US2815131A - Device for lifting boats - Google Patents

Description

Den 3, 1957 J. E. LUNSMAN El'A-L 2,8

DEVICE F03 LIFTING BOATS Filed March 20, 1953 2 Sheets-Sheet 1 INVENTOR. Moe/WA /v Zu/vsMA/v Dec. 3, 1957 J. E. LUNSMAN ETAL DEVICE. FOR LIFTING BOATS 2 Sheets-Sheet 2 Filed March 20, 1953 INVENTOR.

United States Patent thee 2,815,131 DEVICE FOR LIFTING BOATS John E. Lunsman and Norman F. Lunsman, Danbury, Wis., assignors to Lunsman Manufacturing Company, Inc., Daubury, Wis.

Application March 20, 1953, Serial No. 343,688 1 Claim. (Cl. 214-1) This invention relates to boat handling devices. invention, more specifically, lifting small boats from the upon their sides.

The desirability of a structure usable as set forth above is well appreciated. However, previous devices conceived for the same purpose have not, to our knowledge, found wide spread commercial favor. We believe this may be due to the fact that many of the prior art devices have been undesirably complex. Others, we believe, do not act with suitable speed and efiiciency upon a boat floating in the water, to hoist said boat and tilt the same on its side.

In view of the above, we have devised a boat lift which, summarized briefly, includes a main frame which can be mounted upon a dock, landing, or the like, adjacent a body of water.

Hingedly mounted on said frame, to swing in vertical planes, are boat support arms. These swing downwardly into positions in which they extend transversely of, and overlie, a boat floating in the water. When said arms are in these positions, flexible elements, end to the main frame and normally connected at their The has regard to a device for water and turning said boats may include reduction gearing, is then utilized to swing the arms and the supported boat upwardly, while tilting the boat on its side.

Among important objects of the invention are the following:

To devise an improved boat lift and turning device that can be manufactured at a minimum of cost and which will be of simple design;

To speed up and make easier the task of engaging the boat for lifting;

To devise a structure for the purpose set forth above which will be adapted to act upon boats of various sizes and types; and

To facilitate the lifting of boats to positions in which they can be readily repaired, cleaned, or maintained.

Other objects will appear from the following description, the claims appended thereto, and from the annexed drawings, in which like reference characters designate like parts throughout the several views, and wherein:

Figure 1 is a perspective view of a boat lifting and turning device formed in accordance with the present invention, as it appears when ready to lift a boat out of the water;

Figure 2 is an end elevational view, portions being broken away, the dotted lines showing the boat position after the boat has been lifted;

Figure 3 is an enlarged, detail sectional view taken on line 3-3 of Figure 2, showing the means for swinging the boat support arms upwardly and downwardly; and

Figure 4 is an enlarged, detail sectional view on line 'Manually operated means on the main frame, which means 2,815,131 Patented Dec. 3, 1957 44 of Figure 2, showing the connections of the boat support arms to the main frame.

The reference numeral 10 has been applied generally to a dock, landing, wharf, or the like. The reference numeral 12 has been applied generally to the lifting device constituting the present invention, and at 14 we have designated a conventional boat to be lifted.

The lifting device 12 includes a stationary, open main frame generally designated 16 having, at opposite ends thereof, tubular, vertical posts 18. Posts 18 are welded or otherwise rigidly connected, at their lower ends, to feet 20, which can be bolted to the landing 10.

Rigid at its opposite ends with, and extending between, the lower end portions of posts 18 is a lower longitudinal brace bar 22. An upper longitudinal brace bar 24 is rigid at its opposite ends with the upper ends of posts 18, and extends in parallelism with the horizontal bar 22.

Transverse brace members 26 are fixedly connected at one end to the lower ends of the respective posts 18. inclined braces 28 are fixedly connected at one end to the other ends of the transverse braces 26. The inclined braces 28 are rigid, at their other ends, with the upper ends of the posts 18.

Base blocks 30 underlie the rear ends of the brace members 26, 28, and provide means to which said rear ends can be bolted or otherwise fixedly attached.

From the description so far provided, it is seen that we utilize a stationary main frame having a vertically disposed front portion formed as an open, rectangular framework and comprised of posts 18, and bars 22, 24.

We believe that although the main frame 12 has been illustrated as being anchored to the landing, it might, quite possibly, be rollably mounted, for movement to selected locations. In these instances, the main frame could be chocked up at a particular location at which a boat is to be lifted from or returned to the water. Of course, if the main frame were rollably mounted, it would be necessary that weight be applied in the area of the rear ends of transverse braces 26, to counterbalance the boat 14.

An elongated, horizontally disposed shaft 32 is journaled at its opposite ends in bearings 34, a short distance below the upper longitudinal brace bar 24. One bearing 34 is mounted upon a bearing support plate 36 of right angled cross section, fixedly secured to the upper end portion of one post 18. The other bearing 34 (Figure 3) is mounted upon the vertically disposed, inwardly turned flange 38 of the vertical leg of an angular gear support plate 40. Gear support plate 40 has its vertical leg secured fixedly to the other post 18, the horizontal leg of said plate 40 extending to and being rigidly connected to the adjacent inclined brace 28.

Referring to Figure 3, the horizontal leg of plate 40 has an inturned longitudinal flange 42 on which is mounted a bearing 44 for the shaft of a small drive gear 46, said shaft having a crank 48 rigid therewith. In mesh with the gear 46 is a larger, driven gear 50, secured to one end of the shaft 32. A pawl 52 is pivotally mounted upon the upper end of plate 40, and gravitates, normally, to a position in which it will prevent rotation of the gear 50in one direction.

Fixedly attached to shaft 32, adjacent opposite ends thereof, are drums 54, and wound upon said drums are lifting cables 56 secured to the outer ends of boat support arms 58. Arms 58, at their inner ends, have transverse openings through which extend hinge bolts 60, said hinge bolts passing through the forwardly projected ears 62 of hinge sleeves 64 rotatably mounted upon the lower longitudinal brace bar 22.

Secured at one end to the respective sleeves 64 are flexible elements 66. Elements 66 normally are connected, at their other ends, to standards 68 mounted in 58 have been lowered to the spaced relation to the landing 10, in the water. The length of elements 66 is such as to permit a boat to be fioated thereover, when said elements 66 are connected to standards 68.

In use of the device, a boat 14 would be first floated into position over the respective elements 66. Elements 66 are then detached from standards 68, and are attached to the outer ends of the boat support arms 58, after arms positions shown in Figure 1.

The boat, and the associated parts of the boat lift, will now appear as shown in full lines in Figures 1 and 2. The crank 48 is then rotated, in a direction that will cause the arms 58 to be swung upwardly to the dotted line positions shown in Figure 2. The boat is thus lifted from the water, and tilted transversely to facilitate cleaning, maintenance and the repair thereof.

The pawl 52, of course, prevents rotation, normally, of the gear 50 in a direction that would tend to unwind the cables 56 while the boat is in its lifted position.

It is believed apparent that the invention is not neces sarily confined to the specific use or uses thereof described above, since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such construction is only intended to be illustrative of the principles of operation and the means presently devised to carry out said principles, it being considered that the invention comprehends any minor change in construction that may be permitted within the scope of the appended claim.

What is claimed is:

A boat lift comprising a main frame; a plurality of rigid arms connected at one end thereto for vertical swinging movement about a common horizontal axis; U-shaped, flexible slings depending from and connected at their opposite ends to the respective arms, to support a boat thereagainst during swinging movement of the arms; and standards stationarily mounted in vertical positions, said standards corresponding in number to the several arms and being disposed outwardly from and in closely spaced relation to the are described by the other ends of the arms during swinging movement of the arms, said slings being detachably connected at least at one end thereof to the arms for selective connection of the slings to the standards and arms respectively.

References Cited in the file of this patent UNITED STATES PATENTS 207,166 Dunn Aug. 20, 1878 1,061,213 Arbuckle May 6, 1913 1,116,761 Thompson Nov. 10, 1914 1,192,158 Binks July 25, 1916 1,300,567 Brorby Apr. 15, 1919 1,429,432 Irrgang Sept. 19, 1922 2,185,083 Horton Dec. 26, 1939 2,294,864 Palmer Sept. 1, 1942 2,465,118 Platt Mar. 22, 1949 2,552,424 Gorman May 8, 1951 2,581,676 Loaney Jan. 8, 1952 2,632,900 Voigt 1 Mar. 31, 1953

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