CN216578427U - Leak protection thick liquid superimposed sheet mould - Google Patents

Leak protection thick liquid superimposed sheet mould Download PDF

Info

Publication number
CN216578427U
CN216578427U CN202122116985.2U CN202122116985U CN216578427U CN 216578427 U CN216578427 U CN 216578427U CN 202122116985 U CN202122116985 U CN 202122116985U CN 216578427 U CN216578427 U CN 216578427U
Authority
CN
China
Prior art keywords
sealing structure
steel bar
sealing
rib
mold
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202122116985.2U
Other languages
Chinese (zh)
Inventor
李健
马福全
米野
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Foshan Bipinju Construction Industrialization Co.,Ltd.
Original Assignee
Guangdong Bipinju Construction Industrialization Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guangdong Bipinju Construction Industrialization Co ltd filed Critical Guangdong Bipinju Construction Industrialization Co ltd
Priority to CN202122116985.2U priority Critical patent/CN216578427U/en
Application granted granted Critical
Publication of CN216578427U publication Critical patent/CN216578427U/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Moulds, Cores, Or Mandrels (AREA)

Abstract

The utility model provides a slurry leakage prevention laminated plate die, and relates to the technical field of constructional engineering; the rib forming device comprises a side die provided with a rib forming groove and a sealing structure arranged on the rib forming groove, wherein the sealing structure blocks the rib forming groove; the sealing structure is provided with a rib outlet hole with the radial size smaller than that of the steel bar, and the sealing structure is configured to elastically deform in the process that the steel bar enters the rib outlet hole and hermetically wraps the steel bar after the steel bar is placed in the rib outlet hole. According to the utility model, the rib groove is blocked by the sealing structure, the reinforcing steel bar is sealed and wrapped by utilizing the self-deformable characteristic of the sealing structure, and the sealing of the reinforcing steel bar can be realized only by putting the reinforcing steel bar in the sealing operation, so that the sealing structure is simple to operate, saves manpower, improves the operation efficiency, has a good sealing effect, and can realize sealing on the reinforcing steel bars with different diameters due to the deformation characteristic of the sealing structure, so that the die has good universality.

Description

Leak protection thick liquid superimposed sheet mould
Technical Field
The utility model relates to the technical field of constructional engineering, in particular to a slurry leakage prevention laminated plate mold.
Background
Among the existing precast concrete members, a laminated slab is gradually becoming a vital precast member. In the process of producing the rib laminated slab, concrete needs to be poured into a mould system, and the laminated slab is finally formed through the working procedures of vibrating, maintaining and the like.
Wherein the side forms of mould system must guarantee its leakproofness, when pouring the vibration, in order to ensure can not appear leaking the phenomenon of thick liquid in a muscle region, need go out the muscle region at the side forms and carry out the shutoff, current shutoff mode generally utilizes the rubber head to carry out the shutoff operation by the manual work, and work efficiency is low, has increased workman intensity of labour, has improved the cost of generation, and the shutoff effect is not good.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a slurry leakage prevention laminated plate die, which solves the problems of low efficiency, manpower waste and poor plugging effect of the existing manual plugging.
In order to solve the problems, the utility model firstly provides a slurry leakage prevention laminated plate die which comprises a side die, wherein the side die is provided with a plurality of rib outlet grooves for extending reinforcing steel bars; the sealing structure is arranged on the rib outlet groove and used for plugging the rib outlet groove, and the horizontal height of the sealing structure is greater than that of the side die; the sealing structure is provided with a rib outlet hole with the radial size smaller than that of the reinforcing steel bar, and the sealing structure is configured to elastically deform when the reinforcing steel bar is placed into the rib outlet hole and hermetically wrap the reinforcing steel bar.
Furthermore, the sealing structure comprises two elastic sealing elements which are tightly attached, the surfaces of the two elastic sealing elements which are attached to each other are provided with steel bar accommodating grooves, and the steel bar accommodating grooves of the two elastic sealing elements are enclosed to form the steel bar outlet hole.
Furthermore, the top of the elastic sealing element is provided with a guide surface, and the horizontal height of the guide surface is gradually increased along the direction departing from the other elastic sealing element.
Furthermore, one side of each elastic sealing element, which is far away from the other elastic sealing element, is connected with a first connecting piece, and the first connecting piece is connected with the side die.
Furthermore, a second connecting piece is embedded in the elastic sealing element, and the second connecting piece is connected with the first connecting piece.
Furthermore, the side forms comprise side plates and a bottom plate which are vertically connected, the rib outlet grooves are formed in the side plates, and the height of the sealing structure is larger than that of the side plates in the direction perpendicular to the bottom plate.
Furthermore, a plurality of reinforcing rib plates are arranged between the side plate and the bottom plate, and the reinforcing rib plates are respectively connected with the side plate and the bottom plate.
Furthermore, the side forms are in go out muscle groove both sides and all are equipped with the mounting panel, seal structure is located two between the mounting panel, and with the mounting panel is sealed to be cooperated.
Further, when the mounting plate comprises a first connecting piece, the mounting plate is provided with a first connecting hole connected with the first connecting piece.
Furthermore, the side forms are provided with second connecting holes, third connecting pieces penetrate through the second connecting holes, and the third connecting pieces are in sealing fit with the second connecting holes.
According to the slurry leakage prevention laminated plate die, the rib outlet groove is sealed through the sealing structure, the reinforcing steel bars are sealed and wrapped by utilizing the deformable characteristic of the sealing structure, the sealing operation is carried out only by putting the reinforcing steel bars into the rib outlet hole, the sealing of the rib outlet groove and the reinforcing steel bars can be realized, the operation is simple, the labor is saved, the operation efficiency is improved, and the sealing effect is good.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a schematic structural diagram of a slurry leakage prevention laminated plate mold provided in an embodiment of the present invention;
FIG. 2 is an enlarged view of portion A of FIG. 1;
FIG. 3 is a schematic structural diagram of a side form according to an embodiment of the present invention;
FIG. 4 is an enlarged view of the portion B of FIG. 3
Fig. 5 is a schematic view of the sealing structure provided in the present embodiment.
Description of reference numerals:
100-side forms; 110-side plate; 111-rib groove forming; 112-second connection hole; 120-a backplane; 130-reinforcing ribs; 140-a mounting plate; 141-a first connection hole;
200-a sealing structure; 210-rib holes; 220-an elastomeric seal; 221-a steel bar accommodating groove; 222-a guide surface; 230-a first connector; 240-second connector.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.
The current superimposed sheet mould's leak protection measure is generally the manual work and utilizes the rubber shutoff, and the operating efficiency is low, extravagant manpower and sealed effect is not good, in addition, still warp through structures such as gasbag and seal the play muscle position of superimposed sheet mould, and this kind of sealed form structure is complicated, needs a large amount of manual intervention moreover.
In view of the above, the present embodiment provides a slurry leakage prevention laminated board mold to solve the above drawbacks of the existing sealing manner.
Referring to fig. 1 and 2, the grout leakage preventing laminated plate mold provided in this embodiment includes the side forms 100, and a plurality of side forms 100 can enclose into the casting space, and because the preparation of prefabricated out muscle superimposed sheet needs to be carried out, the side forms 100 of this embodiment are provided with a plurality of out muscle grooves 111, and one end of the reinforcing steel bar can be stretched out by out muscle groove 111.
In order to seal the position of the rib outlet groove 111 of the present embodiment and prevent cement slurry from leaking in the pouring process, the slurry leakage prevention laminated plate mold of the present embodiment further includes a sealing structure 200 installed on the rib outlet groove 111, the sealing structure 200 blocks the rib outlet groove 111, the sealing structure 200 of the present embodiment is provided with a rib outlet hole 210 having a radial dimension smaller than that of a steel bar, the sealing structure 200 is configured to elastically deform in the process that the steel bar is inserted into the rib outlet hole 210, and the steel bar is hermetically wrapped after the steel bar is completely inserted into the rib outlet hole 210, so as to seal the steel bar.
Adopt the leak protection thick liquid coincide board mould of above-mentioned structure, build the shaping back at the mould, directly put into seal structure 200 with the reinforcing bar, go out muscle groove 111 through seal structure 200 shutoff, and utilize the characteristic that seal structure 200 self can be deformed to come sealed parcel reinforcing bar, only need put into out muscle hole 210 with the reinforcing bar when sealing operation and can realize the sealed of muscle groove 111 and reinforcing bar, and is not only easy operation, the manpower is saved, the efficiency of operation is improved, good sealed effect has, and because seal structure 200's deformation characteristic, make it be applicable to multiple specification coincide board truss muscle, also can realize sealedly to the reinforcing bar of different diameters, make the mould have good universality.
Referring to fig. 5, in order to facilitate the deformation of the sealing structure 200 and the insertion of the reinforcing steel bars, the specific structural style of the sealing structure 200 is optimally designed in the present embodiment, the sealing structure 200 of the present embodiment is designed to include two elastic sealing elements 220 tightly attached to each other, the elastic sealing elements 220 may be made of rubber or the like, the specific installation and connection styles of the two elastic sealing elements 220 are given below, reinforcing steel bar accommodating grooves 221 are formed on the surfaces of the two elastic sealing elements 220 attached to each other in the present embodiment, the two reinforcing steel bar accommodating grooves 221 are located at the same horizontal position, and the two reinforcing steel bar accommodating grooves can be abutted to each other and enclose the reinforcing steel bar outlet hole 210.
Because this embodiment is the split type structure of constituteing by two sealing members with seal structure 200 design, consequently can be with the reinforcing bar by the laminating department between two elastic sealing member 220 tops directly impress go out muscle hole 210 in, at the in-process of the reinforcing bar of impressing, certain deformation can take place to the direction that deviates from the reinforcing bar respectively in the inboard of two elastic sealing member 220, the putting into of the reinforcing bar of being convenient for, put into play muscle hole 210 back completely at the reinforcing bar, two elastic sealing member 220 of this embodiment wrap up sealed reinforcing bar under the effect of elastic deformation restoring force.
By adopting the structural design, the steel bars do not need to be subjected to inserting operation, after the embedded positions of the steel bars are adjusted, the steel bars are directly pressed into the sealing structure 200 of the embodiment, the operation is fast, and the assembly positioning efficiency and the sealing operation efficiency of the steel bars are further improved.
Of course, the specific structural form of the sealing structure 200 of the present embodiment is not limited to this, for example, the sealing structure 200 may be an integral structure, which is provided with a rib outlet hole 210 and a notch (not shown in the figure) communicating with the rib outlet hole 210, and the steel bar may enter into the rib outlet hole 210 through the notch; for another example, the sealing structure 200 is an elastic body only provided with the bar outlet hole 210, but this form can only satisfy the condition that the steel bar is inserted into the bar outlet hole 210, and cannot realize the pressing of the steel bar, namely, the steel bar can enter the bar outlet hole 210.
In order to reliably mount and fix the elastic sealing elements 220 of the present embodiment, in the present embodiment, a first connecting member 230 is connected to a side of each elastic sealing element 220 away from another elastic sealing element 220, the first connecting member 230 is connected to the side form 100, and preferably, the first connecting member 230 is detachably connected to the side form 100, so as to facilitate the mounting, dismounting and replacing of the elastic sealing elements 220.
The first connecting member 230 of this embodiment may be detachably connected to the side form 100 in various ways, for example, the first connecting member of this embodiment may be a bolt, and the bolt is connected to the side form 100, and for example, the first connecting member of this embodiment may be a buckle (not shown in this figure), and the buckle is engaged with a slot on the side form 100.
Due to the material characteristics of the elastic sealing element 220 of this embodiment, the elastic sealing element 220 and the first connecting element 230 are easily deformed at the direct connection position, so that the first connecting element 230 is not easily directly connected to the elastic sealing element 220, or the stability of the connection between the first connecting element 230 and the elastic sealing element 220 is not good, therefore, in this embodiment, the rigid second connecting element 240 is embedded in the elastic sealing element 220, and the second connecting element 240 is detachably and fixedly connected to the first connecting element 230. The rigid second connector 240 of this embodiment may be a nut directly disposed within the elastomeric seal 220.
Referring to fig. 3 and 4, the side form 100 of this embodiment includes the side plate 110 and the bottom plate 120 that are connected perpendicularly, the bottom plate 120 and the side plate 110 are connected integrally or are integrated into one piece, the rib outlet groove 111 has been seted up to the side plate 110 of this embodiment, and a plurality of rib outlet grooves 111 are evenly spaced and set up, the interval that goes out the rib groove 111 is the same with the reinforcing bar arrangement interval, in the direction perpendicular to the bottom plate 120, the height of the seal structure 200 of this embodiment is greater than the height of the side plate 110, so that the top of the seal structure 200 of this embodiment exceeds the side plate 110, when being convenient for the reinforcing bar to impress, it is sealed to do benefit to install other structures on the side form to go out the rib groove 111.
With reference to fig. 5, in order to further facilitate the pressing of the steel bar, when the sealing structure 200 of the present embodiment includes the two elastic sealing elements 220 tightly attached to each other, the present embodiment is provided with a guiding surface 222 on the top of the elastic sealing element 220, and the guiding surface 222 increases gradually in height in a direction perpendicular to the bottom plate 120 in a direction away from the other elastic sealing element 220, so that the guiding surface 222 facilitates the steel bar to enter between the two elastic sealing elements 220, and the steel bar is more favorable for deforming the two elastic sealing elements 220 during the pressing process.
Referring to fig. 3 again, in order to improve the structural strength of the side form 100 of the present embodiment, a plurality of reinforcing ribs 130 are disposed between the side plate 110 and the bottom plate 120, the reinforcing ribs 130 are respectively connected to the side plate 110 and the bottom plate 120, and the connecting manner of the reinforcing ribs 130 to the side plate 110 and the bottom plate may be various, such as welding or fixing connection by fasteners.
In order to realize the installation of the sealing structure 200 of the present embodiment, the side die 100 of the present embodiment is provided with the mounting plates 140 on both sides of the rib forming groove 111, the height of the mounting plate 140 is the same as that of the sealing structure 200, the sealing structure 200 is located between the two mounting plates 140 and is in sealing fit with the mounting plates 140, the sealing structure 200 of the present embodiment can be installed between the two mounting plates 140 after certain extrusion deformation, the limitation on the left and right sides of one sealing structure 200 can be realized through the two mounting plates 140, the limitation on the sealing structure 200 in the vertical direction is realized by using the bottom plate 120, and the installation of the sealing structure 200 is realized while the rib forming groove 111 is blocked by using the sealing structure 200.
It should be noted that, as shown in fig. 2, in each sealing structure 200, two elastic sealing elements 220 are oppositely arranged, and under the common limiting action of the mounting plate 140 and the bottom plate 120, the two elastic sealing elements 220 are tightly attached.
Moreover, the mounting plate 140 of the embodiment is provided with the first connection hole 141 connected to the first connection member 230, preferably, the first connection hole 141 of the embodiment is designed as a through hole with two through ends, and when the first connection member 230 of the embodiment is a bolt, one of the two opposite sides of the first connection hole 141 of the embodiment is open in a direction perpendicular to the side plate 110, so as to form an open slot, so that the bolt can enter the open slot without inserting the bolt into the first connection hole 141, and only the bolt needs to be placed in the open slot on one side of the first connection hole 141, thereby further improving the assembly efficiency.
In addition, a second connection hole 112 may be further disposed on the side plate 110 of the side form 100 of the present embodiment, a third connection member (not shown in the drawings) for connecting other members is disposed on the second connection hole 112 in a penetrating manner, and the third connection member is in sealing fit with the second connection hole 112, so that the connection between the side form 100 of the present embodiment and other members of the mold system is facilitated.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the utility model as defined in the appended claims.
Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the utility model. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A slurry leakage prevention laminated plate die comprises a side die (100), wherein the side die (100) is provided with a plurality of rib outlet grooves (111) for extending reinforcing steel bars; the rib forming die is characterized by further comprising a sealing structure (200) arranged on the rib forming groove (111), wherein the sealing structure (200) blocks the rib forming groove (111), and the horizontal height of the sealing structure (200) is larger than that of the side die (100);
the sealing structure (200) is provided with a reinforcement outlet hole (210) with the radial dimension smaller than that of the reinforcing steel bar, the sealing structure (200) is configured to be elastically deformed in the process that the reinforcing steel bar enters the reinforcement outlet hole (210), and the reinforcing steel bar is hermetically wrapped after being placed in the reinforcement outlet hole (210).
2. The mold for the laminated leakproof pulp board as claimed in claim 1, wherein the sealing structure (200) comprises two elastic sealing members (220) which are tightly attached, the surfaces of the two elastic sealing members (220) which are attached to each other are provided with reinforcing steel bar accommodating grooves (221), and the reinforcing steel bar accommodating grooves (221) of the two elastic sealing members (220) enclose the reinforcing steel bar outlet hole (210).
3. The mould for leakproof laminated sheets according to claim 2, wherein the top of the elastic sealing member (220) is provided with a guide surface (222), and the level of the guide surface (222) is gradually increased in a direction away from the other elastic sealing member (220).
4. The pulp leakage prevention laminated plate mold according to claim 2, wherein a first connecting piece (230) is connected to one side of each elastic sealing piece (220) facing away from the other elastic sealing piece (220), and the first connecting piece (230) is connected to the side mold (100).
5. The pulp leakage prevention laminated plate mold according to claim 4, wherein a second connecting piece (240) is embedded in the elastic sealing piece (220), and the second connecting piece (240) is connected with the first connecting piece (230).
6. The mold for the composite leakproof pulp board according to any one of the claims 1 to 5, wherein the side mold (100) comprises a side plate (110) and a bottom plate (120) which are vertically connected, the rib outlet groove (111) is opened on the side plate (110), and the height of the sealing structure (200) is larger than that of the side plate (110) in the direction vertical to the bottom plate (120).
7. The mold for laminated leakproof sheet according to claim 6, wherein a plurality of reinforcing ribs (130) are provided between the side plate (110) and the bottom plate (120), and the reinforcing ribs (130) are respectively connected to the side plate (110) and the bottom plate (120).
8. The mold for composite leak-proof boards as claimed in any one of claims 1 to 5, wherein the side forms (100) are provided with mounting plates (140) on both sides of the rib-forming grooves (111), and the sealing structure (200) is located between the two mounting plates (140) and is in sealing engagement with the mounting plates (140).
9. The grout-resistant laminate mold of claim 8, wherein the mounting plate (140), when comprising a first connector (230), is provided with a first connection hole (141) connected with the first connector (230).
10. The slurry leakage preventing laminated plate mold according to any one of claims 1 to 5, wherein the side mold (100) is provided with a second connecting hole (112), a third connecting member is arranged on the second connecting hole (112) in a penetrating manner, and the third connecting member is in sealing fit with the second connecting hole (112).
CN202122116985.2U 2021-09-02 2021-09-02 Leak protection thick liquid superimposed sheet mould Active CN216578427U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202122116985.2U CN216578427U (en) 2021-09-02 2021-09-02 Leak protection thick liquid superimposed sheet mould

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202122116985.2U CN216578427U (en) 2021-09-02 2021-09-02 Leak protection thick liquid superimposed sheet mould

Publications (1)

Publication Number Publication Date
CN216578427U true CN216578427U (en) 2022-05-24

Family

ID=81637653

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202122116985.2U Active CN216578427U (en) 2021-09-02 2021-09-02 Leak protection thick liquid superimposed sheet mould

Country Status (1)

Country Link
CN (1) CN216578427U (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113858394A (en) * 2021-09-02 2021-12-31 广东碧品居建筑工业化有限公司 Slurry leakage prevention laminated plate die

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113858394A (en) * 2021-09-02 2021-12-31 广东碧品居建筑工业化有限公司 Slurry leakage prevention laminated plate die

Similar Documents

Publication Publication Date Title
CN216578427U (en) Leak protection thick liquid superimposed sheet mould
CN213829513U (en) Stifled thick liquid device of precast concrete component mould
CN113858394A (en) Slurry leakage prevention laminated plate die
CN210828318U (en) Be applied to super thick vertical concrete structure template system interior angle reinforced structure
CN212053772U (en) Aluminum mould root clearance plugging device
CN215907387U (en) Shear wall template for building
CN215368690U (en) Building steel-plastic formwork
CN220643759U (en) Highway asphalt concrete template
CN217602681U (en) Bury formula waterstop fixing device in
CN215331511U (en) Template bottom anti-leakage device
CN212176554U (en) Bottom die for steel bar truss floor support plate
CN218437154U (en) Template for pouring floor beam
CN218623280U (en) Assembling die suitable for assembled shear wall
CN215471913U (en) Universal modular assembled shear wall die
CN211415608U (en) Bridge deck mould with leak protection thick liquid device
CN218843738U (en) Superimposed sheet post-cast strip template reinforced structure
CN219451519U (en) Reinforced concrete structure template reinforcing apparatus
CN212767794U (en) Assembled water tank
CN219528390U (en) Superimposed sheet clamping device and superimposed sheet braced system
CN219654274U (en) A leak protection thick liquid device for construction of aluminium template
CN219548381U (en) Wall form reinforcing apparatus
CN214981970U (en) Tubular pile steel mould with locking device
CN217501037U (en) Keel is consolidated in frame post leak protection thick liquid
CN211547789U (en) Bearing platform template with stable structure
CN220247621U (en) Cast-in-situ reinforced concrete row wall bushing structure

Legal Events

Date Code Title Description
GR01 Patent grant
GR01 Patent grant
TR01 Transfer of patent right
TR01 Transfer of patent right

Effective date of registration: 20230105

Address after: A6-18, 6/F, Building A3, No. 1, Panpu Road, Biguiyuan Community, Beijiao Town, Shunde District, Foshan City, Guangdong Province, 528000

Patentee after: Foshan Bipinju Construction Industrialization Co.,Ltd.

Address before: 528300 room 201-34, East office, No. 11, Junye East Road, Beijiao Industrial Park, Shunjiang neighborhood committee, Beijiao Town, Shunde District, Foshan City, Guangdong Province

Patentee before: Guangdong bipinju construction industrialization Co.,Ltd.