Napkin dispenser with dispensing control frame

Abstract

A napkin dispenser includes a housing 12 configured to receive a stack 35 of napkins disposed such that panels of the napkins are facing in a vertical direction and edges of the napkins are horizontally oriented along a front wall. The housing has a vertical slot 28 in the front wall thereof, the horizontal span 30 of the slot being sufficient to allow access to the napkins A dispensing control frame 32 is mounted in the slot for upward and downward motion along the front wall of the housing. The dispensing control frame has at least one and preferably a pair of support members 34, 36 configured to engage the napkin stack and limit downward motion of the control frame. The control frame also has a faceplate 38 disposed between the support members and extending across the vertical slot of the front wall defining an access height relative to the top of the stack in order to promote dispensing of a limited number of napkins.

Description

TECHNICAL FIELD

The present invention relates generally to napkin dispensers. There is provided a napkin dispenser with a portion control frame disposed on top of a napkin stack mounted for upward and downward movement depending on the stack height. The control frame defines a stack access height between the top of the stack and the upper edge of a faceplate to promote dispensing of a limited number of napkins which corresponds to the access height.

BACKGROUND

Napkin dispensers are well known in the art. One class of napkin dispensers frequently seen at eating establishments are spring-loaded napkin dispensers which receive a horizontal stack of napkins. Generally, the napkins are placed in a horizontal stack adjacent a spring-loaded follower which urges the napkins to a dispensing aperture. In this regard such a dispensing is shown in U.S. Pat No. 4,329,001 to Filipowicz et al.

Another class of spring-loaded dispensers includes “elevator” type dispensers for napkin stacks that are vertically oriented and dispensed at the top of the stack. Representative of this class of dispensers is United States Patent Application Publication No. US 2004/0206769 to Sanders et al. This patent application is directed to a dispenser having a plunger urged towards the dispensing opening in order to supply napkins from a cartridge. Also representative of this class of dispensers is U.S. Pat No. 2,540,930 to Campbell et al.

Another popular class of napkin dispensers for commercial establishments is gravity feed napkin dispensers. In this regard, there is disclosed in U.S. Pat. No. 5,100,020 to Petterson et al. a dispenser apparatus for serially dispensing products such as paper napkins from a stack thereof. The dispenser apparatus includes a housing with a back wall which is curved and has a radius of curvature generally corresponding to the radius of curvature of the stack.

Another gravity-feed napkin dispenser is seen in U.S. Pat No. 6,334,544 to Christensen et al. In the '544 patent a napkin dispenser includes a housing having upright walls and a floor together forming a vertical compartment for the reception of a vertical stack of horizontal paper napkins. A dispensing slot in the floor near the front wall communicates with a lower portion of the compartment for facilitating removal of napkins from the dispenser.

Still yet other gravity feed cartridge type napkin dispensers are seen in the following: U.S. Pat No. 6,644,499 to Tramontina; U.S. Pat. No. 6,769,565 to Tramontina et al.; U.S. Pat No. 6,830,151 to Spencer et al.; United States Patent Application Publication No. US 2002/0175179 to Tramontina; United States Patent Application Publication No. US 2002/0179630 to Spencer et al; and United States Patent Application Publication No. US 2004/0206768 to Tramontina et al.

As will be appreciated from the foregoing patents, napkin dispensers for commercial establishments are designed to restrict access in order to avoid waste; an attribute which makes dispensers somewhat complex, difficult to extract napkins from rapidly in predetermined or limited portions, and time consuming to replenish. Existing dispensers thus are seldom used in behind the counter applications such as drive through windows, where peak demands at mealtimes require rapid distribution. That is to say, the paramount consideration of existing dispensers is to restrict access to the napkins in order to avoid waste. On the other hand, behind the counter napkin distribution requirements include speed which leads to poor portion control and waste. The present invention is directed to a napkin dispenser and a control frame which provides speed, ease of use and portion control.

SUMMARY OF INVENTION

There is provided in a first aspect of the invention a napkin dispenser having a housing configured to receive a stack of napkins. The napkin stack is disposed in dispenser such that panels of the napkins are facing in a vertical direction and edges of the napkins are horizontally oriented along a front wall of the housing. The housing also defines a vertical slot in the front wall, the horizontal span of the slot being sufficient to allow access to the napkins in the stack. A slot span of at least about 50% of the length of the edges of the napkins along the front wall and less than about 95% of the length of the edges of the napkins along the front wall is suitable. There is disposed on top of the napkin stack a dispensing control frame mounted for upward and downward motion along the front wall of the housing. The dispensing control frame includes at least one and preferably a pair of support members, one on each side of the frame (and thus one on each side of the vertical slot) that engage the napkin stack in order to position the frame. That is, the support members are configured to engage the napkin stack at a height, H, and limit downward motion of the control frame in response to contact with the napkin stack. The dispensing control frame further includes a dispensing faceplate with an upper edge disposed between the support members and extending between the support members and across the vertical slot of the front wall of the housing of the dispenser. The upper edge of the dispensing faceplate defines a relative dispensing height, H′, which is lower than the height, H, a predetermined distance which we refer to in the specification and claims as the access height of the control frame, ΔH. The control frame provides access to napkins at their edges adjacent the upper edge of the dispensing faceplate over the access height. A front portion of the dispensing faceplate restricts access to the napkin stack below the upper edge of the faceplate (i.e. the faceplate covers the vertical slot of the housing in the vicinity immediately below the top of the stack). The inventive dispenser and control frame thus promote dispensing a limited number of napkins corresponding to the access height of the control frame disposed on the stack. Generally, the access height of the dispensing control frame corresponds to the thickness of from about 2 to about 5 napkins; preferably about 3 napkins.

In one preferred embodiment the support members are hinged to the faceplate such that they are pivotable between an extended position for engaging the napkin stack and a retracted position for upward movement with respect to a stack of napkins in the dispenser. In an especially preferred embodiment the support frame includes means, such as springs, for biasing the support members to their extended position wherein they engage the napkin stack and support the frame thereon. The dispensing control frame may be configured such that the support members are flush with a rearward surface of the faceplate in their retracted position. So also, the upper edge of the control frame preferably defines an inverted arch.

One preferred method of attaching the control frame to the housing is to provide mounting slots on either side of the faceplate for slidable engagement with the dispenser housing.

The horizontal span of the vertical slot in the front wall is typically from about 60 to about 80% of the length of the edges of napkins along the front wall; but any suitable width can be used so long as the user has access to the napkins. The napkins may be any suitable type of napkin, especially preferred are single-fold napkins as discussed hereinafter.

In one embodiment, a dispenser is sized for behind counter use by food processing technicians for dispensing a limited number of napkins with an order. A preferred height of the stack and size of the dispenser is thus a size suitable to accommodate 500 or more napkins in a single loading. Inasmuch as the inventive dispenser does not require gravity feed and does not require the use of springs and so forth to move the napkin stack, refilling and operation is especially simplified as will be appreciated from the following drawings and detailed description.

In another embodiment, there is provided a unitary structure defining a control frame supporting member and the faceplate. Preferably, the unitary structure is an injection-molded unitary structure incorporating a thermoplastic resin. The resin may be selected from polyester resins, polyacetal resins, acrylonitrile-butadiene-styrene resins, polyamide resins, polyolefin resins such as polyethylene resins or polypropylene resins, polycarbonate resins and thermoplastic elastomer resins.

Further aspects of the invention include the dispensing control frame per se and a method of dispensing napkins using the frame.

BRIEF DESCRIPTION OF DRAWINGS

The invention is described in detail below with reference to the drawings wherein like numbers designate similar parts and wherein:

FIG. 1 is a perspective view of a dispenser configured in accordance with the present invention having a stack of napkins disposed therein with a dispensing control frame resting on the napkin stack;

FIG. 2 is a view in perspective of a dispensing control frame configured in accordance with the present invention;

FIG. 3 is an exploded view of the dispensing control frame of FIG. 2;

FIG. 4 is a detail showing a support member of the dispensing control frame in a retracted position;

FIGS. 5A through 5F are schematic diagrams illustrating replenishing of the inventive napkin dispenser and repositioning of the dispensing control frame;

FIG. 6 is a side view schematically representing a single-fold napkin;

FIG. 7 is a view in perspective of another embodiment of a control frame of the invention; and

FIG. 8 is a side view and schematic diagram illustrating operation of the control frame of FIG. 7.

DETAILED DESCRIPTION

The invention is described in detail with reference to a particular embodiment of the invention. Modifications within the spirit and scope of the present invention, set forth in the appended claims, will be readily apparent to one of skill in the art.

Referring to FIGS. 1-4 there is shown a napkin dispenser 10 configured in accordance with the present invention. Napkin dispenser 10 includes a housing 12 with sidewalls 14, 16 and a back wall 18. Housing 12 also has a front wall 20 as well as bottom 22. The front wall is divided into a pair of segments 24 and 26 defining a slot 28 therebetween. The slot has a horizontal span 30 which is somewhat less than the length of the edges of napkins disposed along the front wall as shown in FIG. 1.

Dispenser 10 is also provided with a dispensing control frame 32 in order to promote dispensing of a limited number of napkins in accordance with the invention. Control frame 32 may be secured to housing 12 by way of a chain 33 or any other suitable securing means if so desired. In other embodiments, control frame 32 may be captive within slot 28 as desired.

Dispensing frame 32 includes a first support member 34 and a second support member 36 for disposing on a napkin stack such as stack 35 shown in FIG. 1. A faceplate 38 extends between the support members 34 and 36 and is mounted on a pair of mounting members 40 and 42. Mounting member 40 includes a lateral portion 44 as well as another lateral portion 46. Likewise mounting member 42 includes a first lateral portion 48 and a second lateral portion 50.

The lateral portions of mounting members 40 and 42 define a pair of recesses 52 and 54 for mounting respectively support members 34 and 36. In this regard, the support members are provided with holes 56, 58 and so forth which hold pins 60 and 62 upon which support members 34 and 36 are pivotably mounted.

There is optionally provided a pair of torsion springs 64, 66 mounted about pins 60 and 62 in order to bias the support members in a horizontal or a stack engaging position as shown in FIGS. 1 and 2. It will be appreciated from the various diagrams that support members 34 and 36 may be pivoted into their respective recesses 52, 54 to allow movement of the dispensing frame with respect to a stack of napkins. This feature is particularly useful for refilling the dispenser and repositioning the dispensing frame without having to remove the frame from the dispenser as will be discussed in more detail hereinafter. Other convenient methods of configuring the control frame will occur to the skilled artisan. The 5 support members may be formed of yieldable polymeric material integrally formed with the faceplate or mounting members. In such cases, the support members will have sufficient flexibility to allow the control frame to be repositioned as is discussed hereinafter in connection with FIGS. 5A-5F, 7 and 8. 10

It will be further appreciated from FIGS. 1-3 that the faceplate 38 and mounting members 40 and 42 define a pair of mounting slots 68, 70 which are provided for mounting the dispensing control frame on housing 12. That is to say, slot 68 slides over wall segment 24 while slot 70 slides over wall segment 26 so 15 that frame 32 is mounted for upward and downward motion with respect to housing 12.

Faceplate 38 is provided with an inverted arch 71 which facilitates selection of the proper amount of napkins from stack 35. 20

In this regard, it will be appreciated from FIG. 1 that members 34 and 36 engage stack 35 at a height, H, thereby supporting frame 32. That is to say, stack 35 supports the frame in a dispensing position. The upper surface 72 of faceplate 38 is lower than the engagement height, H, of the frame on the stack. 25 The lowermost part of upper surface 72 of faceplate 38 is designated H′ in FIG. 1. It will be appreciated from the geometry of the dispensing control frame that the difference between the engagement height, H, of the control frame on the napkin stack and the dispensing height, H′, of the lower most surface of the upper edge of faceplate 38 defines an access height, ΔH, indicated at 74. This height 30 promotes dispensing of a limited number of napkins. In this regard, the access height 74 may be selected to correspond to anywhere from about 2 to about 5 napkins; preferably the access height corresponds to the thickness of about three napkins.

Napkins are removed from stack 35 by a user simply by grasping napkins from the top of the stack at the upper edge of faceplate 38; thus the control frame promotes dispensing of a limited number of napkins. Access to the stack below upper edge 72 is restricted by the front of the faceplate.

The inventive dispenser is particularly useful for behind the counter operations at a carry-out food counter where food technicians must quickly select and distribute napkins with an order. In this regard, a minimum of maintenance is desirable. An enclosed dispenser is not necessary and having a dispenser which is complicated to load and unload is simply not cost effective in view of the high demands on food technicians especially at peak meal times. The inventive dispenser keeps the napkins organized and prevents the napkins from blowing away, for example, at a drive up window. The inventive dispenser is also easy to load and unload as will be further appreciated by considering FIGS. 4 and 5.

FIG. 4 is a view in perspective of a portion of support frame 32 showing support member 34 in a retracted position wherein the support member is flush with mounting member 40 and contained within recess 52. This occurs, for example, in use when a napkin dispenser in accordance with the invention is reloaded as shown in FIGS. 5A through 5F.

In FIG. 5A there is shown schematically the bottom of a napkin stack wherein frame 32 is on top of a partially depleted napkin stack and support member 36 is in its extended position for engaging the stack. In FIG. 5B there is shown schematically the addition of a large number of napkins on top of the inventive control frame. In FIG. 5C the control frame is being lifted upwardly where it can be seen that stack 35 is bearing member 36 forcing it downwardly as the frame is raised. In FIG. 5D, support member 36 is fully retracted into mounting member 48 in its retracted position as the control frame is lifted upwardly through a napkin stack 35. In FIG. 5E the control frame is lifted above stack 35 to allow member 36 to a return to a fully extended engagement position as shown in FIG. 5F where the control frame is lowered on to stack 35 and again supported by the support members 34 and 36. Thus, the inventive dispenser can be reloaded without removing the control frame which may be left at the bottom of the dispenser when a fresh stack of napkins is placed on top of the dispenser; further, it is thus possible to provide the control frame captive within slot 28 if so desired.

As noted above, the inventive dispenser is particularly useful for behind the counter applications where the demands for napkins are high especially at peak times. In accordance with the present invention a stack of napkins can be quickly emptied from a bag, for example, on top of a depleted stack and the napkin dispenser is ready for use as soon as the frame is raised to the top of the stack.

The napkin dispenser in accordance with the invention is suitably dimensioned to accommodate a stack of napkins of 500 napkins or more. The napkins may be single-fold napkins as is shown schematically in FIG. 6. In FIG. 6 there is shown a single-fold napkin 76 having an upper panel 78 as well as a lower panel 80 and a fold 82 between panels 78 and 80. Napkin 76 thus has four edges at 82, 84, 86 and 88. This type of napkin is known in the art as a single-fold napkin. In a preferred application of the invention a stack 35 of napkins such as napkin 76 is disposed in housing 12 as shown in FIG. 1 with panels such as panel 78 facing upwardly and lateral edge such as the edge at 82 of napkin 76 extending across the front wall of housing 12 as shown in the diagram. The slot 28 has a horizontal span 30 which is somewhat shorter than the length of adjacent edges of napkins in stack 35 in order to retain the napkins in the stack. Span 30 is suitably 50-95% of the length of adjacent edges of napkins in stack 35. All of the napkins in the stack have substantially the same dimensions allowing for some variance in manufacturing and stacking. While single fold napkins are commonly used for quick service restaurant applications, any convenient napkin configuration may be used including those described in U.S. Pat No. 6,306,480 B1 and co-pending U.S. application Ser. No. 11/004, 323 filed Dec. 3, 2004 both of which are hereby incorporated by reference.

There is shown in FIG. 7 another control frame 132 which includes a first support member 134, a second support member 136, a faceplate 138 with an inverted arch 171 and mounting members 140, 142 provided with lateral portions 144, 146, 148 and 150. Frame 132 operates in substantially the same way as frame 32 described above; however, frame 132 is a unitary injection-molded structure of thermoplastic material.

Support members 134, 136 are yieldable so that the frame is movable through a stack of napkins as discussed above in connection with FIGS. 5A-5F. To this end, there are optionally provided notches 155, 157 in members 134, 136, respectively, to facilitate displacement of the support members in direction 159 shown in FIG. 8. FIG. 8 is a side view in elevation of the frame, schematically illustrating retraction of the support members away from a control frame supporting position as occurs, for example, when the dispenser is replenished and the frame is moved upwardly through a stack of napkins.

While frame 132 is an injection-molded unitary structure, it may be molded with a plurality of injection-moldable compositions in a multi-shot molding process if so desired. Relatively flexible materials, such as thermoplastic elastomers may be used to allow for flexing of the support members from one position to another, that is, between the extended position and the retracted position of member 134 shown progressively in FIG. 8. Thermoplastic elastomers are readily available as is seen in the Kirk-Othmer, Encyclopedia of Chemical Technology, Fourth Ed., Vol. 9 (Wiley). Suitable elastomers may include:

• • polyurethane/elastomer block copolymers;
  • polyester/elastomer block copolymers;
  • polyamide/elastomer block copolymers;
  • polyetherimide/polysiloxane block copolymers;
  • polypropylene/EPDM or EPR blends;
  • polypropylene/EPDM dynamic vulcanizates;
  • polypropylene/butyl rubber dynamic vulcanizates;
  • polypropylene/natural rubber dynamic vulcanizates;
  • polypropylene/nitrile rubber dynamic vulcanizates;
  • PVC/nitrile rubber blends; and
  • halogenated polyolefin/ethylene interpolymer blends These materials are available with a variety of properties to suit a given application. In connection with many constructions of the inventive control frame, polyolefins, nylons and the like will be sufficiently flexible in any event. Likewise, engineering resins such as polyacetals and polyesters posess sufficient toughness and durability to operate as a living hinge portion in a suitable design of an integrally formed, unitary structure forming all or part of the dispensing control frame.

While the invention has been described in connection with a preferred dispenser, modifications within the spirit and scope of the invention will be readily apparent to those with skill in the art. In view of the foregoing discussion, relevant knowledge in the art, references and applications discussed above, the disclosures of which are all incorporated herein by reference, further description is deemed unnecessary.

Claims

1. A napkin dispenser comprising: a housing configured to receive a stack of napkins disposed such that panels of the napkins are facing in a vertical direction and edges of the napkins are horizontally oriented along a front wall; the housing defining a vertical slot in the front wall thereof, the horizontal span of the slot being sufficient to allow manual access to the napkins in the housing; and a napkin stack supported dispensing control frame mounted for upward and downward motion along the front wall of the housing; the dispensing control frame including a control frame supporting member configured to engage the napkin stack at a first relative height, H, and limit downward motion of the control frame in response to contact with the napkin stack; the dispensing control frame further including a dispensing faceplate with an upper edge defining a second relative height, H′, which is lower than the first relative height, H, a predetermined distance, referred to as the access height, ΔH, to promote access to napkins at their edges adjacent the upper edge of the dispensing faceplate over the access height, ΔH, of the dispensing control frame, a front portion of the dispensing faceplate being configured to restrict access to the napkin stack through the vertical slot of the housing below the upper edge of the faceplate, whereby dispensing of a limited number of napkins is promoted at the top of the napkin stack.

2. The napkin dispenser according to claim 1, wherein the access height, ΔH, of the dispensing control frame corresponds to the thickness of from about 2 to about 5 napkins.

3. The napkin dispenser according to claim 1, wherein the access height, ΔH, of the dispensing control frame corresponds to the thickness of about 3 napkins.

4. The napkin dispenser according to claim 1, wherein the control frame supporting member is hinged to the faceplate such that it is pivotable between an extended position for engaging the napkin stack and a retracted position for upward movement with respect to a stack of napkins in the dispenser.

5. The napkin dispenser according to claim 4, further comprising means for biasing the control frame supporting member to its extended position.

6. The napkin dispenser according to claim 4, wherein the control frame supporting member is flush with a rearward surface of the control frame in its retracted position.

7. The napkin dispenser according to claim 1, wherein the upper edge of the faceplate defines an inverted arch.

8. The napkin dispenser according to claim 1, wherein the control frame is slidably engaged to the housing.

9. The napkin dispenser according to claim 1, further comprising means for defining mounting slots on either side of the faceplate for slidable engagement with the dispenser housing.

10. The napkin dispenser according to claim 1, wherein the horizontal span of the vertical slot in the front wall is from about 50 to about 95 percent of the length of the edges of napkins along the front wall.

11. The napkin dispenser according to claim 1, wherein the horizontal span of the vertical slot in the front wall is from about 60 to about 80 percent of the length of the edges of napkins along the front wall.

12. A dispensing control frame for disposing on top of a stack of napkins arranged such that the panels of the napkins are facing in a vertical direction, the dispensing control frame comprising: (a) a control frame supporting member configured to engage the top of the napkin stack at a first relative height, H, and limit downward motion of the control frame in response to contact with the napkin stack; and (b) the dispensing control frame further including a dispensing faceplate with an upper edge defining a second relative height, H′, which is lower than the first relative height, H a predetermined distance, referred to as the access height, ΔH, to promote access to napkins at their edges adjacent the upper edge of the dispensing faceplate over the access height, ΔH, of the dispensing control frame, a front portion of the dispensing faceplate being configured to restrict access to the napkin stack below the upper edge of the faceplate, whereby dispensing of a limited number of napkins is promoted at the top of the napkin stack.

13. The control frame according to claim 12, wherein the access height, ΔH, of the dispensing control frame corresponds to the thickness of from about 2 to about 5 napkins.

14. The control frame according to claim 12, wherein the access height, ΔH, of the dispensing control frame corresponds to the thickness of about 3 napkins.

15. The control frame according to claim 12, wherein the control frame supporting member is hinged to the faceplate such that it is pivotable between an extended position for engaging the napkin stack and a retracted position for upward movement with respect to a stack of napkins in the dispenser.

16. The control frame according to claim 15, further comprising means for biasing the control frame supporting member to its extended position.

17. The control frame according to claim 12, wherein the control frame supporting member is flush with a rearward surface of the control frame in its retracted position.

18. The control frame according to claim 12, wherein the upper edge of the faceplate defines an inverted arch.

19. The control frame according to claim 12, adapted for slidable engagement with a napkin dispenser housing

20. The control frame according to claim 12, further comprising means for defining mounting slots on either side of the faceplate for slidable engagement with a dispenser housing.

21. The control frame according to claim 12, wherein the control frame comprises a pair of control frame supporting members configured to engage the napkin stack at the first relative height, H, and the faceplate extends between the control frame supporting members.

22. The control frame according to claim 21, wherein the control frame supporting members are hinged to the faceplate such that they-are pivotable between an extended position for engaging the napkin stack and a retracted position for upward movement with respect to a stack of napkins.

23. The control frame according to claim 22, further comprising means for biasing the control frame supporting members to their extended position.

24. The control frame according to claim 22, wherein the control frame supporting members are flush with a rearward surface of the control frame in their retracted position.

25. The control frame according to claim 12, including a unitary structure defining the control frame supporting member and a mounting member integrally formed therewith.

26. The control frame according to claim 25, wherein the unitary structure is an injection-molded unitary structure.

27. The control frame according to claim 26, wherein the injection-molded unitary structure comprises a thermoplastic resin.

28. The control frame according to claim 27, wherein the thermoplastic resin is selected from polyester resins, polyacetal resins, acrylonitrile-butadiene-styrene resins, polyamide resins, polyethylene resins, polypropylene resins, polycarbonate resins, and thermoplastic elastomer resins.

29. A method of dispensing napkins comprising: (a) placing a plurality of napkins in a stack such that the panels of napkins are facing in a vertical direction; (b) disposing a dispensing control frame on top of the stack mounted for upward and downward movement with respect to the stack, the dispensing control frame including a control frame supporting member configured to engage the top of the napkin stack at a first relative height, H, and limit downward motion of the control frame in response to contact with the napkin stack, wherein the dispensing control frame further includes a dispensing faceplate with an upper edge defining a second relative height, H′, which is lower than the first relative height, H, a predetermined distance, referred to as the access height, ΔH, to promote access to napkins at their edges adjacent the upper edge of the dispensing faceplate over the access height, ΔH, of the dispensing control frame, a front portion of the dispensing faceplate being configured to restrict access to the napkin stack below the upper edge of the faceplate to promote dispensing of a limited number of napkins; and (c) withdrawing napkins from the top of the stack.

30. The dispensing method according to claim 29, wherein the stack comprises at least about 500 napkins.

31. The dispensing method according to claim 29, wherein the stack of napkins is a stack of single-fold napkins.

32. A unitary thermoplastic control frame for dispensing of napkins from a stack, comprising: a horizontally extending faceplate defining a substantially vertical plane, said face plate having at least one pivotable support arm fixed thereto, said pivotable support arm being pivotable between an orientation extending horizontally normal to the plane defined by said faceplate and a generally vertical downward orientation generally parallel thereto; and means defining at least one vertically extending slot behind said face plate, adapted to engage a vertical plate having a generally vertical edge and allow vertical movement of said faceplate when in engagement with said vertical edge, and means restraining said pivotable support arm from pivoting upwardly.