Canopy hoist

This disclosure relates to agricultural canopies used primarily to control the amount of light, moisture and heat reaching growing plants within the canopy footprint. More specifically, it relates to mechanisms for pulling a flexible canopy over a support structure and then for removing the canopy to uncover the structure and the plants below. The mechanisms include an arm mounted rotationally on a base. When the arm is rotated in one direction the canopy is pulled over the support structure and when the arm is rotated in the other direction the canopy is pulled off the support structure.

FIELD OF THE DISCLOSURE

This disclosure relates to agricultural canopies used primarily to control the amount of light and/or moisture and/or heat reaching growing plants within the canopy footprint. More specifically, it relates to mechanisms for pulling a flexible canopy over a support structure and then for removing the canopy to uncover the structure and the plants below. The canopy may be fitted with a light impeding material for use with light-deprivation techniques or with a clear material such as a plastic. Clear material will allow light to pass through as in a standard greenhouse. However, unlike a standard greenhouse, the disclosed device facilitates the opening of the clear material to release excess thermal gain and the closing of the material in anticipation of inclement weather. Conversely, the material can be opened (removed) to let a controlled amount of rain into the canopy structure. These features make a canopy structure equipped with the disclosed device much more versatile than a standard greenhouse, which cannot be easily opened and closed to the same extent.

BACKGROUND OF THE DISCLOSURE

Farmers who are familiar with using light-deprivation techniques to increase crop yield are also familiar with the struggle and great effort that comes with pulling heavy blackout tarps over their crops twice or four times daily. With the disclosed device, sometimes referred to as a tarp puller, the process of covering or uncovering any length greenhouse can be accomplished in just a few minutes. Typically, the canopy hoist comprises a set of two heavy-duty galvanized steel units. With one installed on each side of the greenhouse, the task can be completed quickly and with much less effort by just one person.

In the disclosed embodiment, telescoping steel tubing as part of the arm can be adjusted to fit typical greenhouse sizes such as 20 feet wide and 10′ tall, but can also be used on much larger greenhouses such as 40 feet wide by 140 feet long by 18 feet tall by increasing the length and other dimensions of the canopy hoist, as would be apparent to those skilled in the art. The tarp puller consists of two heavy duty pivoting steel arms. Each arm is mounted to approximately two cubic feet of concrete at either end of the greenhouse and can be assembled and install with simple hand tools.

SUMMARY OF THE DISCLOSURE

Described herein is a device for lifting a cover, such as a light impeding tarp made of natural or artificial fabric or plastic over a structure. In the disclosed embodiment, the structure has a generally rectangular base to which semi-circular support members are attached to form a half cylinder with the rectangular side placed on the ground over the growing plants. The cover is sized to fit over the semi-circular support members and is positioned near the structure along one of the longer sides of the rectangle, or along any side of the rectangle if it is a square. An arm on the canopy hoist is attached to the canopy. The hoist is then rotated so that the canopy, which had been lying on the ground, is pulled over the semi-circular support members to the side of the rectangle opposite to the side near which the canopy was originally placed. In this position, the canopy inhibits the light passing to the growing plants. When the operation is reversed, the hoist is rotated in the opposite direction and the hoist arm pulls the canopy back to its original position on the ground.

An object of the current disclosure is to provide an efficient and easily operable mechanism to move a canopy over a structure and then to retract the canopy back to its original position. Another object is to accomplish this function with a low cost, simple to manufacture device that is sufficiently strong, can withstand varied outdoor environments and is easily operable.

The accompanying diagrams and descriptions will aid in the visualization of the described features, and functionality of the device.

DESCRIPTION OF THE DISCLOSED EMBODIMENT

FIG. 1is a perspective view of a generic canopy support structure1with two canopy hoist devices at each end of the support structure. Tarp support members2are depicted as rounded hoops attached to a base4. The structure of base4is not shown in detail because the structure could be any configuration to which tarp support members2could be attached. In fact, tarp support members2could be driven into the ground6so that no base is required. Although not depicted, lengthwise cross members parallel to the base4may be added to interconnect the tarp support members to each other to add stability to the support members2. Plants will typically be growing in the ground6within the periphery of the canopy support structure1. The canopy support devices are depicted as near end hoist8and far end hoist10. The details of the near and far end hoists8and10are not shown inFIGS. 1-3for simplicity. Those details are best seen inFIGS. 4, 4A, 6 and 7. The canopy support structure1can be sized as desired. A typical size, for illustrative purposes only, would be a length of between 10 and 100 feet, a width of about 20 feet a height of about 10 feet. In the embodiment described herein, the near end hoist8and the far end hoist10have the same structure. In other words, the same hoist will work at both ends of the canopy support structure1. This allows for greater manufacturing efficiency and lower cost.

A tarp12is shown schematically inFIG. 1. It should be understood that tarp selection depends on a number of variables such as desired thickness, weight and flexibility. In typical use, the tarp12would be bunched up on the ground6when the structure is fully opened. The tarp should also include sufficient extra length to provide slack so that when the tarp12is being moved from the open position as depicted schematically inFIG. 1to the closed position depicted inFIG. 3there is sufficient slack to allow the tarp12to cross over the tarp support members2diagonally as depicted inFIG. 2. For example, if the canopy support structure1is long, perhaps 100 feet, the amount of slack should be on the order of about 3 feet. If the canopy support structure is shorter, perhaps less than 40 feet, the amount of slack needs to be greater, on the order of 10 feet so that the tarp12can be moved as depicted inFIG. 2.

FIG. 2illustrates how the two canopy hoists8and10may be operated by one person.FIG. 1depicts the near end hoist8in the canopy's fully opened position.FIG. 2depicts the near end hoist8having been rotated from the canopy's fully opened position to a partially closed position. At this point, the tarp12has been pulled partially over the tarp support members2of the canopy support structure1. The operator would then move to the far end hoist10and rotate it in a similar fashion in order to pull the balance of tarp12over the tarp support members2. The result is a fully covered structure as depicted inFIG. 3. The near and far end hoists8and10could be rotated by two people as well. This process is reversed in order to pull the tarp in the opposite direction in order to remove the tarp from the tarp support members2.

FIG. 3depicts the tarp12after it has been fully pulled over the tarp support members2. In the figures, the tarp support members2are shown as semi-circular ribs but they could have many different shapes. The most important design constraint would be to provide a shape that allows the tarp to slide over the support members without tearing or becoming hung up on protrusions. For example, instead of the support members being entirely curved they could be “U” shaped, with each having a curved upper portion and a straight lower portion between the curved portion and the ground6area.

FIGS. 2 and 3show a near end tarp flap14that covers the opening at the near end of the canopy support structure1. There is a similar far end tarp flap at the far end16of canopy support structure1. In the disclosed embodiment, the tarp flaps are simply extensions of the tarp12that hang down to cover the openings at each end of the closed canopy18.

FIG. 4. shows details of the construction of near end hoist8. The same structure is present in far end hoist10. In the disclosed embodiment, the near and far end hoists8and10are interchangeable. For simplicity, the structure will be described below referring only to near end hoist8, but the same structure is present in far end hoist10. A foundation19is embedded into the ground6. In the disclosed embodiment, the foundation19is a rectangular solid of concrete. The base plate20is anchored to the foundation19by anchor bolts (not shown) protruding from the foundation19and up through anchor bolt holes22. Typically, there will be four anchor bolts that pass through four anchor bolt holes. As is known in the art, nuts are screwed on the anchor bolts to secure the base plate20to the foundation19. A support frame34is affixed to base plate20preferably by welding. A pivot arm26is attached to the support frame by a pivot pin24that passes through holes in the support frame34and through a compatible through hole in the pivot arm26. The pivot pin24can be a bolt that permits the pivot arm26to rotate about pivot pin24. The pivot arm26has a generally square cross section and in the disclosed embodiment is a hollow tube. The pivot arm26can be sized according to the anticipated load, but for most purposes, the outer cross sectional height will be about two inches and the inner cross sectional height will be about one and a half inches. The thickness of each side will therefore be about one quarter inch. However, the exact sizes are not critical to the functionality of the device.

Sliding over the pivot arm26is a perforated tube28. These components interact telescopically so that the total length of the hoist can be changed to accommodate different size canopy support structures1. For example, the pivot arm26and the perforated tube28can both be about seven feet long. This will allow the total length of the hoist to be adapted to canopy support structures1that are between approximately six feet high to about twelve feet high. The adaptability of the near and far end hoists8and10to various sizes of canopy support structures1give the disclosed device great utility, heretofore unknown in this field.FIG. 4Ashows how the telescoping members26and28can be connected at the chosen length by using an attachment bolt30passing through compatible holes in the pivot arm26and the perforated tube28.FIG. 4Ashows one hole36, but additional holes may be added to accept additional attachment bolts30. Attachment bolt30is shown inFIG. 4Aas passing through one particular hole in perforated tube28, but as the pivot arm26slides telescopically into perforated tube28, attachment bolt30can be moved to other positions to correspond with hole36on the pivot arm26.

A canopy arm32is attached to the perforated tube28using various methods such as welding or bolting. InFIG. 4, an attachment tube38is shown. Attachment tube38telescopically slides into the perforated tube28and is secured by a bolt in much the same manner as the attachment bolt30secures the telescoping portions26and28together. Attachment tube38does not need to have the same telescoping length as the perforated tube28and the pivot arm26and can be much shorter. Having this capability allows the hoist8to be disassembled into components that are easy to package and transport. Adding rigidity to the structure is a gusset plate40that is bolted or screwed to both the perforated tube28and the canopy arm32. The gusset plate40inFIG. 4is shown as partially transparent so that the underlying holes in the perforated tube28and canopy arm32are visible. An opaque depiction of solid gusset plate40can be seen inFIG. 5. Also seen inFIG. 5are the heads of gusset bolts41that pass through compatible holes in the gusset plate40. Two similar gusset plates40can be used, one on each side of the hoist8for added strength, with the gusset bolts41passing through both gusset plates. InFIG. 6, four gusset bolts41are shown as an alternative embodiment.

FIG. 5is a cut-away side view of a portion of the canopy support structure depicting one canopy hoist device at the midpoint of its travel, in other words, at the height of its arc over the canopy support structure1. Tarp12is shown resting on tarp support members2. The tarp12is secured to the hoist8by a clamp bar42, which is shown in more detail inFIGS. 6 and 7.

Clamp bar42can be made in various lengths depending on the weight of the tarp to be pulled over the support members2, but in the depicted embodiment the length is about six feet. The clamp bar42will typically be made of the same material as the canopy hoist itself, preferably aluminum or steel. The portion of the edge of tarp12that is to be held between the clamp bar42and the canopy arm32is folded a number of times into a folded portion46to provide strength because when the carriage bolts44are inserted through the tarp the resulting holes in the tarp create stress risers. Of course, if a tarp has a strongly reinforced edge, the folding may not be required. However, because the intent of the inventors is to have a canopy hoist that can work with many different styles of tarp, the folding step is described so that a common, inexpensive tarp may be used in conjunction with the disclosed canopy hoist device. The folded portion46is shown inFIGS. 6 and 7. It is suggested that the tarp be folded four times prior to pushing the carriage bolts through the tarp in the orientation shown inFIG. 6. Tarp12is shown as being partially transparent inFIG. 6for illustrative purposes only so that the underlying structure can be seen.

FIG. 7shows the same components as inFIG. 6with the friction lining48being more clearly visible. The friction lining48, which can be a resilient material such as rubber, spreads the force of the clamp bar42more evenly over the surface of the folded portion46of the tarp12to hold it securely in place without slipping between the metal surfaces of the clamp bar42and the canopy arm32. The holes made in the tarp12by the carriage bolts44therefore do not take the entire load when the tarp is being moved by the rotational action of the canopy hoists8and10. The directions are shown inFIG. 7as closing direction50and opening direction52. The closing direction50means that the canopy hoists8and/or10are being rotated about their respective pivot pins24and the tarp12is being is being pulled from the position shown inFIG. 1to the position shown inFIG. 3. The opening direction52means the opposite, when the tarp12is being pulled from the closed position depicted inFIG. 3to the open position shown inFIG. 1.

It should be noted that inFIGS. 6 and 7the tarp is cut off at edge54, which is roughly shown inFIGS. 2 and 3. This is for illustrative purposes only and is not meant to depict exact locations. The remainder of the tarp12was omitted fromFIGS. 6 and 7so that the underlying structure would be more clearly visible.

A push arm may be used to assist the operator in rotating the canopy hoist about the pivot pin24to close or open the tarp12. It can be used for any size structure but is especially helpful in conjunction with large canopy support structures1, such as those that are perhaps ten feet tall or higher. In this situation, a canopy hoist would have to be longer than 10 feet in order to pull the tarp12over the tarp support members2. An operator may be able to exert reasonable force up to a height of perhaps six feet or so, but the operator's leverage would decrease quickly at the length of the canopy hoist increased. This discussion is, of course, applicable to both the near end hoist8and far end hoist10. The push arm feature is shown inFIGS. 8 and 9. Push rod56is attached to the perforated tube28at a location relatively near to the gusset40. The operator can then exert force high on the perforated tube28for greater leverage while rotating the near and/or far end hoists8and10. The length of the push rod56may be sized as needed given the total length of the near and far end hoists8and10. The push rod56may have telescoping segments.FIG. 9includes arrows that show directions of force and motion as the push rod56is being operated.

The connection between the push rod56and the perforated tube28is a rotating or universal joint that allows transmission of force over a range of angles. It is depicted in the figures as a “U” shaped end assembly58that includes an attachment pin60that is placed into holes in the perforated tube28. Attachment pin60is a clevis pin that includes a through-hole near its free end. Once installed, a washer61is placed over the end of pin60and a split ring62or cotter pin is inserted into the through-hole to secure the end assembly to the perforated tube28. The assembly58is secured to the push rod56with a clevis pin64. This design allows rotation about both the attachment pin60and clevis pin64. An operator can therefore use the push rod56through an entire range of motion from one side of the canopy support structure to the other when opening or closing tarp12without having to release his hold on the push rod56. Although it is denominated a “push” rod,56can also be used to pull the near and far end hoists8and10as appropriate to open or close the tarp12.

While the above description contains many specifics, these should not be construed as limitations on the scope of the disclosure, but rather as an exemplification of the embodiments therein. It is to be understood that the invention is not limited to these specific embodiments. Accordingly, the invention is not limited to the precise embodiments described in detail hereinabove. With respect to the claims, it is applicant's intention that the claims not be interpreted in accordance with the sixth paragraph of 35 U.S.C. § 112 unless the term “means” is used followed by a functional statement. Further, with respect to the claims, it should be understood that any of the claims described below may be combined for the purposes of the invention.