalk from the center of the propeller.

In the truing operation, it is desired that all points along the radial lines 62 and 63 be straight or fiat, such that a flat rule or the like may be laid along these lines and the surfaces be entirely trued. The pitch, of course, will vary along the different surfaces of the propeller blade and in order to provide a substantially flat surface for the particular point to be bent, such as the bent portion 64, shown in FIGURES 2 and 5 of the propeller blade, it is desired that the propeller blade be adapted to be tilted. This is performed by the tilting device 12 so that when the bent portion is worked upon the propeller blade at this point is horizontal for best results.

In the working operation shown in FIGURE 5, the propeller 43 is first of all securely positioned upon the top of the top filler block 41 and screwed tight by the nuts 49 and 47. Assuming that the bent portion 64 to be worked upon in FIGURE 5 is properly in a horizontal plane, the supporting ram carriage 13 may be moved from the initial position shown in FIGURE 2 by merely rolling it on its wheels 21 and 22 to the working position shown in FIGURE 5. The manual jack 14 is then placed underneath the bent portion and the jack head 33 is elevated into contact with the underneath side of the filler blade. Subsequently the hydraulic ram is operated by operation of the control box 29 and the hydraulic ram head 31 is lowered to exert a great amount of pressure upon the bent portion and to bend the blade back. to the true position.

During this operation, the propeller 48 is securely and immovably maintained in locked position by the tiltable securing device 12 and the application of several thousand pounds per square inch may be applied to the propeller blade. In this working application, the bottom legs 17 and 18 of the hydraulic ram carriage frame will contact the underneath side of the table when the hydraulic ram head 31 is operated and great pressures may be brought to bear through the strong construction of the hydraulic ram and hydraulic ram supporting carriage.

Where the pitch of the propeller is such that the propeller blade must be tilted to present a horizontal surface adjacent to the bent portion to be worked upon, as is usually the case, the propeller shaft must be tilted to a position such as shown in FIGURES 7 and 8 for the tilting device 12. The tilting is effected by inserting a capstan bar or long operating rod, indicated by the reference numeral 65 in FIGURES 1 and 2, in the holes 45 in the filler blocks. In this tilting operation, when capstan bars 65 are inserted in both the top intermediate block 42 and the bottom intermediate block 43, these blocks may be rotated with respect to the intermediate blocks 41 and 44 to effectuate the tilting of the supporting propeller shaft and the propeller. The tilting of the blocks to the relation shown in FIGURES 7 and 8 is effected when the blocks 42 and 43 are caused to be rotated, with respect to their initial position shown in FIGURE 6, through one-half revolution. Thus, for the positions shown in FIGURES 7 and 8, each of the filler blocks 42 and 43 should be operated by a capstan bar to effect the desired relation.

his brings a general tilting relation of the propeller shaft in aclockwise direction as viewed. in the drawings. The operation of the capstan bar in either of the top or bottom blocks 41 and 44 will effect a rotation in the counterclockwise direction. Only one capstan bar is needed in this latter operation since both blocks 41 and 44 are keyed to the propeller shaft.

In the rotation of the filler blocks shown in the set-up of FIGURE 5, it may be required to rotate all filler blocks to insure that the area of the propeller to be worked upon is in proper registry with the table to be presented underneath the carriage supported ram. This is effected by rotating all the blocks together as a cylinder. This operation is carried out by inserting a capstan bar in each of the intermediate blocks 42 and 43, and either one of the top or bottom blocks 41 and 44. Thus, if in an initial adjustment, it is determined that the propeller blade extending to the left in FIGURE 1 is presented in a horizontal position, in the 11 oclock position instead of the 9 oclock position, all of the filler block elements can be rotated about 60 degrees in a counterclockwise position. When this is effected, the desired horizontal positioning will be realized.

The modified tilting device shown in FIGURE 9 is adapted to be employed in the same manner a above described. However, the anchoring device '71 has been substituted for the bottom filler blocks 43 and 44 and the full load and support is accomplished through the use of only the top blocks 41 and 4'2. In the tilting opera tion and rotation of the blocks, either block 41 or 42 may be moved by insertion of the capstan bar 65 into the capstan holes 45 of the blocks. In the operation the top adjustment nut 4? may be loosened or tightened depending upon whether the tilt is to or from the vertical position. The anchoring device 71 and the anchoring plate 72 provide a very simple means for retaining the propeller supporting shaft at the bottom of the base 11.

The operation of the propeller supporting filler blocks shown in FIGURES 11 and 12 is efiected in identical manner with that shown in the modification of FIGURE 9. However, a different anchoring device is employed in both of FIGURES 11 and 12. Thus, FIGURE 11 has a substantially hemispherical anchoring element 85 employed which is adapted to be drawn tight by the lock nut 86. This provides for more even distribution of Stresses through the hemispherical mating surface with the opening in the base 11. This same feature is obtained through the use of the modified anchoring device 31 in FIGURE 12 which uses the anchoring element 91 in the form of a sphere. However, through the employmerit of the bearing bracket 92 the retaining element 91 is maintained in proper position at all times. Thus, in the modification of FIGURE 12, only the top lock nut 49 upon the propeller supporting shaft would be required to be adjusted.

The modification of the filler block structure shown in FIGURE 13 provides for rotation and tilting of the propeller without any adjustment of the top lock nut 49 or the bottom lock nut 47, except in cases where this is desired to lessen friction. The spherical configuration of the interengaging faces of the top of the filler block 163 and the bottom of the top lock 161 provides for any desired combination of rotation or tilting. Through the concentric relationship of all of these surfaces, and the bottom anchoring device using the anchoring element 85, there is no need of loosening or tightening the lock nuts upon the propeller shaft. This is because the distance or spacing between the lock nuts remains the same through all positions and is never required to be changed. This is made possible through the concentric relationship between the blocks and the anchoring element. The rotation of the filler blocks is effected in the same manner as above described for the filler blocks ii and 42, through the use of the capstan bar which is inserted in the capstan holes 45. Further, the filler block ltll may be moved to diflcrent radial positions upon the top of the filler block 103 by merely pushing the propeller to the desired position. This requires that there be no severe tightening of the lock nuts, such as to prevent such manual movement.

In the modification of FlGURE 14, the propeller may be rotated in the same manner as above described for the modification of FEGURE 13. However, tilting can be effected only through movement within the slot H37, and the same freedom of movement of the mechanism shown in FIGURE 13 is not possible. However, a wider degree of tilt is realized since the angle between the faces 108 and 1&9 and also the angle prescribing the funnelshaped opening 83 within the base 11 may be increased. This is quite advantageous in some applications, such as in working upon propellers having high degree of pitch in the blades.

Through the rotation of the filler blocks as above described full universal tilting of the propeller may be efiectuated so that any portion of the surface of the propeller blade on desired to be worked upon may be disposed substantially horizontally. A further ease and convenience in the bending operation is eltectuated by the adjustability of the hydraulic ram through its carriage which is movable upon the table and also by the adjustable feature of the ram itself with respect to its support carriage by virtue of the tracks 23 and 24. It is to be understood that the bottom jack 114 can of course be manually moved to any desired position so that full and complete flexibility is obtainable in the propeller straightening apparatus.

By virtue of the particular construction of the tilting device through the rotatable filler blocks an even stress distribution and a very secure foundation is provided for supporting the propeller in the various tiltable positions. When it is to be understood that the propellers to be worked upon are marine propellers used upon large vessels and are quite heavy and sizable in dimensions and also that pressures in the order of several thousand pounds per squa'e inch are employed, the advantage of a very ecure foundation is readily understood. The bearing relation of the mating filler block and the rotatable relationship provided furnishes a very firm foundation for the bending operation and the same relationship is enjoyed by the bottom filler blocks '43 and 44, when desired to be employed for massive propellers. This structure enables great stresses to be successfully resisted and provides for great flexibility in the handling of various sized propellers. It is to be understood that where propellers are used having a different axial opening of a size larger than the shaft 46 sleeves and shims and the like can be used to provide for the proper support. Further flexibility is provided through the adjustable securing nuts 57 and 49 in the operation of this apparatus.

Various changes and modifications may be made in this invention as will be apparent to those skilled in the art. Such changes and modifications are within the scope and teaching of this invention as defined in the claims appended hereto.

What is claimed is:

1. A work support for use in straightening a selected surface of a propeller blade comprising a flat work table, means including a universal support member for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the work table, said hub supporting means further including a support s .aft engageable with and passing through the universal support member, said support shaft being connected at one end to the propeller hub and at the opposite end to anchoring means at the bottom of the work table, said universal support member being adjustable for tilting the propeller blade to be straightened to a preselected position, said universal support member comprising a pair of cooperating relatively rotatable propeller supporting cylinders, said cylinders being relatively rotatable to a position where the axis of the propeller hub is vertical and wherein the sides of the cylinders are vertical, and the cylinders having a mating surface lying obliquely to the axis of said cylinders.

2. Apparatus for straightening a selected surface of a propeller blade comprising a flat work table, means including a universal support member having a support shaft for supporting the hub of the propeller blade with the Selected surface of the blade to be straightened overlying the work table, and means for straightening the selected surface of the blade comprising an adjustable support movable upon the work table into contacting relation with the underneath side of the propeller blade and an overhead jack operable to exert pressure against the desired portion of the blade to bend it to a desired relationship, said universal support member comprising first and second pairs of relatively rotatable propeller 9 supporting cylinders with each of said pairs of cylinders being comprised of cylinders having mating surfaces formed obliquely to their axis, said first pair of cylinders being supported on the work table and said second pair being supported underneath the work table by a lower end of the support shaft.

3. Apparatus for straightening a selected surface of a propeller blade comprising a flat work table, means including a universal support member having a support shaft for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the work table, and means for straightening the selected surface of the blade comprising an adjustable support movable upon the work table into contacting relation with the underneath side of the propeller blade and an overhead jack operable to exert pressure against the desired portion of the blade to bend it to a desired relationship, said universal support member comprising first and second pairs of relatively rotatable propeller supporting cylinders with each of said pairs of cylinders being comprised of cylinders having mating surfaces formed obliquely to their axis, said first pair of cylinders being supported on the work table and said second pair being supported underneath the work table by a lower end of the support shaft passing through an opening in the work table, said shaft keying a topmost cylinder in the first pair to a bottornmost cylinder in the second pair against relative rotation, said shaft being further secured to the propeller hub.

4. Apparatus for straightening a selected surface of a propeller blade comprising a flat work table, means including a universal support member having a support shaft for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the work table, and means for straightening the selected surface of the blade comprising an adjustable support movable upon the work table into contacting relation with the underneath side of the propeller blade and an overhead jack operable to exert pressure against the desired portion of the blade to bend it to a desired relationship, said universal support member comprising first and second pairs of relatively rotatable propeller supporting cylinders with each of said pairs of cylinders being comprised of cylinders having mating surfaces formed obliquely to their axis, said first pair of cylinders being supported on the work table and said second pair being supported underneath the Work table by a lower end of the support shaft passing through an opening in the work table, said shaft keying a topmost cylinder in the first pair to a bottommost cylinder in the second pair against relative rotation, said shaft being further secured to the propeller hub, and means for maintaining the cylinders in each pair in cooperating relation when they are relatively rotated comprising a circular flange in one of the cylinders disposed in mating relation with a groove in another cylinder.

5. Apparatus for straightening a selected surface of a propeller blade comprising a fiat Work table, means including a universal support member having a support shaft for supporting the hub of the propeller blade with the Selected surface of the blade to be straightened overlying the work table, and means for straightening the selected surface of the blade comprising an adjustable support movable upon the work table into contacting relation with the underneath side of the propeller blade and an overhead jack operable to exert pressure against the desired portion of the blade to bend it to a desired relationship, said universal support member comprising first and second pairs of relatively rotatable propeller supporting cylinders with each of said pairs of cylinders being comprised of cylinders having mating surfaces formed obliquely to their axis, said first pair of cylinders being supported on the Work table and said second pair being supported underneath the work table by a lower end of the support shaft, said cylinders being relatively rotatable to a position where the axis of the propeller hub is vertical and wherein the sides of the cylinders are vertical.

6. A work support for use in straightening a selected surface of a propeller blade comprising a flat work table, means including a universal support member for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the Work table, said hub supporting means further including a support shaft engageable with and passing through the universal support member, said support shaft being connccted at one end to the propeller hub and at the opposite end to anchoring means at the bottom of the work table, said universal support member being adjustable for tilting the propeller blade to be straightened to a pro-selected position, said universal support member comprising a pair of cooperating relatively rotatable propeller supporting members fitting against one another, said members being in rotatable engagement with one another, said members being relatively rotatable with one another from one position where the axis of the propeller support shaft is vertical to another position where the propeller support shaft is tilted.

7. Apparatus for use in straightening a selected surface of a propeller blade comprising a fiat Work table, means including a universal support member for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the work table, said universal support member being pivotable for tilting the propeller blade to be straightened to a pro-selected position, said universal support member comprising a pair of cooperating relatively rotatable propeller supporting cylinders, said cylinders being relatively rotatable to a position where the axis of the propeller hub is vertical and wherein the sides of the cylinders are vertical, and the cylinders having a mating surface lying obliquely to the axis of said cylinders.

8. Apparatus for use in straightening a selected surface of a propeller blade comprising a fiat work table, means including a universal support member for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the work table, said hub supporting means further including a support shaft engageable with and passing through the universal support member, said support shaft being connected at one end to the propeller hub and at the opposite end to anchoring means at the bottom of the work table, said universal support member being pivotable for tilting the propeller blade to be straightened to a preselected position, said universal support member comprising a pair of cooperating relatively rotatable propeller sup porting cylinders, said cylinders being relatively rotatable to a position where the axis of the propeller hub is vertical and wherein the sides of the cylinders are vertical, and the cylinders having a mating surface lying obliquely to the axis of said cylinders, said support shaft extending through an opening in the work table and said anchor means bearing against the bottom of the table.

9. Apparatus for use in straightening a selected surface of a propeller blade comprising a fiat work table, means including a universal support member for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the Work table, said hub supporting means further including a support shaft engageable with and passing through the universal support member, said support shaft being connected at one end to the propeller hub and at the opposite end to anchoring means at the bottom of the work table, said universal support member being pivotable for tilting the propeller blade to be straightened to a pre-selected position, said universal support member comprising a pair of cooperating relatively rotatable propeller supporting cylinders, said cylinders being relatively rotatable to a position where the axis of the propeller hub is i It vertical and wherein the sides of the cylinders are vertical, and the cylinders having a mating surface lying obliquely to the axis of said cylinders, said support shaft extending through an Opening in the Work table and said anchor means bearing against the bottom of the table, said anchoring means comprising an anchoring element having an at least partially spherical bearing surface which bears in a mating cavity in the bottom of the Work table.

10. Apparatus for use in straightening a selected surface of a propeller blade comprising a flat work table, means including a universal support member for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the work table, said hub supporting means further including a support shaft engageable with and passing through the universal support member, said support shaft being connected at one end to the propeller hub and at the opposite end to anchoring means at the bottom of the work table, said universal support member being pivotable for tilting the propeller blade to be straightened to a pre-selected position, said universal support member comprising a pair of cooperating relatively rotatable propeller supporting cylinders, said cylinders being relatively rotatable to a position Where the axis of the propeller hub is vertical and wherein the sides of the cylinders are vertical, and the cylinders having a mating sur ace lying obliquely to the axis of said cylinders, said support shaft extending through an opening in the work table and said anchor means bearing against the bottom of the table, said anchoring means comprising an anchoring element having an at least partially spherical bearing surface which bears in a mating cavity in the bottom of the work table, at the top of said element and a bearing plate secured to the bottom of the work table for supporting the bottom of said element.

11. A work support for use in straightening a selected surface of a propeller blade comprising a fiat Work table, means including a universal support member for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the work table, said hub supporting means further including a support shaft engageable with and passing through the universal support member, said support shaft being connected at one end to the propeller hub and at the opposite end to anchoring means at the bottom of the work table, said universal support member being adjustable for tilting the propeller blade to be straightened to a pre-selected position, said universal support member comprising a pair of cooperating relatively rotatable propeller supporting members fitting against one another, said members being in rotatable engagement with one another, said members being relatively rotatable with one another from one position where the axis of the propeller support shaft is vertical to another position where the propeller support shaft is tilted, said members having mating partially spherical surfaces.

12. A work support for use in straightening a selected surface of a propeller blade comprising a flat work table, means including a universal support member for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the work table, said hub supporting means further including a support shaft engageable with and passing through the universal support member, said support shaft being connected at one end to the propeller hub and at the opposite end to anchoring means at the bottom of the work table, said universal support member being adjustable for tilting the propeller blade to be straightened to a pro-selected position, said universal support member comprising a pair of cooperating relatively rotatable propeller supporting members fitting against one another, said members being in rotatable engagement with one another, said members being relatively rotatable with one another from one position where the axis of the propeller support shaft is vertical to another position where the propeller support shaft is tilted, said members having mating partially spherical surfaces, said support shaft extending through an opening in the work table and said anchor means bearing against the bottom of the table.

13. A work support for use in straightening a selected surface of a propeller blade comprising a fiat work table, means including a universal support member for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the work table, said hub supporting means further including a support shaft engageable with and passing through the universal support member, said support shaft being connected at one end to the propeller hub and at the opposite end to anchoring means at the bottom of the work table, said universal support member being adjustable for tilting the propeller blade to be straightened to a pre-selected position, said universal support member comprising a pair of cooperating relatively rotatable propeller supporting members fitting against one another, said members being in rotatable engagement with one another, said members being relatively rotatable with one another from one position where the axis of the propeller support shaft is vertical to another position where the propeller support shaft is tilted, said members having mating partially spherical surfaces, said support shaft passing through inverted frusto-conical openings in the Work table and the lowermost of said members and said anchor means bearing against the bottom of the table.

14. A work support for use in straightening a selected surface of a propeller blade comprising a flat work table, means including a universal support member for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the work table, said hub supporting means further including a support shaft engageable with and passing through the universal support member, said support shaft being conected at one end to the propeller hub and at the opposite end to anchoring means at the bottom of the work table, said universal support member being adjustable for tilting the propeller blade to be straightened to a pre-selected position, said universal support member comprising a pair of cooperating relatively rotatable propeller supporting members fitting against one another, said members being in rotatable engagement with one another, said members i being relatively rotatable with one another from one position where the axis of the propeller support shaft is vertical to another position where the propeller support shaft is tilted, said members having mating partially spherical surfaces, said support shaft passing through inverted frusto-conical openings in the work table and the lowermost of said members, said anchoring means comprising an anchoring element having an at least partially spherical bearing surface which bears in a mating cavity in the bottom of the work table.

15. A work support for use in straightening a selected surface of a propeller blade comprising a flat work table, means including a universal support member for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the work table, said hub supporting means further including a support shaft engageable with and passing through the uni: versal support member, said support shaft being connected at one end to the propeller hub and at the opposite end to anchoring means at the bottom of the work table, said universal support member being adjustable for tilting the propeller blade to be straightened to a pre-selected position, said universal support member comprising a pair of cooperating relatively rotatable propeller supporting members fitting against one another, said members being in rotatable engagement with one another, said members being relatively rotatable with one another from one position where the axis of the propeller support shaft is vertical to another position Where the propeller support shaft is tilted, said members having mating partially 13 spherical surfaces and said support shaft passing through a slotted opening in the lowermost of said members.

16. A work support for use in straightening a selected surface of a propeller blade comprising a fiat work table, means including a universal support member for supporting the hub of the propeller blade with the selected surface of the blade to be straightened overlying the work table, said hub supporting means further including a support shaft engageable with and passing through the universal support member, said support shaft being connected at one end to the propeller hub and at the opposite end to anchoring means at the bottom of the work table, said universal support member being adjustable for tilting the propeller blade to be straightened to a pre-selected position, said universal support member comprising a pair of cooperating relatively rotatable propeller supporting cylinders, said cylinders being relatively rotatable to a position where the axis of the propeller hub is vertical and wherein the sides of the cylinders are vertical, and the cylinders having a mating surface lying obliquely to the axis of said cylinders, and means for maintaining the cylinders in cooperating relation when they are relatively rotated comprising a circular flange in the mating surface of one of the cylinders disposed in mating relation with a groove in the mating surface of the other cylinder.

References Cited in the file of this patent UNITED STATES PATENTS 1,548,521 Fowler Aug. 4, 1925 1,562,626 Finkbeiner Nov. 24, 1925 1,579,582 Voltz Apr. 6, 1926 1,733,671 Moody Oct. 29, 1929 1,971,821 Johnston Aug. 28, 1934 2,013,705 Warren Sept. 10, 1935 2,233,371 Smith Feb. 25, 1941 2,393,317 Edwards Jan. 22, 1946 2,489,815 Rader Nov. 29, 1949 2,495,065 Hull Jan. 17, 1950 2,726,703 Fnltz Dec. 13, 1955 FOREIGN PATENTS 134,762 Great Britain Nov. 13, 1919 117,577 Sweden Nov. 5, 1946

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