Friction clamp for tubular structures featuring lateral connectors

The friction clamp has a basic configuration including a cylindrical body of elongate form between ends and with a slot into which a tubular item can be snapped. Lateral connectors and such as a receiver with a cylindrical recess therein can receive an end of a tubular member, such as a member similar to that which snaps into the slot. A plug with associated hook can be fitted into this recess of the receiver to allow for items to be suspended from the hook. As an alternative to the receiver, a tab can be provided extending from the clamp laterally. The tab includes a hole through which hardware can be placed, and an item having a similar tab can be placed adjacent to the tab extending from the clamp and the hardware tightened to fix the item to the clamp through the pair of tabs at a desired rotational orientation.

FIELD OF THE INVENTION

The following invention relates to friction clamps with generally semi-cylindrical forms and with a slot into which a tubular or other cylindrical member can snap for holding the clamp (and intermediate items such as flexible sheeting) to the tubular item. More particularly, this invention relates to clamps which feature a lateral connector such as in the form of a receiver which can receive an end of a tubular member similar to that which snaps into the slot, or a tab which can mate to a tab on an item to be connected to the clamp, through associated hardware, so that other items can be coupled to or otherwise suspended from the clamp, other than by being sandwiched between the tubular item and the slot therein.

BACKGROUND OF THE INVENTION

Friction clamps are known in the prior art which are typically formed of injection moldable plastic material, such as PVC (polyvinyl chloride) and which have sufficiently thin walls that they can snap onto a tubular or other cylindrical structure. Often the clamp is sized so that it can snap onto other elongate PVC pipes having a similar diameter. Friction clamps of different standard sizes can be provided for attachment to standard sizes of PVC pipes (or other tubular and/or cylindrical members). An example of such friction clamps is provided by Circo Innovations, Inc. of Grass Valley, Calif., under the trademark “SNAP CLAMPS.” A common use for such friction clamps is to allow thin flexible sheeting material to be attached to tubular structural members, such as when providing simple enclosures such as greenhouses, or when providing shade structures or other structures formed of simple tubular elements and which require some flexible sheeting material to be attached thereto in some fashion.

While a great amount of flexibility is provided with basic friction clamps, allowing them to hold sheeting to a structural tubular skeleton, such as of PVC material, to achieve a variety of different desired configurations, friction clamps have some limits. Often joints between tubular structural members require some form of couplings having receiver recesses which are appropriately sized and oriented to hold tubular members adjacent thereto in a desired orientation. For instance, 90° elbows or three-way 90° elbows can provide contours for various different structures. With prior art friction clamps, the clamp is limited to holding sheeting material onto the underlying tubular member, and the tubular members need appropriate joint hardware to form a desired structure and to provide desired strength to the structure. If a clamp could have a way to attach to an end of a tubular or other structural member, such a clamp could provide the dual function of holding flexible sheeting material to the structure and providing an interface with additional structural members themselves, to join such elongate members together.

Some structural members of a tubular or other elongate nature are more temporary in nature or are desired to be included after a tubular skeletal structure has already been constructed. In the prior art, adding to existing structures at midpoints within the skeletal structure generally requires cutting of existing members so that other elements can be appropriately interposed therein where desired. This cutting and fitting process can be time-consuming and particularly undesirable for temporary modifications to a structure.

As one example, a greenhouse might be initially constructed, and after it has been completed, it may be determined that modifications to the greenhouse are called for, such as providing additional rigidity to the structure to withstand wind loads, or to allow for framing in of windows into walls of the structure, or to provide additional support to keep flexible fabric material of the greenhouse from sagging inwardly undesirably. In the prior art, to accommodate addition of such structural members, locations with an existing structure need to be identified, cut and fitted with new joints and structural members to complete the desired structural modifications. The time and expense associated with such modifications can be prohibitive. Furthermore, after completing the modifications, they might be determined to be suboptimal. If such additional structural elements could be merely “snapped” onto existing structural members in a temporary fashion, such structural modifications would be greatly simplified, reduce time involved and would provide for greater convenience and flexibility in making further modifications if initial modifications are less than optimal.

Accordingly, a need exists for a friction clamp which has a lateral connector thereon, such that tubular members and other items attached to such a lateral connector can be conveniently snapped onto and off of other tubular members through the existing slot in the friction clap.

SUMMARY OF THE INVENTION

With this invention, a friction clamp is provided which has been modified to include a lateral connector thereon. A basic main portion of the clamp is similar to prior art friction clamps, including a cylindrical body formed of at least partially flexible material. The body extends between a first end a second end opposite the first end and with the body having a slot extending between the first end and the second end. The slot is bounded by edges which are typically linear and define a width of the slot. These edges are typically slightly closer to each other than a diameter of an inner semi-cylindrical surface of the slot, and material forming the snap clamp is sufficiently flexible and elastic that a tubular member with a diameter matching the inner surface of the slot can be snapped between these edges, with the edges flexing laterally until the tubular member is captured within the slot.

The clamp of this invention further features a portion of at least one fastener extending laterally from the outer cylindrical surface of the cylindrical body. This portion of a fastener is in one embodiment a receiver extending linearly away from a central axis of the cylindrical body of the clamp. Preferably, this receiver has a cylindrical recess extending into an end of the receiver most distant from the cylindrical body of the clamp. This recess can receive an end of a tubular member, and in a preferred embodiment a tubular member having a similar diameter to that which is snapped into the slot of the clamp. In various embodiments, other sizes (or cross-sectional shapes) of elongate members could have their ends received within the recess of the receiver.

An end of the tubular member could be glued into the recess of the receiver, such as with PVC cement if the end of the tubular member and the clamp are both formed of PVC or other compatible materials, or some other adhesive could be utilized for a permanent attachment with in the recess. Alternatively, a friction fit can be provided and the end of the tubular member can be temporarily (or permanently) fitted within the recesses of the receiver. As another alternative, a fastener can be utilized passing through walls of the receiver and through the recess, as well as through an end of the elongate member, for temporary but secure attachment of an end of an elongate member within the recess of the receiver.

While a circular cross-section is shown for the receiver, other forms of cross-sections could alternatively be provided, such as square, rectangular or triangular, etc. The receiver is shown extending laterally within a plane generally perpendicular to a plane bisecting the edges of the slot of the clamp. However, the receiver could extend in other planes, such as within a plane coplanar with a plane bisecting the edges of the slot, or diagonal relative to the plane bisecting the edges of the slot.

In an alternative embodiment, the lateral connector is in the form of a tab extending laterally away from the outer cylindrical surface of the cylindrical body of the clamp. This tab has a hole passing laterally therethrough and a tab of similar (or other compatible) form on an end of a tubular or other elongate member can be placed adjacent to this tab, with appropriate hardware passing through the holes of the two tabs, and the hardware tightened to secure the elongate member to a clamp through the tabs. The tabs can be rotated relative to each other with the hardware loosened, and then the hardware can be tightened, so that adjustability is provided for the angle at which the elongate member is attached to the clamp through such tabs. Ribs on surfaces of the tab can assist in securely maintaining a desired angular orientation, especially when ribs are provided on both the tab of the clamp and the tab on the end of the tubular member. In one embodiment, a basic plug can be glued or friction fitted into an end of a tubular member, and an outer surface of such a plug can include a basic tab matching the tab extending laterally from the outer cylindrical surface of the clamp, so that any tubular member can have such a tab easily added thereto for connection of the elongate member to the clamp via the tabs at a desired angle.

While in one embodiment a single tab extends laterally from the clamp within a plane generally perpendicular to a plane bisecting the edges of the slot in the clamp, such a single tab could have other orientations relative to this plane bisecting the edges of the slot in the clamp. Furthermore, multiple tabs can be provided, such as two tabs oriented within a common plane on opposite sides of the clamp, or two tabs with an angular spacing other than 180°, such as a 90° spacing. A further alternative is to provide three tabs with generally equal circumferential spacing, and with one tab adjacent to each of the edges of the slot and one tab midway between these other two tabs and opposite the opening into the slot, and with each of the tabs general extending radially away from a central axis of the clamp. With such multiple tabs, the snap clamp can function in a hybrid fashion, both to temporarily and easily snap onto existing tubular structures through the slot thereof, with or without simultaneously also holding sheeting material of a flexible nature to the tubular structure, and also can provide a structural interface for connecting to other items such as elongate members or plugs with hooks, or other similar accessories.

OBJECTS OF THE INVENTION

Accordingly, a primary object of the present invention is to provide a friction clamp which includes a lateral connector through which items can be attached to the clamp, other than through the slot in the clamp.

Another object of the present invention is to provide a friction clamp which can attach both to flexible sheeting material and to elongate structural members and other items.

Another object of the present invention is to provide a coupling for use with tubular skeletal structures which is a hybrid between attaching to ends of structural members and snapping laterally onto structural members.

Another object of the present invention it to provide a connector within a tubular structure which can be temporarily attached and detached securely within the structure to provide temporary and/or simplified structural initial construction or modification to existing structures.

Another object to the present invention is divide a method for attaching items within a tubular skeletal structure by coupling the items to a lateral connector associated with a clamp.

Another object to the present invention is to simplify the modification of an existing tubular structure.

Another object of the present invention is to provide a connector for tubular structures which can be readily modified in its position to optimize the tubular structure in a simple fashion.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, wherein like reference numerals represent like parts throughout the various drawing figures, reference numeral10(FIGS. 1, 7 and 8) is directed to a clamp of a friction clamp variety which can snap onto a cylindrical/tubular member M through a slot30, and which also includes a receiver40as one form of lateral connector which can receive an end of a lateral member L within a recess50thereof. The clamp10can conveniently connect by snapping onto a midpoint of a tubular member M, and can also have an end of a second lateral member L attached thereto through the receiver40. In an alternative embodiment tab clamp110(FIG. 9) a tab130replaces the receiver40and can cooperate with a tab cap115attachable to an end of a lateral member L or other member M to allow for attachment therebetween, and particularly at a variety of different relative angles.

In essence, and with particular reference toFIGS. 1, 7 and 8, basic details of the clamp10are described, according to an exemplary embodiment and certain alternative embodiments. The clamp10includes a cylindrical body20of generally linear elongate form and having a slot30along an undersurface thereof. The slot30is sized sufficiently large to snap onto a tubular member M laterally, but sufficiently small that the cylindrical body20is retained on the tubular member M after having been snapped onto the tubular member M and through the slot30(along arrow B ofFIGS. 1, 7 and 8). The clamp10also includes a receiver40extending laterally from the cylindrical body20, and typically at a midpoint of the cylindrical body20. This receiver40includes a recess50which is typically closed at an interior thereof, and has a generally cylindrical form for receiving an end of a tubular member, such as a lateral member L (FIG. 7) therein. A plug60, such as including a hook70(FIG. 8) can be fitted within this receiver40, as an alternative to fitting of an end of a tubular member M therein.

In an alternative embodiment (FIG. 9), a tab clamp110is provided with a cylindrical body120similar to the cylindrical body20of the clamp10. The tab clamp110replaces the receiver40with the tab130which can have a tip tab119of a tab cap115mated thereto, through a bolt F passing through a central hole138, to provide an alternative lateral connection off of this cylindrical body120, and which facilitates rotational adjustment (along arrow C ofFIG. 9). Other embodiments are also disclosed inFIGS. 15-20with multiple tabs230,330,430thereon.

More specifically, and with particular reference toFIGS. 1-8, particular details of the clamp10are described according to this first exemplary embodiment. The clamp10is preferably entirely formed from a unitary mass of homogenous material, such as injection moldable plastic, and in one embodiment formed of poly vinyl chloride (PVC) such as that commonly used for elongate tubular members M. Other materials could alternatively be utilized, including plastics, metals and composites.

The clamp10includes a cylindrical body20which is preferably generally in the form of a friction clamp which can snap onto a tubular member M laterally (along arrow B ofFIGS. 1, 7 and 8). This cylindrical body20thus includes an outer semi-cylindrical surface22which extends circumferentially until it terminates at edges26adjacent to a slot30in an underside of the cylindrical body20. These edges26are preferably linear and also preferably include enlarged snap lips28to strengthen these edges26and allow them to most smoothly rest against a member M before snapping pressure (along arrow B) is applied to cause this slot30to snap onto the tubular member M (along arrow B ofFIGS. 1, 7 and 8).

This cylindrical body20can have a variety of different lengths between opposing ends24, and most typically is approximately three times longer between the ends24than a diameter of the outer semi-cylindrical surface22. Other lengths for the cylindrical body20could alternatively be provided. Preferably, a taper25is provided directly adjacent to each of the ends24of the outer semi-cylindrical surface22, which is otherwise preferably smooth.

The slot30includes an inner semi-cylindrical surface32facing inwardly and generally spaced from the outer semi-cylindrical surface22by a thickness of the cylindrical body20. This inner semi-cylindrical surface32can be smooth, but most probably includes a series of longitudinal ribs extending parallel to each other between the ends24. These ribs preferably have a height extending away from the inner semi-cylindrical surface32which is less than a thickness of the cylindrical body20, and roughens the inner semi-cylindrical surface32somewhat to allow a member M or other structure upon which the clamp10is snapped to most thoroughly engage the member M. Also, commonly flexible sheeting material can be interposed between the clamp10and the tubular member M, such as plastic sheeting material forming a wall of a temporary structure, such as a greenhouse. Ribs on the inner semi-cylindrical surface32can help to keep such sheeting material from sliding between the clamp10and member M.

The receiver40provides one form of a lateral connector for fastening to other objects, and particularly ends of tubular or other cylindrical lateral members L (FIGS. 7 and 8). This receiver70is generally in the form of a cylindrical structure closed at an end adjacent to the cylindrical body20and open at an opposite end. In particular, the receiver40includes an outer cylindrical surface42which includes a proximal end defined by a combination of a root tip44and a root arch46where the outer cylindrical surface42transitions into the outer semi-cylindrical surface22of the cylindrical body20. The outer cylindrical surface42extends away from this cylindrical body20until it terminates at a distal end defined by a rim48, typically of circular form.

The receiver40in this embodiment has a somewhat truncated and modified form on a lower portion thereof where it comes adjacent to one of the edges26of the snap lips28on the cylindrical body20. In particular, the outer cylindrical surface42transitions into a conical region45opposite the rim48which smoothly transitions an under portion of the receiver40into a central portion of an adjacent one of the edges26and snap lips28.

An interior of the receiver40is defined by the recess50. This recess50includes an inner cylindrical surface52which extends in from the rim48until it terminates at a cylindrical floor54. This cylindrical floor54has a cylindrical form generally defining a constant thickness continuous with the outer semi-cylindrical surface22and maintaining a substantially constant thickness for this cylindrical body20away from the inner semi-cylindrical surface32. On lower portions of the recess50, opposite the conical region45on the outer cylindrical surface42of the receiver40, this cylindrical floor54preferably transitions across an inner corner56to a planar facet58, generally opposite the conical region45angled toward the rim48somewhat as the facet58extends away from the inner corner56. The inner corner56and facet58allow for the receiver50to maintain substantially constant wall thickness on the lower portion of the receiver40where it needs to transition into the edge26and snap lip28adjacent to the receiver40.

The recess50of the receiver40preferably has a diameter similar to that of the slot30of the cylindrical body20. In this manner, a member M can either be attached laterally to the clamp10through the slot30(along arrow B ofFIGS. 1, 7 and 8) or by placement of an end thereof into the recess50of the receiver40(along arrow A ofFIGS. 1, 7 and 8). In an alternative embodiment, the cylindrical body20and slot30can be sized for one size of member M, while the recess50and receiver40can be sized for a different size of elongate tubular lateral member L or other structure (such as the plug60shown inFIGS. 7 and 8). Thus, the clamp10can be provided in various different sizes to fit different structural elements, such as tubular members, either with such structural elements being similar in size for the receiver40and the slot30, or for different sizes for the receiver40and slot30.

Furthermore, while the receiver40is shown extending laterally relative to a direction that the slot30snaps onto a member M, the receiver40could extend away from the cylindrical body20of the clamp10in some other orientation, such as aligned with the direction that the slot30snaps onto a member M, or at some diagonal orientation. The receiver40is preferably located at a middle distance between ends24of the cylindrical body20. However, the receiver40could be provided closer to one end24or the other, if desired. Furthermore, while only a single receiver40is shown, it is conceivable that two (or more) receivers40could be provided, such as one extending laterally in opposite directions so that a receiver40would be provided adjacent to each of the edges26of the cylindrical body20. Other orientations for such receivers40could be provided, similar to the various orientations for tabs130in the embodiment ofFIGS. 15-20.

With particular reference toFIGS. 7 and 8, details of a plug60and hook70, providing an alternative item for attachment to the receiver40, other than an end of a tubular or cylindrical lateral member L, are described. InFIG. 8a plug60is shown which fits within the recess50in the receiver40. This plug60could be formed of similar material from which the clamp10is formed, and attached by friction fit or by utilization of an adhesive, or other fastener, such as a lateral pin extending through the outer cylindrical service42in the receiver40and through the plug60, for retaining the plug60within the receiver40. Such an alternative fastener could similarly be utilized in other environments where an end of a tubular or cylindrical lateral member L is fitted into the recess50of the receiver40.

The plug60could alternatively be formed of a resilient rubber material and sized with a friction fit so that it fits snugly and securely, but removably, into the recess50of the receiver40. The plug60includes a cylindrical sidewall62which is dimensioned to fit with a designed degree of snugness to meet performance objectives of the user, which could include a friction fit or a tight tolerance fit or a loose tolerance fit. An outer flat surface64defines an outer portion of the plug60. Preferably a bore66passes through this outer flat surface64entirely through the plug60. A hook70, such as with an elongate threaded shaft72, can fit through the bore66, and utilize one or more nuts74to be fastened to the plug60. In this way, when the plug60is attached to the receiver40, a hook70is presented from which items can be hung. In one example, this placement of the plug60into the recess50(along arrow A ofFIG. 7) allows for placing an item such as a hanging plant P from the hook70, suspended from the plug60fit within the receiver40of the clamp10. A variety of other items can similarly be suspended from the clamp10in this manner, so that the clamp10can conveniently provide attachment points by snapping such a clamp10onto members L, M where desired.

With particular reference toFIGS. 9-14, details of an alternative embodiment tab clamp110are described. The tab clamp110is similar to the clamp10ofFIGS. 1-8, except that the receiver40is replaced with a different lateral connector in the form of a tab130. Thus, a similar cylindrical body120is provided as the cylindrical body20associated with the clamp10. Importantly, an additional element is typically provided, referred to as a tab cap115, which can attach to an end of a cylindrical/tubular lateral member L through a receiver117and having a tip tab119extending from the tab115. The tip tab119is preferably similar to the tab130.

The tab130is generally a planar structure which is preferably formed as a unitary mass along with other portions of the tab clamp110, such as from injection moldable plastic material. This tab130extends from a root132adjacent to the cylindrical body120out to an arched edge136opposite the root132. The tab130includes opposing faces134which are preferably planer and parallel to each other, defining a thickness of the tab130. A center hole138passes between the faces134and through the tab130laterally. Two such tabs130either on separate tab clamps110, or with one tab130and a tip tap119on a tab cap115(FIG. 9), can be brought adjacent to each other and held together by tightening a bolt F or other fastener along with a wing nut W or other nut onto the bolt F, and tightening until the tab130and tip tab119are tightly held together. Importantly, before such tightening, a pair of such tabs130,119can be rotated relative to each other (about arrow C ofFIG. 9) so that angular adjustability is provided with the tab clamp110.

To assist in holding the tabs119,130in a selected relative orientation when the fastener F and wing nut W are tightened, ribs140preferably extend radially away from the center hole138and away from each of the faces134. Troughs142are provided between the ribs140. With similar ribs140and troughs142on each of the faces134of each of the tabs119,130, when these faces134of adjacent tabs119,130are brought adjacent to each other, the ribs140fit into troughs142to cause a resistance to undesired rotation, especially when the bolt F and wing nut W are tightened.

While the tab130is shown extending laterally from this cylindrical body120and lateral to the direction that this cylindrical body120snaps onto adjacent tubular members, this tab130could be oriented in a plane aligned with a direction that the cylindrical body120snaps onto a tubular member M, or in other orientations than those that are depicted herein.

With particular reference toFIGS. 10, 11, 13 and 14an additional small clamp150is shown, as an option. The small clamp150is shown opposite the tab130, but it could be located closer to the tab130. The small clamp could also be provided in similar positions on the clamp10(FIGS. 1-8). The small clamp150can have small elongate items therein, such as irrigation tubing, wiring W, or other small elongate items removably attached thereto. Each small clamp150includes a pair of opposing fingers that can “snap” onto an elongate item.

With particular reference toFIGS. 15 and 16, an alternative embodiment dual tab clamp210is described. The dual tab clamp210is similar to the tab clamp110, except that two tabs230extend from opposite sides of the cylindrical body220. Thus, two different tabs230are available for attachment to two separate additional members, such as through tab caps115(FIG. 9).

With particular reference toFIGS. 17 and 18, a dual tab 90° clamp310is described. This dual tab 90° clamp includes a cylindrical body320with a pair of tabs330extending therefrom, but not within a single plane, but rather spaced approximately 90° away from each other. This provides further flexibility in presenting tabs330in desirable orientations for use in attaching two adjacent tubular members and/or other items.

With particular reference toFIGS. 19 and 20, a tri-tab clamp410is described. The tri-tab clamp410includes a cylindrical body420with three tabs430extending radially away from a central axis thereof. This cylindrical body420is similar to the cylindrical bodies120,220,320of preceding embodiments. The three tabs430are oriented with one tab opposite the slot in the cylindrical body420, and with two tabs430adjacent to edges of the slot in the cylindrical body420, and generally with each of the tabs430spaced an equal distance away from each other. Further useful options for attachment of adjacent items to such a tri-tab clamp410are thus provided.

This disclosure is provided to reveal a preferred embodiment of the invention and a best mode for practicing the invention. Having thus described the invention in this way, it should be apparent that various different modifications can be made to the preferred embodiment without departing from the scope and spirit of this invention disclosure. When structures are identified as a means to perform a function, the identification is intended to include all structures which can perform the function specified. When structures of this invention are identified as being coupled together, such language should be interpreted broadly to include the structures being coupled directly together or coupled together through intervening structures. Such coupling could be permanent or temporary and either in a rigid fashion or in a fashion which allows pivoting, sliding or other relative motion while still providing some form of attachment, unless specifically restricted.