US3139731A

US3139731A - Band-type barrier encasement for protecting timbers against marine borer attack

Info

Publication number: US3139731A
Application number: US785085A
Authority: US
Inventors: Orval E Liddell
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-01-05
Filing date: 1959-01-05
Publication date: 1964-07-07
Anticipated expiration: 1981-07-07

Description

J l 7, 1964 o. E. LIDDELL 3,139,731

BAND-TYPE; BARRIER ENCASEMENT FOR PROTECTING TIMBERS AGAINST MARINE BORER ATTACK Filed Jan. 5, 1959 2 Sheets-Sheet 1 "II V 01111111 1 VENTOR. 0/91/44 L'Z Z/DQEZL y 7, 1964 o. E. LIDDELL 3,139,731

BAND-TYPE BARRIER ENCASEMENT FOR PROTECTING TIMBERS AGAINST MARINE BORER ATTACK 2 Sheets-Sheet 2 Filed Jan. 5, 1959 w m m 24 W26 f EM; m5 0y B United States Patent 0 3,139,731 BAND-TYPE BARRIER ENCASEMENT FOR PRO- IECTING TIMBERS AGAINST" MARINE EORER ATTACK Orval E. Litldell, Pi). Box 1533, Avalon, Calif. Filed Jan. 5, 1959, Ser. No. 785,085 9 Claims. (Cl. 61-54) The present invention relates generally to the protection of submerged wooden structures against marine borer attack and specifically to a novel protective barrier encasement for such structures.

In my co-pending application for US. Letters Patent Serial No. 688, 596, filed October 7, 1957, now abandoned, I have disclosed methods and apparatus for arresting or preventing marine borer attack by utilizing an encasement around a pile or other structure to create an environment of stagnant water between the pile and the encasement which is toxic to borers. The present application is directed to further novel barrier encasements of this type.

An object of the present invention is to provide novel and improved means of protecting a submerged wooden structure against marine borer attack.

Another object of the present invention is to provide a barrier encasement fabricated from a sheet of pliable material to tubularly enclose a pile, a pair of opposite vertical edges of the sheet being rigidly reinforced to maintain such edges in close abutment with the piling.

Yet another object of the present invention is to provide a barrier encasement fabricated from a sheet of pliable material to tubularly enclose a pile and which is retained in place around said pile by means of a plurality of pile-encircling band members.

It is a further object of the present invention to. provide a barrier encasement of the aforedescribed nature which can be installed within a limited working space, as between the deck of a pier and the water line, without the use of specialized equipment whereby such installation can be accomplished without removal of the pier decking.

A further object of the present invention is to provide a barrier encasement of the aforedescribed nature capable of installation on all lengths and diameter of piles and especially on older but still usable piles such as have had large surface areas eaten away by borers so that they no longer have a uniform taper or diameter.

It is a particular object of the invention to provide a barrier encasement of the aforedescribed nature that can quickly and easily be removed after initial installation. With this arrangement, repairs can be made to the material of the encasement, the encasement can be salvaged for use on another pile, inspection of the protected pile is possible, and the encasement can be vertically adjusted on the pile in accordance with changes in the level of the mud line.

It is an important object of the present invention to provide a barrier encasement which may be shop-fabricated for subsequent installation upon a pile. This atrangement permits the barrier encasement to be manufactured and installed at minimum cost.

It is a particular object of the present invention to provide a barrier encasement of the aforedescribed nature having auxiliary butler wraps around its top and bottom sections so as to protect the lower portion of the encasement against the abrasive action of sand and rocks and the upper portion thereof against damage due to floating objects.

These and other objects and advantages of the present invention will become apparent from the following detailed description thereof when taken in conjunction with the appended drawings wherein:

FIGURE 1 is a side elevational view of a first form of barrier encasement embodying the present invention;

FIGURE 2 is a side elevational view indicating a method of installing said barrier encasement about a pile;

FIGURE 2a is a vertical sectional view in enlarged scale taken along line Za-Za of FIGURE 2;

FIGURE 3 is a horizontal sectional view in enlarged scale taken along line 3-3 of FIGURE 1;

FIGURE 4 is a fragmentary horizontal sectional view in enlarged scale taken along line 4-4 of FIGURE 2;

FIGURES 5, 6 and 7 are fragmentary vertical sectional views in enlarged scale, taken along lines 5-5, 6-6 and 7-7, respectively, of FIGURE 1;

FIGURE 8 is a perspective view showing a first type of band member that may be utilized with said barrier encasement;

FIGURES 9 and 10 are perspective views showing a second form of band member usable with said barrier encasement;

FIGURE 11 is a perspective view showing a second form of barrier encasement embodying the present inven tion;

FiGURE 12 is a horizontal sectional view in enlarged scale taken along line 12-12 of FIGURE 11;

FIGURE 13 is a horizontal sectional view showing the form of barrier encasement of FIGURES 11 and 12 applied to a pile;

FIGURES 14, 15 and 16 are vertical sectional views in enlarged scale taken along lines 14-14, 15-15 and 16-16, respectively of FIGURE 11; and

FIGURE 17 is a perspective view showing a barrier encasement provided with auxiliary buiier wraps in accordance with the invention.

In the appended drawings the improved barrier encasements illustrated are particularly adapted for application to wooden piles. However, it will appear to those skilled in the art that the principles of construction herein disclosed are not necessarily so limited and can be utilized with certain other types of submerged wooden structures.

In general, the barrier encasement of the present invention comprises a substantially rectangular sheet of a pliable material which is rigidly reinforced against bending along its opposite vertical edges. The rigidity of such reinforced edges enables the entire unit to be readily manipulated to arrange the encasement in tubular configuration around the pile to be protected. Thereafter, the encasement is contracted into engagement with the pile and fastening means in the form of a plurality of band members are wrapped about the encasement so as to maintain the encasement in snug engagement with the pile.

The barrier encasement sheet is preferably made of a waterproof material which may also be somewhat elastic but it is believed that neither of these qualities is essential. In practice, the use of a synthetic plastic such as polyvinyl chloride has proven satisfactory, although natural or synthetic rubber may likewise be utilized. Alternately, a woven fabric may be employed. In any event, it is necessary that the sheet should be substantially waterproof in the sense that while it may be porous, the ratio of the volume of pores or interstices to the volume of mass restricts the circulation of sea water around the encased timber to such an extent that the rate of circulation is less than that required to sustain marine borer life. When the salt, oxygen and organic matter which the borers extract from the sea to sustain themselves are not supplied at a sufficiently high rate the borers die as a consequence. The extent that the rate of circulation must be restricted will vary according to the type of borer, the salt, oxygen and organic matter contents of the sea and other local conditions, and is therefore subject to many variables. It is essential, however, that the total rate of circulation into the barrier encasement through the material of the sheet or into the ends of the encasement must be low enough to arrest or prevent marine borer activity, i.e. create a toxic condition of stagnation inside the encasement wherein the water lacks supplies of salt, oxygen and organic matter in amounts sufiicient to sustain life.

Referring now to FIGURE 1, there is shown a first form of barrier encasement B embodying the present invention wrapped about a pile P to be protected. The encasement B includes a thin, substantially rectangular sheet 30 of a suitable material as hereinbefore described. The sheet 30 should be cut to a length at least as great as the length of the portion of the pile to be protected against marine borer attack. The sheet throughout its length is of a width preferably greater than the corresponding circumference of the pile. The two vertical edges of the sheet are reinforced by means of

stiffeners

32 and 34. Additional reinforcing may be provided in the form of one or more vertical stiifeners affixed to the intermediate portion of the sheet 3:). Such additional stiffening is generally not essential, however. The stifleners are preferably formed of steel, although they may be formed of other suitable material.

Referring to FIGURE 4, there is shown a vertical sectional view through one of the vertical edges of sheet 39. It will be observed that

stilfeners

32 and 34 are preferably affixed to the sheet edges by overlapping the outermost portion of each sheet edge and securing the overlapped portion 36 to the main body of the sheet. The overlapped portion 36 may be affixed to the main body of the sheet by means of a suitable adhesive or by bonding under heat. As indicated in FIGURE 2a, the lower portion of the

stiffeners

32 and 34 preferably terminate above the lower edge of the sheet 30. The lower portion of the overlapped portion 36 of the sheet below the stiffeners may then be bent inwardly and suitably aifixed to the main body of the sheet 30, as indicated in this figure. The upper end of the

stiffeners

32 and 34 may likewise terminate short of the upper sheet edge.

Referring again to FIGURE 1 and additionally to FIG- URES through 8, the sheet 30 is maintained in place upon the piling P by band members 40, and a preferred form of such band member 4t? is shown in these figures. Each band member 40 is identical and has a length somewhat greater than the circumference of the pile P at the uppermost portion thereof covered by the sheet 3%). The band members 40 each include a resilient steel strip or open-ended hoop 42 which is pre-formed to the spiral configuration indicated in FIGURE 8. This steel hoop 42 is covered with a Waterproof material 44, such as natural or synthetic rubber applied over the hoop in any suitable manner. Other resilient materials may likewise be employed, as for example, salt water-resistant synthetic plastics. Referring now to FIGURES 5, 6 and 7, it should be particularly observed that the inwardly-facing surface of the band member 49 is formed with one or more friction knobs 46 that restrain slipping of the band member relative to the pile P. The relaxed diameter of each hoop 42 is less than that of the pile P.

Referring now to FIGURES 9 and 10, there is shown another form of band member 50 usable with the sheet 30. This band member 50 has a length approximately the same as the circumference of the portion of the pile P whereon it is to be applied. Preferably the band member 50 will be formed of any suitable elastic material, such as natural rubber or synthetic rubber or plastic. At one of its ends, the band member Stl is formed with a longitudinally elongated eye 52 adapted for cooperative engagement by a hook 54 formed in the opposite end of the band member. Inasmuch as the band member is preferably in a state of tension when wrapped about the sheet 39, the eye 52 and hook 54 should be of such coufiguration as to avoid the rupture of the material of the band particularly at the eye. This is important for insuring a long service life for the hand. To accomplish this, the eye 52 comprises a longitudinally elongated slit 56 of a length approximately the same as the width of the band member and terminating at both ends in arcuate openings 58 adapted to avoid the concentration of rupturing stresses in the ends of the eye 52 when the hook 54 is placed therein. The hook 54 is generally T-shaped in configuration and has a stem section 64) which is wider on the inside of the band member than on the outer surface thereof. The stem 60 is therefore wedge-shaped in cross-section and narrows as it develops towards the adjacent end of the band member. The head 62 of hook 54 is of the same width as the major portion of the band member proper and has a junction with the stem portion 60 in a pair of opposite shoulders 64 which are preferably angularly related and converge towards the adjacent end of the band.

Referring now to FIGURE 2, the method of installing the aforedescribed barrier encasement B about the piling P to be protected is indicated. It will be observed that the sheet 30 is lowered about the pile P until the lower edge of the sheet is disposed below the portion of the pile to be protected. If the

stiffeners

32 and 34 are sufficiently rigid, it is possible in some cases to manipulate the sheet 30 into the desired position from the surface of the water. It may be desirable, however, to utilize a diver for placing the sheet in the desired position. It should be observed that the sheet 30 will assume a buoyancy when submerged making it relatively easy for a single workman to manipulate even a very long sheet. It is also possible to install the sheet 30 about the piling P even Where the piles are spaced closely together. Additionally, it is not necessary to remove any decking from a pier supported by the piling in order to install the sheet 36.

As indicated in FIGURE 2, one of the stiffeners 34 will first be abutted against the pile P, whereafter a number of fastening devices such as nails 78 may be driven through the upper and lower edges of the sheet 30 so as to temporarily retain it in place. Thereafter, the opposite stiffener 32 will be manipulated about the pile P whereby the originally-free edge of the sheet 30 will overlap the first-applied edge. Where it is desired to dispose the lower end of the barrier encasement B below the mud line 72, a lance 74 is directed to the junction of the pile P with the bottom 76 and compressed air or water is directed through the lance so as to create a small crater '73 one or two feet in depth. Alternately, a diver may create the crater 78 with hand tools. This crater is, of course, created before the nails are driven through the sheet 35 into the pile P. After the originally-free edge of the sheet 3% has been overlapped around the firstapplied edge of the sheet, the band members 40 are installed about the sheet. Prior to this time, if desired, the originally-free edge of the sheet may be affixed to the piling P by nails or other suitable fastening devices.

To install the band members 4t), the free ends of the band members are flexed apart whereby they may be applied at various elevations along the length of the sheet 32.. This work can be readily accomplished by a diver.

It may also be handled from the surface by means of suitable tools which can be extended into the water. Preferably, the lowermost band member 4% will be positioned below the lower end of the

stiffeners

32 and 34. In this manner, a substantially water-tight seal will be provided at this point. If desired, a suitable sealing compound such as a mastic may be interposed between the pile and the upper and lower edge of the sheet. Such sealing compound may be also utilized along the overlapping portion of the sheet. It should be noted, however, that it is not always necessary to provide such a sealing compound. This is particularly true inasmuch as the resilient nature of the band members will cause the overlapping portion of the sheet to serve as a seal. As indicated in FIGURE 1, the aforedescribed crater 78 will generally be filled-in by the action of the sea water after a short period of time whereby any circulation of sea water upwardly through the lower end of the barrier encasement B will be restrained.

It should be particularly noted that the aforedescribed construction of the barrier encasement B permits the sheet 36) to be removed if desired. A number of important advantages are provided in this feature. For example, in the event of rupture of the material of the sheet 30 by floating debris or other mechanical action, the sheet can be quickly removed and readily repaired by a conventional patch. If it is desired to make periodic inspections of the encased pile P, the barrier encasement B can be removed and replaced with a minimum expenditure of time and effort to expose the pile to view to ascertain whether or not any marine borer activity is taking place. This removable feature also permits vertical adjustment of the barrier encasement B to change its position to meet a change in the area of the pile subjected to marine borer attack. For example, if the mud line '72 should lower as it will in some locations to such an extent that it exposes the lower end of the pile P, the encasement B can be readily lowered into a new position in a new crater and once again fastened in place. The sheet 39 is easily removed by flexing the band members 44 open whereby they may be removed from about the sheet 3%. These band members may generally be re-used during the reinstallation of the barrier encasement B.

Where the band members 50 of FIGURES 9 and 10 are utilized instead of those shown in FIGURES l, and 3 through 8, the band members 5t) can be installed either from the surface of the body of water 80 or by a diver. With the former procedure, the hook 54 and eye 52 are connected after the band member has been placed around the pile P or around the upper end of the sheet 30, whereafter, even though the band member is under tension, it can be slid downwardly over the sheet until it snaps or contracts into place around the sheet at the desired level. This can be accomplished by using a pair of long poles (not shown), notched at their lower ends to hold the band member and inserted on opposite sides of the band member to push it down the pile. As is apparent, when the band member is to be installed by a diver, it can be carried in open position to the desired elevation by the diver who thereafter stretches it around the sheet and connects the hook 54 to the eye 52. In making this connection, it is preferable to twist the head 62 of hook 54 ninety degrees from its normal condition to pass it through the eye 52, which is of approximately the same width as the head. After engagement, it will be noted that the wedge-like configuration of stem section 60 of the hook 54 prevents a sharply divergent separation of the opposite sides of eye 52 so that concentration of stresses at this point is minimized.

Referring now to FIGURES 11 through 16, there is shown a second form of barrier encasement B embodying the present invention. The encasement B includes a thin, substantially rectangular sheet 1% of a suitable material as hereinbefore described. The sheet 100 should be cut to a length at least as great as the length of the portion of the pile to be protected against marine borer attack. The sheet 1 30 throughout its length is of a width preferably greater than the corresponding circumference of the pile to be protected. A pair of vertical stiffeners 102 and 164 are affixed to the vertical edges of the sheet 100. A

6. plurality of additional

vertical stitfeners

106, 107 and 198 are aflixed to intermediate portions of the sheet 100. The vertical stiffeners are preferably formed of steel although they may be formed ofother suitable material. A plurality of band members 110 are also affixed to the sheet 100.

As indicated in FIGURE 12, the pair of

vertical stiffeners

102 and 104 are preferably aflixed to the sheet edges by overlapping the outermost portion of each sheet edge and securing the overlapped portion to the main body of the sheet in the same manner as described in conjunction with the. aforedescribed barrier encasement B and shown particularly in FIGURE 4. The intermediate

vertical stiffeners

106 and 108 may be aflixed to the surface of the sheet by means of a vertically extending strip 112 of waterproof material, as for example synthetic plastic or natural or synthetic rubber, the central portion of each such strips covering its respective vertical stiffener, with the outer edges of the strip being affixed to the sheet 100. by means of a suitable adhesive or by bonding under heat.

Referring now to FIGURES 14, 15 and 16, band members 116} include a resilient steel strip or hoop 111. The upper and lower strips 111 may be athxed to the sheet 1% by overlapping the upper and lower extremities of the sheet and securing the overlapped portions 114 and 116, respectively thereof, to the main body of the sheet by means of a suitable adhesive or by bonding under heat. The intermediate band elements 111 may be applied to the sheet 190 by an elongated strip 118 of waterproof material similar to that utilized to form the aforedescribed strips 112, with the center portion of each strip 118 covering its respective band element and the upper and lower edges of said strip 118 being suitably afiixed to the sheet 1%.

Preferably, the vertical stiffeners and the band memhere will be affixed to the same side of the sheet member 1%. Thereafter, the sheet will be sprung into the generally spiral relaxed configuration indicated, in FIGURES l1 and 12. The resiliency of the band members 111 will serve to retain the sheet in this relaxed configuration.

In order to install the barrier encasement B about a pile P to be protected, its vertical edges are sprung apart sufficiently that it may encompass the pile. Thereafter, the springing force is removed and the encasement will automatically flex radially inwardly into snug engagement with the pile. As indicated in FIGURE 13, the opposite vertical edges of the sheet 100 will overlap. so as to restrain the free flow of sea water through the vertical edges into the generally annular gap defined between the inner surface of the sheet and the exterior surface of the pile P. It will be apparent that the aforedescribed construction of the barrier encasement B permits it to be readily removed and replaced from the pile P if desired so as to provide the important advantages set forth hereinbefore in conjunction with the description of the first form of barrier encasement B. If desired, a suitable sealing compound such as a mastic may be interposed between the pile and the upper and lower edge of the sheet. Such sealing compound may be also utilized along the overlapping portion of the sheet. It should be noted, however, that it is not always necessary to provide such a sealing compound. This is particularly true inasmuch as the resilient nature of the band members will cause the overlapping portion of the sheet to serve as a seal.

Both of the aforedescribed barrier encasements B and B will serve to reduce the rate of circulation of ambient sea water over the areas of piles to be protected to a mag nitude insufficient to sustain the life of marine borers on such area. It is likewise possible to seal the ends of the encasement relative to the pile and deposit a chemical compound toxic to marine borers in the generally annular space between the encasement and the pile. Additionally, it should be noted that both of the aforedescribed 7 barrier encasements B and B may be shop fabricated f subsequent delivery to the site at which they are to be installed. This permits these barrier encasements to be manufactured and installed at a minimum cost.

When either of the aforedescribed barrier encasements Ber B is positioned upon a piling, the taper of the piling will be automatically compensated for by virtue of the fact that the lower portion of the barrier encasement may be overlapped to a greater extent than the upper portion thereof. If desired, however, the sheets from which the barrier encasements are formed may have a tapered configuration so as to compensate for any taper of the pile.

Referring now to FIGURE 17, there is shown a barrier encasement B embodying the present invention and pro vided with auxiliary buffer wraps consisting of a top buffer wrap 15% and a bottom buffer wrap 152. The auxiliary buffer wraps 15d and 152 may be formed of a material having greater resistance to impact and abrasion than the material from which the sheet member of the barrier encasement B is formed. By Way of example, these auxiliary buffer wraps may be formed of a heavier synthetic plastic material than that utilized to form the sheet of the barrier encasement B. Alternately, natural or synthetic rubber, plastic foam or fabric reinforced sheets may be employed. As indicated in FIGURE 17, the top and bottom buffer wraps are held in place upon the piling P by means of band members 4% similar to those described hereinbefore. Various other means may employed, however, for mounting these buffer wraps in place upon the piling P.

The top butler wrap 15th is particularly adapted to protect the upper portion of the barrier encasement B from damage resulting from contact with floating debris, boats and the like. The bottom buffer wrap 152 is particularly adapted to protect the lower portion of the barrier encasement B from damage due to the abrasive action of currents-carried sand and rock, as indicated at 154-. It is preferable that the auxiliary buffer wraps 150 and 152 be readily removable whereby they may be replaced when worn.

Various modifications and changes may be made with respect to the foregoing detailed description without departing from the spirit of the present invention or the scope of the following claims.

I claim:

1. In a piling construction: a partially submerged, structure-bearing wooden pile, a sheet of substantially waterproof, pliable material Wrapped around said pile in substantially circumferential configuration, said sheet having a pair of opposite longitudinal edges in juxtaposition extending generally longitudinally of said pile, vertical stiffeners affixed to said opposite longitudinal edges of said sheet, and band members that extend about said pile at vertically spaced portions thereof to cause said sheet to closely surround said pile for substantially the full vertical length of said sheet to define a generally circumferential water-filled space between said pile and said sheet, with water circulation between said space and the water surrounding said sheet being restricted to thereby render the water in said space stagnant to prevent marine borer attack on the submerged portion of said pile encased by said sheet.

2. A construction as set forth in claim 1 wherein said band members each include a resilient open-ended hoop that when relaxed assumes a generally spiral configuration of smaller diameter than said pile.

3. A construction as set forth in claim 1 wherein said band members each include an elastic strip having a length smaller than the diameter of said pile and formed at its ends with means to connect said ends.

4. In a piling construction: a partially submerged, structure-bearing wooden pile, a sheet of pliable substantially Waterproof material placed around said pile in substantially cylindrical configuration with a pair of opposite longitudinal edges disposed substantially parallel one an other and extending generally longitudinally of said pile, elongated generally longitudinally extending stiffener means cooperatively associated with both of said edges to cause said sheet to closely surround said pile whereby circulation of the ambient water between said sheet and said pile is inhibited to thereby render said ambient water stagnant to prevent marine borer attack on the submerged portion of said pile surrounded by said sheet, and band members that extend about said pile at vertically spaced portions thereof to hold said stiffener means against movement away from said pile.

5. A construction as set forth in claim 4 wherein said band members each include a resilient open-ended hoop that when relaxed assumes a generally spiral configuration of smaller diameter than said pile.

6. A construction as set forth in claim 4 wherein said band members each include an elastic strip having a length smaller than the diameter of said pile and formed at its ends with means to connect said ends.

7. In a piling construction: a partially submerged, structure-bearing wooden pile, a sheet of substantially Waterproof, pliable material wrapped around said pile in substantially circumferential configuration, said sheet having a pair of opposite longitudinal edges in juxtaposition extending generally longitudinally of said pile, vertical stiffeners aiiixed to said opposite longitudinal edges of said sheet, auxiliary buffer wrap means encircling said sheet and pile at elevations subjected to greater Wear than the portion of said sheet disposed between the mud line and the water level; and fastening means connecting said stiffener means, sheet and auxiliary buffer wrap means to said pile with said sheet closely surrounding said pile for substantially the full vertical length of said sheet to define a generally circumferential Water-filled space between said pile and said sheet, with water circulation between said space and the water surrounding said sheet being restricted to thereby render the water in said space stagnant to prevent marine borer attack on the submerged portion of said pile encased by said sheet.

8. In a piling construction: a partially submerged, structure-bearing wooden pile, a sheet of substantially waterproof, pliable synthetic plastic material wrapped around said pile in substantially circumferential configuration, said sheet having a pair of opposite longitudinal edges in juxtaposition extending generally longitudinally of said pile, vertical stiifeners aflixed to said opposite longitudinal edges of said sheet, and fastening members that are engaged with said pile at vertically spaced portions thereof to cause said sheet to closely surround said pile for substantially the full vertical length of said sheet to define a generally circumferential water-filled space between said pile and said sheet, with water circulation between said space and the water surrounding said sheet being restricted to thereby render the water in said space stagnant to prevent marine borer attack on the submerged portion of said pile encased by said sheet.

9. In a piling construction: a partially submerged, structure-bearing wooden pile, a sheet of pliable substantially waterproof synthetic plastic material placed around said pile in substantially cylindrical configuration with a pair of opposite longitudinal edges disposed substantially parallel one another and extending generally longitudinally of said pile, elongated generally longitudinally extending stiffener means cooperatively associated with both of said edges to cause said sh et to closely surround said pile whereby circulation of the ambient water between said sheet and said pile is inhibited to thereby render said ambient water stagnant to prevent marine borer attack on the submerged portion of said pile surrounded by said sheet, and fastening members that are engaged with said pile at vertically spaced portions thereof to hold said stiffener means against movement away from said pile.

' (References on following page) References Cited in the file of this patent UNITED STATES PATENTS Culver Oct. 9, 1877 Frantz Mar. 27, 1888 5 Cripps Jan. 20, 1891 Sudden Dec. 26, 1893 Clines Feb. 6, 1894 Brown May 26, 1896 Hindes Jan. 25, 1910 10 Helm Oct. 7, 1913 Ripley Jan. 12, 1915 FOREIGN PATENTS Germany Oct. 23, 1891