US 3575373 A
Description (OCR text may contain errors)
United States Patent lnventors Richard N. Reinhardt 621 W. Yale St., Ontario, Calif. 91762;
Frank L. Ellings, 2074 White Bluff, San Dimas, Calif. 91773 Appl. No. 797,653
Filed Feb. 7, 1969 Patented Apr. 20, 1971 HOLDDOWN DEVICE 4 Claims, 2 Drawing Figs.
US. Cl 248/361, 248/ l 25 Int. Cl B65j 1/22 Field of Search 248/361,
361(B),125,124,122,410,154,(T.C.);211/84  References Cited UNITED STATES PATENTS 936.767 10/ 1 909 Van Eyck 248/154X 1,785,746 12/1930 Pilling 248/154 2,160,433 5/1939 Griffin... 248/147 2,891,753 6/1959 Bittle 248/154X Primary ExaminerChancellor E. Harris Att0rneyChristie, Parker & Hale nowoovvn nisvrca BACKGROUND OF THE INVENTION The present invention relates to devices for holding objects in place and, more in particular, to a friction-type holddown device which is particularly well suited for holding various sized articles in place while they are being transported.
Meters for natural gas service are typically transported in pickup trucks in specially designed racks. Typically, the racks have a rail circumscribing them to retain the meters in place. This guard or rail necessitates the lifting of the gas meters into and out of the racks. Moreover, meters are not held firmly in place and often bounce in transit.
Another problem attendant with the use of racks is that the racks do not lend themselves to use other than in the carriage of gas meters. Thus, when a service truck is called upon to transport articles other than gas meters, the racks serve only as a hindrance.
In an effort to make access to the meters more convenient, a new type of meter rack has recently been introduced which accepts the meter in a pivotable cradle. For transit, the cradle is pivoted into a stable position interiorly of the sides of a truck with a guard or frame about each meter. When it is desired to remove the meter, the cradle is merely pivoted to an outboard position where meter access is possible. While meter accessibility is well served by this rack, the rack is relatively expensive and does not accommodate itself to the problem of transporting things other than gas meters. Moreover, the meter size accommodation of the improved rack is not as broad as would be desired.
Therefore, there is a present need for a holddown device SUMMARY OF THE INVENTION The present invention provides a holddown device which employs an arm which, when canted on a shaft, locks in place to hold an article.
In one form, the present invention contemplates that the arm have a hole for the arms receipt by the shaft. The relationship between the arm and shaft is such that canting of the arm produces seizure on the shaft along opposite comers of the hole. A retaining member, preferably a pad, is used to engage the article being held. The retaining member is on a pin and is force coupled to the arm through a compression spring. The pin, in turn, is coupled to the arm, as in a hole in the arm, by a keeper.
In use, an upward reaction force from an article is exerted on the retaining member to compress the spring. The spring, in turn, exerts an upward force on the arm which cants the arm on the shaft to effect a friction lock between the arm and the shaft.
It has been found that the clearance between the hole in the arm and its cooperating shaft should be such that an inclination from the horizontal of the arm of about 3 to about 5 is possible, the inclination being produced by a holddown load transferred through the pad to the arm. In other words, the angle between the shaft and the arm under load should be from about 85 to about 87. If the amount of arm inclination possible is less than this, the arm is too tight on the shaft and, as a consequence, it is difficult to adjust the arm's height to accommodate different sized articles to be held. Obviously, the greater the angle of the arm to the horizontal when holding down an article, the greater will be the locking force. However, with large angles from the horizontal, the device is often difficult to use because the arm can interfere with an article. Large angles from the horizontal of the arm in its inuse position also require an excessive hole diameter in the arm for the retaining member s pin to keep the retaining member level. The large hole diameter for the pin produces problems in keeper design to retain the pin with the arm.
It is contemplated that a typical gas meter service truck will be equipped with an assembly having several of the holddown devices in a row. This assembly may be secured to the bed of the truck and adjacent, for example, a service box for tools and the like. When no meters are to be transported, the arms can either be removed or swung inwardly against the service box allowing considerable room for transporting of articles other than meters.
The present invention provides a very simple but highly reliable holddown device which may be used, for example, in service trucks for transporting meters used in natural gas service. The holddown device is very simple, lightweight, and effects a positive retention of articles being held. Moreover, it does not occupy a large amount of space and therefore, when it is not in use, there is ample room for transporting other articles.
These and other features, aspects and advantages of the present invention will become more apparent from the following description, appended claims and drawings.
BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is an elevational view, partly in section, of a preferred form of the holddown device of the present invention as it would appear in use; and
FIG. 2 is a perspective view showing a typical bank of holddown devices as they would be employed, for example, in a service truck.
DESCRIPTION OF THE PREFERRED EMBODIMENTS A holddown device 10 according to the present invention is illustrated in FIG. I. Briefly, the holddown device includes a shaft I2, an arm 14 and a holddown pad assembly 16.
The arm is received on shaft 112 through a bore or a hole 18 in the arm. A clearance exists between the wall of the arm defining the bore and the shaft in order to permit the arm to be angularly displaced an amount equal to an angle a from the horizontal and to engage the shaft as is illustrated in FIG. 1, the displacement being in response to an upward force indicated by the arrow in this FIG.
It has been found that there must be sufficient angular displacement of the arm relative to the shaft to facilitate vertical position adjustment of the arm. If the angle of inclination from the horizontal is too small, the arm tends to bind on the shaft. On the other hand, excessive angular displacement from the horizontal makes it difficult to provide an effective keeper for holddown pad assembly 16. A value of angle a of from about 3 to about 5 has been found highly satisfactory in the resolution of these conflicting requirements by permitting arm adjustment without binding on the shaft while permitting effective keeper design for holddown assembly 16.
In the holddown device of the present invention, the holddown pad preferably consists of a neoprene pad or disc 20 and a complementary cylindrical backing member 22 of, for example, steel. The pad should be of a resilient material to provide a firm gripping engagement with an article despite surface irregularities thereon. Moreover, a resilient pad of, say neoprene, provides a high coefiicient of friction for retaining an article against horizontal displacement forces.
A shaft or pin 24 is secured as by threads to the backing member. This shaft or pin is loosely received in a bore 26 of arm M. Bore 26 is oversized to allow pin 24 to parallel shaft 12 when arm I4 is canted. The possibility of this parallelism pennits pad or disc 20 to keep level and in effective engagement with the flat top of an article, such as a gas meter, being held. A keeper in the form of a lock ring 23 is secured in a groove in pin 24 and retains the pin with the arm. It is this keeper which necessitates an upper limit of angular displacement from the horizontal of arm 114. Bore 26 must progressively be increased in diameter relative to pin 24 with increasing angular displacement of arm 14 from the horizontal if pad or disc 20 is to have the facility of being level during holddown. With increased clearance between pin 24 and the wall defining bore 26, there is an increased possibility of keeper 28 pulling through the bore.
A compression spring 30 is provided for transmitting the force of article engagement to the arm and from the arm to the shaft. The spring constant of spring 30 must be sufficient to keep the spring from completely collapsing when engaging an article. This is necessary to accommodate vertical displacement forces experienced while transporting meters or the like with a truck over, say, a bump in the road while maintaining arm and shaft engagement.
Neoprene disc may be secured to backing member 22 by any suitable commercially available cementing compound.
Shaft 12 is preferably of seamless tubing. The shaft may be secured to a baseplate 32 as by welding. This baseplate may, in turn, be secured to the bed of the truck as is illustrated in FIG. 2.
For a series of holddown devices, a top brace 34 extending across the tops of the holddown devices is preferably provided. This top brace, which provides rigidity, may be in the form of a standard channel. Each holddown device is coupled to the brace through a collar 36 secured as by welding to the web of the channel. Each collar is sized to receive within its bore an associated one of the shafts 12. A thumbscrew 38 may be provided to secure the top brace to the end holddown devices in a series of holddown devices. Preferably, if several of the holddown devices are employed, additional thumbscrews may be provided at regular intervals along the length of the brace.
In use, an article, say a gas meter, is placed on the bed of the truck beneath an arm 14 of one of the holddown devices. The arm is then raised or lowered such that pad or disc 20 engages the top of the meter and spring 30 is compressed. This will cant arm 14 such that it firmly engages shaft 12 to apply a substantial holddown force on the meter. It should be appreciated that the holddown force is equal to the spring constant of spring 30 multiplied by the displacement of the spring. lt should also be appreciated that it is this force which must be balanced by the friction force produced by the engagement of the arm and the shaft at the inclined angle illustrated. When it is time to release the holddown device, spring 30 is further compressed and arm 14 is rotated to free it from shaft 12. The arm may then be freely lifted upwardly to free the article.
The holddown device of the present invention is marked in its simplicity while providing a reliable and easily used means for positively restraining various articles. One of the desirable features of the holddown device is its ability to accommodate various sized articles by simply positioning arm 14 on shaft 12.
1. A holddown device for use in securing various sized articles comprising:
a. a shaft;
b. an arm extending laterally of the shaft having a hole proximate a first end thereof which receives the shaft, the hole having a diameter sufficiently larger than the diameter of the shaft that the arm is capable of seizing on the shaft along opposite comers of the wall of the hole when the arm is canted with respect to the shaft;
c. a pin received in the arm proximate the second end thereof for displacement generally parallel to the shaft;
(1. a keeper retaining the pin with the arm;
e. a retaining member secured to the pin for compressively engaging an article;
f. a compression spring disposed about the pin between the arm and the retaining member for transmitting a holding force to an article through the retaining member;
g. a baseplate secured to the shaft for the mounting of the device; and
h. a top brace rcmovably secured to the shaft at the top thereof for providing rigidity.
2. The holddown device claimed in claim 1 wherein the diameter of the hole in the arm is sufiiciently larger than the diameter of the shaft that the arm 15 capable of angular displacement from a position normal to the axis of the shaft of from about 3 to about 5.
3. The holddown device claimed in claim 2 wherein the retaining member comprises a disclike pad of resilient material for engaging an article and a rigid backing member secured to the pad, the pin being secured to the backing member.
4. The holddown device claimed in claim 1 wherein the top brace is in the form of a channel and a collar is provided for slipping over the top of the shaft and securing the top brace to the shaft, the collar being affixed to the interior side of the channel s web.