Improved oarlock

Abstract

This improved oarlock places the oar in front of the pin, as opposed to traditional oarlocks, which place the oar behind the pin. With the positions of the pin and the oar reversed, when the oarlock swivels, the effective inboard length of the oar is lengthened at the catch and reduced at the release, increasing the mechanical advantage at the catch. The benefit of relocating the oar is increased by lengthening the oarlock to place the oar farther in front of the pin. A tab attached to the forward outboard side of the oarlock contacts the oar and keeps the oar perpendicular to the oarlock, preventing a delay and reduction in stroke distance. An adaptor allows a prior art oarlock to be mounted so that the assembly can be placed on a pin attached to a boat, and used to gain the advantages of the improved oarlock of this invention.

Description

Improved OarlockBackground of the Invention

[0001] The earliest form of oarlocks on boats was just a notch or hole for the oar to go against or through. During rowing, the oar would push against the forward side of the notch or hole to propel the boat forward. The oar could also be placed between two pins, so the oar would push against the forward pin. The concept of having the oar or oarlock push against the boat or an attachment to propel the boat has historically been followed. In prior art related to rowing and oarlocks, the oar is above or behind the point of connection to the boat, so that the oar will push the boat forward.

[0002] In the development of competitive rowing, it was found desirable to reduce the resistance of the oar blade as it travels through the air during the recovery portion of the rowing stroke.This is done by turning the oar approximately 90 degrees from the position that it is in when immersed in water. In the turned position, only the thickness of the edge of the blade is passing through the air and generating air resistance. The surface of the edge of the blade is significantly smaller than the surface area of the face of the oar blade. This act of turning the oar during the recovery is called feathering the oar. Originally, feathering of oars during the recovery was allowed for by having a round oar in a round hole in the oarlock. With round oars going through a round hole in the oarlock, turning the oar to the face position during the stroke and to the edge position during recovery was entirely controlled by the skill of the rower.

[0003] To strengthen and protect the oars from wear and being damaged by the oarlocks, leather sleeves were placed around oars to cover the portion of the oar that passed through the oarlocks.

[0004] Later, to control the angle that the face of the blade of the oar presents to the water during the stroke, a sleeve with a flat portion on the outer layer / circumference was permanently attached to the shaft of the oar or scull. The flat on the sleeve is approximately parallel with the face of the blade of the oar. The sleeves with flats were used in oarlocks that had two flats that were approximately 90 degrees apart. One flat was positioned so the oar would be at the proper angle when the blade was in the water during the power stroke, and the other flat was positioned so that the flat of the oar would be against the flat on the sleeve when the oar was out of the water, and in the feathered position.1SUBSTITUTE SHEET ( RULE 26)

[0005] To determine and control the length of the oar that is inboard of the oarlock, a collar is attached around the sleeve. The additional height or thickness of the collar is enough to stop against the oarlock. The position of the collar can be moved along the oar to change the inboard and outboard lengths of the oar. Many people think of the inboard and outboard lengths of the oar as constants that remain the same during all the different phases of the rowing stroke.

[0006] As the oarlock swivels on the pin, if the centerline of the oar is not over the centerline of the pin, the effective inboard and outboard length of the oar will change. The amount of change in the effective length is determined by the direction and angle from perpendicular, the distance between the centerlines of the pin and the oar, and whether the oar is behind or in front of the pin. The text and figures of this disclosure explain why the effective inboard and outboard lengths of the oar change and when they change.

[0007] For many years, the standard design of the oarlocks used for competitive rowing competition have been constructed using prior art that places the oar behind the pin that the oarlock pivots or swivels on, to move the oar to the catch, stroke, release and recovery positions during the rowing stroke.

[0008] The field of prior art related to rowing and oarlocks includes three US Patents granted to (Alden) A. H. Rollins that are of interest. US Patent 700,827, Swivel Rowlock (Filed Aug. 8, 1901 & Granted May 27, 1902) Fig. 1 & Fig. 5 and US patent 1,488,836, Adjustable Support (Filed Nov. 13, 1922 & Granted April 1, 1924) Fig. 1 show oarlocks that swivel, in which the oar is shown placed in front of the pin or attachment on which the oarlock swiveled. The specifications of these patents did not mention that the oar was in front of the swivel. The claims of these two patents made no mention of the oar being placed in front of the pin or swivel attached to the boat, and they do not mention any advantage that would be gained or derived by placing the oar in front of the swivel pin or point of attachment of the oarlock.

[0009] The third patent granted to A. H. Rollins, US Patent 1,656,534, Rowlock (Filed Feb. 26, 1925 & Granted Jan. 17, 1928) Fig. 1 and Fig. 3 show the centerline of the oar placed in the normal location behind the swiveling point of the oarlock. The claims of this later patent only relate to the swivel mechanism and method of attaching the oarlock to the boat, and they do not mention an advantage that would or could be gained by placing the centerline of the oar in front of the pin or the point of the swivel. These figures in Rollins’ later patent corrected the oar / pin2SUBSTITUTE SHEET ( RULE 26)placement to that which was and still is considered to be proper placement - the oar behind the pin.

[0010] Because, as will be explained, the effect of having the oar located in front of the pin gives such a noticeable and significant mechanical advantage to the rower, and no mention is made in the text or claims of the first two patents issued to A. H. Rollins in 1902 and 1924 regarding the oar being in front of the pin, and the illustrations in the third patent show the oar located behind the pin, it can be assumed that the illustrations for the first two patents that deal primarily with the structural means of attaching the oarlocks to the boat were an error with respect to the location of the oar relative to the pin or swiveling point, and that this error was noticed later and corrected in the illustrations for the third patent issued to A.H. Rollins in 1928.Brief Summary of the Invention

[0011] The oarlock of this invention differs from prior art in that this oarlock places the oar in front of a pin attached to the boat. With the oarlock of this invention, the oarlock acts like a link in a chain to pull the boat forward. In addition to placing the oar in front of the pin, this invention also claims a greater mechanical advantage to the rower by deliberately increasing the length of this linking oarlock, the use of an extension tab that can be added to one side of the oarlock to maintain perpendicularity of the oar relative to the oarlock during the recovery portion of the stroke, and an adaptor bracket on which an oarlock of existing prior art can be mounted, that is constructed so that the assembly can be mounted on the swiveling pin attached to a boat, so the oarlock of prior art will be in front of the pin attached to the rigging of the boat and the mechanical advantages of the art of this invention can be used for propelling the boat.

[0012] The new art of the oarlock of this invention is the opposite of the prior art with respect to the position of the oar, in relation to the center of the swiveling pin that is attached to the rigging of the boat. In this disclosure, the “front” of the boat refers to the bow or the end of the boat that is first in the direction of travel, and anything in “front” of a given part of the boat would be closer to the “front” of the boat than that given part. In the prior art, the oar is located behind the pin, or closer to the stern or the back of the boat as it travels. In the new art of this invention using the oarlock or the adaptor bracket herein described, the oar is relocated to in front of the swiveling pin. With oarlocks of the old art, the swiveling of the oarlock makes the effective length of the inboard portion of the oar shorter, and the outboard length longer at the start of the3SUBSTITUTE SHEET ( RULE 26)rowing stroke. This causes a reduction in the mechanical advantage that occurs at the start of the rowing stroke. The impact of this reduction in the mechanical advantage is compounded by the fact that the reduction takes place when the speed of the boat is at its slowest rate of travel. With an oarlock of this new art that relocates the oar in front of the swiveling pin, this oarlock causes an increase in the effective length of the inboard position of the oar, and a reduction in the outboard length of the oar at the start of the stroke. This increase in the mechanical advantage at the beginning of the stroke, when it is most needed, is useful since the boat is moving slowest at the start of the stroke or catch. The art of the oarlock of this invention gives the rower the greatest mechanical advantage at the beginning of the stroke rather than at the end of the stroke, when the speed of the boat is fastest. This reversing of the time of the greatest mechanical advantage will help the rower in more quickly getting the speed of the boat up to a higher rate of travel.Brief Description of the Several Views of the Drawings

[0013] Figure 1 is a section view from the side of a prior art oarlock.

[0014] Figure 2 is a section view from the side of a novel oarlock, with extension structure not shown.

[0015] Figure 3B is top view of a prior art oarlock and section of oar, in a catch position.

[0016] Figure 3 A is a top view of a prior art oarlock and section of oar, in a perpendicular position.

[0017] Figure 3C is a top view of a prior art oarlock and section of oar, in a finish position.

[0018] Figure 4B is a top view of a novel oarlock with pins and section of oar, in a catch position.

[0019] Figure 4A is a top view of a novel oarlock with pins and section of oar, in a perpendicular position.

[0020] Figure 4C is a top view of -a novel oarlock with pins and section of oar, in a finish position.

[0021] Figure 5 is a top view of an oar attached to a prior art oarlock, shown in the catch B, perpendicular / middle A and release C positions.

[0022] Figure 6 is a top view of an oar attached to a novel oarlock, shown in the catch B, perpendicular / middle A and release C positions.4SUBSTITUTE SHEET ( RULE 26)

[0023] Figure 7 is a top view of an oar attached to a novel oarlock which is longer than that shown in Figure 6, shown in the catch B, perpendicular / middle A and release C positions.

[0024] Figure 8 is a section view from the side of the full length of a novel oarlock.

[0025] Figure 9 is a view from the side of a novel oarlock which is longer than that shown in Figure 8.

[0026] Figure 10 is a detail view from the side of a novel tab used to maintain oarlock perpendicularity during recovery.

[0027] Figure 11 is a view from the side of a prior art oarlock mounted on the pin of a novel adaptor bracket.Detailed Description of the Invention

[0028] The new art of the oarlock claimed in this invention is significantly different than that described in the patents issued to A. H. Rollins. The oarlock of this invention claims the significant mechanical advantage that is derived by deliberately placing the centerline of the oar in front of the pin. It further specifically states that the oar should be placed at least a distance of two diameters of the oar shaft in front of the center of the swiveling pin. The oarlock of this invention also claims the use of upper and lower pin bearing inserts having their holes at complementary offset angles that facilitate changing the angle at which the face of the blade of the oar is presented to the water. The oarlock of this invention also includes the use of a central core body of the oarlock to which an extension tab of new art can be attached onto either side, so that the same central core oarlock can modified to be used with oars on either side of the boat.

[0029] Figure 1 shows the cross section of an oarlock 30 of the prior art in the field of rowing. The oarlock 30 of the prior art is mounted on a pin 10 that is attached to the rigging of the boat. The pin 10 allows the oarlock 30 to be swiveled or turned to different positions during the cycle of the rowing stroke. With oarlocks 30 of the prior art, the oar is located behind the pin 10, and the centerline of the oar is indicated by the centerline mark + 22, and is behind the pin. The distance D- is the distance that the centerline mark + 22 of the oar is located behind the centerline 11 of the pin 10. During rowing, the oar will apply a force to the vertical face of the oarlock 30 in the direction of the large arrow 33. The oarlock 30 then pushes against the pin 10 attached to the rigging of the boat to propel the boat in the direction of travel 100.5SUBSTITUTE SHEET ( RULE 26)

[0030] Figure 1 shows several other parts that are commonly used on oarlocks 30 based on prior art.bushings 70 with the holes for the pin 10 at complimentary angles + and - are shown in the upper and lower holes of the tubular portion of the oarlock 30. A gate hole 82is configured to accept a cross pin that allows pivoting of a retainer bar, used to keep the oar in the oarlock in the event that the boat is submerged. A slot 85is an opening that accepts the other end of the pivoting retainer bar.

[0031] Figure 2 shows a cross section of an oarlock 30’ that is based on the new art of this invention. The significant difference between the oarlock 30 in Figure 1 based on prior art and this oarlock 30’ based on the new art of this invention is the difference in the location of the centerline mark + 22 relative to the location of the centerline 11 of the pin 10. With the oarlock 30 based on prior art the centerline mark + 22 of the oar is behind the centerline 11 of the pin 10. With the oarlock 30’ based on the art of this invention the centerline line mark + 22 which is the centerline 22 of the oar is located in front of the centerline 11 of the pin 10 that is attached to the boat. The distance from the centerline + 22 of the oar to the centerline 11 of the pin 10 is indicated by distance D+ (also shown in Figures 8 and 9). To conserve space, the view in Figure 2 of the oarlock 30' is a broken section. In practice, to take full advantage of the benefits of the art of this invention, an embodiment of oarlock 30’ need to have distance D+ of more the two (2) times the diameter of the oar, and up to six (6) times the diameter of the oar.

[0032] During rowing, the force applied by the oar will push against the forward face 33’ of the oarlock 30’ in the direction of the large arrow. That force will create a tension force in the oarlock 30’. The tension force will pull against the pin 10 attached to the boat, so that the boat will be pulled in the direction of travel 100. When the oarlock 30’ swivels on the pin 10 to the different position during the rowing cycle, it will change the effective inboard and outboard lengths of the oar.

[0033] Figurel and 2 also show several other parts that are commonly used on oarlocks 30 based on prior art. Insert bushings 70 configured to be placed in the holes for the pin 10 at complimentary angles + and - are shown in the upper and lower entrances of the tubular portion of the oarlock 30 and 30’. The gate hole 82 is configured to accept a cross pin that allows pivoting of a retainer bar used to keep the oar in the oarlock even if the boat is submerged. Slot 85 is an opening that accepts the other end of the pivoting retainer bar. The retainer bar 80 is shown in Figures 8, 9 and 11 of this disclosure.6SUBSTITUTE SHEET ( RULE 26)

[0034] The effect of reversing the location of the oar in relation to the pin 10 reverses the timing of the effect that swiveling of the oarlock 30 or 30’ on the pin 10 has on the effective lengths of the oar during the cycle of the rowing stroke. Figures 3A, 3B and 3C and Figures 4A, 4B and 4C explain the reversal of the timing of the changes in the effective lengths of the oar and the causes of this reversal.

[0035] Figures 3A, 3B and 3C are top views that show an oarlock 30 of the existing art in which the oar 20 is located behind the swiveling pin 10 relative to the direction of travel 100 of the boat. With oarlocks 30 of previous art, the oar 20 pushes against the forward or vertical leading stem 31 of the oarlock 30, the body of which is behind the swiveling pin 10. The force applied by the oar 20 to the oarlock 30 pushes against the pin 10 to push the boat forward. To keep the oar in place during the recovery portion of the rowing stroke, the oarlock 30 also has a vertical aft or trailing side 32. The oar 20 with a sleeve around it will stay between the leading stem 3 land trailing side 32 of the oarlock 30 during the cycle of the rowing stroke, while the oarlock 30 swivels on the pin 10.

[0036] Persons familiar with the art of rowing will understand the length of the oar and the motion of the oar and oarlock in relation to the force applied to the oar and the direction of travel of the boat. Figures 3A, 3B and 3C illustrate the effect that swiveling of a prior art oarlock 20 on the pin 10 has on the effective length increase of the oar. Only the intersection of the oar 20 and the oarlock 30 mounted on the swiveling pin 10 are shown with the direction of travel 100 of the boat, which is to the right. The relationship of the centerline 11 of the swiveling pin 10 to the centerline 22 of the oar 20 is shown in the three principal positions that occur during the rowing stroke. The three positions are: the perpendicular position A, the catch position B and the release position C. In the A position, the oar is perpendicular to the centerline of the boat and the line of travel 100. The perpendicular A position is thought of as being the center of the stroke. The catch position B is the start of the rowing stroke. In the catch position, the handle of the oar is as far toward the back of the boat as the rower can reach. In the catch position B, the rower raises the handle of the oar 20 so that the blade of the oar drops and enters the water. The rower then pulls the oar forward while the oarlock swivels on the pin 10 to reach the release position C. At the release position, the rower lowers the handle of the oar to lift the blade of the oar out of the water. The release position C is the finish or end of the application of power. From the release position C, the rower goes through the recovery phase of the rowing cycle. During recovery, the7SUBSTITUTE SHEET ( RULE 26)oar is rotated to the feathered position, and the handle of the oar 20 is moved back to the catch position B.

[0037] The perpendicular position A is the position that is used to establish the inboard and outboard lengths of the oar. To divide the oar 20 into the inboard and outboard lengths of the oar 20, a larger diameter collar 23 or “button” is attached around the oar over the protective sleeve around the portion of the oar 20 that goes through the oarlock 30. The thickness of the larger diameter collar 23 provides a face that contacts the inboard surface 32 of the oarlock 30 to control the inboard length of the oar 20.

[0038] In Figures 3A, 3B and 3C, in all three views of the positions, catch B, perpendicular A and release C, the centerlines 11 of the swiveling pin 10 are all shown on the line of the direction of travel 100. The oar 20 applies force to the forward face 33 of the oarlock 30. That force is applied to the pin 10 and converted into a force that acts along the direction of travel 100 of the boat. In the perpendicular position B, the centerline 22 of the oar 20 is in line with the centerline 11 of the pin 10, and both centerlines are based upon the direction of travel 100. The length of the oar 20 on either side of the line going in the direction of travel 100 arrow has not been changed. In this position there has been no swiveling and the effective length EL of the inboard length and outboard lengths of the oar 20 have not been changed.

[0039] When the oar 20 and oarlock 30 are swiveled on the pin 10 to the catch position B, the centerline 22 of the oar 20 moves back away from the line of travel 100. In the catch position B when the center line 22 of the oar 20 is located behind the pin 10, the effective inboard length of the oar has been shortened by the distance EL- and the effective outboard length of the oar has been increased by the distance EL-. This shortening of the effective inboard length and the increase in the effective outboard lengths reduces the mechanical advantage to the rower as compared with when the oar 20 and the oarlock 30 were in the perpendicular position A.

[0040] In the later portion of the rowing stroke, the oar 20 and oarlock 30 are swiveled on the pin 10 to the release position C. After the oar 20 and the oarlock are swiveled past the perpendicular position A, the swiveling will move the centerline 22 of the oar 20 in from the line of travel 100.

[0041] The distance EL+ that the centerline 22 of the oar 20 is in front of the line of travel 100 increases the effective inboard length and reduces the effective outboard length of the oar 20.8SUBSTITUTE SHEET ( RULE 26)

[0042] The length of the oar 20 on each side of the line of the direction of travel 100 has been changed by the swiveling of the oarlock 30 on the pin 10.

[0043] The collar 23 around the oar 20 has remained in the same position on the oar 20, but in the catch position B, the location of the centerline of the oar 22 has been moved out away from the line of the direction of travel 100 arrow; and in the finish position C, the centerline 22 of the oar 20 has been moved in from the line of travel 100. These changes in the location of the centerline 22 of the oar 20 show that the effective inboard and outboard lengths of the oar 20 have been changed by the oarlock 30 swiveling on the pin 10. The force that the oar 20 applies to the forward face 33 of the oarlock 30 is applied to the pin 10, and the force will only act along the line of travel 100. The force applied by the oar 20 to the oarlock 30 swiveling on the pin 10 will be applied along the line of travel 100. The swiveling of the oarlock 30 on the pin 10 applies the force as always coming from the location of the centerline 22 of the oar 20 in relation to the centerline of the pin 10. The amount of the reduction in the inboard effective length EL- of the oar 20 at the catch position B and the amount of the increase EL+ in the effective inboard length at the release position C can be calculated mathematically. To find the change in the effective length, the sine of the angle that the oar 20 is from being perpendicular to the line of travel is multiplied by the distance between the centerline 22 of the oar 20 and the centerline 11 of the pin 10.

[0044] Figures 4A, 4B and 4C show a top view of the intersection of a swiveling pin 10 and oar 20 and an oarlock 30’ based on the new art of this invention, in which the oar 20 is located in front of the swiveling pin 10. The effect of placing the oar 20 in front of the swiveling pin 10 reverses the positions in which the increase and the reduction in the effective lengths of the oar 20 occur during the cycle of the rowing stroke.

[0045] Figures 4A, 4B and 4C are similar to Figures 3A, 3B and 3C in that they all show the relationships between the centerline 22 of the oar 20 and the centerline 11 of the swiveling pin 10 in the three principal positions of the rowing stroke; perpendicular A, catch B and release C. In the perpendicular position A, the centerline 22 of the oar 20 in the oarlock 30’ is in line with the line of travel 100 of the boat. The perpendicular position is a neutral position, and in this position the oarlock 30’ of the new art does not cause any change in the mechanical advantage to the rower.9SUBSTITUTE SHEET ( RULE 26)

[0046] When the handle of an oar 20 in an oarlock 30' based on the new art that places the oar in front of the pin is moved forward toward the catch position B, swiveling of the oarlock 30’ moves the centerline of the oar 22 in the oarlock 30’ inward from the center line 11 of the pin 10 toward the center of the boat. When the centerline 22 of the oar 20 in the oarlock 30’ is moved in this direction, it increases the effective inboard length of the oar 20, and reduces the effective outboard length of the oar 20 by the same amount. EL+ is the distance that has been converted from the outboard length of the oar 20, and added to the effective inboard length of the oar 20. The increase in the effective inboard length of the oar is the EL+ distance.

[0047] With an oarlock 30’ based on the art of this invention, swiveling of the oar 20 in an oarlock 30” on a pin 10 toward the catch position results in an increase in the mechanical advantage to the rower. With the same force applied to the handle of the oar 20, the force that is applied to the pin to propel the boat will be increased (as compared to a prior art oarlock.) The actual amount of the increase in the inboard length of the oar and the reduction in the outboard length of the oar can be calculated. The change in effective lengths is the product of the distance between the centerline 22 of the oar 20 and the centerline 11 of the pin 10 times the sine of the angle that the oar is from being perpendicular to the line of travel 100.

[0048] When the handle of the oar 20 in the oarlock 30’ of this invention swivels forward from the perpendicular position A toward the catch position B, the oarlock 30’ of this invention gives a mechanical advantage to the rower that increases the force that is applied to the pin 10 to propel the boat. The formula for calculating the change in the effective length of the oar (sine of the angle times the distance between the centerline 22 of the oar 20 and the centerline 11 of the pin) shows that there are two ways to increase the mechanical advantage to the rower.

[0049] The first way would be to increase the angle that the oar 20 is brought to for the catch. The other way to increase the mechanical advantage would be to change the oarlock 30’. The change would be to make the oarlock structure longer with an increased distance between the centerline 22 of the oar 20 and the centerline 11 of the pin.

[0050] When the handle of the oar 20 in an oarlock 30’ of this invention is swiveled on the pin 10 back past the perpendicular position A to the release position C, it moves the centerline 22 of the oar 20 out from the line of travel 100. Moving the centerline 22 of the oar 20 out beyond the line of travel 100 reduces the effective inboard length of the oar 20, and increases the effective outboard length of the oar. This change reduces the mechanical advantage to the rower. The10SUBSTITUTE SHEET ( RULE 26)formula for calculating the change in the effective length of the oar shows that reducing the angle at the release will reduce the reduction in the mechanical advantage to the rower.

[0051] Examination of the three positions in Figures 4A, 4B and 4C teaches three things about how the art of this invention can be used to increase the mechanical advantage to the rower. First, the mechanical advantage can be increased by increasing the distance between the centerline 22 of the oar 20 and the centerline 11 of the pin 10. Second, the mechanical advantage can be increased by increasing the angle at the catch position B. Third, the loss of mechanical advantage at the end of the stroke can be reduced by reducing the angle at the release position C. The first method involves the construction of the oarlock 30’. The second and third methods involve changing the angle of the oar at the catch position B and release position C. Increasing the catch angle and reducing the release angle can both be accomplished by moving the pin forward. The need to move the pin back toward the stem has been created by the use the oarlock 30’ which relocates the oar 20 in front of the pin 10. Determination of the correct distance that the pin 10 should be moved back depends on several factors that include the oarlock’s designed length, the rower’s reach and the balance of the boat.

[0052] In Figures 4A, 4B and 4C, the ratio of the diameter of the oar 20 with a sleeve to the distance D+ is 1:2.5. In the illustration in Figures 8 and 9, the ratios of the oar 20 diameter 0 to the distance D+ (centerline 22 to centerline 11) are 1 :3 and 1 :3.5. These larger ratios are used to increase the mechanical advantage that the art of this invention offers to rowers.

[0053] In Figures 4A, 4B and 4C, an “L” shaped extension tab 60 is shown in all three views of the principal positions. The tab 60 is shown located near the forward outboard side 33’ of the vertical stem 31’ of the oarlock 30’. This tab 60 is a separate, related invention having useful new art that can be used to improve the advantage of oarlocks 30’, that places the oar 20 in front of the pin 10. The function of and the need for the tabs 60 will be explained in the text related to Figure 10 of this disclosure.

[0054] Figures 5, 6 and 7 all show a top view of oars mounted in oarlocks as they would swivel on pins 10 attached to boats as the oar is moved through the rowing stroke. The oars are shown in the three main positions; B - the catch or start of the stroke, A - the perpendicular or middle of the stroke and C - the release or end of the stroke. These figures show the changes that take place in the effective inboard and outboard length of the oars that are caused by the swiveling angle, the location of the oar behind or in front of the pin, and how far the oar is in front of the pin. The11SUBSTITUTE SHEET ( RULE 26)effective inboard and outboard lengths of the oar are measured from the end of the handle 21 of the oar or the end of the blade 25 of the oar to the centerline of the pin along the line of travel 100 of the boat. In all three figures, the angle of the catch B is 45 degrees in front of the middle / perpendicular A position, and the release is 35 degrees behind the middle / perpendicular A position. The dotted line shows the path of travel of the end of the oar handles.

[0055] Figure 5 shows the effect of an oarlock of prior art swiveling closely behind the pin 10. In the catch B position, the effective inboard length of the oar is shorter than the length in the perpendicular A position. In the release C position, the effective inboard oar length is slightly shorter than in the perpendicular A position, but it is still longer than in the catch B position. The distance from the end of the oar handle to the line of travel 100 is least at the catch B position of the stroke. This means that the mechanical advantage at the start of the stroke is smaller than during all the rest of the stroke. The inboard length of the oar and the mechanical advantage both increase as the oar comes to the middle of the stroke, and the length remains longer than at the catch B until the release C of the stroke. This series of changes is typical of oarlocks of prior art that have the oar located behind the pin 10.

[0056] Figure 6 shows the effect of an oarlock based on the art of this invention with the oar swiveling in front of the pin 10. The oar pushes against the vertical face 33’ of the vertical stem 31’ of the U-shaped portion of the oarlock that is opposite to the tubular chamber that goes over the pin 10. In Figure 6, the vertical face 33’ of the U-shaped portion of the oarlock 30’ that the oar pushes against is located at a distance of 4 times the diameter of the oar. In the catch B position, the effective inboard length of the oar and the mechanical advantage is more than that of the oarlock based on prior art, and the length is almost as long as the inboard length of the oar in the perpendicular A position. After the perpendicular A position, the inboard length shortens rapidly going toward the release C position. The change in timing of the increase and decrease in the mechanical advantage provided by locating the oar in front of the pin better matches the requirements for propelling a boat. Due to the interval when the oars are out of the water, the speed of the boat is slowest at the catch, and the increased mechanical advantage at this time will help to restore and even increase the speed of the boat. The reduction in inboard oar length and mechanical advantage after the perpendicular position will be less noticeable since the boat will be moving faster. With the greater boat speed at the end of the stroke, the reduced inboard length and increased outboard length will reduce the drawing speed of the hands needed at the release.12SUBSTITUTE SHEET ( RULE 26)

[0057] Figure 7 shows the effect that a longer oarlock based on the art of this invention with the oar swiveling in front of the pin 10, with the vertical face 33’ of the U-shaped portion of the oarlock that the oar pushes against located at a distance of 6 times the diameter of the oar. In the catch B position, the effective inboard length of the oar and the mechanical advantage is even greater than that of the shorter oarlock shown in Figure 6. With the oar farther in front of the pin 10, the inboard length of the oar at the catch B is virtually the same as the inboard length at the middle or perpendicular A position. This means that the travel of the handle of the oar will be in a nearly straight line from the catch B to the perpendicular A position. Although the handle travels in a straight line, the mechanical advantage will be decreasing, since the offset distance of the oar in front of the swiveling pin 10 will be increasing the outboard length of the oar. After the perpendicular A position, the inboard length of the oar decreases rapidly. Figures 6 and 7 both show that when the oar is located in front of the pin 10, the mechanical advantage increases by creating a longer inboard length at the start of the stroke. The effect of the greater force is further increased by the fact that that force is then applied to the oar blade along a shortened outboard effective oar length. Not until after the middle A position of the stroke when the speed of the boat has been increased, will the changes in the effective lengths be reversed, and the mechanical advantage be reduced.

[0058] Figure 8 shows a cross section of an oarlock 30’ of the art of this invention. The direction of the line of travel 100 in Figure 8 is to the left. The oarlock 30’ of this invention shown in Figure 8 consists of three functional or structural zones. Shown at the left is a U-shaped structure 35’ with an opening to hold the oar. Shown in the center is an extension structure 36’ zone that increases the distance between the inner vertical face 33’ of the U-shaped structure 35’ of the that the oar will push against. Shown at the right is a tubular chamber 37’ with openings that accept insert bushings 70 that go over the swiveling pin 10 that is attached to the rigging of the boat. The sectioned drawing in Figure 2 has the same three functional zones (35’, 36’ & 37’) that are shown in Figure 8, but the extension zone 36’ was omitted from Figure 2 to conserve space. The oarlock 30’ in Figure 8 is a preferred embodiment with dimensions that are typical of those that would be used to increase the mechanical advantage to be gained from the art of this invention. This places the vertical face 33’ that the oar 20 contacts at a distance of 3 U times the diameter of the oar 20 in front of the pin. The length D+ of the oarlock 30’ from the centerline 11 of the pin 10 to the centerline 22 of the oar 20 is approximately 3 times the diameter of the13SUBSTITUTE SHEET ( RULE 26)space or throat 40 of the oarlock 30’ for the oar 20. With oarlocks 30’ having the art of this invention, when the distance D+ is increased, the mechanical advantage to the rower at the catch position of the stroke is increased. The distance D+ from the centerline 22 of the oar 20 to the centerline 11 of the pin 10 should be at least twice the diameter of the oar 20 with a sleeve, or the throat 40 of the oarlock 30’, to gain a substantial benefit from the art of this invention.

[0059] The oarlock 30’ has the insert bushings 70 that allow the alignment of the oarlock with the pin 10 to be changed. A retainer bar 80 is shown going across the top of the throat 40 opening of the oarlock 30’. Retainer bars are used on the oarlocks of competing boats to insure that the oars 20 will stay attached to the boats. One end of the retainer bar 80 has a cross pin 81, and the other end of the retainer bar has threads 83 and a knurled nut 84. To install an oar in the oarlock 30’, the retainer bar can pivot up on the cross pin 81. After the oar is place, the retainer bar 82 can be brought down and the knurled nut 84 can be turned in to keep the retainer bar 82 in place.

[0060] Two holes 62 are shown in the forward vertical stem 31’ of the oarlock 30’. These holes are configured for attaching an extension tab. In Figures 4A, 4B and 4C, all three positions show the tab 60 in its position relative to the oarlock 30’. The tab is a related invention of new art that is useful with the oarlock 30’ of this invention. The tab 60 is shown in Figure 10 with cross section of the vertical stem 31’ of the oarlock 30’ . The text related to Figure 10 explains the new art of this tab.

[0061] Figure 9 shows an oarlock 30’ based on the art of this invention that is similar to the sectioned oarlock 30’ shown in Figure 8. The direction of travel 100 for a boat using this oarlock 30’ is to the right. The distance D+ from the centerline 11 of the swiveling pin 10 to the center of the oarlock 30’ is approximately 3 times the width of the throat 40 of the diameter of the oar 20. The increased distance for D+ gives the rower a greater mechanical advantage. With the oar three diameters in front of the pin 10, the path of travel of the handle of the oar when going from the perpendicular position to the catch will be changed from an arc into a line that is almost a straight line until it reaches the perpendicular position, see Figure 7, dotted arc from B to A. After the perpendicular position, the line of travel of the oar handle will curve out from the center of the boat - again, see Figure 7, dotted arc from A to C. The straightening of the line of travel of the oar handle to and from the catch will be welcomed by rowers. The arc for rowers14SUBSTITUTE SHEET ( RULE 26)using a single longer oar or sweep commonly goes quite a distance to the side, when using an oarlock of prior art 30 with the oar behind the pin, see Figure 5, dotted arc from B to A.

[0062] The function of the two holes 62 in the forward vertical stem 31’ of the throat 40 of the oarlock 30’ will be now be explained, as shown in Figure 10.

[0063] Tab 60 - Outboard Forward to Maintain Perpendicularity

[0064] Figure 10 shows an extension tab 60 that can be attached to the oarlock 30’ of this new art. The tab location on the oarlock 30’ is on the outboard forward 33’ stem of the throat 40 of the oarlock 30’. The tab is “L” shaped. The base leg 63 of the “L” has a hole or holes 64 through which threaded fasteners 66 can be inserted to attach the tab 60 to the oarlock 30’. The shape of the longer leg and face of the “L” shaped tab 60 is symmetrical, so that the tab can be attached to either side of the oarlock 30’. This allows the tab to be used on oars for either side of the boat. Figure 10 also shows two cross section views (31’A and 31’B) of the forward stem 31’ of the throat 40 of the oarlock 30’, with two holes 62 to which the tab 60 would be attached. The thickness of the oarlock 30’ alone is not enough to keep the oar from twisting across the throat 40 of the oarlock 30’ when the oar 20 is moved forward and back. The function of this tab 60 is to provide an extended surface that reduces the amount of twisting, and keeps the oarlock 30’ closer to being perpendicular to the oar 20 during the recovery portion of the rowing stroke.

[0065] In Figures 8 and 9, two holes 62 are shown in the forward vertical stem 31’ of the throat 40 of the oarlock 30’ that is farther from the pin 10. These holes 62 are shown in the approximate locations where they would be used for attaching the perpendicularity tab 60 that is a useful invention that keeps the oarlock 30’ closer to being perpendicular to the oar 20 during the recovery portion of the rowing stroke cycle while the oar is out of the water and in the feathered position. The two cross section views in Figure 10 of the forward stem 31’ of the throat 40 of the oarlock 30’ each having a pair of holes that correspond with two holes 64 in a perpendicularity tab 60.

[0066] Threaded fasteners 66 can be inserted through the two holes 64 in the tab 60 and the holes 62 in the outboard forward vertical stem 31’ of the throat 40 of the oarlock 30’, to attach the tabs 60 to the outboard forward vertical stem 31’ of the throat 40 of the oarlock 30’ . Two options are shown with respect to the holes 62 in the forward vertical stem 31’ of the throat 40 of the oar lock 30’. If the holes are tapped with threads, see 31’A, the tab 60 can be attached with bolts or screws alone. If the holes do not have threads, see 31 ’B, then nuts are needed. To15SUBSTITUTE SHEET ( RULE 26)prevent the nuts and the heads of the bolts or screws from contacting the collars around the oars, the holes 62 should be counterbored on both sides of the oarlock 30’, as shown at 31’B.

[0067] Oarlocks 30’ of this invention intentionally place the oar 20 far in front of the pin 10, in order to increase the mechanical advantage to the rower. The additional length of the oarlock 30’ based on the art of this invention increases the radius and length of the arc that the oar 20 being held in the throat 40 of the oarlock 30’ will need to move through during the cycle of the rowing stroke. The increased radius of this larger arc increases the tendency of the oarlock 30’ to lag behind the oar 20, and not remain perpendicular to the oar 20. The oarlock 30’ will lag and not move until the oar makes contact with both the inboard aft vertical leg 32’ of the oarlock 30’ and the outboard forward leg 31’ of the throat 40 of the oarlock 30’. The space in the throat 40 of the oarlock 30’ that allows this lag or twisting of the oar 20 in the throat 40 of the oarlock 30’ to happen is needed because the flats on the sleeves on the oar 20 that identify the position of the face of the blade of the oar 20 require additional space in the throat 40 of the oarlock 30’ to allow the oar 20 that is covered by the sleeve with the flat to be turned to the feathered position during the recovery portion of the rowing stroke cycle.

[0068] At the catch of the stroke, when the blade of the oar 20 is being lowered into the water, if the oar 20 has twisted in the oarlock 30’ and allowed the oarlock 30’ to lag behind being perpendicular to the blade of the oar, it will do the following three things that work against the rower.

[0069] First, the oar will not have been brought as far forward as it would have been if the oarlock 30’ had been perpendicular to the oar 20. The effect of the blade of the oar not being brought as far forward as it would have been if the oarlock 30’ had been perpendicular to the oar 20 shortens the stroke. Shortening the stroke reduces the effectiveness of the rower.

[0070] Second, the lack of perpendicularity reduces the distance between the centerline 22 of the oar 20 and the centerline 11 of the pin 10. This reduces the mechanical advantage at the catch.

[0071] Third, if the oarlock 30’ is not perpendicular to the oar 20, there will be a delay until the pressure of the oar 20 against the oarlock 30’ brings the oarlock 30’ back to being perpendicular to the oar 20. During this delay, the full power of the oar 20 cannot be applied to the oarlock 30’ and to the pin 10. This delay is noticeable and disconcerting to rowers that are used to immediately pulling against the heavy load that is imposed by the mechanical disadvantage placed on them by oarlocks of the prior art.16SUBSTITUTE SHEET ( RULE 26)

[0072] The tab 60 of this invention provides an extended forward outboard surface on the forward vertical stem 31’ of the throat 40 of the oarlock 30’. This extension on the oarlock 30’ forces the oarlock 30’ to stay closer to being perpendicular to the oar 20 during the recovery. In a preferred embodiment, the length L of the tab is at least half the diameter of the oar 20 with a sleeve. The length L of the tab 60 can be increased to one or one and one half times the diameter of the oar to further reduce the amount of twisting of the oarlock 30’. In a preferred embodiment, the height of the tab, meaning its base dimension, is comparable to the diameter of the oar and sleeve.

[0073] In addition to the benefits that the art of this invention offers to the rower, the perpendicularity tabs 60 also offer significant benefits to the manufacturers and producers of the oarlocks 30’. The perpendicularity tabs 60 are needed on the outboard forward vertical stem 31’ of the throat 40 of the oarlock 30’. Since oars are used on both sides of the boats, this means that the producers of oarlocks would need to make different oarlocks for the right side and left side of the boat. Since the extensions or tabs 60 of this invention can be installed on either side of an oarlock 30’, they eliminate the need to produce right hand oarlocks and left hand oarlocks. With the tabs of this invention, a single central core oarlock can be produced, and a tab 60 of this invention can be attached to either side of the oarlock as needed to allow the oarlock to be used on the right or left side of the boat as needed. The tabs of this invention reduce the amount of tooling needed to produce two different oarlocks 30’, and they eliminate the need to stock and inventory two different oarlocks 30’. When a single oarlock is needed for a longer oar or sweep, rather than a pair of oarlocks for the shorter sculls, there will be no confusion regarding which side of the boat the oarlock is to be used on.

[0074] The invention of this tab also claims the use of holes 62 through the forward vertical stem 31’ of the throat of the oarlock 30’, to be used for attaching the tabs 60 to either side of the oarlock 30’. The holes 62 through the forward vertical stem 31’ of the throat 40 of the oarlock 30’ can be tapped to eliminate the need to use nuts, or unthreaded holes can be used with counter sinks or counterbores on each side so that the heads of screws or nuts will not project and make contact with the collar 23 on the oar 20.

[0075] With the tabs 60, a central core oarlock 30’ having the holes 62 in the forward vertical stem 31’ of the throat 40 of the oarlock can be supplied with appropriate threaded fasteners 66,17SUBSTITUTE SHEET ( RULE 26)and the tab 60 can then be attached to either side of the oarlock 30’ so that the assembly of oarlock 30’ and tab 60 can be used on the right or left side of the boat.

[0076] The use of the tabs 60 of this invention also offer the potential for weight savings. The oarlocks 30’ of this invention need to withstand tension loads so they will most likely be made from metal. The loads on the tabs 60 are not high. The normal load on the tabs 60 is only that of keeping the oarlock perpendicular to the oar during the recovery, and at the very start of the catch, the tab 60 will see enough load to bring the oarlock 30’ to be fully perpendicular to the oar. The tab also needs to be strong enough to withstand unexpected loads of wave impacts and accidental catches. These anticipated loads allow the tabs to be produced from plastic material like those currently used to produce the oarlocks of prior art 30.

[0077] Figure 11 shows an adaptor bracket 90 on which an oarlock 30 based on prior art that places the oar 20 behind the pin 10 can be mounted on a pin 910 which is of the adaptor bracket, so that the oar 20 in the prior art oarlock 30 is positioned in front of the pin 10 attached to the boat that the adapter bracket swivels on. The resulting assembly places the oar in front of the pin 10 attached to the boat, so that the advantages of the new art can be used to propel the boat.

[0078] The principal features of the adaptor bracket 90 are a tubular portion 91 to engage the pin 10 attached to the boat, a strong lower beam 92 and a pin 910 on which the oarlock 30 of existing art can be mounted. The tubular chamber portion 91 of the adapter bracket 90 has holes in the upper and lower ends into which a pair of insert bushings 70 can be installed. The inside diameters of the insert bushings 70 should be compatible with the outside diameter of a swiveling pin 10 that is attached to a boat so that the adapter bracket 90 can be mounted on the rigging of the boat. The adaptor bracket 90 has a rigid lower beam 92 with a stiffening element 93 which is needed to resist the tension and bending forces that are applied during rowing. Near the end of the lower beam 92, a rigid pin 910 is firmly attached as part of the adapter bracket 90. The diameter and length of the rigid pin 910 are comparable with the dimensions of the insert bushings 70 that are normally used on commercially available oarlocks 30 based on prior art, so that an existing oarlock 30 can be installed on the pin 910 on the adaptor bracket 90 to make a composite oarlock assembly that can be used for rowing. To be functional, the adaptor bracket 90 needs to be provided with a point of attachment for keeping the prior art oarlock 30 restrained, and prevent it from swiveling. The means of keeping the aft facing side of the oarlock 30 in line and attached to the beam 92 of the adaptor bracket 90 can be wire, duct tape, a hose18SUBSTITUTE SHEET ( RULE 26)clamp, or another method. The beam 92 can have a restraining post 94 to which the wire, duct tape or hose clamp can be attached. The wire can go through a hole or eye (not shown) in the beam 92 of the adaptor bracket. Small holes can also be drilled through the oarlock 30 of exiting art without weakening it, for wires to go through.

[0079] This patent application contains three items of new art that are related to rowing. The three items of new art claimed in this invention are; 1. An oarlock that places the oar between two (2) and six (6) times the diameter of the oar in front of the pin. 2. A tab to be attached to the forward outboard side of the oarlock to keep the oarlock perpendicular to the oar during the recovery and catch portions of the rowing stroke. 3. An adaptor bracket on which an oarlock based on prior art can be mounted so that the assembly can be attached to the pin on a boat so that the composite assembly functions the same as an oarlock of the new art that places the oar in front of the swiveling pin.

[0080] All three of these inventions of new art can be used with oars of different sizes. There are two common sizes of oars: the shorter oars, two of which are used by each rower, and which may be called oars or sculls, each having a sleeved diameter of approximately 2 ’A inches or 64 mm; and the longer oar, only one of which is used by each rower which may be called an oar or a sweep, and has a sleeved diameter of approximately 3 inches or 76 mm. Based on these diameters and the ranges of distances from the pin to the face of the oarlock being 2 to 6 times the diameter of the sleeved oar, the distances would be 5 inches to 14 inches (127 mm to 355 mm) for the sculls and 6 inches to 18 inches (152 mm to 483 mm) for the longer sweeps.

[0081] The terms port and starboard are commonly used nautical terms to indicate the left and right side of a boat or ship when the viewer is facing forward. When a person is rowing a boat, they are facing backward, and the meaning of the terms port and starboard would be reversed. For this reason, the terms port and starboard are not used in this disclosure.

[0082] The terms right and left as used this disclosure refer to the right and left hands of the rower when they are seated in the boat, facing the rear of the boat, in the normal position for rowing.SUBSTITUTE SHEET ( RULE 26)

Claims

I claim:

1. An oarlock assembly, comprising a U-shaped structure, configured to receive a shaft of an oar, or the shaft of an oar with a sleeve installed thereon; a tubular chamber, configured to receive a swiveling pin to connect the oarlock assembly to a gunwale or outrigger of a boat; and an extension structure, positioned between a side of the U-shaped structure and the tubular chamber; wherein the U-shaped structure to receive the oar shaft is positioned in front of the swiveling pin, in relation to the boat’s direction of travel, when the oarlock assembly is installed on the gunwale or outrigger of a boat.

2. The oarlock assembly of claim 1, wherein the tubular chamber has an axial centerline; and wherein the U-shaped structure to receive the oar shaft has a first inner vertical surface located on a first stem adjacent to the extension structure (inner stem), and a second inner vertical surface located on a second stem opposite to the extension structure (outer stem); and wherein the distance between the tubular chamber centerline and the inner surface of the outer stem is at least twice the diameter of an oar’s shaft with a sleeve installed.

3. The oarlock assembly of claim 2, wherein the distance between the tubular chamber centerline and the inner surface of the outer stem is between two and six times the diameter of an oar’s shaft with a sleeve installed.

4. The oarlock assembly of claim 1, further comprising:20SUBSTITUTE SHEET ( RULE 26)one or more insert bushings configured to fit inside of top and bottom portions of the tubular chamber, alongside the swiveling pin, for the purpose of altering the alignment of the oarlock assembly on the swiveling pin.

5. An extension tab, configured to attach to a forward outboard side of an oarlock for the purpose of keeping an oar perpendicular to the oarlock during recovery and catch portions of a rowing stroke, the extension tab having a height similar to the diameter of an oar’s shaft with a sleeve installed, and a length greater than half the diameter of an oar’s shaft with a sleeve installed.

6. The oarlock of claim 1, wherein the outer stem is configured to receive an extension tab on either side of the oarlock’s outer stem, wherein the extension tab has a height comparable to the diameter of an oar’s shaft with a sleeve installed, and a length greater than half the diameter of an oar’s shaft with a sleeve installed.

7. An adaptor bracket for an oarlock, comprising: a tubular chamber with upper and lower ends, configured to receive a swiveling pin to connect the adaptor bracket to a gunwale or outrigger of a boat; an oarlock pin configured to receive a tubular chamber of an oarlock in a position that places an oar in the oarlock in front of the swiveling pin; and an extension structure positioned between the oarlock pin and the tubular chamber; wherein the distance between the axis of the tubular chamber and the axis of the oarlock pin is between three (3) and seven (7) times the diameter of an oar’s shaft with a sleeve installed.

8. The adaptor bracket of claim 7, wherein the upper and lower ends of the tubular chamber are configured to receive insert bushings alongside the swiveling pin, for the purpose of altering the alignment of the adaptor bracket on the swiveling pin.21SUBSTITUTE SHEET ( RULE 26)

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