US2578535A

US2578535A - Manually operated rotor oar for boats

Info

Publication number: US2578535A
Application number: US99559A
Authority: US
Inventors: Graci Anthony
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-06-11
Filing date: 1949-06-11
Publication date: 1951-12-11
Anticipated expiration: 1968-12-11

Description

Dec. 11, 1951 Filed June 11, 1949 A. GRACI MANUALLY OPERATED ROTOR-OAR FOR BOATS 2 SHEETS-SHEET l Dec. 1 1, 195.] GRAC] 2,578,535

MANUALLY OPERATED ROTOR-OAR FOR BOATS Filegi June 11, 1949 2 SHEETSffSHEET 2 INVENTOR. ANTHONY GRACI v Patented Dec. 11, 1951 OFFICE MANUALLY OPERATED ROTOR OAR FOR BOATS Anthony Graci, Bronx, N. Y. Application June 11, 1949, Serial N 0. 99,559

13 Claims. 1 E

This invention relates to new and useful improvements in boats, as those of the ordinary rowboat sizes, and, more particularly, the aim is to provide a novel and valuable type of manually operated propulsion and steering means for a boat of the kind indicated or of other appropriate class which, by virtue of the unique advantages afforded by the new propulsion and steering means, may be employed for providing what is aptly designated as a rotor-oar water-borne craft.

According to the present invention, the manually operable propulsion and steering means proposed is characterized by the combination of a pair of bearings suitably factory inbuilt into the boat or arranged for easy attachment to the sides of a boat hull near the gunwales thereof; an

athwart-extending shaft which at a central portion along its length is shaped to incorporate a pair of cranks at 180 angular displacement one from another, said shaft near each of its outer ends having fixed thereon a collar or equivalent and said shaft at its opposite end portions outwardly extended beyond said collars being axially movably journalled in said bearings; a pair of outboard paddle groups with each such groups having a hub journalled on one of the two lastnamed end portions of the shaft, the paddles of each wheel being oar-like and at the outer ends of arms radiating spider-fashion from the Wheels hub; with each hub at its outer side carrying one of the two complementary members of a clutch and with the other member of each clutch splined or keyed on the shaft outward of the associated clutch member adjacent to a hub; and a pair of identical minor assemblies each comprising a shiftable member incorporating a fork, ring or the like for straddling or embracing the shaft at a point therealong betweenone of said collars and the adjacent one of said hubs, a spring means for coacting with the similar spring means of the other of said minor assemblies for equalizingly or balancingly acting on both said shiftable members and for normally maintaining both clutches effective, thereby to render negligible the muscular effort required to move the shaft slightly axially in one direction or the other for then temporarily disabling one clutch or the other and so for steering in one direction or the other; with the last-named spring means in association with further spring means for normally maintaining both clutches effective, for straight ahead propulsion.

Because of these provisions, there is made practicable a relatively simple and inexpensive yet rugged and delicately manually controllable propulsion and steering means for a boat, and even for a standard size and type of row-boat, wherein there is attainable a high speed of propulsion at relatively small muscular effort while affording an ideal exercise for the healthful development of arm, leg and torso muscles; wherein steering is particularly easily and readily effected; and wherein various other advantages are present as will be pointed out or become apparent hereinafter.

For further comprehension of the invention, and. of the objects and advantages thereof, reference will be had to the following description and accompanying drawing, and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Fig. 1 is a side elevational view of a boat formed with a propulsion means in accordance with the present invention.

Fig. 2 is a plan view of Fig. 1.

Fig. 3 is an enlarged partial transverse vertical sectional view taken on the line 3-3 of Fig. 2.

Fig. 4 is a sectional view taken on the line 4--4 of Fig. 3.

Fig. 5 is a reduced partial vertical sectional view taken substantially on the line 5-5 of Fig. 3.

Fig. 6 is a view similar to a portion of Fig. 3, but illustrating a modification of the present invention.

The manually operable oars, according to the first form of the invention shown in Figs. 1 to 5, are shown applied to a row-boat l0, having an outer sheathed gunwale H at each side and interiorly fitted with the usual bow seat l2, stern seat l4 and midship seat l5.

Transverse to the boat l0 and along a line within convenient hand hold reach of a person on the seat l5 in ordinary double oar rowing position, a shaft ll is extended, with the two crank formations I8 and I9 thereof, these the two cranks already mentioned, having at their intermediate or handle portions a circular path of swing appropriate to the seated location of said person, with the latter facing forward or toward the bow carrying' the seat [2.

Bearings 28 are provided for rotatively and axially slidably supporting the shaft l1. The bearings 20 are engaged over the tops of the gunwales 7 II at opposite sides of the row-boat l0 slightly forward of the midship seat 15, as shown in Fig. 2. The bearings 29 are secured in position on the'gunwales II by removable bolts 2| held in position by winged nuts 22. All parts of the propelling mechanism of the present invention are supported by the bearings 23 so that when the bolts 21 are removed the bearings 28 and all the mechanism supported thereby can be lifted clear of the row-boat H3.

The ends of the shaft ii are slidably and rotatively extended through hubs Z3 comprised of inner hub portions 23* and mating outer hub portions 23 The bearings 29 have separate top portions 24; removably secured in position by removable bolts 25. The inner hub portions 23 are formed with integral bearing portions 26 which are rotatively but non-slidably retained in the bearings by the removable top portions 24.

The adjacent faces of the

hub portions

23 and 23* are formed with matching semi-circular recesses 21 which form holes which extend radially of the hub portion and which open to the periphery thereof to have the inner ends of car stems 28 mounted therein. The holes formed by the recesses 2'5 are somewhat smaller in diameter than the diameter of the oar stems 28 so as to securely clamp the car stems 33 in position in the holes when the hub portions are securell clamped together by nut and bolt assemblies 25.

The car stems 23 extend radially from the hubs 23 as shown in Fig. 1, and have mounted on the outer ends thereof paddles 33. The oar stems s are of a length so that the paddles 36 will have a path of circular sweep to be successively dipped into the water below the water line 3!, see Fig. l, as the shaft ii is rotated.

The outer faces of the outer hub portions 23 are integrally formed with reduced clutch portions 32 formed with clutch teeth 33 of any known configuration. Slidably mounted on the outer ends of the shaft ii beyond the hubs 23 there are clutch discs 33 formed with clutch teeth 35 matching the clutch teeth 33 of the clutch portions 32. The outer faces of the clutch discs are formed with reduced end portions slidably received in tubular housings 31.

The tubular housings 3'; are formed of opposed sections releasably secured together by screws as, see Fig. i. The outer ends of the sections forming the tubular housings 31 are closed by semi-circular wall portions 33 which engage opposed flat surfaces 48 milled into the ends of the shaft if, as shown in Fig. 4. The

engagement of the semi-circular wall portions 39 with the opposed flat surfaces serves to non-rotatively and non-sliclably secure the housings 3? to the shaft I? so that when the shaft is rotated the housings will rotate therewith.

Means is provided for slidably but non-rotatively connecting the clutch discs 34 to the housings 3? so that those clutch discs 34 will rotate with the housings when the shaft if is rotated. That means comprises pins ll which extend laterally from diametrically opposite sides of the reduced end portions 38 of the clutch discs 34 and which are slidably extended through complementary elongated slots 32 formed in the opposed sections of the tubular housings 3i. Coil springs as of the expansion type are located in the tubular housings 3i and operate between the adjacent faces of the reduced end portions 33 of the clutch discs 3 and the semi-circular wall portions 39 of the tubular housings 31.

The coil springs 43 function to urge the clutch discs 33 inward relative to the tubular housings 3i and toward the clutch portions 32 to retain the clutch teeth 33 and 35 engaged so that the hubs 23 and the oars carried thereby will be rotated when the shaft If is rotated.

Equalizing devices are provided for urging the shaft it into a neutral position with relation to the bearings 23 in which the clutch teeth 33 and 35 at each end of the shaft will be engaged, as shown in Fig. 3, so that the two hubs 23 will be turned in unison as the shaft H is turned. The equalizing devices are comprised of equalizing levers M which are pivotally supported intermediate of their ends upon brackets 65 which extend laterally inward from the bearings 2i), by means of pivot pins it. The top ends of the equalizing levers i!) are bifurcated and have their tines t! extended vertically along opposite sides of the shaft i? inward of the bearings 20. Cup-shaped members 48 are secured to the shaft ii inward of the equalizing levers M, by means or" pins 39. The cup-shaped members 48 are secured to the shaft if at suitable locations to engage between the tines M, as clearly shown in Figs. 2 and 3.

Contraction springs 5s have their ends securely attached to the bottom ends of the equalizing levers 2d and their other ends securely attached to the bottom ends of downward extensions 5i formed on the bearings 23. The contraction springs as are of equal strength and somewhat stronger than the springs 43 so as to pivot the equalizing levers 54 into positions in which the tines will be engaged against the outer faces of the cup-shaped members 48. Thus, the contraction springs '55 function to urge the shaft E'i into a centrally located position with relation to the bearings 23 in which the ratchet teeth 33 and 35 at each end of the shaft ll will be engaged.

The operation of the boat constructed in accordance with the present invention is as follows:

With the shaft I? retained in the centrally located position, shown in Figs. 2 and 3, by the contraction springs 53, the shaft I! can be rotated in one direction or the other by gripping the cranl; formations i8 and is to similarly turn the hubs 23 and the cars carried thereby to propel the row-boat it either in a forward or a rearward direction, depending upon the direction of rotation of the shaft If.

Should it be desired to turn the row-boat in one direction or the other, this is simply accomplished by pushing the shaft [1 in the direction in which it is desired to turn while simultaneously rotating the shaft.

This will load the equalizing spring 53 at the end of the shaft i! in which it has been pushed and free the spring 59 at the other end of the shaft. As the shaft if was pushed in the direction in which it was desired to turn, the shaft ll moved axially relative to the hubs 23 which are retained stationary by reason of their r-otative engagement with the bearings 28. However, at the end of the shaft H in the direction in which it was pushed, the tubular housing 3? is moved away from the respective hub 23 and the respective clutch disc 34, which is urged toward that hub 23 by the expansion spring 43, until the inner ends of the slots 42 contact the pins cl. When that contact occurs the clutch disc 3:; will move with the tubular housing 31 away from the respective hub 23 separating the clutch teeth 33 and 35 at that side. This separation of the clutch teeth 33 and 35 will leave the hub 23 on that side of the row-boat free, which is the near side of the turn which is to be executed.

At the other end of the shaft 17, on the outside of the turn which is to be executed, the reverse action takes place. That is, the shaft ll carries the tubular housing 37, at that other end, with it toward the respective hub 23. That action loads the respective spring 43 and presses the adjacent clutch disc 34 more firmly toward the clutch portion 32 causing the clutch teeth 33 and 35 at that end of the shaft to be more firmly engaged. Therefore, as the shaf U I! is turned with it in its axially shifted position, the hub 23 on the outside of the turn to be executed will be turned independently of the hub 23 on the inside of the turn causing the row-boat to be turned as long as the shaft I I is rotated and held in its axially shifted position. When the force holding the shaft I! in its axially shifted position is relaxed, the contraction springs 50 will urge the shaft I! back to its centrally located position in which the ratchet teeth 33 and 35 at each end of the shaft will be in engagement so that rotations of the shaft H will again rotate both of the hubs 23 in unison for for ward or rearward propelling of the row-boat H In the modification of the invention shown in Fig. 6, the tubular housing 3'! is of one-piece construction and is slipped over the end of the shaft H and the adjacent reduced end portion 36 of the clutch disc. The tubular housing 37 is fixedly and non-rotatively secured to the shaft I? by set screws 60 threaded through diametrically opposite sides of the closed end of the tubular housing to be tightened against the shaft ll. If desired, the end of the shaft I? could be formed with holes to receive the ends of the set screws 60.

The inner end of the tubular housing is formed with the elongated slots 42 extended parallel to the length of the shaft [1 and pins 4!, in the form'of bolts, are passed through the slots 32 and threaded into receiving holes formed in the reduced end portion 36 so as to slidably but nonrotatively connect the clutch disc to the tubular housing 31. Removalof the bolts 4 l and loosening of the set screws 60 will permit the tubular housing 31' to be slipped off the end of the shaft H.

In other respects this modification of the invention is similar to the first form and like reference numerals are used to identify like parts in all of the views.

In the forms of the invention illustrated and described both the springs 43 and 50 are used to maintain the shaft I? in a neutral position; however, it is appreciated that the rowing mechanism of the present invention could be effectively used with either the springs 43 or the springs 53.

While I have illustrated and described the preferred embodiments of my invention, it is to be understood that I do not limit myself to the precise constructions herein disclosed and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claims.

Having thus described my invention, what I claim as new and desire to secure by United States Letters Patent is:

1. A manually operable propulsion and steering mechanism fora boat having a seat for a person to operate said mechanism, said mechanism comprising a transverse shaft, bearings for securement to the boat at opposite sides thereof and supporting said shaft to be moved axially, the shaft having near the middle point of its length a pair of crank portions oppositely offset from the general line of extension of the main portions of the shaft, said crank portions spaced in the direction of length of the shaft for grasp of each crank portion by a different hand of the person, a pair of propulsion instrumentalities each incorporating a hub-structure and a plurality of outwardly radiating oars carrying paddle formations at their outer ends, each of said instrumentalities being at a different one of the two sides of the boat and outboard relative thereto, a pair of clutches each having the two complementary members thereof on said shaft outboard relative to the hub-structure at that side of the boat, in each clutch the inner one of said members being fixed relative to the adjacent hub-structure, means rotatively connecting the outer member of each clutch to the shaft for rotation therewith and also for endwise movement with said shaft relative to its respective inner clutch member, and a plurality of springs for normally maintaining the members of both. clutches in engagement to render both clutches normally effective, said shaft being axially movable for disabling the clutch at the starboard or port side of the boat and at the same time permitting the clutch at the other side of the boat to remain effective.

2. A manually operable propulsion and steering mechanism for a boat having a seat for a person to operate said mechanism, said mechanism comprising a transverse shaft, bearings for securenient to the boat at opposite sides thereof and supporting said shaft to be moved axially, the shaft having near the middle point of its length a pair of crank portions oppositely offset from the general line of extension of the main portions of the shaft, said crank portions spaced in the direction of length of the shaft for grasp of each crank portion by a different hand of the person, a pair of propulsion instrumentalities each incorporating a hub-structure and a plurality of outwardly radiating oars carrying paddle formations at their outer ends, each of said instrumentalities being at a different one of the two sides of the boat and outboard relative thereto, a pair of clutches each having the two complementary members thereof on said shaft outboard relative to the hub-structure at that side of the boat, in each clutch the inner one of said members being fixed relative to the adjacent hub-structure, means rotatively connecting the outer member of each clutch to the shaft for rotation therewith and also for endwise movement with said shaft relative to its respective inner clutch member, and a plurality of springs for normally maintaining the members of both clutches in engagement to render both clutches normally efiective, said shaft being axially movable for disabling the clutch at the starboard or port side of the boat at the same time permitting the clutch at the other side of the boat to remain effective, said hub-structures being split and each of such split portions having radially extending registering half round recesses, the

root ends of said oars being seated in and girthed by said recesses, and clamping means for conpling said split portions thereby to grip and anchor said root ends.

A manually operable propulsion and steering mechanism for a boat having a seat for a person to operate said mechanism, said. mechanism comprising a transverse shaft, bearings for securement to the boat at opposite sides thereof and supporting said shaft to be moved axially, the shaft having near the middle point of its length a pair of crank portions oppositely offset from the general line of extension of the main portions of the shaft, said crank portions spaced in the direction of length of the shaft for grasp of each crank portion by a different hand of the person, a pair of propulsion instrumentalities each incorporating a hub-structure and a plurality of outwardly radiating oars carrying paddle formations at their outer ends, each of said instrumentalities being at a different one of the two sides of the boat and outboard relative thereto, a pair of clutches each having the two complementary members thereof on said shaft outboard relative to the hub-structure at that side of the boat, in each clutch the inner one of said members being fixed relative to the adjacent hub-structure, means rotatively connecting the outer member of each clutch to the shaft for rotation therewith and also for endwise movement with said shaft relative to its respective inner clutch member, a plurality of springs for normally maintaining the members of both clutches in engagement to render both clutches normally effective, said shaft being axially movable for disabling the clutch at the starboard or port side of the boat and at the same time permitting the clutch at the other side of the coat to remain effective, and means including a pair of elements each fixed on the shaft near a different end thereof at a point inboard relative to said hub-structures {or moving said shaft to a centrally located position with relation to said bearings.

l. A manually operable propulsion and steering mechanism for a boat having a seat for a person to operate said mechanism, mecha nism comprising a transverse shaft, bearings for securement to the boat at opposite sides thereof and supporting said shaft to be moved axially, the shaft having near the middle point of its length a pair of crank portion oppositely offset from the general line of extension of the main portions of the shaft, said crank portions spaced in the direction of length of the shaft for grasp of each crank portion by a different hand of the person, a pair of propulsion instrumentalities each incorporating a hub-structure and a plurality of outwardly radiating oars carrying paddle formations at their outer ends, each of said instrumentalities being at a different one of the two sides of the boat and outboard relative thereto, a pair of clutches each having the two complementary members thereof on said shaft outboard relative to the huh-structure at that side of the boat, in each ciutch the inner one of members being fixed relative to the adjacent hubstructure, means rotatively connecting the outer member of each clutch to the shaft for rotation therewith and also for endwise movement with said shaft relative to its respective inner clutch member, a plurality of springs for normally maintaining the members of both clutches in engagement to re: or both clutches normally effective, said shaft being axially movable for disabling the clutch at the starboard or port side of the boat and at the same time permitting the clutch at the other side of the boat to remain effective, means including a pair of elements each on the shaft near a difierent end thereof at a t relative to said hubstructures for moving said shaft to a centrally n relation to said bearings, said last-1 ned further including, for coastion w l each of said a pivotally mounted equalizing lever, and springs acting on each of said le ers, said last-named springs being arranged individually to yield according as 8 the shaft is endwisely moved in one direction or the other.

5. A manually operable propulsion and steering mechanism for a boat having a seat for a person to operate said mechanism, comprising a transverse shaft, bearings for securement to the boat at opposite sides thereof and supporting said shaft to be moved axially, the shaft having near the middle point of its length a pair of crank portions oppositely offset from the general line of extension of the main portions of the shaft, said crank portions spaced in the direction of length of the shaft for grasp of each crank portion by a different hand of the person, a pair of propulsion instrumentalities each incorporating a hub-structure and a plurality of outwardly radiating oars carrying paddle formations at their outer ends, each of said instrumentalities being at a different one of the two sides of t -e boat and outboard relative thereto, a pair of clutches each having the two complementary members thereof on said shaft outboard relative to the hub-structure at that of the boat, in each clutch the inner one of said i iembers being fixed relative to the adjacent hub-structure, means rotativay connecting the outer member of each clutch to the shaft for rotation therewith and also for endwise movement with said shaft relative to its respective inner clutch member, and a plurality of springs for normally maintaining the members of both clutches in engagement to render both clutches normally effective, said shaft being axially movable for disabling the clutch at the starboard or port side of the boat and at the same time permitting the clutch at the other side of the boat to remain effective, said bearings being removably secured to the top of the boats hull at opposite sides of the boat, each of said bearings rotatively carrying one of said hub-structures.

S. A manually operable propulsion and steering mechanism for boat having a seat for a sccurement to the boat at opposite sides thereof and supporting said shaft to be moved axially, the shaft having ear the middle point of its length a pair of crank portions oppositely offset from the general line of extension of the main portions of the shaft, said crank portions spaced in the direction of length of the shaft for grasp of each crank portion by a different hand of the person, a pair of propulsion instrumentalities each incorporating a hub-structure and a plurality of outwardly radiating oars carrying paddle formations at their outer ends, each of said instrumentalities being at a different one of the two sides of the boat and outboard relative thereto, a pair of clutches each having the two complementary members thereof on said shaft outboard relative to the hub-structure at that side of the boat, in each clutch the inner one of said members being fixed relative to the adjacent hubstructure, means rotatively connecting the outer member of each clutch to the shaft for rotation therewith and also for endwise movement with said shaft relative to its respective inner clutch member, a plurality of springs for normally mainta ng the members of both clutches in engagement to render both clutches normally effective, said shaft being axially movable for disabling the clutch at the starboard or port side of the boat and at the same time permitting the clutch at the other side of the boat to remain effective, and means including a pair of elements each fixed on the shaft near a different 51d thereof at a point inboard relative to said hubstructures for moving said shaft to a centrally located position with relation to said bearings, said last-named means further including, for coaction with each of said elements, a pivotally mounted equalizing lever, and springs acting on each of said levers, said last-named springs being arranged individually to yield according as the shaft is endwisely moved in one direction or the other, the first named springs including a pair of like springs and the second-named springs including a pair of like springs.

7. A manually operable propulsion and steering mechanism for a boat having a seat for a person to operate said mechanism, said mechanism comprising a transverse shaft, bearings for securement to the boat at opposite sides thereof and supporting said shaft to be moved axially, the shaft having near the middle point of its length a pair of crank portions oppositely offset from the general line of extension of the main portions of the shaft, said crank portions spaced in the direction of length of the shaft for grasp of each crank portion by a different hand of the person, a pair of propulsion instrumentalities each incorporating a hub-structure and a plurality of outwardly radiating oars carrying paddle formations at their outer ends, each of said instrumentalities being at a different one of the two sides of the boat and outboard relative thereto, a pair of clutches each having the two complementary members thereof on said shaft outboard relative to the hub-structure at that side of the boat, in each bers being fixed relative to the adjacent hubstructure, means rotatively connecting the outer member of each clutch to the shaft for rotation therewith and also for endwise movement with said shaft relative to its respective inner clutch member, a plurality of springs for normally maintaining the members of both merit to render both clutches normally effective, said shaft being axially movable for disabling the clutch at the starboard or port side of the boat and at the same time permitting the clutch at the other side of the boat to remain effective, and means including a pair of elements each fixed on the shaft near a different end thereof at a point inboard relative to said hub-structures for moving said shaft to a centrall located position with relation to said bearings, said last-named means further including, for coaction with each of said elements a pivotally mounted equalizing lever, and springs acting on each of said levers, said last-named springs being arranged individually to yield according as the shaft is endwisely moved in one direction or the other, the firstnamed springs including a pair of like springs and the second-named springs including a pair of like springs, one of said pairs of springs being expansion springs.

8. A manually operable propulsion and steering mechanism for a boat having a seat for a person to operate said mechanism, said mechanism comprising a transverse shaft, bearings for securement to the boat at oppostie sides thereof and supporting said shaft to be moved axially, the shaft having near the middle point of its length a pair of crank portions oppositely offset from the general line of extension of the main portions of the shaft, said crank portions spaced in the direction of length of the shaft for grasp of each crank portion by a different hand of the person, a pair of propulsion instrumenclutch the inner one of said mernclutches in engage- 10 talities' each incorporating a hub-structure and a plurality of outwardly radiating oars carrying paddle formations at their outer ends, each of said instrumentalities being at a different one of the two sides of the boat and outboard relative thereto, a pair of clutches each having the two complementary members thereof on said shaft outboard relative to the hub-structure at that side of the boat, in each clutch the inner one of said members being fixed relative to the adjacent hubstructure, means rotatively connecting the outer member of each clutch to the shaft for rotation therewith and also for endwise movement with said shaft relative to its respective inner clutch member, a plurality of springs for normally maintaining the' members of both clutches in engagement to render both clutches normally effective, said shaft being axially movable for disabling the clutch at the starboard or port side of the boat and at the same time permitting the clutch at the other side of the boat to remain effective, and means including a pair of elements each fixed on the shaft near a different end thereof at a point inboard relative to said hub-structures for moving said shaft to a centrally located position with relation to said bearings, said last-named means further including, for coaction with each of said elements a pivotally mounted equalizing lever, and springs acting on each of said levers, said last-named springs being arranged individually to yield according as the shaft is endwisely moved in one direction or the other, the first-named springs including a pair of like springs and the second-harried springs including a pair of like springs, one of said pairs of springs being expansion springs, and the other pair thereof being contraction springs.

9. In combination with a boat having opposed gunwales, bearings removably mounted on the gunwales, tubular hubs rotatably and removably mounted in said bearings in end alignment, oars extending radially from said hubs, a crank shaft having its ends rotatively and slidably extended through and beyond said hubs, clutch teeth formed on the outer faces of said hubs, clutch discs rotatively and slidably mounted on the outer ends of said shaft and having clutch teeth arranged to engage the clutch teeth of said hub, tubular housings engaged over the free ends of said shaft and having their outer ends closed and their inner ends engaged over said clutch discs, means non-rotatively and non-slidably connecting said tubular housings to said shaft, means slidably but non-rotatively connecting said clutch discs to said housings, and a spring within each of said housings operating between the closed ends thereof and the adjacent ends of said clutch discs urging said clutch discs into a position in which said clutch teeth of said clutch discs will be engaged with the clutch teeth of said hubs.

10. In combination with a boat having opposed gunwales, bearings removably mounted on the gunwales, tubular hubs rotatably and removably mounted in said bearings in end alignment, oars extending radially from said hubs, a crank shaft having its ends rotatively and slidabl extended through and beyond said hubs, clutch teeth formed on the outer faces of said hubs, clutch discs rotatively and slidably mounted on the outer ends of said shaft and having clutch teeth arranged to engage the clutch teeth of said hub, tubular housings engaged over the free ends of said shaft and having their outer ends closed and their inner ends engaged over said clutch discs, means non-rotatively and non-slidably connecting said tubular housings to said shaft, means slidably but non-rotatively connecting said clutch discs to said housings, a spring within each of said housings operating between the closed ends thereof and the adjacent ends of said clutch discs urging said clutch discs into a position in which said clutch teeth of said clutch discs will be engaged with the clutch teeth of said hubs, said housings being formed of opposed sections having semi-circular end walls closing the said end thereof and engaging fiat surfaces milled into the extended end of said shaft, and screws releasably connecting said sections together forming the means non-rotatively and non-slidably connecting said housings to said shaft.

11. In combination with a boat having opposed gunwales, bearings reznovably mounted on the gunwales, tubular hubs rotatably and removably mounted in said bearings in end alignment, oars extending radially from said hubs, a crank shaft having its ends rotatively and slidably extended through and beyond said hubs, clutch teeth formed on the outer faces of said hubs, clutch discs rotatively and slidably mounted on the outer ends of said shaft and having clutch teeth arranged to engage the clutch teeth of said hub, tubular housings engaged over the free ends of said shaft and having their outer ends closed and 9 their inner ends engaged over said clutch discs, means non-rotativel and non-slidably connect ing said tubular housings to said shaft, means slidably but non-rotatively connecting said clutch discs to said housings, a spring within each of said housings operating between the closed ends thereof and the adjacent ends of said clutch discs urging said clutch discs into a position in which said clutch teeth of said clutch discs will be engaged with the clutch teeth of said hubs, said housings being formed of opposed sections having semi-circular end walls closing the said end thereof and engaging flat surfaces milled into the extended end of said shaft, and screws releasably connecting said sections together forming the means non-rotatively and non-slidably connecting said housings to said shaft, said lattermentioned means comprising pins extending from said clutch discs and engaging elongated slots formed in said housing and extended parallel to said shaft.

12. In combination with a boat having opposed gunwales, bearings removably mounted on the gunwales, tubular hubs rotatably and removably mounted in said bearings in end alignment, oars extending radially from said hubs, a crank shaft having its ends rotatively and slidably extended through and beyond said hubs, clutch teeth formed on the outer faces of said hubs, clutch discs rotatively and slidably mounted on the outer ends of said shaft and having clutch teeth position in arranged to engage the clutch teeth of said hub, tubular housings engaged over the free ends of said shaft and having their outer ends closed and their inner ends engaged over said clutch discs, means non-rotatively and non-slidably connecting said tubular housings to said shaft, means slidably but non-rotatively connecting said clutch discs to said housings, and a spring within each of said housings operating between the closed ends thereof and the adjacent ends of said clutch discs urging said clutch discs into a position in which said clutch teeth of said clutch discs will be engaged with the clutch teeth of said hubs, said housings being of one-piece construction, said first-mentioned means comprising set screws threaded through the closed end of said housings and tightened against the end of the shaft.

13. In combination with a boat having opposed gunwales, bearings removably mounted on the gunwales, tubular hubs rotatably and removably mounted in said bearings in end alignment, oars extending radially from said hubs, a crank shaft having its ends rotatively and slidably extended through and beyond said hubs, clutch teeth formed on the outer faces of said hubs, clutch discs rotatively and slidably mounted on the outer ends of said shaft and having clutch teeth arranged to engage the clutch teeth of said hub, tubular housings engaged over the free ends of said shaft and having their outer ends closed and their inner ends engaged over said clutch discs, means non-rotatively and non-slidably connecting said tubular housings to said shaft, means slidably but non-rotatively connecting said clutch discs to said housings, and a spring within each of said housings operating between the closed ends thereof and the adjacent ends of said clutch discs urging said clutch discs into a which said clutch teeth of said clutch discs will be engaged with the clutch teeth of said hubs, said housings being of one-piece construction, said first-mentioned means comprising set screws threaded through the closed end of said housings and tightened against the end of the shaft, said housings being formed with slots extended parallel to said shaft, said latterrnentioned means comprising bolts extended through said slots and threaded into said clutch discs.

ANTHONY GRACI.

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

UNITED STATES PATENTS Number Name Date 658,043 Pfautz Sept. 18, 1900 1,589,708 Lavigne June 22, 1926 1,600,084 Adolph Sept. 14, 1926