CA3023650A1 - Shaft clamp - Google Patents

Description

2 SHAFT CLAMP
Field of the invention:
The present invention relates to the field of counterbalancing mechanisms.
More particularly, the present invention relates to an improved component (hereinafter referred to also as a "shaft clamp") that may be used in a drive mechanism, such as a chain hoist, for example, and also relates to a drive mechanism provided with such a shaft clamp, to a kit with corresponding components for assembling the same, and to corresponding methods of manufacturing, assembling and/or operating associated thereto.
Background:
Garage doors and the like are well known in the art. Indeed, most garage doors usually require to be provided with a counterbalancing system for counterbalancing the weight of the door in order to decrease the force required to open the door and also safely facilitate its closing from a raised to a lowered position.
Counterbalancing systems can be found in many other types of cable-operated doors, such as slidable truck doors and trailer doors, for example.
It is also known in the art that a widely used type of counterbalancing system generally comprises a pair of spaced apart cable drums connected to corresponding cables, each cable being in turn connected to a lower opposite side edge of the garage door. The cable drums are usually mounted on an overhead shaft which is typically supported above the door opening and is connected to one or more torsion springs which are each fixed to the shaft at one end, and operatively secured to a fixed structure such as the wall, or a wall bracket, for example, at the other end, so that the cable drums are biased to rotate in a direction which winds the cables onto the drums

3 and counteracts the weight of the door connected to the cables. The torsion springs are adjusted to properly balance the weight of the door so that minimal opening and closing efforts are required, either manually or when motor controlled.
It is also known in the art that conventional, low cost adjustment devices used for the above-mentioned type of counterbalancing system, and widely utilized in the garage door industry, are generally cylindrical "anchors" commonly referred to also as "plugs" ("collars", "cones", etc.) which are connected to the ends of the torsion springs and are thus mounted on the aforementioned shaft for adjusting the deflection of the springs to preset the torsional (or counterbalancing) force of the spring.
In operation, torque is transferred between the torsion spring, overhead shaft, and anchors or plugs, which operatively connect the shaft to the spring, in order to counterbalance the weight of the garage door. Usually, each torsion spring is fixed to the overhead shaft at one end, by means of a plug known as a "winding plug", and operatively secured to the wall via a bracket at the other end, by means of another plug known as a "stationary plug".
Large, vertical opening door assemblies, such as commercial and residential sectional garage doors, also usually require mechanisms to counterbalance the weight of the door in order to minimize door opening efforts and to control movement of the door from an opened to a closed position. Large sectional garage doors for commercial and residential applications may be manually or power operated. In either case, but particularly for manual operation, counterbalancing mechanisms have been used for many years to counterbalance the weight of the door and control its opening and closing movements so that one person can easily control operation of the door.
Counterbalancing mechanisms are also advantageous for power operated vertical opening doors since they reduce motor power requirements and the required strength of the door opening and closing mechanism. In other words, lighter weight, lower cost,

4 door control mechanisms may be used if a counterbalancing mechanism is connected to the door to assist the opening and closing actions.
It is also known that in North American markets, there are mainly two types of counterbalancing systems that are used with overhead doors.
The first type is with a "live" axle. Typically, a cable links together the bottom of the door to a drum. This drum is fixed to a corresponding rotating shaft (i.e.
"live" axle) of the counterbalancing system. Counterbalancing is usually made with a spring-plug assembly including a stationary plug fixed to an anchor plate, a winding plug fixed to the shaft, and a torsion spring that links the two plugs together.
The second type of counterbalancing systems is with a "dead" axle shaft. In this case, a "drum-plug" is free to move and rotate on the counterbalancing shaft.
Typically, a cable links together the bottom of the door to the drum-plug. On the other side, a winding plug is fixed to the shaft. The counterbalancing system typically links the winding plug to the drum-plug via the spring.
Similarly, self-storage doors and the like generally use these two concepts in order to provide the closing/opening function:
a) the first concept is "live axle" where the main shaft is turning when the door opens or closes ¨ in the case of such a "live" axle, the axle assembly turns with the door when operated; and b) the second concept is "dead axle" where the shaft is fixed/clamped, and where other components, such as steel drum, have bearings inserted in to allow rotation of the complete door curtain ¨ in the case of such a "dead"
axle, the axle assembly that remains stationary when the door is operated.

5 Most of the small doors are operated manually since their height allow the operator to reach the upper limit of the opening height. For higher door, a manual chain hoist is usually used in order to completely open the door, that is, out of a normal human reach.
In the dead axle application, because the shaft is not turning, the drive mechanism has to somehow be linked to the moving/rotating part, here said the drum.
Most common torque transmission means are sprocket and roller chain or gears, and the like, for example.
In transmitting the torque, three conditions generally have to be met to insure adequate function of the product:
1) good axial alignment between the driving and driven member (sprocket or gear);
2) blocking of the rotational movement of the hoist when the torque is exerted on the hand chain by the person opening/closing the door; and 3) proper center distance for gear or sprocket drive mechanism.
The function of locating the shaft center-to-center distances and locking the hoist on the round hollow shaft is usually made by the same components heresaid shaft sleeve.
Over the years, the Assignee of the present application has developed various innovative products and manufacturing processes to be used in the field of counterbalancing mechanisms (ex. garage doors, truck doors, etc.), particularly in relation to cones, plugs, chain hoists, and the like, examples of which are described in the following US patents, patent applications and/or industrial designs, the contents of which are incorporated herein by reference: 6,174,575 B1; 6,279,268131;

6,378,170 Bl; 6,485,006 B1; 6,502,281 B2;
6,681,809 B2; 6,694,673 B2;

6,712,116 B2; 6,907,964 B2; 6,931,810 B2;
6,959,751 B2; 6,986,378 B2;
6,988,527 B2; 7,000,292 B2; 7,000,354 B2;

7,086,441 B2; 7,350,333 B2;
7,441,749 B2; 7,543,625 B2; 7,600,344 B2; D490,685; D520,338; D524,633;
2002/0117787 Al; 2003/0024658 Al; 2003/0115928 Al;
2003/0198790 Al;
2003/0221801 Al; 2003/0230389 Al; 2004/0000109 Al;
2004/0003554 Al;
2004/0020609 Al; 2004/0089097 Al; 2004/0103505 Al;
2004/0124050 Al;
2004/0182007 Al; 2005/0006545 Al; 2005/0183341 Al;
2006/0185800 Al;
2007/0012410 Al; 2007/0084012 Al; 2007/0145339 Al;
2007/0204515 Al;
2007/0283525 Al; 2008/0023603 Al; 2009/0314869 Al; 2011/0240236 Al;
2017/0241498 Al; and 2017/0328104 A.
Examples of these products developed by the Assignee are also described in the following Canadian patents and/or patent applications: 2,184,507;
2,206,547;
2,220,710; 2,253,692; 2,263,666; 2,277,646; 2,293,224; 2,303,047; 2,306,610;
2,313,945; 2,313,946; 2,328,814; 2,344,952; 2,348,101; 2,352,620; 2,353,067;
2,369,705, 2,376,399; 2,381,027; 2,381,051, 2,381,054; 2,382,601; 2,382,606;
2,382,607; 2,382,661; 2,382,822; 2,384,219; 2,390,433; 2,392,417; 2,393,866;
2,398,684, 2,400,701; 2,401,084; 2,401,329; 2,407,464; 2,416,246; 2,419,185;
2,422,491; 2,425,108; 2,426,068; 2,430,434; 2,430,680; 2,435,362; 2,444,509;
2,445,719; 2,454,939; 2,458,157; 2,477,679; 2,497,471; 2,453,838; 2,504,030;
2,519,142; 2,568,048; 2,603,178; 2,642,857; 2,651,530; and 2,897,206.
Further examples of these products developed by the Assignee are also described and illustrated in the following Canadian industrial designs:
102881;
110443; and 110502.
Despite these various improvements over the years, there is always a need to continue innovating and finding better and/or different ways of manufacturing, assembling and/or operating components of a chain hoist, for example.

Indeed, it would be particularly advantageous to provide a component to be used with a chain hoist in a more efficient, more precise, more accurate, more reliable, more adjustable, more versatile, more adaptable, more ergonomic and/or more desirable manner, than what is possible with a standard shaft sleeve.
Thus, it would be particularly useful to be able to provide such an improved component which would be able to overcome or at the very least minimize some of known drawbacks associated with conventional shaft sleeves, for example.
Summary of the invention:
An object of the present invention is to provide a shaft clamp which, by virtue of its design and components, would be an improvement over other related .. conventional shaft sleeves and/or chain hoist methods known in the prior art.
In accordance with the present invention, the above object is achieved, as will be easily understood from the present description, with a shaft clamp (also referred to herein simply as "clamp") such as the one briefly described herein and such as the one exemplified in the accompanying drawings.
More particularly, according to one aspect of the present invention, an object is to provide a shaft clamp to be used with a chain hoist of a counterbalancing mechanism, the shaft clamp comprising:
a non-circular main body being mountable onto the chain hoist for cooperating with a drive shaft of the counterbalancing mechanism, the main body of the shaft clamp having a cross-sectional profile with a plurality of segmented sides, each side being provided with a corresponding threaded orifice for receiving a corresponding setscrew intended to be secured against the drive shaft. The shaft clamp may have a

8 substantially V-shaped body, with at least two segmented sides, each side being provided with a corresponding orifice for receiving a corresponding setscrew, and each side being connected to one another via a bridging portion. The shaft clamp may comprise at least one mounting component for removably mounting the shaft clamp onto at least one side panel (and/or frame) of the chain hoist. According to one possible embodiment, each segmented side of the shaft clamp is substantially T-shaped, and includes a pair of opposite inserts (and/or protrusions) configured for removably inserted into corresponding slots of oppositely distanced side panels of the chain hoist. The shaft clamp may also be provided with at least one visual indication representative of tightening direction of setscrew and/or recommended and/or maximum torque to be used.
According to yet another aspect of the invention, there is also provided a chain hoist provided with the above-mentioned shaft clamp.
According to yet another aspect of the invention, there is also provided a counterbalancing mechanism provided with the above-mentioned shaft clamp and/or chain hoist.
According to yet another aspect of the invention, there is also provided a door assembly provided with the above-mentioned shaft clamp, chain hoist and/or counterbalancing mechanism.
According to yet another aspect of the invention, there is also provided a method of manufacturing components of the above-mentioned shaft clamp, chain hoist, counterbalancing mechanism and/or door assembly.

9 According to yet another aspect of the invention, there is also provided a method of assembling components of the above-mentioned shaft clamp, chain hoist, counterbalancing mechanism and/or door assembly.
According to yet another aspect of the invention, there is also provided a method of using the above-mentioned shaft clamp, chain hoist, counterbalancing mechanism and/or door asseMbly, and/or component(s) thereof.
According to yet another aspect of the invention, there is also provided a kit with components for assembling the above-mentioned shaft clamp, chain hoist, counterbalancing mechanism and/or door assembly.
According to yet another aspect of the present invention, there is also provided a set of components for interchanging with components of the above-mentioned kit.
According to yet another aspect of the present invention, there is also provided a method of assembling components of the above-mentioned kit and/or set.
According to yet another aspect of the present invention, there is also provided a method of doing business with the above-mentioned shaft clamp, chain hoist, counterbalancing mechanism, door assembly, component(s) thereof, kit, set and/or method(s).
The objects, advantages, and other features of the present invention will become more apparent upon reading of the following non-restrictive description of preferred embodiments thereof, given for the purpose of exemplification only, with reference to the accompanying drawings.

10 Brief description of the drawings:
Figure 1 is a cross-sectional representation a conventional chain hoist cooperating with a drive shaft of a counterbalancing mechanism, the chain hoist being .. provided with a conventional shaft sleeve mounted concentrically about the drive shaft of the counterbalancing mechanism according to the prior art.
Figure 2 is a side picture of a conventional chain hoist.
Figure 3 is an enlarged view of a portion of what is shown in Figure 2 to better illustrate the conventional shaft sleeve being welded onto opposite side panels of the frame of the chain hoist according to the prior art.
Figure 4 is a perspective view of a conventional shaft sleeve having been .. manufactured via steel casting, the shaft sleeve being shown provided with two setscrews inserted into corresponding threaded orifices of the shaft sleeve.
Figure 5 is a perspective view of a conventional shaft sleeve having been manufactured via aluminum die casting, the shaft sleeve being shown provided with two setscrews inserted into corresponding threaded orifices of the shaft sleeve.
Figure 6 is an exploded view of some of the components shown in Figure 1 to better illustrate inner components of the chain hoist and to better illustrate the shaft sleeve thereof.
Figure 7 is a cross-sectional representation a new chain hoist cooperating with a drive shaft of a counterbalancing mechanism, the chain hoist being provided with a shaft clamp cooperating with the drive shaft of the counterbalancing mechanism according to a possible embodiment of the present invention.

ii Figure 8 is an exploded view of some of the components shown in Figure 1 to better illustrate inner components of the chain hoist and to better illustrate the shaft sleeve thereof.
Figure 9 is a top perspective view of a shaft clamp according to a possible embodiment of the present invention.
Detailed description of preferred embodiments of the invention:
In the following description, the same numerical references refer to similar elements. Furthermore, for sake of simplicity and clarity, namely so as to not unduly burden the figures with several reference numbers, only some figures have been provided with reference numbers, and components and features of the present invention illustrated in other figures can be easily inferred therefrom. The embodiments, geometrical configurations, materials mentioned and/or dimensions shown in the figures are preferred, for exemplification purposes only.
Moreover, although the present invention was primarily designed for use with drive mechanisms of counterbalancing mechanisms, such as chain hoists used for opening and closing doors, for example, it may be used with other objects and/or in other types of applications, as apparent to a person skilled in the art. For this reason, expressions such as "drive mechanism", "counterbalancing mechanism", "chain hoist", "opening", "closing", "door", etc., used herein should not be taken so as to limit the scope of the present invention and include all other kinds of objects and/or applications with which the present invention could be used and may be useful.
For example, the present shaft clamp could also be used with and/or for various other types of "hoists" and/or "drive mechanisms", as can be easily understood by a person skilled in the art.

Moreover, in the context of the present invention, the expressions "shaft clamp", "clamp", "assembly", "system", "device", "apparatus", "product", "unit", "equipment", "tool", "method" and "kit", as well as any other equivalent expression(s) and/or .. compound word(s) thereof known in the art will be used interchangeably, as apparent to a person skilled in the art. This applies also for any other mutually equivalent expressions, such as, for example: a) "closing"; "opening", "raising", "lowering", "moving", "driving", "displacing", "adjusting", etc.; b) "door", "curtain", etc.; c) "stroke", "travel", "range", "motion", etc.; d) "distance", "position", "location", etc.; e) "hole", .. "orifice", "passage", "channel", "conduit", "path", "flow", etc.; f) "fastening", "securing", "locking", "restraining", "affixing", "holding", "adjusting", etc.; as well as for any other mutually equivalent expressions, pertaining to the aforementioned expressions and/or to any other structural and/or functional aspects of the present invention, as also apparent to a person skilled in the art. Also, in the context of the present description, expressions such as "can", "may", "might", "will", "could", "should", "would", etc., may also be used interchangeably, whenever appropriate, as also apparent to a person skilled in the art.
Furthermore, in the context of the present description, it will be considered that all elongated objects will have an implicit "longitudinal axis" or "centerline", such as the longitudinal axis of shaft for example, or the centerline of a coiled spring, for example, and that expressions such as "connected" and "connectable", or "mounted"
and "mountable", may be interchangeable, in that the present invention also relates to a kit with corresponding components for assembling a resulting fully-assembled and fully-operational shaft clamp, and/or associated chain hoist and/or counterbalancing mechanism, and/or resulting door assembly.
Moreover, components of the present system(s) and/or steps of the method(s) described herein could be modified, simplified, altered, omitted and/or interchanged, without departing from the scope of the present invention, depending on the particular applications which the present invention is intended for, and the desired end results, as briefly exemplified herein and as also apparent to a person skilled in the art.
In addition, although the preferred embodiments of the present invention as illustrated in the accompanying drawings comprise various components, and although the preferred embodiments of the present chain hoist and corresponding portion(s)/part(s)/component(s) (ex. shaft clamp) as shown consist of certain geometrical configurations, as explained and illustrated herein, not all of these components and geometries are essential to the invention and thus should not be taken in their restrictive sense, i.e. should not be taken so as to limit the scope of the present invention. It is to be understood, as also apparent to a person skilled in the art, that other suitable components and cooperation thereinbetween, as well as other suitable geometrical configurations may be used for the present chain hoist and corresponding portion(s)/part(s)/component(s) (ex. shaft clamp) according to the present invention, as will be briefly explained herein and as can be easily inferred herefrom by a person skilled in the art, without departing from the scope of the present invention.
Broadly described, and as better exemplified in the accompanying drawings, the present invention relates to a shaft clamp to be used with a chain hoist in a simpler, easier, faster, more accurate, more effective, more functional, more reliable and/or more versatile manner than what is possible with other conventional devices (ex. shaft sleeves).
List of numerical references for some of the corresponding possible components illustrated in the accompanying drawings:
1. threaded fastener (ex. setscrew) 2. hoist frame 3. pocket wheel 4. input shaft 5. driving component (ex. driving sprocket (or gear)) 6. retaining clip 7. shaft clamp 8. threaded hole 9. protrusion

11. angle

12. frame hole (or "opening")

13. door shaft

14 bearing

15. tab

16. opening

17. driven component (ex. sprocket (or gear))

18. mounted drum Following is a brief description of how the present invention works according to possible embodiment(s).
Indeed, the present shaft clamp and/or other associated inventive aspects (ex.

chain hoist, counterbalancing mechanism, door assembly, etc.) may include one and/or several of the following possible components and features (and/or different possible combination(s) and/or permutation(s) thereof):
Indeed, according to one possible embodiment, and as can be easily understood when referring to the accompanying drawings, there is provided a chain hoist.

Optionally, the chain hoist can be a manual chain hoist composed of an input shaft (4), on which is assembled a pocket wheel (3), a driving sprocket (or gear) (5) and a retaining clip (6) (retaining clip may be replaced by riveting, for example).
The input shaft (4) can be hexagonal in a preferred embodiment in order to lock in rotation both the pocket wheel (3) and the driving sprocket (or gear) (5).
The shaft can also have a groove to receive the retaining clip (6) (if not riveted, for example).
Regarding the overall concept of hoist allows bottom-up assembly:
The input shaft (4) can slid through bearing (14). The pocket wheel (3) can be slid on input shaft (4), and the other frame (2) can be slid on shaft, through its bearing.
The assembly can be locked in place with retaining clip (or riveting, for example).
The hoist frame (2) can be made of an asymmetric part, assembled with a bearing (14). The said frame can also have tabs (15) designed to be fold (shown already folded in the accompanying drawings) and thus insure a permanent assembly of the device.
The hoist frame can comprise an opening (12) to receive door shaft (13). The said hoist frame can also have at least one opening (16) to receive shaft clamp (7).
The said opening is optionally meant to be oriented in such a way so as to help prevent an improper assembly of the shaft clamp (7).
Setscrews (1) can be designed with a red head, for example, and designed in a way that they will be accessible, from the top of the hoist by an installer.
As shown in the drawings, a possible embodiment of the shaft clamp (7) may comprise at least one threaded hole (8), to receive a threaded fastener (1), heresaid setscrews, that will be tightened to exert a pressure on shaft (13) and therefore act as a locking mean for the hoist. Once the setscrews are appropriate tightened, the shaft will be firmly pressed in the bottom section of frame holes (12), which ensures good center-to-center distance between driven mechanisms.
The present system therefore provides several advantages over conventional devices (ex. a shaft sleeve) in that: a) the hoist is therefore locked in translation and in rotation on the shaft; b) translation restriction allows proper axial alignment of the driven mechanism (gear or sprocket) over time; c) good axial alignment and center-to-center distance between sprockets allows proper tension on the chain and avoid chain link slippage and/or premature wear; d) rotation restriction avoids unwanted rotation of the hoist on the shaft when load is applied on the hand chain; e) etc.
According to another possible embodiment, the shaft clamp (7) may also be bent at an angle (11), in order to have the axis of threads symmetrical on each side of the door shaft axis. This angle can also create a distinct feature that helps in avoiding the shaft clamp (7) from being assembled improperly onto the hoist frame (2).
The shaft clamp (7) may also comprise protrusions (9) that will guide and hold the part vertically in hoist frame (2) during the assembly process of the complete hoist.
The shaft clamp (7) may also comprise stamped text and/or visual indication(s) in order to provide information to the installer on setting torque of setscrew (1).
When the present hoist is used to manually open a door, it allows door opening by mean of a hand chain, which when put under load rotates a pocket wheel (3).
The pocket wheel, which is fixed to the input shaft (4), induces rotation of the gear or sprocket (5). This gear or sprocket (5) (i.e. "driving" component of the chain hoist) transmits torque to a gear or sprocket (17) (i.e. "driven" component of the chain hoist) fixed on a bearing mounted drum (18). This torque allows rotation of the drum and opening of the door. Reduction ratio between mechanisms allows an easy opening of the door.
It is worth mentioning that several modifications could be made to the present system and corresponding components, without departing from the scope of the present invention. For example: a) preferred embodiment of the shaft clamp is in stamped steel, however, other combinations of material(s)/process(es) could be used, such as die casting, casting, machining, plastic, etc.; b) forming could be added on the shaft clamp to provide longer threads; c) the shaft clamp could be an assembly of a stamping part and/or threaded inserts; d) the number, size and type of fixing setscrews could vary depending of the torque to retain; e) several steel plate(s) with one setscrew could be used, instead of having one component with several setscrews assembled on it; f) the shape, location and number of protrusions into the hoist frame (2) could vary; g) the diameter of hole (12) could vary to accommodate different shaft diameters; h) the shape of hole (12) in hoist frame (2) could vary to adapt different door shaft (ex. hexagonal shaft, for instance); i) the hoist frame dimensions and/or shape could be different; j) etc.
The present shaft clamp (7) and corresponding parts are preferably made of substantially rigid materials, such as metallic materials, hardened polymers, composite materials, polymeric materials, and/or the like, so as to ensure a proper operation thereof depending on the particular applications for which the shaft clamp (7) is intended and the different parameters (forces, moments, etc.) in cause, as apparent to a person skilled in the art.
As may now be better appreciated, the present invention is advantageous in that it provides for a shaft clamp which can be used with a chain hoist in a more efficient, more precise, more accurate, more reliable, more adjustable, more versatile, more adaptable, more ergonomic and/or more desirable manner, than what is possible with other existing conventional devices.
Of course, and as can be easily understood by a person skilled in the art, the .. scope of the claims should not be limited by the possible embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.
Furthermore, although preferred embodiments of the present invention have been briefly described herein and illustrated in the accompanying drawings, it is to be understood that the invention is not limited to these embodiments and that various changes and modifications could be made without departing form the scope and spirit of the present invention, as apparent to a person skilled in the art.