US2818596A

US2818596A - Suction cleaner clamp construction

Info

Publication number: US2818596A
Application number: US509758A
Authority: US
Inventors: Eugene F Martinec
Original assignee: Health-Mor Inc
Current assignee: Health-Mor Inc
Priority date: 1955-05-20
Filing date: 1955-05-20
Publication date: 1958-01-07
Anticipated expiration: 1975-01-07

Description

Jan. 7, 1958 E. F. MARTINEC 2,818,596

SUCTION CLEANER CLAMP CONSTRUCTION Filed May 20, 1955 3 Sheets-Sheet 1 INVENTO'R. Eugene FZMwrhnea AT TORAEYS Jan. 7, 1958 E. F. MARTINEC SUCTION CLEANER CLAMP CONSTRUCTION 3 Sheets-Sheet 2 Filed May 20, 1955 INVENTOR. Eugene EMwz'fiineo' BY ATTORNEYS Jan. 7, 1958 E. F. MARTINEC SUCTION CLEANER CLAMP CONSTRUCTION 3 Sheets-Sheet 3 Filed May 20, 1955 INVENTOR. EMwz'b inec Hyena ATTORNEYS United States Patent SUCTION CLEANER CLAMP CONSTRUCTION Eugene F. Martinec, East'Cleveland, Ohio, assignor to Health-Mor, Inc., Chicago, 111., a corporation of Illinois Application May 20, 1955, Serial No. 509,758

Claims. (Cl. -327) This invention relates to swinging link bar clamps of the type shown in United States Patent No. 2,602,685. More particularly it pertains to swinging link bar. clamps adapted for use with a tank type suction cleaner. for securing a closure on the open end of. the tank housing, and for securing the cleaner on a dolly or casterring.

In the past the purpose of swinging link bar clamps used for tank type suction cleaners has been to ,provide an airtight joint by compression of a gasket at the joint between the outer housing portions of a cleaner. This is necessary because of the high suction condition under which tank type suction cleaners operate. The clamp disclosed in said Patent No. 2,602,685 is adapted for use'with tank type cleaners operating under high suctionconditions.

More recently, there has been a tendency to mount tank type suction cleaners on wheels or casters in order to make them more mobile. In somecases, the wheels or casters are attached directly to the outer housing of the cleaner. In other cases it has been found expedient to mount the cleaner on a dolly or caster ring having casters attached thereto. Where a cleaner is mounted on a dolly or caster ring, rather than having the casters secured directly to the housing of the cleaner, the cleaner may be detachably mounted on the dolly by one or more clamps. Thetendency to mount cleaners on dollies has increased the number of clamps on the cleaner which in turn addsto the cost ofthe product. Thus, it is desirable to provide a clamp for a suction cleaner that not only secures the housing portions of the cleaner together at an airtight gasketed joint, but also attaches the cleaner on the dolly.

The problem has been further complicated because the clamp disclosed in said Patent No. 2,602,685 is frequently used as a handle in the unclarnped position for lifting the portion of the cleaner to which the clamp is attached, causing excessive stretching of the clamp spring which was not designed for such use. A solution to this problem has been found by the provision of a clamp spring guard which limits the transverse movement of the spring, thereby protecting the spring against undue stretching beyond its yield point.

Accordingly, it is a general object of the present invention to provide an improved clamp construction for a tank type suction cleaner.

It is another object of the present invention to provide an improved clamp constructionfor a tank type suction cleaner that serves the double clamping function of securing the housing portions together in an airtight joint and-securing the cleaner ona dolly..

Another object of this invention is to provide a clamp construction which is operable in a number of'clamping positions.

It is another object of this invention to provide an improvedclamp construction which permits the automatic clamping of the dolly when the cleaner is placed thereon.

Itis another objectofthis inventionto provide a clamp construction-which permitsthe lifting of the cleaner from the dolly releasing the clamp from engagementwith the 2,818,596 Patented Jan. 7, 1958 dolly without separating the members constituting. the housing of the cleaner.

Another object of the present invention is to provide an improved clampconstruction which permits the engagement of the clamp withthe dolly while being released from the clamping position in the airtight joint.

Still another object of the present-invention is to provide a clamp spring guard or bar which limits the extent to which the clamp spring may be distorted under certain uses of the clamp.

Finally, it is an object of the present invention to provide an improved clamp construction of the type shown in said Patent No. 2,602,685, by which the described prob: lems and difficulties are overcome and the foregoing objects and desiderata are obtained in a simple, effective and inexpensive manner without creating maintenance, repair and adjustment problems in maintaining efiiciency and satisfactory suction cleaner operation.

These and other objects and advantages apparent to those skilled in the art from the foregoing descriptionand claims may be obtained, the stated results achieved, and the described difficulties and problems overcome and solved by the parts, elements, constructions, mechanisms, combinations, subcornbinations andarrangernents, which comprise the present invention, the nature of which is set, forth in the following general statement preferred embodiments of which-illustrative of the, best mode in; which applicant has contemplated applying the principlesare set forth in the following description and shown, in the drawings, and which are particularly. anddistinctly pointed out and set forth in the appended claims forming. part hereof.

The nature of the improvements inthe suction cleaner clamp construction of the presentinvention may be stated, in general terms as including a suction cleaner. having.

a dirt container with a removable top and a removable dolly or caster ring thereunder, a pair of. swinging link bar clamps mountedon clamp springs on opposite, sides, of the container, each clamp having hooked meansen gageable with the removable top, eachclamp having hook; means engageable with the dollyor caster ring, andthe clamp including a clamp spring guard associated with the, clamp spring limiting the extent to which the spring may. be extended under varying positions of the clamp.

In the drawings which are illustrative of the preferred. embodiment of the invention, by way of example, and in which similar, numerals refer to similar parts thereof:

Fig. l is a perspective view of a tank type suction cleaner. having clamps disposed on opposite sides thereof;

Fig.2 isan enlarged, fragmentary, vertical sectional. view throughone of the clamps and a portionof the cleaner, showing the clamp in the-closed position;

Fig. 3 is an elevational view of the clamp partly in section and taken on the line 3-3 of Fig. 2;

Fig. 4 is a sectionalview, similar to that of Fig. 2, showing the clamp in the partially releasedpositionand, showing the manner in which the cleaner may be lifted from the dolly at the lower end thereof;

Fig 5 is another; view showing the clamp imanother partially released position whereby the upper part ofth cleanermaybe separated from .thelower part; I v

Fig. 6 is an enlargedfragmentary view of thecla mp in a fully released and extended positiomand Fig. 7 is. an enlarged fragmentarytview of, theclamp in the partially released position with the upper end at; tached.

' In Fig. 1 a tanktype suction cleaner is generallyindi:

cated at 1.- It includesa lower housing or pot 2, an

5 (F 0f the we ou n A sq he lcaner 15 includes a pair of oppositely disposed clamps, generally indicated at 6, having

hook portions

7 and 8 at the upper and lower ends, respectively.

The lower housing 2 is seated within a dolly or caster ring, generally indicated at 9, which includes an annular base member 10 (Fig. 2) having a peripheral flange 11 on which is mounted an annular resilient member 16 preferably composed of rubber. To the undersurface of the base member 10 are attached a number of casters 12 which include ball bearings 13 (Fig. 2) and a plate member 14 that is secured to the base member 11) by rivets 15.

The annular resilient member 16, as shown in Fig. 2, includes a peripheral bumper portion 17 and a clamp-receiving rib 18 that forms an annular groove 19 near the top of the member 16. The hook 8 is constructed to swing into and out of the groove 19 when the clamps 6 are moved between the positions of Figs. 2 and 4. Also, the upper portion of the rib 13 includes an annular beveled edge 20.

In addition the lower housing or pot 2 includes an air inlet port 21 as shown in Fig. l on the outer surface of which is disposed a number of bayonet joint lock pins 22 to which a flexible air hose may be attached in the usual manner.

The upper housing 3 includes a dome 23 surmounting which is a cleaner handle 24. As shown in Fig. 2, the upper housing 3 is provided with an annular end sleeve 25 at the upper end of which is a flange 26 and an outwardly opening annular catch groove 27 all of which are integral with the upper housing. Within the upper housing 3 is a motor (not shown) by which the cleaner is operated.

Adjacent the inner surfaces of the sleeve 25 and the groove 27 is an annular mounting ring 28 composed of a resilient material such as rubber. The mounting ring 28 is partially retained in position by a partition member 29 within the cleaner, the periphery of which is seated within an inwardly opening groove at 30. In addition, a conical perforated support 31 is attached to the upper housing 3 below the mounting ring 28. When assembled, the lower edge of the sleeve 25 and the perforated support 31 are in airtight contact with the gasket 4. Finally, a filter member 32 is mounted within the cleaner adjacent the undersurface of the perforated support 31 and with its outer periphery between the gasket 4 and the support 31, as shown in Fig. 2.

As shown in Figs. 2 and 3, each clamp 6 includes an elongated channel member 33, a swinging clamp link 34, a clamp spring 35, and a clamp fulcrum bar 36. The channel member 33 is elongated and includes a web 37 and side flanges 38. The upper and lower ends of the member 33 include the

hook portions

7 and 8. The upper hook 7 extends laterally of the clamp and is provided at the end of the web 37. The lower hook 8 is provided in the side flanges 38 which are notched at 39 to fit around the clamp-receiving rib 18. The hook 8 engages the annular groove 19 in the annular resilient member 16 of the dolly 9. In addition, the hook 8 includes an angled reinforcing member 40 attached to the lower end of the web 37 by rivets 40a. The lower ends of the flanges 38 below the hook 8, as well as the reinforcing member 40 are inclined inwardly and upwardly at 41 for a purpose to be described hereinbelow. Further, as shown in Figs. 2-6, the upper extremities of the flanges 38 of the channel member 33 are notched at 42 in conformity with the overall configuration of the gasket 4 and sleeve 25.

The clamp links 34 are channel members having a base 43 and a pair of legs 44 extending longitudinally of the clamp and beyond the ends of the base 43. The lower end of the legs 44 are rotatably mounted on a laterally extending pivot pin 45, the ends of which pin are mounted in the flanges 38 of the member 33, as shown in Fig. 3. The upper ends of the legs 44 are rotatably mounted on opposite ends of' a pivot pin 46 parallel to the pin 45. As

4 shown in Fig. 2, the pivot pin 46 is mounted'in a pivot pin bearing loop 47 of the spring 35.

The clamp spring 35 is attached to the housing 2 by rivets 48, which rivets also secure the fulcrum bar 36 in place between the housing and the spring. Above the rivets the spring 35 is provided with a J-bend 49 to permit the spring to stretch longitudinally of the clamp 6. Further, the spring 35 includes an outturned portion 50 at the outer end of which is provided the loop 47. The outturned portion 50 spaces the pivot pin 46 at a greater distance from the outer surface of the housing 2 than the pivot pin 45 when the clamp is in the closed position, as shown in Fig. 2. The construction of the foregoing assembly is set forth in said Patent No. 2,602,685.

Hence, the clamp 6 may be opened from the position shown in Fig. 2 to that of Fig. 4 by swinging the lower end of the member 33 outwardly from the housing to disengage the hook 8 from the groove 19. Thereafter the clamp 6 may be released by disengaging the hook 7 from the hook-receiving groove 27 in the upper housing 3.

The remaining part of the clamp to be described is the fulcrum bar 36. As was set forth above, the lower portion of the fulcrum bar 36 is attached to the lower housing by the rivets 48. The upper portion of the bar 36 is an inverted U-member including a laterally extending portion 51 and a vertical portion 52 spaced from the cleaner housing 2. The

portions

51 and 52 of the bar 36 extend over and around the upper portion of the spring 35 including the loop 47.

Inasmuch as the clamp spring 35 is made from a flat strip metal, such as spring steel (which after forming is hardened and tempered), the spring 35 functions when the clamp 6 is actuated between the various clamped and unclamped position. However, the spring 35 may become deformed due to the use of the clamps 6 in the position of Fig. 6 as handles for lifting the dirt containing housing 2. The fulcrum bar 36 is composed of a rigid material, such as a metal having little or no elastic properties compared with that of the spring 35. As shown in Fig. 3, the bar 36 includes a pair of ears or stop members 53 extending in opposite directions from the edges of the fulcrum bar and aligned with the legs 44.

As was set forth above, the clamp 6 is provided with

hooks

7 and 8 at the upper and lower ends, respectively. When the clamp is in the closed position, as shown in Fig. 2, the upper hook 7 engages the hook-receiving groove 27 in the upper housing 3 and the lower hook 8 engages the hook-receiving groove 19 below the rib 18. Thus, the clamp 6 serves the double function of retaining the upper and

lower housing

3 and 2 together, as well as holding the dolly 9 to the lower portion of the cleaner.

As shown in Figs. 2, 4, 5, 6, and 7, the clamps 6 operate in a number of positions. The fully closed position is shown in Fig. 2 in which the channel member 33 is adjacent the tank wall and the upper and

lower hooks

7 and 8 engage the grooves 27 and 19, respectively. In this position the pivot pin 46 is spaced laterally farther from the outer wall of the cleaner 1 than is the pivot pin 45, the portion 50 of the spring 35 and the loop 47 being stretched upwardly and outwardly by the link 34, whereby a space 55 is sustained between the spring 35 and the bar 36. Thus, the spring 35 retains the clamp 6 in equilibrium.

To overcome that equilibrium the lower end of the clamp 6 is moved outwardly to an angled position (Fig. 7) with respect to the cleaner 1. During this movement the clamp 6 rotates pivotally about the hook 7 within the groove 27 until the movement is arrested by contact at 53a of the legs 44 of the link 35 with the ears 53 of the fulcrum bar 36. Further outward movement is then necessary to disengage the hook 7 from the groove 27, however, the fulcrum bar 36 yieldingly resists such further movement.

In the position of the clamp 6 shown in Fig. 7, the

spring 35 is under slight tension with the hook 7 remaining engaged within theannular groove 27 due to the contact of the cars 53 and the link 34 at-53a. Without theears 53 preventing the link 34 from moving outwardly, any slight movement of the dome 23, such as starting to lift the cleaner 1, would. disengage the clamp 6 from the groove 27 at hook '7, because there would .be no. tension holding the hook in position and the clampwould then fall back. out of. position into thatshown in Fig. 5. The ears 53 prevent this further shifting of the. clamp 6 when released upon being disengaged at the lower end from the groove 19 of the dolly 9. The cars 53 by contacting the link 34.at 5.3a sustain the clamp assembly in theequilibrium position shown in Fig. 7, thereby holding the hook 7 in engagement with thegroove27 until a .further force is applied to the clamp, 6 to overcome the slight resistance offered by the bar 36. through the cars 53 on the :link34jin-order to lift the hook 7 out of thegroove 27.

One. reasonv for disengaging the lower hook. 8 without disengaging the upper hook 71 from theirv respective positions is shown in Fig. 4. Frequently, it is desirable to lift the cleaner 1. fromthe dolly 9 to place the cleaner on a stair for the. purpose of cleaning a carpeted stairway. During the lifting, the positions of-the various-parts are shown in Fig. 4, the upper portion 3 of the cleaner being separated by a space 5.4'from the gasket 4 at the upper end of .the lower portion Zand. the lower portion 2 being separated from the usual seated position within the dolly.

9. Upon complete removal of the cleanerfrom the dolly 9, the clamp 6.may be returned to the positionshown in Fig. 2 without engaging the dolly groove 9. However, during the liftingofthe cleaner from the dolly, the ears 5.3 of. the fulcrum bar 36 continue to engage the link 34 at 53a, thereby preventing the link 34 from rotating completely around. the. pivot pin 46, and thereby preventing the spring 35 from being stretched beyond the limit for which itwas designed to function.

When the cleaner is replaced upon the dolly 9, the clamps.6. need. not be removed from their positions. adjacent the lower housing 2. Rather, the inclined lower edge of the lower hook 8 slides over the beveled edge 20' of-the rib 18 in a camming action and into clamping position within the groove '19.

To empty dirt from the lower housing 2 from time to time, the hook 7 at the upper end of the clamp 6 may be removedfrom the groove 27 in which event the clamp 6 may assume by gravity the angledposition shown in Fig. 5. With the clamps disengaged from the groove 27, the upper housing 3 may be separated from the lower housing 2 whereupon the filter member 32 may be removed and dirt emptied from the lower housing 2.

It frequently happens that the cleaner is lifted by the clamps 6. In such event the fulcrum bars 36 prevent the springs 35 from being stretched excessively or permanently out-.of-shape. As shown in Fig. 6, the members 33, when used as handles, may become displaced from their clampedpositions adjacent the cleaner. Thus, the vertical-portion 52. of the bar 36is contactedv by the loop 47 of thespring 35 at 47a, thereby preventing further extension of the spring 35 beyond a space 55 (Fig. 6). At the same time the clamp links 34 are sustained horizontally between the pivot. pins 45 and 46 by the cars 53 on the clamp guards contacting the legs 44 of the link. Hence, the position and construction of the fulcrum bar 36 is such that it does not inhibit the normal use of the clamp 6. However, .when the clamps 6 are used in such a way that the springs 35 are apt to be stretched abnormally, the fulcrum bars 36, are operable to prevent permanent disfiguration of the springs 35.

InFig. 2 the spring 35 is shown in the fully clamped position, the loop 47 being slightly spaced from the outer vertical ,portion 52. In Fig. 4 whenthe cleaner 1 is lifted from its position on the dolly 9, the weight of the dust container or lower housing 2 is transmitted through the clamp 6, causing the legs 44 of the link 34 to be raised outwardly of the tank and terminating in a bearing loop, a clamp link pivotally connected at one end to the bearing against the stop members or ears 53, and causing the loop. 47 to beslightlyloweredidueto limitedyieldingof the spring35. In Fig. 6 the clamp 6- is shown when it is used as a handle for lifting the cleaner. 1, In that. position the spring 35 yields until the loop 47' contacts the bar 36. Also, the legs 44 contact the ears 53' to prevent the spring. 35 from being stretched vertically. Hence, the bar 36 protects the spring 35 by limiting its outward and upward movement.

Accordingly, the present invention provides an improvedclamp construction for tank. type suction cleaners eliminating prior artditficulties, solving problems which have existed'in the art, and-obtaining thedescribed: new results not obtained. by. prior structures such as disclosed in said PatentNo. 2,602,685.

The improved clamp structure serves a double purpose of securing together the several members of thecleaner. The improved clamp construction also provides a guard means by which the clamp springs may not be overextended.

In the'foregoing description, certain terms have been used for brevity, clearness and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are utilized for descriptive purposes herein and not for the purpose of limitation and are intended to be broadly construed.

Moreover, the description of the improvements is by way of example and the scope of the present invention is not limited to the exact details illustrated, or to the specific mechanisms shown.

Having now described the features, discoveries and principles of the invention, the construction, operation and use of the improved mechanisms and the advantageous, new and useful results obtained thereby; the new and useful parts, elements, constructions, mechanisms, combinations, subcombinations, and arrangements, and mechanical equivalents obvious to those.

skilled in the art, are set forth in the appended claims.

I claim:

1. A clamp for a tank-type suction cleaner having a, top closure with a clamp-receiving means and mounted. on a dolly, includinga laterally rigid spring secured at.

one end to thecleaner tank, the other end of the spring being bent outwardly of the tank and terminating in a 'bearing loop, a clamp link pivotally connected at one,

end to the bearing loop, a rigid clamp member pivotally connected to the other end of the clamplink, the clamp.

member having a first hook engageable with the means on the top closure, the dolly having a clamp-receiving means, and a second clamp hook on the clampmember engageable with the clamp-receiving means on the dolly.

2. A clamp for a tank-type suction cleaner having atop.

closure with a clamp-receiving means and mounted on a dolly, including a laterally rigid springsecured at one end, to the cleaner tank, the other end of the spring being bent.

outwardly of the tank and terminating in a bearing loop, a clamp link pivotally connected at one end to the bearing loop, a rigid clamp member pivotally connected to the other end of the clamp link, the clamp member having a first hook engageable with the means on the top closure the dolly having a second clamp-receiving meanswith an inclined upper surface, a second clamp hook on the clamp member engageablewith the second clamp-receiving means and having an inclined bottom surface slidable over the inclined surface of the second clamp-receiving means.

3. A clamp for a tank-type suction cleaner having a top closure with aclamp-receiving mean and mounted on a dolly, including a laterally rigid spring secured at one end to the cleaner tank, the other end of the spring being bent loop, a rigid clamp member pivotally connected to the other end of the clamp link, a fulcrum bar rigidly fixed with respect to the spring and having a laterally extending portion near the outer side of the bearing loop limiting outward movement of the spring from the cleaner tank, the clamp member having a first hook engageable with the means on the top closure, the dolly having a second clamp-receiving means, and a second clamp hook on the clamp member engageable with the second clamp-receiving means.

4. A clamp for a tank-type suction cleaner having a top closure with a clamp-receiving means and mounted on a dolly, including a laterally rigid spring secured at one end to the cleaner tank, the other end of the spring being bent outwardly of the tank and terminating in a bearing loop, a clamp link having spaced legs pivotally connected at one end on opposite sides to the bearing loop, a rigid clamp member pivotally connected to the other end of the link, a fulcrum bar rigidly fixed with respect to the spring and having a laterally extending portion near the outer side of the bearing loop limiting outward movement of the spring from the cleaner tank, the fulcrum bar having surfaces engageable with the legs of the link, the clamp member having a first hook engageable with the means on the top closure, a second clamp-receiving means on the dolly, and a second clamp hook on the clamp member engageable with the second clamp-receiving means.

5. A clamp for a tank-type suction cleaner having a top closure with a clamp-receiving means and mounted on a dolly including a laterally rigid spring secured at one end to the cleaner tank, the other end of the spring being bent outwardly of the tank and terminating in a bearing loop, a clamp link having spaced legs pivotally connected at one end on opposite sides to the bearing loop, a rigid clamp member pivotally connected to the other end of the clamp link, the clamp member having a first hook engageable with the means on the closure, a second clampreceiving means on the dolly, a second clamp hook on the clamp member engageable with the second clamp-receiving means, the clamp member being movable between a clamped position and an unclamped position, a fulcrum bar rigidly fixed with respect to the spring and having a laterally extending portion near the outer side of the bearing loop limiting outward movement of the spring from the cleaner tank, the fulcrum bar also having a pair of oppositely disposed stop members aligned with the legs of the clamp link, and the legs engaging the stop mem bers when the clamp member is in the unclamped position.

6. A clamp for a tank-type suction cleaner having a top closure and mounted on a dolly, including a laterally rigid spring secured at one end to the cleaner tank, the other end of the spring being bent outwardly of the tank and terminating in a bearing loop, a clamp link pivotally connected at one end to the bearing loop, a rigid clamp member pivotally connected to the other end of the link, a fulcrum bar rigidly fixed with respect to the spring and having a laterally extending portion near the outer side of the bearing loop limiting outward movement of the spring from the cleaner tank, the fulcrum bar extending over the bearing loop, and the fulcrum bar being engage able by the link limiting upward movement of the link.

7. A clamp for a tank-type suction cleaner having a top closure with clamp-receiving means and mounted on a dolly, including a laterally rigid spring secured at one end to the cleaner tank, the other end of the spring being bent outwardly of the tank and terminating in a bearing loop, a clamp link connected at one end to the bearing loop, a rigid clamp member pivotally connected at one end to the other end of the clamp link, the clamp memher having a first hook engageable with the means on the top closure, a second clamp-receiving means on the dolly, a second clamp hook on the clamp member engageable with the second clamp-receiving means, the clamp member being movable between a clamped position and an unclamped position of the second clamp hook, the clamp member also being movable between a clamped position and an unclamped position of the first clamp hook, a fulcrum bar rigidly fixed with respect to the spring and having a laterally extending portion near the outer side of the bearing loop, and the fulcrum bar retaining the first clamp hook engaged with the means on the closure by limiting movement of the link when the clamp Ifilel'rllbel is in the unclamped position of the second clamp 8. In tank type suction cleaner clamp construction, a cleaner tank, a removable cover for the tank, a separable dolly for the tank; spring tensioned toggle clamp means including a spring link bar mounted at one end on the tank, a swinging link bar pivoted at one end to the other end of the spring link bar, a hook link bar pivoted intermediate its ends to the other end of the swinging link bar, and the clamp means being movable to cover-clamping and cover-released positions; the cover being provided with an annular axially opening groove, hook means formed at one end of said hook link bar engageable in said cover groove to clamp the cover to the tank when the clamp means is moved to cover-clamping position, the dolly having an annular radially outwardly opening groove formed therein. and second hook means formed at the other end of said hook link bar engageable with said dolly groove in both cover-clamping and cover-released positions of the clamp means to secure the dolly to the tank regardless of the position of the cover hook means.

9. The construction defined in claim 8 in which the dolly is provided with a ring in which the tank is received when the tank is placed on the dolly, in which the dolly groove is formed in said ring, in which the ring has an inclined annular surface above the dolly groove, and in which the hook link bar is formed with an inclined surface at said other end below said second hook means, whereby the cleaner tank may be secured to the dolly by placing the tank thereon within said dolly ring, and whereby said second hook means automatically engages said dolly groove during such placement by camming engagement between said dolly and hook link bar inclined surfaces regardless of the position of the cover hook means.

10. In tank type suction cleaner clamp construction, a cleaner tank, a removable cover for the tank; spring tensioned toggle clamp means including a spring link bar mounted at one end on the tank, a swinging link bar pivoted at one end to the other end of the spring link bar, a hook link bar pivoted to the other end of the swinging link bar, and the clamp means being movable to cover-clamping and cover-released positions; said other end of the spring link bar being movable generally longitudinally of the spring link bar and also being movable in a direction generally normal to the bar to provide the clamping engagement and tension for the clamp means, a guard member mounted on the tank having a U-shaped portion partially surrounding said other end of the spring link bar, said guard member limiting movement of said other end of the spring link bar in a direction generally normal to the bar, and said swinging link bar engaging said guard member when the tank is lifted by grasping the hook link bar to limit stress on the spring link bar when the tank is so lifted.

References Cited in the file of this patent UNITED STATES PATENTS 1,769,696 Kocher July 1, 1930 1,823,465 ONeill Sept. 15, 1931 2,328,003 Gardes Aug. 31, 1943 2,602,685 Martinet et al. July 8, 1952