US3906815A

US3906815A - Latching device

Info

Publication number: US3906815A
Application number: US516392A
Authority: US
Inventors: Joseph Buono
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-10-21
Filing date: 1974-10-21
Publication date: 1975-09-23
Anticipated expiration: 1992-09-23

Abstract

A positive acting latching device particularly suited for dental units comprises guide rods that have a forward and rearward end. A carriage is carried on the guide rods and is slidable relative thereto. An elongated rail is positioned parallel to the guide rods and has a lateral leading edge spaced from the forward end of the guide rods. A control member is placed between the guide rod''s forward end and the rail leading edge. A toggle formed with two opposed notches is attached to the carriage and is pivotable thereon. The toggle is operable to slide adjacent the rail and strike the control member whereby it orients the notch so that when the toggle moves back and strikes the leading edge, the leading edge coacts with the notch and locks the toggle and carriage thereat. Release is accomplished by moving the toggle from the leading edge causing it to strike the control member. In so doing, the control member orients the toggle and allows it to move past the rail leading edge towards the rearward end of guide rods.

Description

[ Sept. 23, 1975 United States Patent Buono LATCHING DEVICE for dental units Comprises guide rods that have a for- Inventor: Joseph Buono 86 75 Midland Pky ward and rearward end. A carriage is carried on the Apt. 3T, Jamaica, NY. 11432 Oct. 21, 1974 guide rods and is slidable relative thereto. An elongated rail is positioned parallel to the guide rods and has a lateral leading edge spaced from the forward end of the guide rods. A control. member is placed between the guide rod dge. A toggle form [22] Filed:

s forward end and the rail leading 21 App]. No.2 516,392

e ed with two opposed notches is at- [52] US. 74/527; 74/520 tached to the carriage and is pivotable thereon. The

Int. Cl. GOSG 5/06 toggle is operable to slide adjacent the rail and strike the control member whereby it orients the notch so that when the toggle moves back and strikes the leading edge, the leading edge coacts with the notch and locks the toggle and carriage thereat. Release is ac- References Cited UNITED STATES PATENTS complished by moving the toggle from the leading edge causing it to strike the control member. In so do- 3,436 983 4/1969 74 521 the control member miems the toggle and allows it to move past the rail leading edge towards the rearward end of guide rods.

Primary Examiner-Samuel Scott or FirmLeonard H. King ABSTRACT A positive acting latching device particularly suited 6 Claims, 4 Drawing Figures US Patent Sept. 23,1975 Sheet 1 of2 3,906,815

US Patent Sept. 23,1975 Sheet 2 of2 LATCHING DEVICE FIELD OF THE INVENTION This invention relates to a retraction mechanism for a hose or cable, or the like, and more particularly to a retraction device having means to latch the hose in an extended position.

BACKGROUND OF THE INVENTION Many instruments particularly those used by dentists are attached to cables or hoses through which the various fluids, gases or motive means are supplied. For example, the familiar dentists rack contains an array of instruments some of which utilize fluid pressure, vac'- uum, electric or ultrasonic power. Since the rack is p sitioned remote from the patient, it is obvious that an appreciable amount of cable or hose need be stored in the rack so that the instrument can reach the patient. Some means then is necessary to rewind or retract the cable back into the rack. Usually the rewind sequence is accomplished by biasing the hose or cable with linear acting springs that provide a constant tension against which the dentist must pull as he withdraws the instrument from the rack. Unless some type of locking or stop action is provided an unacceptable pulling or retractive force is experienced by the dentist as he uses the instrument. While the amount of tension exhibited by those linear acting springs is minimal, the tension in the line would unduly confine or interfere with use of the instrument. Some type of locking action is needed to lock a portion of the cable and thereby free the extended end of the hose which carries the instrument. The reliability of these locking devices is critical. If, for example, a dentist is drilling a tooth, the positioning of the drill is of utmost importance. With the power line being extended from the instrument during this opera tion, and the line locked while so extended, the biasing or retracting force on the line is counteracted, hence, the dentist uses the instrument freely. If the locking device were to fail the cord or hose will rapidly retract jerking the instrument with potentially disasterous results.

To avoid such failures prior apparatus have gone'to extensive and complicated lengths to insure the reliability of the cable lock or latching means. Prior devices have used ratchet blocks, locking pins or various frictional devices to lock the cable. For example, US. Pat. No. 3,436,983 discloses a latch structure for pull lines. In part, the device utilizes the elasticity inherent in a hook element whose bending and flexing permits it to engage a V-shaped member that is tilted with respect to the path of travel. Upon release, the hook element must then align properly so that it can pass through an accurately placed opening.

Generally, the present invention employs a pivotal toggle extending from a carriage. The dental cable or hose passes over a pulley attached to the carriage. The toggle has opposed longitudinal edges and at its lateral edges is formed with a pair of opposed notches that in conjunction with the longitudinal edges provide a plurality of surfaces. The position of these surfaces in relation to and acting on a control member, which is a stop, effect a locking or latching action. The carriage assembly slides adjacent to a rail with the rail defined by a leading edge. As the cable is withdrawn from the apparatus the toggle strikes the control member stopping forward movement of the carriage and attached cable.

In so doing the control member acts to orient the toggle so that when thecable is momentarily released, the cable and carriage undergo a retractive movement until the toggle strikes and locks about the rail leading edge. To release the cable, the cable is pulled a short distance from the rack causing the toggle to engage the control stop. This action orients the toggle so that same is then able to slide past the rail leading edge as the cable retracts. Since no flexing of the locking elements is required, fatigue inherent from such bending is eliminated.

It is therefore an object of the present invention to provide a locking device particularly suited for use in locking retractable cables, hoses and the like.

It is another object of the present invention to provide a positively acting latching mechanism having a one stop lock position whose release therefrom depends on a forward pull on the cable.

It is still a further object of the present invention to provide a locking apparatus particularly suited for retractable cables that is simple in design, easy to manufacture, and one that will provide reliable locking and releasing action. I

Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood however that the drawings are designed for purposes of illustration only and not as a definition of the limits of the invention for which reference should be made to the appending claims.

BRIEF DESCRIPTION OF DRAWINGS In the drawings wherein similar reference numerals denote similar elements throughout the several views:

FIG. 1 is a perspective view of the locking device positioned in a dental unit with a part of the unit broken away for clarity;

FIG. 2 is an elevational view of the inventive carriage assembly and attached toggle that is revealed in FIG. 1;

FIG. 3 is an enlarged partial perspective view of the apparatus of FIGS. 1 and 2 showing suspension of the notched toggle from the carriage and pulley support and positioned between the guide rail and control stop; and

FIG. 4 shows the sequence of positions through which the inventive apparatus traverses to provide the unique one-stop latching feature.

DETAILED DESCRIPTIONS OF THE PREFERRED EMBODIMENT Referring now to the drawings and particularly FIGS. 1, 2, and 3, there is shown the apparatus of the present invention operable in a dental unit. A dental unit indicated generally by reference numeral 10 comprises a cowling 12, a front panel 14 and a rear panel 15. Panel 14 includes a plurality of apertures 16 through which the various dental instruments are arranged. A plurality of guide rods 18 are disposed :in unit 10 and attached between the front and rear panel so that a pair of guide rods is spaced parallel adjacent each aperture as shown. A carriage 20 is formed with a pair of opposed channels 22. The channels are dimensioned so as to fit about the periphery of respective rods 18. With the construction shown, carriage 20 is able to slide along rods 18 while being confined thereon. A support strut 24 is attached toone face of carriage 20 by means 28 while a pulley 26 is attached to the other face of carriage 20 by the same means. Support 24 is formed with a right-angled extension 30 that projects outboard from the face of carriage 20, as more clearly seen in FIG. 2. A toggle or pawl piece 32 is pivotably suspended from one side of arm 30 by a pin 34. Hence toggle 32 is operable to rotate relative to arm 30.

Toggle 32 is defined by a pair of parallel opposed

longitudinal edges

36 and 38 which define the two longitudinal sides of the toggle. The opposed lateral sides of the toggle are defined by complimentary, although oppositely positioned

notches

40 and 42. Notch 40 is defined by a relatively long side or face 44 and a short side or face 46 with the faces merging at a common edge or point. In a similar manner, notch 42 is defined by a relatively long side or face 48 and a relatively short face 50 that likewise merges along a common edge or point. It will be observed, however, that positions of the respective long and short faces of each notch are reversed. That is, whereas notch 42 has long face 48 merging with a longitudinal edge 36, notch 40 has its short face merging with this last mentioned edge. Hence when comparing one notch to the other it will be observed that the respective faces thereof are reversed.

Positioned in housing is a control block or stop 52. Control block 52 is attached to the floor of the housing and is placed adjacent to front panel 14. The height of control block 52 as well as the lateral distance from a plane defined by connecting a respective rod pair 18, is such as to insure that the toggle will strike block 52 so that the block acts as a stop for the toggle. Control block 52 includes a control edge 53 whose operation will be described hereinafter.

Positioned rearward of control block 52 and disposed substantially parallel to the plane defined by rods 18 is a guide rail 54. Guide rail 54 includes a leading edge 56 disposed so as to face control block 52.

A cable or hose 58 is carried on pulley 26 so that free end of the hose extends through aperture 16 where it may be coupled onto a given dental instrument 62. Thus, the hose or cable, as the case may be, carries, for example, fluid pressure, electric current, or the various dental utilities. The other end of hose 50 extends through a rearward portion of unit 10 where it may be coupled to the given dental utility, the dental utility, now shown.

A constant tension spring, 60, one such spring being known in the art as a Neg-A-Tor, is on one end attached to rear panel of unit 10, and on the other end the spring is coupled to carriage 20. Spring 60 normally biases carriage towards a retracted position causing the carriage to slide on rods 18 until nearly adjacent the rear panel.

Operation of the inventive device can best be understood by reference to FIG. 4 and referring back to FIGS. 1, 2 and 3. As noted, constant tension spring 60 normally biases carriage 20 into a retracted position with carriage 20 nearly adjacent rearward wall 15 and unit 10. In this retracted position, instrument 62 extends into aperture 16 by being pulled therethrough by cable 58 as the cable and carriage is urged rearward in unit 10 by action of the spring.

To withdraw the instrument the following sequence of movements occur and now particular reference is made to FIG. 4. As the dentist pulls on instrument 62, carriage 20 begins to slide on rods 18, causing toggle 32 to move relative to rail 54. In this configuration, longitudinal edge 38 of the toggle is spaced opposed from the inboard face of rail 54. In the position shown at 32a, toggle 32 is about to leave the region of rail 54 and is moving in the direction of arrow 1. Continued pull on cable 58 causes toggle 32 to strike stop 52 stopping forward movement of the carriage. More particularly, the dimensional constrants of the inboard face of rail 54 in relation to longitudinal edge 32 mandates that as the toggle leaves the region of rail 54 in the direction indicated, toggle 32 is positioned with notch 40 facing con trol stop 52. In this configuration, face 46 is in a position to strike control edge 53. As the toggle strikes control block 52, the position at 32b is obtained. Further application of tension in the direction of arrow 1 causes a pivoting of toggle 32 as carriage 20 moves a small distance forward. The toggle pivots about control edge 53 until reaching the position shown in at 32c where toggle face 44 abuts against control 52 stopping any further forward movement of carriage 20. At this point the carriage, and so cable, is in its most extended position. A momentary release of the instrument or the cable, depending which is held, allows spring 60 to pull the carriage back towards rear panel 15. In so doing, the carriage moves toggle 32 in the direction of the arrow 2 causing the relatively long face 44 of notch 40 to slide along control edge 53. The sliding on edge 53 acts to orient the toggle to the position shown at 32d. Spring 60 continues to urge carriage 20 and hence toggle 32 in the direction of arrow 2 until edge or face 50 of notch 42 strikes leading edge 56 of rail 54. At this point the configuration indicated at 32e is assumed. Spring 60 continually applies tension to the carriage causing a slight movement of the carriage and pivoting of toggle 32. This pivoting drives the leading top of toggle face 48 onto the inboard surface of rail 54. This is indicated at position 32f, where toggle 32 is prevented from further travel towards rear panel 15. The toggle remains so configured by application of tension from spring 60. In the position of 32f the toggle jams against the rail and so is latched or locked from moving further in direction of arrow 2.

To release the toggle and retract the cable and dental instrument, one merely tugs on either the instrument or extended cable portion causing toggle 32 to move in direction of arrow 3 and strike control edge 53 as shown at position 32g. Further pulling on the cable or instrument in direction of arrow 3 causes longitudinal edge 38 of the toggle to slide relative to and on control edge 53 and in so doing pivots toggle 32 into the position indicated at 3211. At this configuration the toggle and carriage are prevented from further movement in the direction of arrow 3 so that a momentary releasing of the instrument or cable, as the case may be, allows spring 60 to urge carriage 20 in the direction of arrow 2 which is towards guide rail 54. As toggle 32 travels towards guide rail 54 and strikes same, the position shown at 321' is reached where a portion of longitudinal face 36 of the toggle strikes leading edge 56 of rail 54 thereby acting to slightly pivot the toggle and drive it to the position shown at 32j. In this last mentioned position, spring 60 is then free to retract carriage 20 as the toggle slides rearward lightly wiping against, or spaced parallel from the inboard face of rail 54. Completion of the above sequence from, 32a to 32j causes the toggle to rotate on pin 34. This rotation has now placed notch 42 in a position to repeat the above action.

Of course it is to be understood that the above action is fast acting so that in effect the operation of the device produces two independent sequences, one for lock and one for release. The first sequence is withdrawal of the instrument until the pawl hits the control stop, then a momentary release allowing the carriage to travel a minute distance back towards rear panel until toggle 32 locks or latches against the leading edge of reel 54.

The second sequence is for unlock, where a forward tug on the instrument causes the toggle to strike and stop against control block 52 reorienting the toggle and allowing it to slide past and adjacent to rail 54 retracting the cable when the cable or instrument is released.

It will be appreciated that owing to the inherent sim'- plicity in the inventive apparatus the same will be virtually maintenance free and free from periodic adjustment.

While reference has been made to the guide rods being mounted between the front and rear panels, it should be appreciated that the chassis may carry brack ets for mounting the guide rods without departing from the spirit of the invention.

While the latching apparatus of the present invention has been shown and described in connection with dental apparatus utility therefor is not to be limited thereby. The inventive lock will find utility in a variety of machines where it is necessary to detachably lock one part in relation to another.

While only a single embodiment of the present invention has been shown and described, it is to be understood that many changes and modifications may be made hereto without departing from the spirit and scope thereof.

What we claim as new and desire to secure by Letters Patent is:

1. A latching device comprising:

a. guide means having forward and rearward ends;

b. a carriage by said guide means and slidable relative thereto;

c. an elongated guide rail parallel to said guide means and having a lateral leading edge spaced from said guide means forward end;

d. a control piece placed intermediate said guide means forward end and the leading edge; and,

e. toggle means formed with notch means and attached to said carriage and pivotal thereon, said toggle means operable to strike said control piece and orient said notch means so that when said toggle means strikes the leading edge, the leading edge will coact with said notch means to lock said toggle means and carriage thereat, then when said toggle means is caused to strike said control piece, said control piece will orient said toggle means allowing it to move past the leading edge and permit said carriage to traverse said guide means toward said rearward end.

2. The device of claim 1 further comprising biasing means adapted to normally urge said carriage towards said rearward end.

3. The device of claim 2 further including:

a. pulley means attached to said carriage;

b. line means having two ends and wrapped about said pulley means so that pulling one of said two ends causes the relative movement of said carriage whereby said one line end moves to an extended position as said toggle means assumes said locked configuration, said one line end being automatically driven into a retracted position by operation of said biasing means when said toggle means is so orientated that it passes the leading edge and traverses towards said rearward end.

4. The device of claim 3 enclosed in a console, the console defined by a forward face having a plurality of apertures formed therethrough, and wherein said one line end extends through one of said plurality of apertures, and the other end of said line extends from said console.

5. A positive acting latch comprises in combination:

a. a dental unit having a front panel and a rear panel opposed thereto with said front panel being formed with at least one aperture therethrough;

b. a pair of guide members adjacent said aperture and extending between said front and rear panels;

c. a carriage having a pulley and slidable relative to said guide members for confinement thereby;

d. an elongated rail substantially parallel to said guide members and having a leading edge spaced from said front panel;

e. a stop having a control edge that faces said rail leading edge;

f. pawl means formed with notch means and attached to said carriage and pivotal thereon;

g. spring means normally biasing said carriage towards the rear panel; and

h. a dental line having two ends one of which enters said unit and wraps around the pulley so that the other line end exits through said aperture whereby pulling on said other line end allows a portion of said line to exit said aperture as said pawl means and carriage slides relative to said guide rail and past said leading edge until said notch means thereof strikes said control edge a first time to limit movement of said line, then momentarily releasing said line allows said carriage to move back towards, and strike, said leading edge locking said pawl means thereabout, then pulling on said line other end causes said pawl means to strike said control edge a second time orienting said pawl means whereby releasing said line permits said spring means to drive said pawl means past leading edge returning said carriage and line adjacent said rear panel.

6. A retractable cable assembly and lock therefore,

comprising:

a. a guide element having a forward and rearward end;

b. a carriage movable relative to and on said element and coupled to the cable;

c. an elongated rail substantially parallel to said element and having a leading edge spaced rearward of said element forward end;

d. a stop block placed intermediate said element forward end and said leading edge; and

e. pawl means formed with a pair of opposed V- shaped grooves and pivotally attached to said carriage, said pawl means operable to strike said stop block and orient the grooves so that when said pawl means is caused to strike said leading edge, the same will coact with one of said groove pair to lock said pawl means and carriage thereat whereby the cable assumes an extended position, then when said toggle means is caused to strike said block, said block will orient said pawl means allowing it to move passed said leading edge permitting said carriagc to traverse said element towards said rearward end thereof driving the cable to a retracted position.

Claims

1. A latching device comprising: a. guide means having forward and rearward ends; b. a carriage by said guide means and slidable relative thereto; c. an elongated guide rail parallel to said guide means and having a lateral leading edge spaced from said guide means forward end; d. a control piece placed intermediate said guide means forward end and the leading edge; and, e. toggle means formed with notch means and attached to said carriage and pivotal thereon, said toggle means operable to strike said control piece and orient said notch means so that when said toggle means strikes the leading edge, the leading edge will coact with said notch means to lock said toggle means and carriage thereat, then when said toggle means is caused to strike said control piece, said control piece will orient said toggle means allowing it to move past the leading edge and permit said carriage to traverse said guide means toward said rearward end.

3. The device of claim 2 further including: a. pulley means attached to said carriage; b. line means having two ends and wrapped about said pulley means so that pulling one of said two ends causes the relative movement of said carriage whereby said one line end moves to an extended position as said toggle means assumes said locked configuration, said one line end being automatically driven into a retracted position by operation of said biasing means when said toggle means is so orientated that it passes the leading edge and traverses towards said rearward end.

5. A positive acting latch comprises in combination: a. a dental unit having a front panel and a rear panel opposed thereto with said front panel being formed with at least one aperture therethrough; b. a pair of guide members adjacent said aperture and extending between said front and rear panels; c. a carriage having a pulley and slidable relative to said guide members for confinement thereby; d. an elongated rail substantially parallel to said guide members and having a leading edge spaced from said front panel; e. a stop having a control edge that faces said rail leading edge; f. pawl means formed with notch means and attached to said carriage and pivotal thereon; g. spring means normally biasing said carriage towards the rear panel; and h. a dental line having two ends one of which enters said unit and wraps around the pulley so that the other line end exits through said aperture whereby pulling on said other line end allows a pOrtion of said line to exit said aperture as said pawl means and carriage slides relative to said guide rail and past said leading edge until said notch means thereof strikes said control edge a first time to limit movement of said line, then momentarily releasing said line allows said carriage to move back towards, and strike, said leading edge locking said pawl means thereabout, then pulling on said line other end causes said pawl means to strike said control edge a second time orienting said pawl means whereby releasing said line permits said spring means to drive said pawl means past leading edge returning said carriage and line adjacent said rear panel.

6. A retractable cable assembly and lock therefore, comprising: a. a guide element having a forward and rearward end; b. a carriage movable relative to and on said element and coupled to the cable; c. an elongated rail substantially parallel to said element and having a leading edge spaced rearward of said element forward end; d. a stop block placed intermediate said element forward end and said leading edge; and e. pawl means formed with a pair of opposed V-shaped grooves and pivotally attached to said carriage, said pawl means operable to strike said stop block and orient the grooves so that when said pawl means is caused to strike said leading edge, the same will coact with one of said groove pair to lock said pawl means and carriage thereat whereby the cable assumes an extended position, then when said toggle means is caused to strike said block, said block will orient said pawl means allowing it to move passed said leading edge permitting said carriage to traverse said element towards said rearward end thereof driving the cable to a retracted position.