Patent Publication Number: US-3874318-A

Title: Mounting assembly for small outboard motors

Description:
United States Patent [191 Langley Apr. 1, 1975 MOUNTING ASSEMBLY FOR SMALL OUTBOARD MOTORS John A. Langley, Zion, Ill.  
 [73] Assignee: Outboard Marine Corporation,  
 Waukegan, Ill.  
  22 Filed: Mar. 15,1974  
  211 Appl. N0.;4s1,ss3  
 [75] Inventor:  
 Primary E.ruminerTrygve M. Blix Assistant Examiner-Sherman D. Basinger Altornev, Agent, or FirmMichael, Best &amp; Friedrich [57] ABSTRACT Disclosed herein is an outboard motor including a propulsion unit having an upper unit, a lower unit carrying a propeller, and an elongated, tubular member connecting the upper and lower units. The propulsion unit is pivotally supported by a support assembly from a mounting bracket mounted on a boat hull for movement between an operating position where the tubular member is generally upright outboard of the boat and the lower unit is submerged in the water and a storage position where the tubular member is generally horizontal and the lower unit is located inboard of the boat. The support assembly includes a support member fixedly connected to the tubular member at a location intermediate the upper and lower units, a first sleeve slidably mounted on the tubular member below the support member, a second sleeve slidably mounted on the tubular member above the support member, and a pair of links respectively pivotally connected to the first and second sleeves and pivotally connected at spaced locations to the mounting bracket.  
 13 Claims, 4 Drawing Figures PATENTEDAPR 1 I975 lfll lF-Ll MOUNTING ASSEMBLY FOR SMALL OUTBOARD MOTORS I BACKGROUND OF THE INVENTION This invention relates to outboard motors for boats and, more particularly, to mounting arrangements for small outboard motors.  
  Low-powered, electrically-operated outboard motors are used for fishing, particularly when a low&#39;speed, silent operation of the boat is desired. These small mo tors are mounted on the boat in a manner so they can be withdrawn from the water and retained inside the boat in a retracted position when the boat is to be propelled at normal speed by a higher horsepower motor or to be transported. When in the retracted position, the entire motor, including the propeller, preferably should be located inboard of the boat. In order to minimize the effort required for moving the motor between the operating and storage positions, the motor mount desirably should be arranged so that the motor is swung through as small an arc as possible.  
  Examples of prior art outboard mounting arrangements are disclosed in the following US. patents:  
 SUMMARY OF THE INVENTION The invention provides an outboard motor including a propulsion unit having an upper unit, a lower unit carrying a propeller, means connecting the upper and lower units including an elongated member, a bracket adapted to be mounted on a boat hull, and means mounted on the elongated member and pivotally connected to the bracket for supporting the propulsion unit from the boat and for affording movement of the propulsion unit between an operating position where the elongated member is generally upright outboard of the boat and the lower unit is submerged in the water and a storage position where the elongated member is generally horizontal and the lower unit is located inboard of the boat.  
  More specifically, there is provided a support member which is fixedly connected to the elongated member at a location intermediate the upper&#39;and lower units, a first sleeve means which is slidably mounted on the tubular member between the support member and lower unit and is engaged by the support member to support the-propulsion unit in the operating position and a second sleeve means which is slidably mounted on the tubular member between the support member and the upper unit. Arcuate movement of the propulsion unit is provided by first and second link means which are respectively pivotally connected to the sleeve means and are pivotally connected to the bracket for pivotal movement relative to the bracket between the operating and storage positions.  
  In a preferred embodiment, a latch means is provided for releasably and selectively holding the first link means in the operating and storage positions. Also, means can be provided for limiting the pivotal movement of the first link means relative to the bracket in the direction toward the storage position so as to establish the angular position of the elongated member to the vertical, and thus the propeller trim, when the propulsion unit is in theoperating position. In further accordance with the invention, the limiting means comprises a stop member which is vertically adjustable relative to the bracket so that the propeller trim can be adjusted.  
  One of the principal features of the invention is the provision of an improved mounting arrangement for an outboard motor whereby the outboard motor can be moved between an operating position and a storage position with a minimum of effort.  
  Another of the principal&#39;features of the invention is the provision of such a mounting arrangement including a latching mechanism which is operable to selectively and releasably retain the outboard motor in either the operating or storage position.  
  Another of the principal features of the invention is the provision of such a mounting arrangement including means for conveniently adjusting the propeller trim.  
  Another of the principal features of the invention is the provision of such a mounting arrangement whereby the propeller section of the outboard motor is automatically retracted to a location inboard of the boat during movement of the outboard motor from an operating to a storage position.  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view of an outboard motor which embodies various of the features of the invention and which is shown in the storage position.  
  FIG. 2 is a fragmentary view of the outboard. motor of FIG. 1 shown in the operating position.  
  FIG. 3 is a fragmentary, top view of the outboard motor shown in FIG. 1 taken along the line designated 33 in FIG. 1.  
  FIG. 4 is an end view of the outboard motor shown in FIG. 3.  
 DESCRIPTION OFTI-IE PREFERRED EMBODIMENTS Before explaining the invention in detail,,it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawing. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purposes of description and should not be regarded as limiting.  
  Illustrated in the drawings is an outboard motor 10 havinga propulsion unit 12 including a lower unit 14 which has an immersible housing 15 encasing an electric motor (notshown) for driving a propeller 16 rotatably mounted in the housing 15. The lower unit 14 is secured to the lower end of an elongated, tubular member 18 which carries suitable wiring for connecting a boat battery (not shown) to the lower unit motor. Located on the upper end of the tubular member 18 is an upper unit 20 which can include the actuating portion of a steering mechanism (not shown) by which the tubular member 18 can be selectively rotated for steering the lower unit 14. In the illustrated construction, the tubular member 18 comprises the so-called motor tube of the propulsion unit. The tubular member 18 can be a tubular housing which surrounds and extends parallel with the motor tube. Fixedly mounted on a boat hull 22 is a mounting bracket 24.  
  In accordance with the invention, the propulsion unit 12 is supported from the mounting bracket 24 by a support assembly 26 which provides pivotal movement of the propulsion unit 12 relative to the mounting bracket 24 between an operating position where the tubular member 18 is generally upright outboard of the boat and the lower unit 14 is submerged in the water (FIG. 2) and a storage position where the tubular member 18 is generally horizontal and the lower unit 14 is located inboard of the boat (FIG. 1).  
  More specifically, the support assembly 26 includes a support member 28 fixedly connected to the tubular member 18 at a point intermediate the lower unit 14 and the upper unit 20, a first or lower sleeve 30 slidably mounted on the tubular member 18 below the support member 28, and a second or upper sleeve 32 slidably mounted on the tubular member 18 above the support member 28.  
  When the propulsion unit 12 is in the operating position (FIG. 2), the support member 28 seats against the lower sleeve 30 and thereby limits the depth at which the lower unit 14 is submerged in the water. The support member 28 preferably is mounted on the tubular member 18 for selective and axial movement relative to the tubular member 18 so that the submersion depth of the lower unit 14 can be adjusted. In the specific construction illustrated, the support member 28 is in the form of a split sleeve clamp including leg portions 33 which encircle the tubular member 18 and can be tightened into gripping engagement with the tubular member 18 by tightening a bolt 34 threadably connecting the leg portions 33.  
  Located on the lower end of the tubular member 18 near the lower unit 14 for limiting relative axial movement between the tubular member 18 and the lower sleeve 30 is a first pair of diametrically opposed stops or lugs 35 (one shown). Located on the upper end of the tubular member 18 near the upper unit for limiting relative axial movement between the tubular member 18 and the upper sleeve 32 is a second pair of diametrically opposed stops or lugs 36 (one shown).  
  The lower sleeve 30 is pivotally mounted to a first or outboard link unit 37 which, in turn, is connected to the mounting bracket 24 for pivotal movement relative to the mounting bracket 24 between an extended or operating position (FIG. 2), and a retracted or storage position (FIG. 1). The upper sleeve 32 is pivotally connected to a second or inboard link unit 38 which, in turn, is pivotally connected to the mounting bracket 24 for pivotal movement relative to the mounting bracket 24 between the operating and storage positions.  
  More specifically, the mounting bracket 24 includes a base member 39, a first pair of laterally spaced, upstanding ears 40 which are located near the outboard end of the base member 39 and a second pair of laterally spaced, upstanding ears 42 (one shown) which are located near the inboard end of the base member 39. The outboard link unit 37 includes a pair of laterally spaced parallel, arcuate links 44 which at one end are pivotally connected to the lower sleeve 30, such as by diametrically opposed pins 46, and at the other end are pivotally connected to the mounting bracket 24 by a pin 48 extending transversely between the cars 40. The inboard link unit 38 includes a pair of laterally spaced, parallel, elongated arms 50 (one shown) which at one end are pivotally connected to the upper sleeve 32, such. as by diametrically opposed pins 52 (one shown) and at the other end are pivotally connected to the mounting bracket 24 by a pin 53 extending transversely between the ears 42.  
  Connected to the support member 28 for effecting movement of the propulsion unit 12 between the operation and storage positions is a pull rope 54. During movement of the link units 37 and 38 between the operating and storage positions, the lower sleeve travels through a generally arcuate path defined by the pivot radius of the links 44 and the upper sleeve 32 travels through a generally arcuate path defined by the pivot radius of the arms 50.  
  Provided on each of the mounting bracket ears 40 for limiting the arcuate travel of the link unit 37 in the counterclockwise direction as viewed in FIGS. 1 and 2, is an arcuate bearing surface 55 which is engaged by a respective link 44 to serve as a stop therefor. The bearing surfaces 55 are arranged to assist in locating the tubular member 18 in a substantially horizontal position when the link units 37 and 38 are in the storage position.  
  When the outboard link 37 is in the operating position, the links 44 bear against a stop member 56 which is provided on the outboard end of the mounting bracket 24 and which limits arcuate movement of the outboard link unit 37 in the clockwise direction as viewed in FIGS. 1 and 2. In accordance with a preferred embodiment of the invention, means are provided for selectively adjusting the vertical position of the stop member 56 relative to the mounting bracket 24 so as to facilitate adjustment of the angular position of the tubular member 18 relative to the vertical, and thus the trim of the propeller 16, when the propulsion unit 12 is in the operating position. While various arrangements can be used, in the specific construction illustrated, the opposite ends of the stop member 56 are slidably mounted in respective guide slots 58 provided in a pair of laterally spaced flanges 60 extending upwardly from the mounting bracket base member 39. The stop member 56 is supported on the base member 39 by a threaded member or stud 62 which is threaded through the stop member 56 and bears against the base member 39. The vertical position of the stop member 56 can be adjusted by rotating the stud 62 either clockwise or counterclockwise.  
  Means are provided for releasably and selectively latching the outboard link unit 37 in the operating and storage positions. While various arrangements can be used, in the specific construction illustrated, such means includes a latch member 64 which is slidably mounted in a guideway 66 provided in the mounting bracket base member 39 and includes a pair of spaced, upstanding latch elements 68 and 70 having respective hook portions 72 and 74. The hook portions 72 and 74 are engageable with a pin 76 extending transversely between the links 44 to releasably hold the outboard link unit 37 in the operating position and in the storage position, respectively. The hook portions 72 and 74 can be provided with respective camming edges 78 and 80 to facilitate initial movement of the pin 74 into latching engagement.  
  Means are provided for biasing the latch elements 68 and 70 in the direction to effect engagement of the respective hook portions 72 and 74 with the pin 76. While other arrangements can be used, in the specific construction illustrated, such means comprises a compression spring 82 located between the inboard end of the latch member 64 and the base member 39 to urge the latch member 64 to the right as viewed in FIGS. 1-3. Suitable means, such as a pull rope 84 attached to the latch element 70, is provided for moving the latch member 64 against the action of the spring 82 (i.e. move the latch member 64 to the left as viewed in FIGS. 1 and 2) to release the latch elements 68 and 70 from the pin 76.  
  Accordingly, when the propulsion unit 12 is in the operating position, the hook portion &#39;72 of the latch element 68 is in engagement with the pin 76. To move the propulsion unit 12 from the operating position to the storage position, the pull rope 84 is first pulled rearwardly to release the latch element 68 from the pin 76 and the pull rope 54 then is pulled upwardly to swing the propulsion unit 12 towards the storage position. After the upper sleeve 32 has been swung past the apogee of its arcuate path, the pull rope 54 can be used to control downward movement of the propulsion unit 12 to the storage position and to ease passage of the pin 76 into the hook portion 74 of the latch element 70.  
  Since the sleeves 30 and 32 are slidably mounted on tubular member 18, the upper sleeve 32 is free to slide axially on the tubular member 18 (while the support member 38 remains in engagement with the lower sleeve 30 due to the weight of the propulsion unit 12) during initial movement of the propulsion unit 12 towards the storage position. During continued movement of the propulsion unit 12 towards the storage position, the upper sleeve 32 eventually engages the lugs 36 and the tubular member 18 thereafter is moved axially with respect to the lower sleeve 30, by the pulling action applied thereto by the upper sleeve 32, until the lugs 35 are engaged by the lower sleeve 30. Thus, by  
 the time the propulsion unit 12 reaches the storage po-&#39; sition (FIG. 1), the lower unit 14 has been automatically retracted to a position inboard of the boat.  
  Referring to FIGS. 1 and 2, it can be seen that the links 44, the bearing surfaces 55 and the arms 50 are arranged so that, while being moved between the operating and storage positions, the arms 50 travel through an arc (e.g. 155) larger than the travel arc (e.g. 120) for the links 44. With this arrangement, the tubular member 18 assumes a generally horizontal position when the propulsion unit 12 is in the storage position. Also, since the radius of the arcuate path through which the lower end of the propulsion unit 12 travels is relatively short, the effort required to move the propulsion unit 12 between the operating and storage position is considerably less than that required with many prior art mounting arrangements.  
  During return movement of the propulsion unit 12 from the storage position toward the operating position, the combined effect of the weight of the propulsion unit and the relative axial movement between the tubular member 18 and the sleeves 30 and 32 causes the propulsion unit 12 to be returned to the operating position where the support member 28 engages the lower sleeve 30.  
  Various of the features of the invention are set forth in the following claims.  
 I claim:  
  1. An outboard motor comprising a propulsion unit including an upper unit, a lower unit carrying a propeller, and means connecting said upper and lower units including an elongated member, a support member fixedly connected to said elongated member at a location intermediate said upper and lower units, a bracket adapted to .be mounted on a boat hull, first sleeve means slidably mounted on said elongated member between said support member and said lower unit for relative movement between said elongated member and said first sleeve means, said first sleeve means engaging said support member when said propulsion unit is in an operating position, second sleeve means mounted on said elongated member between said support member and said upper unit for relative movement between said elongated member and said second sleeve means, and first and second link means respectively pivotally connected to said first and second sleeve means and pivotally connected to said bracket for pivotal movement of said link means relative to said bracket to afford movement of said propulsion unit between an operating position and a storage position.  
  2. An outboard motor according to claim 1 including latch means for releasably and selectively holding said first link means in positions corresponding to the operating and storage positions.  
  3. An outboard motor according to claim 2 wherein said latch means comprises a pin on said first link means, a latch means on said mounting bracket and including a pair of spaced latching elements having a hook portion, said latching elements being located such that said pin is latchably engaged by the hook portion of one of said latching elements when said first link means is in the operating position and said pin is latchably engaged by the hook portion of the other of said latching elements when said first link means is in the storage position.  
  4. An outboard motor according to claim 3 wherein said latch member is movably mounted relative to said bracket and said latch means further includes means biasing said latch member in the direction to retain engagement of said latch elements with said pin and means connected to said latch member for releasing said latch member against the action of said biasing means.  
  5. An outboard motor according to claim 1 including means for limiting the pivotal movement of said first link means relative to said bracket in the direction towards the operating position to thereby establish the angular position of said elongated member relative to the vertical when said propulsion unit is in the operating position.  
  6. An outboard motor according to claim 5 wherein said limiting means comprises a stop member mounted for vertical movement relative to said bracket and located to act as a seat for said first link means when said first link means is in the operating position, and means for adjusting the vertical position of said stop member relative to said bracket.  
  7. An outboard motor according to claim 1 including means for limiting the pivotal movement of said first link means relative to said mounting bracket in the direction toward the storage position to thereby assist in locating said elongated member in the horizontal posi- 7 tion when said propulsion unit is in the storage position.  
  8. An outboard motor according to claim 1 including stop means on said elongated member for limiting axial movement of said first and second sleeve means toward said lower unit and said upper unit, respectively.  
  9. An outboard motor according to claim 1 including means for selectively adjusting the axial position of said support member on said elongated member and thereby varying the depth at which said lower unit is submerged in the water when said propulsion unit is in the operating position.  
  10. An outboard motor according to claim 9 wherein said support member is a clamp slidably mounted on said tubular member and said adjustment means comprises means for selectively tightening said clamp into gripping engagement with said elongated member.  
  11. An outboard motor comprising a propulsion unit including an upper unit, a lower unit carrying a propeller, and means connecting said upper and lower units including an elongated member, a support member fixedly connected to said elongated member at a location intermediate said upper and lower units, a bracket adapted to be mounted on a boat hull, first sleeve means slidably mounted on said elongated member between said support member and said lower unit for relative movement between said elongated member and said first sleeve means, said first sleeve means engaging said support member when said propulsion unit is in an operating position, second sleeve means mounted on said elongated member between said support member and said upper unit for relative movement between said elongated member and said first sleeve means, first and second link means respectively pivotally connected to said first and second sleeve means and pivotally connected to said bracket for pivotal movement of said link means relative to said bracket to afford movement of said propulsion unit between the operating position and a storage position, latch means for releasably and selectively holding said first link means in positions corresponding to the operating and storage positions, means for limiting the pivotal movement of said first link means relative to said bracket in the direction toward the operating position to thereby establish the angular position of said elongated member relative to the vertical when said propulsion unit is in the operating position, and means for limiting pivotal movement of said first link means relative to said bracket in the direction toward the storage position to thereby assist in locating said elongated member in a horizontal position when said propulsion unit is in the storage position.  
  12. An outboard motor according to claim 11 wherein said latch means comprises a pin on said first link means, a latch member mounted for movement relative to said bracket and including a pair of spaced latching elements, said latching elements each having a hook portion being located such that said pin is latchably engaged by the hook portion of one of said latching elements when said first link means is in the operating position and said pin is latchably engaged by the hook portion of the other of said latching elements when said first link means is in the storage position,  
 means biasing said latch member in the direction to re-- turn engagement of said latch elements with said pin, and means for releasing said latch member against the action of said biasing means.  
  13. An outboard motor according to claim 12 including a stop member mounted for vertical movement relative to said bracket and located to act as a seat for said first link means when said first link means is in the operating position, and means for adjusting the vertical position of said stop member relative to said bracket.  
  UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. Dated April 1975 Inventor s) John A. Langley Page 1 of 3 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:  
  Columns 5 and I- as shown on the attached sheet should be included, but will apply exclusively to the grant.  
 of a steering mechanism (not shown) by which the tubular member 18 can be selectively rotated for steering the lower unit 14. in the illustrated construction, the tubular member 18 comprises the so-called motor tube of the propulsion unit. The tubular member 18 can be a tubular housing which surrounds and extends parallel with the motor tube. Fixedly mounted on a boat hull 22 &#39;is a mounting bracket 24.  
  in accordance with the invention, the propulsion unit 12 is supported from the mounting bracket 24 by a support assembly 26 which provides pivotal movement of the propulsion unit 12 relative to the mounting bracket 24 between an operating position where the tubular member 18 is generally upright outboard of the boat and the lower unit 14 is submerged in the water (FIG. 2) and a storage position where the tubular member 18 is generally horizontal and the lower unit 14 is located inboard of the boat (FIG. 1).  
  More specifically, the support assembly 26 includes a support member 28 fixedly connected to the tubular member 18 at a point intermediate the lower unit 14 and the upper unit 20, a first or lower sleeve 30 slidably mounted on the tubular member 18 below the support member 28, and a second or upper sleeve 32 slidably mounted on the tubular member 18 above the support member 28.  
  When the propulsion unit 12 is in the operating position (FIG. 2), the support member 28 seats against the lower sleeve 30 and thereby limits the depth at which the lower unit 14 is submerged in the water. The support member 28 preferably is mounted on the tubular member 18 for selective and axial movement relative to the tubular member 18 so that the submersion depth of the lower unit 14 can. be adjusted. In the specific construction illustrated, the support member 28 is in the form of a split sleeve clamp including leg portions 33 which encircle the tubular member 18 and can be tightened into gripping engagement with the tubular member 18 by tightening a bolt 34 threadably connecting the leg portions 33.  
  Located on the lower end of the tubular member 18 near the lower unit 14 for limiting relative axial movement between the tubular member 18 and the lower sleeve 30 is a first pair of diametrically opposed stops or lugs 35 (one shown). Located on the upper end of the tubular member 18 near the upper unit for limiting relative axial movement between the tubular member 18 and the upper sleeve 32 is a second pair of diametrically opposed stops or lugs 36 (one shown).  
  The lower sleeve is pivotally mounted to a first or outboard link unit 37 which, in turn, is connected to the mounting bracket 24 for pivotal movement relative to the mounting bracket 24 between an extended or operating position (FIG. 2), and a retracted or storage position (FIG. 1). The upper sleeve 32 is pivotally connected to a second or inboard link unit 38 which, in turn, is pivotally connected to the mounting bracket 24 for pivotal movement relative to the mounting bracket 24 between the operating and storage positions.  
  More specifically, the mounting bracket 24 includes a base member 39, a first pair of laterally spaced, upstanding ears 40 which are located near the outboard end of the base member 39 and a second pair of later- .ally spaced, upstanding cars 42 (one shown) which are located near the inboard end of the base member 39. The outboard link unit 37 includes a pair of laterally spaced parallel, arcuate links 44 which at one end are Page 2 of 3 pivotally connected to the lower sleeve 30, such as by diametrically opposed pins 46, and at the other end are pivotally connected to the mounting bracket 24 by a pin 48 extending transversely between the cars 40. The inboard link unit 38 includes a pair of laterally spaced, parallel, elongated arms 50 (.one shown) which at one end are pivotally connected to the upper sleeve 32, such as by diametrically opposed pins 52 (one shown) and at the other end are pivotally connected to the mounting bracket 24 by a pin 53 extending transversely between the ears 42.  
  Connected to the support member 28 for effecting movement of the propulsion unit 12 between the operation and storage positions is a pull rope 54. During movement of the link units 37 and 38 between the operating and storage positions, the lower sleeve 30 travels through a generally arcuate path defined by the pivot radius of the links 44 and the upper sleeve 32 travels through a generally arcuate path defined by the pivot radius of the arms 50.  
  Provided on each of the mounting bracket cars 40 for limiting the arcuate travel of the link unit 37 in the counterclockwise direction as viewed in FIGS. 1 and 2, is an arcuate bearing surface 55 which is engaged by a respective link 44 to serve as a stop therefor. The bearing surfaces 55 are arranged to assist in locating the tubular member 18 in a substantially horizontal position when the link units 37 and 38 are in the storage position.  
  When the outboard link 37 is in the operating position, the links 44 bear against a stop member 56 which is provided on the outboard end of the mounting bracket 24 and which limits arcuate movement of the outboard link unit 37 in the clockwise direction as viewed in H68. 1 and 2. In accordance with a preferred embodiment of the invention, means are provided for selectively adjusting the vertical position of the stop member 56 relative to the mounting bracket 24 so as to facilitate adjustment of the angular position of the tubular member 18 relative to the vertical, and thus the trim of the propeller 16, when the propulsion unit 12 is in the operating position. While various arrangements can be used, in the specific construction illustrated, the opposite ends of the stop member 56 are slidably mounted in respective guide slots 58 provided in a pair of laterally spaced flanges 60 extending up wardly from the mounting bracket base member 39. The stop member 56 is supported on the base member 39 by a threaded member or stud 62 which is threaded through the stop member 56 and bears against the base member 39. The vertical position of the stop member 56 can be adjusted by rotating the stud 62 either clockwise or counterclockwise.  
  Means are provided for releasably and selectively latching the outboard link unit 37 in the operating and storage positions. While various arrangements can be used, in the specific construction illustrated, such means includes a latch member 64 which is slidably mounted in a guideway 66 provided in the mounting bracket base member 39 and includes a pair of spaced. upstanding latch elements 68 and 70 having respective hook portions 72 and 74. The hook portions 72 and 74 are engageable with a pin 76 extending transversely between the links 44 to releasably hold the outboard link unit 37 in the operating position and in the storage position, respectively. The hook portions 72 and 74 can be provided with respective camming edges 78 and 80 I Page 3 of 5.. UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Tatent No. 3 318 Dated pril 1 1975 Inventofls) John A. Lan lev It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:  
 O Column 5, line 41, &#34;thereto&#34; should be thereon--.  
 Column 6 line 33 After &#34;latch&#34;, delete &#34;means&#34; insert membere Signed and Sealed this ninth Day Of March1976 [SEAL] Attest: 0  
 I RUTH C. MAHSON C. MARSHALL DANN Attestmg Ojfwer Commissioner ufParents and Trademarks